EP0256777A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Method and apparatus for injection blow moulding pet containers
Assignee: Hoover Universal Inc
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Filing: 1987-08-05
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Granted: —
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Expires: 2007-08-05
Abstract
Abstract Method and apparatus for injection blow molding hollow articles from polyethylene terephthalate (PET) resin utilizing a hollow core rod on which a parison is first injection molded, and subsequently stretched and blown to form the hollow article. Fluid is continuously circulated through the hollow core rod to promote cooling of the plastic and insure the production of hollow articles that are transparent and of high quality from a clarity standpoint. A separate supply of blow air is provided at the blow molding station so as not to interfere with the continuous flow of coolant through the hollow core rod.
Inventors
- 👤 John Joseph Granata
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-07 03:07
CPC Classifications
B; B29; B29C; B29C49/00; B29C49/42; B29C49/64; B29C49/6409; B29C49/6436; B29C49/6445; B29C49/08; B29C49/10; B29C49/12; B29C49/6463; B29C2949/00; B29C2949/07; B29C2949/0715; B29C33/00; B29C33/02; B29C33/04; B29C35/00; B29C35/16; B29C49/02; B29C49/06; B29C49/1202; B29K; B29K2067/00
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
251 words
A method for injection blow molding transparent containers from a PET melt at a temperature in the 260-302°C (500-575°F) range utilizing an injection mold, a hollow core rod and a blow mold, and employing injection mold, blow mold and strip stations, said method comprising the steps of: a) injecting said PET melt into said injection mold at a position around said core rod so as to form a hollow parison in said mold on said core rod; b) cooling the injection mold by subjecting the mold to the action of circulating cooling water maintained at predetermined temperatures in separated zones along the length of said core rod in said injection mold; c) profiling the cooling water temperatures in the injection mold zones so that the various parts of the molded parison are at temperatures that will yield a desired distribution of material in the blow molded container; d) maintaining the parison in the injection mold for a time sufficient to insure a uniform temperature of the molded parison through the walls thereof to further insure the desired distribution of material in the blow molded container; e) circulating fluid internally through said core rod during injection and blow molding so as to cool said core rod; f) providing a supply of blow air to said core rod in the blow mold station to blow the previously injection molded parison and expand said parison to form a container; and g) stripping the blow molded container from said core rod at said strip station.
Claim 2
Independent Claim
251 words
A method for injection blow molding transparent containers from a PET melt at a temperature in the 260-302°C (500-575°F) range utilizing an injection mold, a hollow core rod and a blow mold, and employing injection mold, blow mold and strip stations, said method comprising the steps of: a) injecting said PET melt into said injection mold at a position around said core rod so as to form a hollow parison in said mold on said core rod; b) cooling the injection mold by subjecting the mold to the action of circulating cooling water maintained at predetermined temperatures in separated zones along the length of said core rod in said injection mold; c) profiling the cooling water temperatures in the injection mold zones so that the various parts of the molded parison are at temperatures that will yield a desired distribution of material in the blow molded container; d) maintaining the parison in the injection mold for a time sufficient to insure a uniform temperature of the molded parison through the walls thereof to further insure the desired distribution of material in the blow molded container; e) circulating fluid internally through said core rod during injection and blow molding so as to cool said core rod; f) providing a supply of blow air to said core rod in the blow mold station to blow the previously injection molded parison and expand said parison to form a container; and g) stripping the blow molded container from said core rod at said strip station.
Claim 3
Independent Claim
151 words
A method for injection blow molding transparent containers from a PET melt at a temperature in the range 260-302°C (500-575°F) utilizing an injection mold, a hollow core rod and a blow mold, and employing injection mold, blow mold and strip stations, said method comprising the steps of: a) cooling the injection mold by subjecting the mold to the action of circulating water at predetermined temperatures in separated zones along the length of said core rod; b) circulating fluid internally through said core rod during injection and blow molding so as to cool said core rod; c) providing a supply of blow air to said core rod in the blow mold station substantially concurrently with extending said blow rod axially to stretch and blow the previously injection molded parison and expand said parison to form a container; and d) stripping the blow molded container from said core rod at said strip station.
Claim 4
Independent Claim
151 words
A method for injection blow molding transparent containers from a PET melt at a temperature in the range 260-302°C (500-575°F) utilizing an injection mold, a hollow core rod and a blow mold, and employing injection mold, blow mold and strip stations, said method comprising the steps of: a) cooling the injection mold by subjecting the mold to the action of circulating water at predetermined temperatures in separated zones along the length of said core rod; b) circulating fluid internally through said core rod during injection and blow molding so as to cool said core rod; c) providing a supply of blow air to said core rod in the blow mold station substantially concurrently with extending said blow rod axially to stretch and blow the previously injection molded parison and expand said parison to form a container; and d) stripping the blow molded container from said core rod at said strip station.
Claim 5
Dependent Claim
17 words
The method according claim 2 further including circulating fluid through said core rod at said strip station.
Claim 6
Dependent Claim
156 words
For use in apparatus having injection, and blow molding stations for injection blow molding PET to form transparent containers, a core rod assembly comprising a base section having a first inlet for blow air and a second inlet for cooling fluid, an elongated hollow body mounted on said base section for axial sliding movement between a retracted injection position and an extending blow position, said body communicating the inside of said parison with said blow air inlet in the extended position, said body having a tip section remote from said base section, and means forming a cooling fluid supply conduit internally of said body communicating with said inlet for cooling fluid in both said injection and blow mold stations, said conduit being spaced from said body and terminating in a spaced relation with said tip section so as to form a return passage in said body for said cooling fluid between said body and said conduit.
Claim 7
Dependent Claim
156 words
For use in apparatus having injection, and blow molding stations for injection blow molding PET to form transparent containers, a core rod assembly comprising a base section having a first inlet for blow air and a second inlet for cooling fluid, an elongated hollow body mounted on said base section for axial sliding movement between a retracted injection position and an extending blow position, said body communicating the inside of said parison with said blow air inlet in the extended position, said body having a tip section remote from said base section, and means forming a cooling fluid supply conduit internally of said body communicating with said inlet for cooling fluid in both said injection and blow mold stations, said conduit being spaced from said body and terminating in a spaced relation with said tip section so as to form a return passage in said body for said cooling fluid between said body and said conduit.
Claim 8
Dependent Claim
64 words
The core rod assembly according to claim 4 wherein said conduit has circumferentially spaced and radially outwardly extending terminal end sections frictionally engaging said tip section to locate said conduit radially with said body and in a predetermined fixed position relative to said body in which fluid from said conduit can flow outwardly into said body through the spaces between said terminal end sections.
References Cited (Backward Citations)
No citation records indexed.
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