Methods for injection molding and injection blow molding multi-layer articles

Claim 1

A method for forming multi-layer plastics articles wherein said method involves use of a multi-cavity injection molding machine, characterized in that a combined material stream is injected from each of a plurality of co-injection nozzle means of said machine into an associated injection cavity to form each article, said method being further characterized by: providing streams of polymeric materials to form the corresponding layers of the articles, and moving each material stream separately to each of the nozzle means, forming the combined stream in the plural nozzle means from the separate material streams, and injecting the combined streams to form the multi-layer plastics articles.

Claim 2

A method for forming multi-layer plastics articles wherein said method involves use of a multi-cavity injection molding machine, characterized in that a combined material stream is injected from each of a plurality of co-injection nozzle means of said machine into an associated injection cavity to form each article, said method being further characterized by: providing streams of polymeric materials to form the corresponding layers of the articles, and moving each material stream separately to each of the nozzle means, forming the combined stream in the plural nozzle means from the separate material streams, and injecting the combined streams to form the multi-layer plastics articles.

Claim 16

A method of controlling the relative flow rates of at least one of three polymeric material melt flow streams into and through at least three passageways and orifices and into the central channel of a co-injection nozzle in an injection molding machine, which comprises providing at least three polymeric material melt flow streams, providing a co-injection nozzle having a central channel with an open end, a gate at the open end, a polymer flow stream passageway for each polymeric material melt flow stream, each passageway having an orifice in communication with the central channel, (i) the first orifice being located more proximate the gate than the other orifices for routing an outer layer material into the channel, (ii) the third orifice being further removed from the gate than said first or second orifices for routing the core material into the channel for forming the inside layer, (iii) a second orifice positioned adjacent and close to the first orifice intermediate the first and third orifices, for routing intermediate layer material into the channel, and connecting each of the polymeric material melt flow streams of the outer layer and of the core material for forming an inside layer to common moving means for moving each stream to its respective nozzle passageway, means operative in the central channel and adapted for blocking and not blocking the flow of intermediate melt material through its orifice into the central channel without blocking flow into the central channel of melt material for either the outer layer or the inside layer, and utilizing the common moving means to move said outer and core layer material streams through their passageways while utilizing the blocking means for blocking the orifice for the intermediate melt material without blocking flow into the central channel of melt material for either the outer layer or the inside layer.

Claim 17

A method of controlling the relative flow rates of at least one of three polymeric material melt flow streams into and through at least three passageways and orifices and into the central channel of a co-injection nozzle in an injection molding machine, which comprises providing at least three polymeric material melt flow streams, providing a co-injection nozzle having a central channel with an open end, a gate at the open end, a polymer flow stream passageway for each polymeric material melt flow stream, each passageway having an orifice in communication with the central channel, (i) the first orifice being located more proximate the gate than the other orifices for routing an outer layer material into the channel, (ii) the third orifice being further removed from the gate than said first or second orifices for routing the core material into the channel for forming the inside layer, (iii) a second orifice positioned adjacent and close to the first orifice intermediate the first and third orifices, for routing intermediate layer material into the channel, and connecting each of the polymeric material melt flow streams of the outer layer and of the core material for forming an inside layer to common moving means for moving each stream to its respective nozzle passageway, means operative in the central channel and adapted for blocking and not blocking the flow of intermediate melt material through its orifice into the central channel without blocking flow into the central channel of melt material for either the outer layer or the inside layer, and utilizing the common moving means to move said outer and core layer material streams through their passageways while utilizing the blocking means for blocking the orifice for the intermediate melt material without blocking flow into the central channel of melt material for either the outer layer or the inside layer.

Claim 18

A method of co-injecting a five layer plastic article from each co-injecting nozzle of a multi-coinjection nozzle injection molding machine, which comprises, providing a plurality of injection nozzle means, each having: (a) a central channel having a gate at one end, (b) five polymer melt flow stream passageways, each having an orifice which communicates with the central channel, wherein (i) the first orifice is located more proximate to the open end than the other orifices for routing structural material to the channel for forming primarily the outside surface layer of the article, (ii) the third orifice is more removed from the open end than the other orifices for routing material to the channel for forming primarily the inside surface layer of the article, (iii) the second orifice is located between the first third orifices for routing a polymeric material to the channel for forming an internal layer of the article, (iv) the fourth orifice is located intermediate the first and second orifices for routing a polymeric material to the channel for forming an intermediate layer between the first and the internal layer of the article, and (v) the fifth orifice is located intermediate the second and third orifices for routing a polymeric material to the channel for forming an intermediate layer between the internal layer and the inside surface layer of the article, (c) valve means in the co-injection nozzle operative in the central channel adjacent and with respect to each of the five orifices for blocking, unblocking and controlling the flow and non-flow of the respective materials from their orifices into the central channel, and (d) a common moving means associated with both of the outside ind inside surface materials for commonly moving them into and through their respective passageways and orifices, and, (e) a common moving means associated with both of the respective intermediate materials for commonly moving them into and through their respective passageways and orifices, and utilizing the valve means in the co-injection nozzle means for injecting a combined stream of the materials to form the five layered article, by (i) preventing flow of polymeric material through the fourth, second and fifth orifices while allowing flow of polymer material through the third orifice, (ii) then also allowing the flow of polymeric material through the first orifice while continuing to prevent flow through the fourth, second and fifth orifices, (iii) allowing the flow of polymeric material through the fourth, second and fifth orifices while allowing polymeric material to flow through the first and third orifices, (iv) reducing the flow of polymeric material through the third orifice by partially blocking said third orifie while utilizing the common moving means associated with said orifice to reduce the flow of polymer material to the first and third orifices, and while allowing polymeric material to flow through the fourth, second and fifth orifices, (v) reducing the flow of polymeric material through the fifth orifice by partially blocking the fifth orifice and utilizing the common moving means associated with said orifice for reducing the flow of polymeric material to the fourth and fifth orifice, (vi) terminating the flow of polymeric material through the second orifice and then through the fourth orifice, and (vii) restricting the flow of polymeric material through the second orifice while allowing flow of polymeric material through the first or third orifices or both the first and third orifices to knit the internal layer material with itself through the inside layer material and to substantially encapsulate the internal layer within the inside and/or outside layer material.

Claim 19

A method of co-injecting a five layer plastic article from each co-injecting nozzle of a multi-coinjection nozzle injection molding machine, which comprises, providing a plurality of injection nozzle means, each having: (a) a central channel having a gate at one end, (b) five polymer melt flow stream passageways, each having an orifice which communicates with the central channel, wherein (i) the first orifice is located more proximate to the open end than the other orifices for routing structural material to the channel for forming primarily the outside surface layer of the article, (ii) the third orifice is more removed from the open end than the other orifices for routing material to the channel for forming primarily the inside surface layer of the article, (iii) the second orifice is located between the first third orifices for routing a polymeric material to the channel for forming an internal layer of the article, (iv) the fourth orifice is located intermediate the first and second orifices for routing a polymeric material to the channel for forming an intermediate layer between the first and the internal layer of the article, and (v) the fifth orifice is located intermediate the second and third orifices for routing a polymeric material to the channel for forming an intermediate layer between the internal layer and the inside surface layer of the article, (c) valve means in the co-injection nozzle operative in the central channel adjacent and with respect to each of the five orifices for blocking, unblocking and controlling the flow and non-flow of the respective materials from their orifices into the central channel, and (d) a common moving means associated with both of the outside ind inside surface materials for commonly moving them into and through their respective passageways and orifices, and, (e) a common moving means associated with both of the respective intermediate materials for commonly moving them into and through their respective passageways and orifices, and utilizing the valve means in the co-injection nozzle means for injecting a combined stream of the materials to form the five layered article, by (i) preventing flow of polymeric material through the fourth, second and fifth orifices while allowing flow of polymer material through the third orifice, (ii) then also allowing the flow of polymeric material through the first orifice while continuing to prevent flow through the fourth, second and fifth orifices, (iii) allowing the flow of polymeric material through the fourth, second and fifth orifices while allowing polymeric material to flow through the first and third orifices, (iv) reducing the flow of polymeric material through the third orifice by partially blocking said third orifie while utilizing the common moving means associated with said orifice to reduce the flow of polymer material to the first and third orifices, and while allowing polymeric material to flow through the fourth, second and fifth orifices, (v) reducing the flow of polymeric material through the fifth orifice by partially blocking the fifth orifice and utilizing the common moving means associated with said orifice for reducing the flow of polymeric material to the fourth and fifth orifice, (vi) terminating the flow of polymeric material through the second orifice and then through the fourth orifice, and (vii) restricting the flow of polymeric material through the second orifice while allowing flow of polymeric material through the first or third orifices or both the first and third orifices to knit the internal layer material with itself through the inside layer material and to substantially encapsulate the internal layer within the inside and/or outside layer material.

Claim 20

A method of injection molding a multi-layer article having at least three layers, in an apparatus including a co-injection nozzle for co-injecting at least three melt material streams and having a central channel, at least three melt stream passageways each with an orifice which communicates with the central channel, and containing valve means in the central channel, comprising the steps of moving the valve means to a first position to prevent flow of the melt material streams into the nozzle central channel, moving the valve means to a second position to permit the flow of a first material stream into the nozzle central channel, moving the valve means to a third position to permit continued flow of said first material stream and to permit flow of a second material stream into the nozzle central channel, and moving the valve means to a fourth position to permit continued flow of said first and second streams, and to permit flow of a third material stream into the nozzle central channel between the first and second streams.

Claim 21

A method of injection molding a multi-layer article having at least three layers, in an apparatus including a co-injection nozzle for co-injecting at least three melt material streams and having a central channel, at least three melt stream passageways each with an orifice which communicates with the central channel, and containing valve means in the central channel, comprising the steps of moving the valve means to a first position to prevent flow of the melt material streams into the nozzle central channel, moving the valve means to a second position to permit the flow of a first material stream into the nozzle central channel, moving the valve means to a third position to permit continued flow of said first material stream and to permit flow of a second material stream into the nozzle central channel, and moving the valve means to a fourth position to permit continued flow of said first and second streams, and to permit flow of a third material stream into the nozzle central channel between the first and second streams.

Claim 22

A method of injection molding a multi-layer article having at least three layers, in an apparatus including a co-injection nozzle for co-injecting at least three melt material streams and having a central channel, at least three melt stream passageways each with an orifice which communicates with the central channel, and containing valve means in the central channel, comprising the steps of moving the valve means to a first position to prevent flow of the melt material streams into the nozzle central channel, moving the valve means to a second position to permit the flow of a first material stream into the nozzle central channel, moving the valve means to a third position to permit continued flow of said first stream and to permit annular flow of a second material stream into the nozzle central channel around said first stream, and moving the valve means to a fourth position to permit continued flow of said first stream, to permit annular flow of a third material stream into the nozzle central channel around said first stream and to permit annular flow of said second stream into the nozzle central channel around the third stream.

Claim 23

A method of injection molding a multi-layer article having at least three layers, in an apparatus including a co-injection nozzle for co-injecting at least three melt material streams and having a central channel, at least three melt stream passageways each with an orifice which communicates with the central channel, and containing valve means in the central channel, comprising the steps of moving the valve means to a first position to prevent flow of the melt material streams into the nozzle central channel, moving the valve means to a second position to permit the flow of a first material stream into the nozzle central channel, moving the valve means to a third position to permit continued flow of said first stream and to permit annular flow of a second material stream into the nozzle central channel around said first stream, and moving the valve means to a fourth position to permit continued flow of said first stream, to permit annular flow of a third material stream into the nozzle central channel around said first stream and to permit annular flow of said second stream into the nozzle central channel around the third stream.

Claim 24

A method of injection molding a substantially rigid, multi-layer, plastic article having at least three layers, in an apparatus including a co-injection nozzle for co-injecting at least three melt material streams which comprise the side wall and having a central channel and at least three melt stream passageways each having an orifice which communicates with the central channel, and containing valve means in the central channel for controlling flow of the material streams, comprising the steps of moving the valve means to a first position to prevent flow of the melt material streams into the nozzle central channel, moving the valve means to a second position to permit the flow of a first material stream into the nozzle central channel, moving the valve means to a third position to permit continued flow of said first material stream and to permit annular flow of a second stream into the nozzle central channel around said first stream, and moving the valve means to a fourth position to permit continued flow of the first material stream, to permit annular flow of a third material stream into the nozzle central channel around said first stream and to permit annular flow of said second material stream into the nozzle central channel around the third stream.

Claim 25

A method of injection molding a substantially rigid, multi-layer, plastic article having at least three layers, in an apparatus including a co-injection nozzle for co-injecting at least three melt material streams which comprise the side wall and having a central channel and at least three melt stream passageways each having an orifice which communicates with the central channel, and containing valve means in the central channel for controlling flow of the material streams, comprising the steps of moving the valve means to a first position to prevent flow of the melt material streams into the nozzle central channel, moving the valve means to a second position to permit the flow of a first material stream into the nozzle central channel, moving the valve means to a third position to permit continued flow of said first material stream and to permit annular flow of a second stream into the nozzle central channel around said first stream, and moving the valve means to a fourth position to permit continued flow of the first material stream, to permit annular flow of a third material stream into the nozzle central channel around said first stream and to permit annular flow of said second material stream into the nozzle central channel around the third stream.

Claim 26

A method of injection molding a substantially rigid, multi-layer, plastic parison having a side wall which comprises at least three layers, in an apparatus including a co-injection nozzle for co-injecting at least three melt material streams which comprise the side wall and having a central channel and at least three melt stream passageways each having an orifice which communicates with the central channel, and containing valve means in the central channel for controlling flow of the material streams, comprising the steps of moving the valve means to a first position to prevent flow of the melt material streams into the nozzle central channel, moving the valve means to a second position to permit the flow of a first material stream into the nozzle central channel, moving the valve means to a third position to permit continued flow of said first material stream and to permit annular flow of a second stream into the nozzle central channel around said first stream, and moving the valve means to a fourth position to permit continued flow of the first material stream, to permit annular flow of a third material stream into the nozzle central channel around said first stream and to permit annular flow of said second material stream into the nozzle central channel around the third stream.

Claim 27

A method of injection molding a substantially rigid, multi-layer, plastic parison having a side wall which comprises at least three layers, in an apparatus including a co-injection nozzle for co-injecting at least three melt material streams which comprise the side wall and having a central channel and at least three melt stream passageways each having an orifice which communicates with the central channel, and containing valve means in the central channel for controlling flow of the material streams, comprising the steps of moving the valve means to a first position to prevent flow of the melt material streams into the nozzle central channel, moving the valve means to a second position to permit the flow of a first material stream into the nozzle central channel, moving the valve means to a third position to permit continued flow of said first material stream and to permit annular flow of a second stream into the nozzle central channel around said first stream, and moving the valve means to a fourth position to permit continued flow of the first material stream, to permit annular flow of a third material stream into the nozzle central channel around said first stream and to permit annular flow of said second material stream into the nozzle central channel around the third stream.

Claim 28

A method of forming a multi-layer combined stream of a plurality of polymer materials in an injection nozzle for injection into a cavity such that the planes of the leading edges of the respective layers in the combined stream in the nozzle are substantially unbiased when viewed in vertical cross-section, which comprises, providing a co-injection nozzle having a central channel having, a gate at one end, at least first, second and third passageways, each having an orifice at one end in communication with the central channel, there being one passageway for each layer to be formed in the multi-layer combined stream, the first passageway orifice being more proximate the gate than the other passageway orifices for flow through the orifice of the polymer material Which will form the outside layer of the combined stream, the third passageway orifice being in a position removed from the gate for flow through the orifice of the polymer material which Will form the inside structural layer, one or more second passageway orifices intermediate the first and third passageway orifices for flow through said one or more second orifices of the polymer material or materials which will form the internal layer or layers of the stream, providing valve means operative in the central channel for blocking the flow of polymer material from the orifices into the central channel, and for independently and selectively controlling the flow of polymer material from the orifice, said means being effective for, preventing flow from all of the orifices, preventing the flow of polymer material from the second passageway orifice if there is only one, or orifices if there is more than one, while allowing flow of material from the third orifice, the first orifice, or both the third and first orifices, and allowing flow of material through the one or more second orifices while allowing material to flow through the third orifice or both the third and first orifices.

Claim 29

A method of forming a multi-layer combined stream of a plurality of polymer materials in an injection nozzle for injection into a cavity such that the planes of the leading edges of the respective layers in the combined stream in the nozzle are substantially unbiased when viewed in vertical cross-section, which comprises, providing a co-injection nozzle having a central channel having, a gate at one end, at least first, second and third passageways, each having an orifice at one end in communication with the central channel, there being one passageway for each layer to be formed in the multi-layer combined stream, the first passageway orifice being more proximate the gate than the other passageway orifices for flow through the orifice of the polymer material Which will form the outside layer of the combined stream, the third passageway orifice being in a position removed from the gate for flow through the orifice of the polymer material which Will form the inside structural layer, one or more second passageway orifices intermediate the first and third passageway orifices for flow through said one or more second orifices of the polymer material or materials which will form the internal layer or layers of the stream, providing valve means operative in the central channel for blocking the flow of polymer material from the orifices into the central channel, and for independently and selectively controlling the flow of polymer material from the orifice, said means being effective for, preventing flow from all of the orifices, preventing the flow of polymer material from the second passageway orifice if there is only one, or orifices if there is more than one, while allowing flow of material from the third orifice, the first orifice, or both the third and first orifices, and allowing flow of material through the one or more second orifices while allowing material to flow through the third orifice or both the third and first orifices.

Claim 34

A method of forming in a co-injection nozzle a multi-layer substantially concentric combined stream of at least three polymeric materials for injection as a shot continuously injected as it is formed, into a cavity to form a multi-layer article, such that the combined stream and continuously injected shot have an outer melt stream layer of polymeric material for forming the outside layer of the article, a core melt stream of polymeric material for forming the inside layer of the article, and at least one internal melt stream layer of polymeric material for forming an internal layer of the article, which comprises, providing co-injection nozzle means including a co-injection nozzle having: (a) a gate at one end, (b) a cylindrical central channel in communication with the gate, (c) a plurality of at least three polymer passageways communicating with the central channel, each of said at least three passageways having an orifice which communicates with the central channel, (i) the first orifice being located more proximate the gate than the other orifices for routing outer layer material into the channel, (ii) the third orifice being further removed from the gate than said first and second orifices for routing the inside layer material into the channel, (iii) a second orifice being positioned between the first and third orifices, for routing internal layer material into the channel, and (d) valve means in the nozzle operative adjacent the orifices and adapted to prevent and to allow the flow of the internal layer material through the second orifice, and for independently controlling the flow or non-flow of the inside layer material through the third orifice, and utilizing the valve means in the nozzle means for (i) preventing flow of material through the second orifice while allowing flow of material through the first, the third, or both the first and third orifices, and then, (ii) allowing flow of material through the second orifice while allowing flow of material through the third orifice.

Claim 35

A method of forming in a co-injection nozzle a multi-layer substantially concentric combined stream of at least three polymeric materials for injection as a shot continuously injected as it is formed, into a cavity to form a multi-layer article, such that the combined stream and continuously injected shot have an outer melt stream layer of polymeric material for forming the outside layer of the article, a core melt stream of polymeric material for forming the inside layer of the article, and at least one internal melt stream layer of polymeric material for forming an internal layer of the article, which comprises, providing co-injection nozzle means including a co-injection nozzle having: (a) a gate at one end, (b) a cylindrical central channel in communication with the gate, (c) a plurality of at least three polymer passageways communicating with the central channel, each of said at least three passageways having an orifice which communicates with the central channel, (i) the first orifice being located more proximate the gate than the other orifices for routing outer layer material into the channel, (ii) the third orifice being further removed from the gate than said first and second orifices for routing the inside layer material into the channel, (iii) a second orifice being positioned between the first and third orifices, for routing internal layer material into the channel, and (d) valve means in the nozzle operative adjacent the orifices and adapted to prevent and to allow the flow of the internal layer material through the second orifice, and for independently controlling the flow or non-flow of the inside layer material through the third orifice, and utilizing the valve means in the nozzle means for (i) preventing flow of material through the second orifice while allowing flow of material through the first, the third, or both the first and third orifices, and then, (ii) allowing flow of material through the second orifice while allowing flow of material through the third orifice.

Claim 54

A method of forming in a co-injection nozzle a multi-layer substantially concentric combined stream of at least three polymeric materials for injection as a shot continuously injected as it is formed, into an injection cavity to form a multi-layer injected article such that the combined stream and continuously injected shot have an outer layer of structural material for forming the outer layer of the article, a core of structural material for forming the inner layer of the article, and one or more internal layer(s) of material for forming one or more internal layer(s) of the article, which comprises, providing co-injection nozzle means including a co-injection nozzle having: (a) a gate at one end, (b) a cylindrical central channel in communication with the gate, (c) a plurality of at least three polymer passageways communicating with the central channel, each of at least the first, second and third of said passageways having an orifice which communicates with the central channel, (i) the first orifice being located close to and proximate the gate for routing the outer layer structural material into the channel, (ii) the third orifice being further removed from the gate than said first and second orifices, for routing the inside layer material into the channel, (iii) a second orifice positioned adjacent and close to the first orifice intermediate the first and third orifices, for routing internal layer material into the channel, and (a) valve means in the nozzle operative adjacent the orifices and adapted to prevent and allow the flow of internal polymer material through the second orifice and for independently controlling the flow or non-flow of the inside layer material through the third orifice, (b) utilizing the valve means in the nozzle means for (i) preventing flow of polymer material from all of the orifices, (ii) preventing flow of polymer material through the second orifice while allowing flow of structural material through the first, the third or both the first and third orifices, then, (iii) allowing flow of polymer material through the second orifice while allowing material to flow through the third orifice, (iv) restricting the flow of polymer material through the third orifice while allowing the flow of material through the second orifice, (v) restricting the flow of polymer material through the second orifice while allowing flow of polymer material through the first or third orifices or both the first and third orifices to knit the inside layer material with itself through the core material and substantially encapsulate the internal layer in the combined stream and in the shot.

Claim 55

A method of forming in a co-injection nozzle a multi-layer substantially concentric combined stream of at least three polymeric materials for injection as a shot continuously injected as it is formed, into an injection cavity to form a multi-layer injected article such that the combined stream and continuously injected shot have an outer layer of structural material for forming the outer layer of the article, a core of structural material for forming the inner layer of the article, and one or more internal layer(s) of material for forming one or more internal layer(s) of the article, which comprises, providing co-injection nozzle means including a co-injection nozzle having: (a) a gate at one end, (b) a cylindrical central channel in communication with the gate, (c) a plurality of at least three polymer passageways communicating with the central channel, each of at least the first, second and third of said passageways having an orifice which communicates with the central channel, (i) the first orifice being located close to and proximate the gate for routing the outer layer structural material into the channel, (ii) the third orifice being further removed from the gate than said first and second orifices, for routing the inside layer material into the channel, (iii) a second orifice positioned adjacent and close to the first orifice intermediate the first and third orifices, for routing internal layer material into the channel, and (a) valve means in the nozzle operative adjacent the orifices and adapted to prevent and allow the flow of internal polymer material through the second orifice and for independently controlling the flow or non-flow of the inside layer material through the third orifice, (b) utilizing the valve means in the nozzle means for (i) preventing flow of polymer material from all of the orifices, (ii) preventing flow of polymer material through the second orifice while allowing flow of structural material through the first, the third or both the first and third orifices, then, (iii) allowing flow of polymer material through the second orifice while allowing material to flow through the third orifice, (iv) restricting the flow of polymer material through the third orifice while allowing the flow of material through the second orifice, (v) restricting the flow of polymer material through the second orifice while allowing flow of polymer material through the first or third orifices or both the first and third orifices to knit the inside layer material with itself through the core material and substantially encapsulate the internal layer in the combined stream and in the shot.

Claim 67

A method of forming a multi-layer combined stream of at least three polymer materials in an injection nozzle for injection as a combined stream into a cavity such that the combined stream has an outer layer of structural material, a radially innermost core of structural material and one or more internal layer(s) of material, which comprises, providing injection nozzle means having: (a) a central channel having a gate at one end, (b) a plurality of polymer passageways communicating with the central channel, at least three of said passageways each having an orifice which communicates with the central channel, (i) the first orifice located more proximate to the open end than the other orifices for routing structural material to the channel, (ii) the third orifice being removed from the open end for routing structural material to the channel, (iii) a second orifice positioned adjacent the first orifice intermediate the first and third orifices, for routing the one or more internal polymer material(s) to the channel, (c) valve means in the nozzle operative adjacent the orifices for controlling the flow or non-flow of the internal polymer material through the second orifice, if there is only one, or through the orifices, if there are more than one, and for independently controlling the flow or non-flow of the structural material through the third orifice, (d) utilizing the valve means in the nozzle means for forming the combined stream by (i) preventing flow of internal polymer material through the second orifice while allowing flow of polymer structural material through the first orifice, the third orifice or both the first and third orifices, (ii) then allowing flow of polymer material through the second orifice while al)owing polymer material to flow through the third orifice, (iii) reducing the flow of polymer material through the third orifice while allowing polymer material to flow through the second orifice, (iv) terminating the flow of polymer material through the second orifice, (v) allowing flow of polymer material only through the first orifice while preventing flow of polymer material from the second and third orifices to substantially encapsulate the intermediate polymer material in the combined stream.

Claim 68

A method of forming a multi-layer combined stream of at least three polymer materials in an injection nozzle for injection as a combined stream into a cavity such that the combined stream has an outer layer of structural material, a radially innermost core of structural material and one or more internal layer(s) of material, which comprises, providing injection nozzle means having: (a) a central channel having a gate at one end, (b) a plurality of polymer passageways communicating with the central channel, at least three of said passageways each having an orifice which communicates with the central channel, (i) the first orifice located more proximate to the open end than the other orifices for routing structural material to the channel, (ii) the third orifice being removed from the open end for routing structural material to the channel, (iii) a second orifice positioned adjacent the first orifice intermediate the first and third orifices, for routing the one or more internal polymer material(s) to the channel, (c) valve means in the nozzle operative adjacent the orifices for controlling the flow or non-flow of the internal polymer material through the second orifice, if there is only one, or through the orifices, if there are more than one, and for independently controlling the flow or non-flow of the structural material through the third orifice, (d) utilizing the valve means in the nozzle means for forming the combined stream by (i) preventing flow of internal polymer material through the second orifice while allowing flow of polymer structural material through the first orifice, the third orifice or both the first and third orifices, (ii) then allowing flow of polymer material through the second orifice while al)owing polymer material to flow through the third orifice, (iii) reducing the flow of polymer material through the third orifice while allowing polymer material to flow through the second orifice, (iv) terminating the flow of polymer material through the second orifice, (v) allowing flow of polymer material only through the first orifice while preventing flow of polymer material from the second and third orifices to substantially encapsulate the intermediate polymer material in the combined stream.

Claim 75

A method of injection molding an at least three layer multi-material plastic container having a side wall with a marginal end portion, and whose total side wall thickness below the marginal end portion is from about 0.010 inch to about 0.035 inch, by use of a multi-coinjection nozzle, multi-cavity injection molding apparatus, which comprises, providing a source of supply for each polymer melt material which is to form a layer of the more than one container, providing a co-injection nozzle for each cavity, said co-injection nozzle having a central channel, providing a separate flow stream from each source of supply of polymer material, moving said separate flow streams to each of the injection nozzles, bringing each of the separate flow streams together as a combined flow stream of at least three materials in the central channel of each co-injection nozzle, and injecting the combined flow stream through each injection nozzle into a juxtaposed cavity to form the multi-layer, multi-material plastic container.

Claim 76

A method of injection molding an at least three layer multi-material plastic container having a side wall with a marginal end portion, and whose total side wall thickness below the marginal end portion is from about 0.010 inch to about 0.035 inch, by use of a multi-coinjection nozzle, multi-cavity injection molding apparatus, which comprises, providing a source of supply for each polymer melt material which is to form a layer of the more than one container, providing a co-injection nozzle for each cavity, said co-injection nozzle having a central channel, providing a separate flow stream from each source of supply of polymer material, moving said separate flow streams to each of the injection nozzles, bringing each of the separate flow streams together as a combined flow stream of at least three materials in the central channel of each co-injection nozzle, and injecting the combined flow stream through each injection nozzle into a juxtaposed cavity to form the multi-layer, multi-material plastic container.

Claim 94

A method of injection molding a five layer, five-material plastic container having a side wall with a marginal end portion, and whose total side wall thickness below the marginal end portion is from about 0.010 inch to about 0.035 inch, by use of a multi-coinjection nozzle, multi-cavity injection molding apparatus, which comprises, providing a source of supply for each polymer material which is to form a layer of the container, providing a means for moving each polymer material separately to each of the nozzles, moving each material that is to form a layer of the article from the moving means separately to each of more than one the respective nozzles, combining the separately moved materials in each of the respective nozzles, and injecting the combined flow stream through each injection nozzle into a juxtaposed cavity to form the multi-layer, multi-material container.

Claim 95

A method of injection molding a five layer, five-material plastic container having a side wall with a marginal end portion, and whose total side wall thickness below the marginal end portion is from about 0.010 inch to about 0.035 inch, by use of a multi-coinjection nozzle, multi-cavity injection molding apparatus, which comprises, providing a source of supply for each polymer material which is to form a layer of the container, providing a means for moving each polymer material separately to each of the nozzles, moving each material that is to form a layer of the article from the moving means separately to each of more than one the respective nozzles, combining the separately moved materials in each of the respective nozzles, and injecting the combined flow stream through each injection nozzle into a juxtaposed cavity to form the multi-layer, multi-material container.

Claim 98

A method of injection molding an at least three multi-material plastic container having a side Wall with a marginal end portion, and whose total side wall thickness below the marginal end portion is from about (0.010 inch to about 0.035 inch, by use of a multi-coinjection nozzle, multi-cavity injection molding apparatus, which comprises, providing a source of supply and a source of polymer flow movement for each polymer melt material, channelling each polymer material flow stream from its source of flow movement separately to each of more than one nozzle, and providing valve means operative in each of the respective co-injection nozzles and utilizing the valve means in each of said co-injection nozzles for combining the separately channelled flow streams.

Claim 99

A method of injection molding an at least three multi-material plastic container having a side Wall with a marginal end portion, and whose total side wall thickness below the marginal end portion is from about (0.010 inch to about 0.035 inch, by use of a multi-coinjection nozzle, multi-cavity injection molding apparatus, which comprises, providing a source of supply and a source of polymer flow movement for each polymer melt material, channelling each polymer material flow stream from its source of flow movement separately to each of more than one nozzle, and providing valve means operative in each of the respective co-injection nozzles and utilizing the valve means in each of said co-injection nozzles for combining the separately channelled flow streams.

Claim 102

A method of forming in a co-injection nozzle a multi-layer substantially concentric combined stream of at least three polymeric materials in a co-injection nozzle for injection as a combined stream into a cavity to form a multi-layer article such that the combined steam has an outer layer of structural material for forming the outer layer of the article, a core of structural material for forming the inner layer of the article, and one or more intermediate layer(s) of material for forming an internal layer(s) of the article, which comprises, providing co-injection nozzle means including a co-injection nozzle having, (a) a gate at one end, (b) a cylindrical central channel in communication with the gate, (c) a plurality of at least three polymer passageways communicating with the central channel, each of at least the first and second of said passageways having annular passageways communicating with annular orifices which communicate with the central channel, each of said passageways having portions of shorter length relative to its orifice than other longer portions thereof, (i) the first orifice being located more proximate the gate than the other orifices for routing the outer layer structural material into the channel, (ii) the third orifice being further removed from the gate than said first or second orifices for routing the core material into the channel, (iii) a second orifice positioned adjacent and close to the first orifice intermediate the first and third orifices, for routing intermediate layer material into the channel, and controlling the thickness, uniformity and radial position of the resulting annular internal layer in the combined stream by providing and utilizing means in the first and second passageways for balancing the flow of the respective polymer flow streams passing through the first and second passageways, said flow balancing being effected by redistributing the flow of the respective materials around the circumference of the annular passageways of the respective first and second annular passageways by restricting the flow along the passageway portions of shorter length relative to the passageway portions of longer length and thereby reducing or eliminating velocity bias of the annular stream of the internal layer in the central channel, such that, as the respective streams from the first and second orifices enter the central channel, each flow stream is substantially balanced and uniform in terms of pressure and temperature about its circumference such that in the combining area of the nozzle, each of the respective layers which form the combined stream are substantially concentric relative to each other.

Claim 103

A method of forming in a co-injection nozzle a multi-layer substantially concentric combined stream of at least three polymeric materials in a co-injection nozzle for injection as a combined stream into a cavity to form a multi-layer article such that the combined steam has an outer layer of structural material for forming the outer layer of the article, a core of structural material for forming the inner layer of the article, and one or more intermediate layer(s) of material for forming an internal layer(s) of the article, which comprises, providing co-injection nozzle means including a co-injection nozzle having, (a) a gate at one end, (b) a cylindrical central channel in communication with the gate, (c) a plurality of at least three polymer passageways communicating with the central channel, each of at least the first and second of said passageways having annular passageways communicating with annular orifices which communicate with the central channel, each of said passageways having portions of shorter length relative to its orifice than other longer portions thereof, (i) the first orifice being located more proximate the gate than the other orifices for routing the outer layer structural material into the channel, (ii) the third orifice being further removed from the gate than said first or second orifices for routing the core material into the channel, (iii) a second orifice positioned adjacent and close to the first orifice intermediate the first and third orifices, for routing intermediate layer material into the channel, and controlling the thickness, uniformity and radial position of the resulting annular internal layer in the combined stream by providing and utilizing means in the first and second passageways for balancing the flow of the respective polymer flow streams passing through the first and second passageways, said flow balancing being effected by redistributing the flow of the respective materials around the circumference of the annular passageways of the respective first and second annular passageways by restricting the flow along the passageway portions of shorter length relative to the passageway portions of longer length and thereby reducing or eliminating velocity bias of the annular stream of the internal layer in the central channel, such that, as the respective streams from the first and second orifices enter the central channel, each flow stream is substantially balanced and uniform in terms of pressure and temperature about its circumference such that in the combining area of the nozzle, each of the respective layers which form the combined stream are substantially concentric relative to each other.

Claim 107

A method of controlling the final lateral location of internal layer material within the wall of an injected parison formed of a plurality of layers of plastic materials and including at least an inner structural layer, an internal layer, and an outer structural layer, which comprises, displacing from a plurality of different sources of material, each polymeric material which is to form a layer of the parison, providing a plurality of co-injection nozzles each having a central channel with a polymer stream combining area, and having an annular passageway and associated annular orifice for each layer to be formed, said passageway orifices being in communication with the central channel, each of said passageways having portions of shorter length relative to its orifice than other longer portions thereof, separately channeling each displaced polymer flow stream which is to form a layer, from its source of displacement to a passageway in each nozzle, continuously controlling the displacement of each polymeric material, and controlling the radial location and reducing or eliminating velocity bias of the internal layer within the combining area of the central channel, by positively controlling the flow of the streams which respectively form the outer and internal layers through their orifices by moving the streams past flow balancing means operative in their respective passageways in each of more than one nozzle for there selectively and respectively providing materials, said flow balancing being effected by redistributing the flow of the respective materials around the circumference of the annular passageways of the respective first and second annular passageways by restricting the flow along the passageway portions of shorter length relative to the passageway portions of longer length and thereby reducing or eliminating velocity bias of the annular stream of the internal layer in the central channel, and displacing the respective outer and internal layer materials and the inner layer materials through their respective passageways to achieve their respective desired design flows, to place the annuluses of the respective materials uniformly radially in the combining area, and to thereby control the radial location of the internal layer material in the combined flow stream in the combining area of each nozzle and in the injected material in each injection cavity.

Claim 108

A method of controlling the final lateral location of internal layer material within the wall of an injected parison formed of a plurality of layers of plastic materials and including at least an inner structural layer, an internal layer, and an outer structural layer, which comprises, displacing from a plurality of different sources of material, each polymeric material which is to form a layer of the parison, providing a plurality of co-injection nozzles each having a central channel with a polymer stream combining area, and having an annular passageway and associated annular orifice for each layer to be formed, said passageway orifices being in communication with the central channel, each of said passageways having portions of shorter length relative to its orifice than other longer portions thereof, separately channeling each displaced polymer flow stream which is to form a layer, from its source of displacement to a passageway in each nozzle, continuously controlling the displacement of each polymeric material, and controlling the radial location and reducing or eliminating velocity bias of the internal layer within the combining area of the central channel, by positively controlling the flow of the streams which respectively form the outer and internal layers through their orifices by moving the streams past flow balancing means operative in their respective passageways in each of more than one nozzle for there selectively and respectively providing materials, said flow balancing being effected by redistributing the flow of the respective materials around the circumference of the annular passageways of the respective first and second annular passageways by restricting the flow along the passageway portions of shorter length relative to the passageway portions of longer length and thereby reducing or eliminating velocity bias of the annular stream of the internal layer in the central channel, and displacing the respective outer and internal layer materials and the inner layer materials through their respective passageways to achieve their respective desired design flows, to place the annuluses of the respective materials uniformly radially in the combining area, and to thereby control the radial location of the internal layer material in the combined flow stream in the combining area of each nozzle and in the injected material in each injection cavity.

Claim 109

A method of controlling the relative flow rates of at least three polymeric material melt flow streams into and through at least three passageways and orifices and into the central channel of a co-injection nozzle in an injection molding machine, which comprises providing at least three polymeric material melt flow streams, providing a co-injection nozzle having a central channel with an open end, a gate at the open end, a polymer flow stream passageway for each polymeric material melt flow stream, each passageway having an orifice in communication with the central channel, (i) the first orifice being located more proximate the gate than the other orifices for routing the outer layer structural material into the channel, (ii) the third orifice being further removed from the gate than said first or second orifices for routing the core material into the channel, (iii) a second orifice positioned adjacent and close to the first orifice intermediate the first and third orifices, for routing intermediate layer material into the channel, and connecting each of the polymeric material melt flow streams of the outer layer and core layer materials to common moving means for moving each stream to its respective nozzle passageway, and utilizing the common moving means to move said outer and core layer material streams through their passageways while positively partially blocking the flow of one of the flow streams and not blocking the flow of the other stream.

Claim 110

A method of controlling the relative flow rates of at least three polymeric material melt flow streams into and through at least three passageways and orifices and into the central channel of a co-injection nozzle in an injection molding machine, which comprises providing at least three polymeric material melt flow streams, providing a co-injection nozzle having a central channel with an open end, a gate at the open end, a polymer flow stream passageway for each polymeric material melt flow stream, each passageway having an orifice in communication with the central channel, (i) the first orifice being located more proximate the gate than the other orifices for routing the outer layer structural material into the channel, (ii) the third orifice being further removed from the gate than said first or second orifices for routing the core material into the channel, (iii) a second orifice positioned adjacent and close to the first orifice intermediate the first and third orifices, for routing intermediate layer material into the channel, and connecting each of the polymeric material melt flow streams of the outer layer and core layer materials to common moving means for moving each stream to its respective nozzle passageway, and utilizing the common moving means to move said outer and core layer material streams through their passageways while positively partially blocking the flow of one of the flow streams and not blocking the flow of the other stream.

Claim 113

A method of controlling the flow of polymeric material melt flow streams into the central channel of a co-injection nozzle, which comprises, providing a plurality of co-injection nozzle means, each having: (a) a central channel having a gate at one end, (b) five polymer melt flow stream passageways, each having an orifice which communicates with the central channel, wherein (i) the first orifice is located more proximate to the open end than the other orifices for routing material to the channel for forming primarily the outside surface layer of the article, (ii) the third orifice is more removed from the open end than the other orifices for routing material to the channel for forming primarily the inside surface layer of the article, (iii) the second orifice is located between the first and third orifices for routing a polymeric material to the channel for forming an internal layer of the article, (iv) the fourth orifice is located intermediate the first and second orifices for routing a polymeric material to the channel for forming an intermediate layer between the first and the internal layer of the article, and (v) the fifth orifice is located intermediate the second and third orifices for routing a polymeric material to the channel for forming an intermediate layer between the internal layer and the inside surface layer of the article, (c) valve means in the co-injection nozzle operative in the central channel adjacent and with respect to each of the five orifices for blocking, unblocking and controlling the flow and non-flow of the respective materials from their orifices into the central channel, and (d) a common moving means associated with both of the outside and inside surface materials for commonly moving them into and through their respective passageways and orifices, and, (e) a common moving means associated with both of the respective intermediate materials for commonly moving them into and through their respective passageways and orifices, and utilizing the common moving means for moving the melt flow stream through the first and third passageways while utilizing the valve means for not blocking the first orifice and for partially blocking the third orifice, while polymeric material is flowing channel from the second orifice and thereby inserting in the central the flow of the polymeric material from the second orifice between the flows of the materials from the first and third orifices.

Claim 114

A method of controlling the flow of polymeric material melt flow streams into the central channel of a co-injection nozzle, which comprises, providing a plurality of co-injection nozzle means, each having: (a) a central channel having a gate at one end, (b) five polymer melt flow stream passageways, each having an orifice which communicates with the central channel, wherein (i) the first orifice is located more proximate to the open end than the other orifices for routing material to the channel for forming primarily the outside surface layer of the article, (ii) the third orifice is more removed from the open end than the other orifices for routing material to the channel for forming primarily the inside surface layer of the article, (iii) the second orifice is located between the first and third orifices for routing a polymeric material to the channel for forming an internal layer of the article, (iv) the fourth orifice is located intermediate the first and second orifices for routing a polymeric material to the channel for forming an intermediate layer between the first and the internal layer of the article, and (v) the fifth orifice is located intermediate the second and third orifices for routing a polymeric material to the channel for forming an intermediate layer between the internal layer and the inside surface layer of the article, (c) valve means in the co-injection nozzle operative in the central channel adjacent and with respect to each of the five orifices for blocking, unblocking and controlling the flow and non-flow of the respective materials from their orifices into the central channel, and (d) a common moving means associated with both of the outside and inside surface materials for commonly moving them into and through their respective passageways and orifices, and, (e) a common moving means associated with both of the respective intermediate materials for commonly moving them into and through their respective passageways and orifices, and utilizing the common moving means for moving the melt flow stream through the first and third passageways while utilizing the valve means for not blocking the first orifice and for partially blocking the third orifice, while polymeric material is flowing channel from the second orifice and thereby inserting in the central the flow of the polymeric material from the second orifice between the flows of the materials from the first and third orifices.

Claim 116

A method of controlling the flow of polymeric material melt flow streams into the central channel of a co-injection nozzle, which comprise, providing a plurality of co-injection nozzle means each having: (a) a central channel having a gate at one end, (b) five polymer melt flow stream passageways, each having an orifice which communicates with the central channel, wherein (i) the first orifice is located more proximate to the open end than the other orifices for routing material to the channel for forming primarily the outside surface layer of the article, (ii) the third orifice is more removed from the open end than the other orifices for routing material to the channel for forming primarily the inside surface layer of the article, (iii) the second orifice is located between the first and third orifices for routing a polymeric material to the channel for forming an internal layer of the article, (iv) the fourth orifice is located intermediate the first and second orifices for routing a polymeric material to the channel for forming an intermediate layer between the first and internal layer of the article, and (v) the fifth orifice is located intermediate the second the third orifices for routing a polymeric material to the channel for forming an intermediate layer between the internal layer and the inside surface layer of the article, (c) valve means in the co-injection nozzle operative in the central channel adjacent and with respect to each of the five orifices for blocking, unblocking and controlling the flow and non-flow of the respective materials from their orifices into the central channel, and (d) a common moving means associated with both of the outside and inside surface materials for commonly moving them into and through their respective passageways and orifices, and (e) a common moving means associated with both of the respective intermediate materials for commonly moving them into and through their respective passageways and orifices, and utilizing the common moving means for moving the melt flow stream through the fourth and fifth passageways at a first rate of flow while utilizing the valve means for not blocking the fourth orifice and for partially blocking the fifth orifice while polymeric material flows from the first, second and third orifices.

Claim 117

A method of controlling the flow of polymeric material melt flow streams into the central channel of a co-injection nozzle, which comprise, providing a plurality of co-injection nozzle means each having: (a) a central channel having a gate at one end, (b) five polymer melt flow stream passageways, each having an orifice which communicates with the central channel, wherein (i) the first orifice is located more proximate to the open end than the other orifices for routing material to the channel for forming primarily the outside surface layer of the article, (ii) the third orifice is more removed from the open end than the other orifices for routing material to the channel for forming primarily the inside surface layer of the article, (iii) the second orifice is located between the first and third orifices for routing a polymeric material to the channel for forming an internal layer of the article, (iv) the fourth orifice is located intermediate the first and second orifices for routing a polymeric material to the channel for forming an intermediate layer between the first and internal layer of the article, and (v) the fifth orifice is located intermediate the second the third orifices for routing a polymeric material to the channel for forming an intermediate layer between the internal layer and the inside surface layer of the article, (c) valve means in the co-injection nozzle operative in the central channel adjacent and with respect to each of the five orifices for blocking, unblocking and controlling the flow and non-flow of the respective materials from their orifices into the central channel, and (d) a common moving means associated with both of the outside and inside surface materials for commonly moving them into and through their respective passageways and orifices, and (e) a common moving means associated with both of the respective intermediate materials for commonly moving them into and through their respective passageways and orifices, and utilizing the common moving means for moving the melt flow stream through the fourth and fifth passageways at a first rate of flow while utilizing the valve means for not blocking the fourth orifice and for partially blocking the fifth orifice while polymeric material flows from the first, second and third orifices.