US4950532A — Process for producing glass fiber reinforced ther…

Claim 1

Independent Claim 213 words

Process of molding fiber reinforced thermoplastic parts having at least one smooth surface, comprising: preheating at least one laminate of predominantly amorphous thermoplastic polymer, copolymer, terpolymer, blend or alloy that is reinforced with glass fiber strand reinforcing mat selected from the group consisting of needled, continuous glass fiber strand mat, chemically bonded glass fiber strand mat, and continuous glass fiber strand mat where the mat is present in an amount in the range of less than 40 weight percent of the laminate where preheating is at an effective temperature that is in the range of less than the degradation temperature of the polymer to a temperature to at least soften the amorphous polymer and to melt any semicrystalline polymer whereby the polymer has a viscosity less than 20,000 poise and whereby the laminate expands; and molding an effective charge of the heated laminate by compression molding at a pressure in the range of about 500 to about 6,000 psi and with at least one mold surface at a temperature in the range of from the Tg temperature to 70° F. (39° C.) below the Tg temperature of the polymer to reduce the shear modulus at the surface of the laminate contacting said mold surface to produce the molded, reinforced, predominantly amorphous thermoplastic part.

Claim 2

Dependent Claim 213 words

Process of molding fiber reinforced thermoplastic parts having at least one smooth surface, comprising: preheating at least one laminate of predominantly amorphous thermoplastic polymer, copolymer, terpolymer, blend or alloy that is reinforced with glass fiber strand reinforcing mat selected from the group consisting of needled, continuous glass fiber strand mat, chemically bonded glass fiber strand mat, and continuous glass fiber strand mat where the mat is present in an amount in the range of less than 40 weight percent of the laminate where preheating is at an effective temperature that is in the range of less than the degradation temperature of the polymer to a temperature to at least soften the amorphous polymer and to melt any semicrystalline polymer whereby the polymer has a viscosity less than 20,000 poise and whereby the laminate expands; and molding an effective charge of the heated laminate by compression molding at a pressure in the range of about 500 to about 6,000 psi and with at least one mold surface at a temperature in the range of from the Tg temperature to 70° F. (39° C.) below the Tg temperature of the polymer to reduce the shear modulus at the surface of the laminate contacting said mold surface to produce the molded, reinforced, predominantly amorphous thermoplastic part.

Claim 3

Dependent Claim 24 words

Process of claim 1, wherein the temperature of preheating is at least 50° F. (28° C.) above the glass transition temperature of the polymer.

Claim 4

Dependent Claim 24 words

Process of claim 1, wherein the temperature of preheating is greater than the melting temperature of any primary crystalline phase present in the polymer.

Claim 5

Dependent Claim 23 words

Process of claim 1, wherein the predominantly amorphous thermoplastic polymer is a polycarbonate/polyester polyblend having the differential scanning "calorimeter" curve of FIG. 3.

Claim 6

Dependent Claim 66 words

Process of claim 1, wherein the predominantly amorphous thermoplastic polymer is selected from the group consisting of: polyether imides; polycarbonates; copolymer, polyblends and polymer alloys of polycarbonate and thermoplastic polyesters including polyalkylene terephthalate selected from polyurethane terephthalate and polybutylene terephthalate and mixtures thereof; and copolymers, polyblends, and alloys of polyphenylene oxide and polystyrene; and copolymers, polyblends and alloys of polycarbonates, acrylonitrile and of butadiene and styrene.

Claim 7

Dependent Claim 37 words

Process of claim 1, wherein the effective charge of the heated laminate to molding is sufficient to allow for at least five percent flow of the laminate to fill and mold during compression to produce the part.

Claim 8

Dependent Claim 45 words

Process of claim 1, wherein the reinforcing mat is selected from the group consisting of needled glass fiber strand mat and chemically bound continuous glass fiber stand mat, wherein the fiber diameters of the glass fibers range from 5 micrometers to greater than 30 micrometers.

Claim 9

Dependent Claim 71 words

Process of claim 1, which includes preparing the laminates to be preheated and molded by combining at least one ply of reinforcing mat between at least two plies of the predominantly amorphous thermoplastic polymer under pressure at a temperature in the range of at least 50° F. (28° C.) greater than the glass transition temperature of the polymer and to a temperature of less than the decomposition temperature of the polymer.

Claim 10

Dependent Claim 54 words

Process of claim 1, wherein the predominantly amorphous thermoplastic polymer is a homogeneous wholly amorphous polymer, copolymer, polyblend or polymer alloy, and where one or more of the preheated laminates are transferred to molding in a manner to avoid any substantial decrease in temperature of the laminate and concomitant increase in the laminate's viscosity.

Claim 11

Dependent Claim 87 words

Process of claim 1, wherein the predominantly amorphous thermoplastic polymer is a semicrystalline polymer exhibiting at least two glass transition temperatures because of the several components of the polymer, and wherein the laminate is preheated at a temperature above the highest melting temperature of the semicrystalline polymer and wherein the heated laminate is molded at a temperature in the range between the glass transition temperature of the dominant component of the semicrystalline polymer to a temperature of 60° F. (33° C.) less than said glass transition temperature.

Claim 12

Dependent Claim 19 words

Process of claim 1, wherein the laminate is essentially free of any surfacing fiber mat and separating polymeric film.

Claim 13

Dependent Claim 21 words

Process of claim 1, wherein the predominantly amorphous polymer in the preheated laminate has a viscosity of less than 20,000 poise.

Claim 14

Dependent Claim 18 words

Process of claim 1, wherein the predominantly amorphous polymer has a glass transition temperature greater than 100° C.

Claim 15

Dependent Claim 13 words

The molded fiber reinforced thermoplastic part produced by the process of claim 1.

Claim 16

Dependent Claim 217 words

Process of molding glass fiber reinforced thermoplastic parts having at least one smooth surface, comprising: a. preheating laminates of at least one ply of glass fiber strand reinforcing mat selected from needled continuous strand mat and chemically bonded mat, where the mat is positioned between at least two plies of a substantially amorphous polymer, copolymer, terpolymer, blend or alloy, wherein the glass fiber strand mat is present in an amount less than 40 weight percent of the laminate, and wherein preheating is at a temperature of around 100° C. greater than the polymeric glass transition temperature for a wholly amorphous polymer, copolymer, terpolymer blend or alloy and at least at the melting temperature of a semicrystalline polymer, copolymer, terpolymer blend or alloy to give the polymer a flowable viscosity and whereby the laminate expands, and b. molding an effective charge of the preheated laminate to yield at least 5 percent flow of the laminate by compression molding at a pressure of about 500 to about 6,000 psi where at least one surface of the mold are maintained at a temperature in the range of from the glass transition temperature of the polymer to a temperature of 60° F. (35° C.) below the glass transition temperature of the polymer to produce the molded, reinforced, predominantly amorphous thermoplastic part.

Claim 17

Dependent Claim 217 words

Process of molding glass fiber reinforced thermoplastic parts having at least one smooth surface, comprising: a. preheating laminates of at least one ply of glass fiber strand reinforcing mat selected from needled continuous strand mat and chemically bonded mat, where the mat is positioned between at least two plies of a substantially amorphous polymer, copolymer, terpolymer, blend or alloy, wherein the glass fiber strand mat is present in an amount less than 40 weight percent of the laminate, and wherein preheating is at a temperature of around 100° C. greater than the polymeric glass transition temperature for a wholly amorphous polymer, copolymer, terpolymer blend or alloy and at least at the melting temperature of a semicrystalline polymer, copolymer, terpolymer blend or alloy to give the polymer a flowable viscosity and whereby the laminate expands, and b. molding an effective charge of the preheated laminate to yield at least 5 percent flow of the laminate by compression molding at a pressure of about 500 to about 6,000 psi where at least one surface of the mold are maintained at a temperature in the range of from the glass transition temperature of the polymer to a temperature of 60° F. (35° C.) below the glass transition temperature of the polymer to produce the molded, reinforced, predominantly amorphous thermoplastic part.

Claim 18

Dependent Claim 28 words

Process of claim 15, wherein the amorphous polymer is a compatible copolymer, blend or alloy of polycarbonate and copolyester having a differential scanning colorimeter curve of FIG. 3.

Claim 19

Dependent Claim 65 words

Process of claim 15, which includes producing the laminate to be preheated at a temperature in the range of at least 100° C. higher than the glass transition temperature of the polymer and of less than the decomposition temperature of the polymer and at an elevated pressure and for a sufficient period of time to allow the polymer to impregnate the glass fiber strand mat.

Claim 20

Dependent Claim 12 words

The molded fiber reinforced thermoplastic part produced the process of claim 15.

Claim 21

Dependent Claim 16 words

The glass fiber strand reinforced polycarbonate/copolyester thermoplastic polymeric part produced by the process of claim 16.

Claim 22

Dependent Claim 225 words

Process of molding fiber reinforced thermoplastic parts having at least one smooth surface, comprising: a. preheating laminates of a semicrystalline, thermoplastic polymer, copolymer, terpolymer, blend or alloy having around 50% polybutylene terephthalate, 45% polycarbonate and 5% elastomer that is reinforced with a reinforcing glass fiber strand mat selected from the group consisting of needled continuous strand mat, and chemically bonded mat in an amount in the range of less than 40 weight percent of the laminate at a temperature greater than the melting point of the polymer but less than the decomposition temperature of the polymer to render the polymer to have a flowable viscosity of less than around 20,000 poise and to expand the laminate, and b. molding and effective charging of the heated laminate by compression molding to obtain at least 5% flow of the laminate at a pressure of about 500 to about 6,000 psi and where at least one die surface of the mold is maintained at a temperature in the range from about the glass transition temperature of the poly(butylene terephthalate) to a temperature of 60° F. (33° C.) less than said glass transition temperature and greater than the lowest glass transition temperature exhibited by differential scanning colorimetry for the polymer between the primary and secondary glass transition temperature of the resin to produce the molded, reinforced, semicrystalline thermoplastic part.

Claim 23

Dependent Claim 225 words

Process of molding fiber reinforced thermoplastic parts having at least one smooth surface, comprising: a. preheating laminates of a semicrystalline, thermoplastic polymer, copolymer, terpolymer, blend or alloy having around 50% polybutylene terephthalate, 45% polycarbonate and 5% elastomer that is reinforced with a reinforcing glass fiber strand mat selected from the group consisting of needled continuous strand mat, and chemically bonded mat in an amount in the range of less than 40 weight percent of the laminate at a temperature greater than the melting point of the polymer but less than the decomposition temperature of the polymer to render the polymer to have a flowable viscosity of less than around 20,000 poise and to expand the laminate, and b. molding and effective charging of the heated laminate by compression molding to obtain at least 5% flow of the laminate at a pressure of about 500 to about 6,000 psi and where at least one die surface of the mold is maintained at a temperature in the range from about the glass transition temperature of the poly(butylene terephthalate) to a temperature of 60° F. (33° C.) less than said glass transition temperature and greater than the lowest glass transition temperature exhibited by differential scanning colorimetry for the polymer between the primary and secondary glass transition temperature of the resin to produce the molded, reinforced, semicrystalline thermoplastic part.

Claim 24

Dependent Claim 25 words

Process of claim 20, wherein the laminates to be preheated are produced under pressure at a temperature greater than the melting point of the polymer.

Claim 25

Dependent Claim 13 words

Molded glass fiber reinforced thermoplastic parts produced by the process of claim 20.

Claim 26

Dependent Claim 30 words

Process of claim 20, wherein the temperature regulation of the at least one die surface of the mold during molding results in controlled rheological conditioning of the part being molded.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1993-08-20	1994-02-19	1994-08-21	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1997-08-20	1998-02-19	1998-08-21	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2001-08-20	2002-02-19	2002-08-21	$7700.00	Window Closed / Lapsed

Process for producing glass fiber reinforced thermoplastic compression molded materials and said molded materials

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