Inventor(s):
Schloss; Francis M. , Perrysburg, OH
Balduff; Dennis C. , Whitehouse, OH
Applicant(s):
The Coca-Cola Company, Atlanta, GA
Issued/Filed
Dates:
Dec. 22, 1998 / May. 16, 1996
Application
Number:
US1996000648669
IPC Class:
B29B 011/08; B29C 045/16;
Class:
264/250; 264/279; 264/328.8; 264/513;
Field of Search:
264/255,279,328.8,537,513,250 425/130
428/35.7,36.6,36.7,542.8
Abstract:
A method of injection molding a multi-layer preform from a
combination of virgin and recycled plastic such as PET so
that the resultant blow-molded bottle has a reduced
tendency for bottom failure in spite of the use of
recycled
plastic. A first plastic preform for providing the inner
layer
of the multi-layer preform is provided with spaced
channels on the exterior surface of a closed end thereof
extending from a central region of that end to the
sidewalls. An injection mold cavity is provided with a
like
plurality of channels formed therein in a closed end
thereof
communicating with the injection gate of an injection
molding apparatus. The first plastic preform is inserted
into the injection mold cavity with the respective
channels
of the preform and the injection mold cavity substantially
aligned. A second layer of plastic material is overmolded
onto the first layer by injection molding in the cavity. A
third
layer of plastic material may be overmolded on the second
layer to form a three-layer preform. Preferably the first
and
third layers are formed from virgin plastic and the second
layer is formed from recycled plastic.
Attorney, Agent, or
Firm:
Birch, Stewart, Kolasch & Birch, LLP;
Primary/Assistant
Examiners:
Timm; Catherine; Mason; Suzanne E.
U.S. References:
(No patents reference this one)
Patent
Inventor
Issued
Title
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* some details unavailable
First Claim:
Show all 14 claims
What is claimed is:
1. A method of injection molding a multi-layer plastic
preform to be blow molded into
a container comprising the steps of:
forming an inner layer of a preform of a first plastic
material having an open end,
sidewalls, and a closed end, said closed end having a
plurality of spaced
channels on the exterior surface thereof extending from
a central area on the
closed end to the sidewalls.
providing an overmolding mold cavity defined by
sidewalls, an open end for
accommodating a core rod, and a closed end with an
injection gate therethrough,
and a plurality of channels on the interior surface of
the closed end communicating
with the gate and extending from the gate to the
sidewalls;
inserting a core rod and the inner plastic layer of the
preform into said
overmolding mold cavity with respective channels of the
inner plastic layer of the
preform and the overmolding mold cavity substantially
aligned; and
overmolding a second layer of a second plastic material
on the inner plastic layer
of the preform to form an overmolded multi-layer perform
in said overmolding
mold cavity by flowing the second plastic material from
the gate only through the
respective channels to the sidewalls of the overmolding
mold cavity thereby
limiting the second material in the closed end of the
multi-layer preform to regions
of the channels, and wherein the first plastic has a
higher resistance to stress
cracking than the second plastic.
Foreign
References:
Publication Number
Country
Date
IPC
Class
WO1995WO0000325
World Intellectual Property
Organization (WIPO)
1 /1995
:
____________________________________
Peter Anderson
RecycleWorlds Consulting
4513 Vernon Blvd. Ste. 15
Madison, WI 53705-4964
Phone:(608) 231-1100/Fax: (608) 233-0011
E-mail:recycle@msn.fullfeed.com
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