U.S. patent application number 11/283566 was filed with the patent office on 2006-04-06 for container preform assembly and method of manufacture.
This patent application is currently assigned to Graham Packaging PET Technologies Inc.. Invention is credited to Jeffrey D. DiPasquale, Brian A. Lynch, Thomas E. Nahill.
Application Number | 20060073296 11/283566 |
Document ID | / |
Family ID | 35465535 |
Filed Date | 2006-04-06 |
United States Patent
Application |
20060073296 |
Kind Code |
A1 |
Nahill; Thomas E. ; et
al. |
April 6, 2006 |
Container preform assembly and method of manufacture
Abstract
A preform assembly for blow molding a container includes a
molded plastic preform having a body and a neck with an external
surface. At least one circumferential channel is molded into the
external surface of the preform neck for removing the preform from
the forming mold. A plastic finish ring separate from the preform
is externally secured to the preform neck over the external surface
of the neck.
Inventors: |
Nahill; Thomas E.; (Amherst,
NH) ; Lynch; Brian A.; (Merrimack, NH) ;
DiPasquale; Jeffrey D.; (Maumee, OH) |
Correspondence
Address: |
KUDIRKA & JOBSE, LLP
ONE STATE STREET
SUITE 800
BOSTON
MA
02109
US
|
Assignee: |
Graham Packaging PET Technologies
Inc.
York
PA
|
Family ID: |
35465535 |
Appl. No.: |
11/283566 |
Filed: |
November 18, 2005 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
10403415 |
Mar 28, 2003 |
6977104 |
|
|
11283566 |
Nov 18, 2005 |
|
|
|
Current U.S.
Class: |
428/35.7 |
Current CPC
Class: |
B29B 2911/14106
20130101; B29B 2911/14113 20130101; B29K 2023/086 20130101; B29B
2911/1404 20130101; B29B 2911/14126 20130101; B29C 2049/2026
20130101; B29K 2067/00 20130101; B29B 2911/1406 20130101; B29B
2911/1402 20130101; B29B 2911/1412 20130101; B29C 66/71 20130101;
B29C 49/06 20130101; B29B 2911/14333 20130101; B29B 2911/14226
20130101; B29B 2911/14328 20150501; B29B 2911/1442 20130101; B29B
2911/14033 20130101; B29C 49/0073 20130101; B29C 66/7234 20130101;
B29C 66/71 20130101; B29B 2911/14026 20130101; B29K 2023/12
20130101; B29K 2623/086 20130101; Y10T 428/1352 20150115; B29C
66/1222 20130101; B29C 66/1224 20130101; B29B 2911/14213 20130101;
B29C 66/712 20130101; B29K 2995/004 20130101; B29B 2911/1408
20130101; B29B 2911/14053 20130101; B29B 2911/14153 20130101; B29B
2911/14335 20150501; B29C 66/1312 20130101; B29C 66/71 20130101;
B29K 2995/0041 20130101; B29B 2911/14133 20130101; B29C 2049/021
20130101; B29C 2049/2017 20130101; B29C 65/00 20130101; B29C 66/71
20130101; B29K 2077/00 20130101; B29K 2023/086 20130101; B29K
2023/06 20130101; B29K 2023/12 20130101; B29K 2067/00 20130101;
B29K 2067/003 20130101; B29B 2911/14146 20130101; B29C 66/5344
20130101; B29C 66/73773 20130101; B29C 65/00 20130101; B29C 65/02
20130101; B29K 2023/06 20130101; B29C 66/71 20130101; B29B
2911/14466 20130101; B29B 2911/14337 20150501; B29C 66/71 20130101;
B29B 2911/14066 20130101; B29B 2911/14341 20150501; B29B 2911/14413
20130101; B29C 66/71 20130101; B29B 2911/14093 20130101; B29C
66/712 20130101; B29B 2911/1444 20130101; B29C 65/48 20130101; B29B
2911/14326 20130101; B29B 2911/1458 20130101; B29C 65/565 20130101;
B29C 66/73921 20130101; B29B 2911/14233 20130101 |
Class at
Publication: |
428/035.7 |
International
Class: |
B32B 27/08 20060101
B32B027/08 |
Claims
1. A preform assembly for blow molding a container, which includes:
a molded plastic preform having a body and a neck with an external
surface, at least one external circumferential channel molded into
said neck external surface for removing said preform from a forming
mold, and a plastic finish ring molded separately from said preform
and externally secured to said neck over said surface.
2. The preform assembly set forth in claim 1 wherein said neck has
a pair of axially spaced external circumferential channels molded
into said neck.
3. The preform assembly set forth in claim 2 wherein said neck has
at least one external axial channel extending between said
circumferential channels on said external surface of said neck.
4. The preform assembly set forth in claim 3 wherein said preform
has an open mouth at one end of said neck, and wherein a first of
said circumferential channels spaced from said open end is at least
partially uncovered by said finish ring.
5. The preform assembly set forth in claim 4 wherein said preform
has an external flange surrounding said mouth, a second of said
circumferential channels being adjacent to said flange.
6. The preform assembly set forth in claim 1 wherein said finish
ring has at least one external thread and an external capping
flange at one axial end of said ring.
7. The preform assembly set forth in claim 1 wherein said finish
ring is externally secured to said neck by interference fit,
adhesive, or welding
8. The preform assembly set forth in claim 1 wherein said plastic
finish ring is of a different material construction from said
plastic preform.
9. The preform assembly set forth in claim 1 wherein said plastic
finish ring is of a material construction selected from the group
consisting of: PET, PP, PE, PEN, REG, PCR, and wholly or partially
crystallized polyester.
10. A method of making a preform assembly for blow molding a
container, which includes the steps of: (a) molding a preform
having a body and a neck with an external surface and at least one
circumferential channel molded into said neck external surface, (b)
providing a plastic finish ring, and (c) externally securing said
finish ring over said external surface of said cylindrical
neck.
11. The method set forth in claim 10 wherein said step (c) is
carried out by interference fit, adhesion or welding.
12. The method set forth in claim 10 wherein said plastic finish
ring is of polyester construction, and wherein said step (b)
includes wholly or partially crystallizing said finish ring prior
to said step (c).
Description
BACKGROUND AND SUMMARY OF THE INVENTION
[0001] In the manufacture of plastic containers, it is conventional
to injection mold or compression mold a container preform having a
body and a finish with one or more external threads. The finish
typically is molded to its final geometry, while the body of the
preform is subsequently blow molded to the desired geometry of the
container body. The preform may be of monolayer construction, or
may be of multilayer construction in which one or more intermediate
layers in the preform body may or may not extend into the finish
area of the preform. U.S. Pat. Nos. 4,609,516, 4,710,118 and
4,954,376 illustrate injection molding of multilayer container
preforms.
[0002] Molding the finish portion of the container as part of the
preform presents a number of problems. For example, when the
preforms are formed by injection molding, the plastic material
typically is injected into a mold cavity at the closed end of the
preform body, so that the material must flow along the sides of the
preform cavity into the area in which the finish is molded. The
finish typically requires more accurate and stable dimensioning
than the body of the preform, which may limit the cycle time of the
molding process. Furthermore, the finish portion of the preform is
of the same material as at least the outer layers of the preform
body, which limits the ability to obtain the most desirable
characteristics at the finish. When the preform is of polyester
construction, such as polyethylene terephthalate (PET), the finish
portion of the preform can be wholly or partially crystallized to
improve the operating characteristics of the finish area,
particularly in hot-fill container applications. However, the
requirement that the finish be of the same material as at least the
outer layers of the preform body still limits the design
capabilities of preform manufacture.
[0003] A preform assembly for blow molding a container in
accordance with a first aspect of the present invention includes a
molded plastic preform having a body and a neck with an external
surface. At least one circumferential channel is molded into the
external surface of the preform neck for removing the preform from
the forming mold. A plastic finish ring separate from the preform
is externally secured to the preform neck over the external surface
of the neck. A method of making a preform assembly for blow molding
a container in accordance with a second aspect of the invention
includes molding a preform having a body and a cylindrical neck
with an external surface, and at least one circumferential channel
molded into the external surface of the neck. A plastic finish ring
is secured over the external surface of the cylindrical neck.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] The invention, together with additional objects, features,
advantages and aspects thereof, will be best understood from the
following description, the appended claims and the accompanying
drawings, in which:
[0005] FIG. 1 is an elevational view of a preform assembly in
accordance with one exemplary presently preferred embodiment of the
invention;
[0006] FIG. 2 is an exploded elevational view of the preform
assembly illustrated in FIG. 1;
[0007] FIG. 3 is a fragmentary elevational view on an enlarged
scale of the portion of FIG. 2 within the area 3;
[0008] FIG. 4 is a sectional view of the finish ring in the preform
assembly of FIGS. 1 and 2, being taken substantially along the line
4-4 in FIG. 2;
[0009] FIG. 5 is a top plan view of the finish ring in FIG. 4;
[0010] FIG. 6 is an elevational view of a preform assembly in
accordance with a second embodiment of the invention;
[0011] FIG. 7 is an elevational view of the preform in the assembly
of FIG. 6; and
[0012] FIGS. 8 and 9 are sectional views taken substantially along
the respective lines 8-8 and 9-9 in FIG. 7.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0013] FIGS. 1-5 illustrate a preform assembly 20 in accordance
with one presently preferred embodiment of the invention as
comprising a preform 22 and a separate finish ring 24 secured over
the neck of preform 22. Preform 22 includes a body 26 having a
closed lower end, and a neck 28 integrally molded with body 26.
(Directional words such as "upper" and "lower" are employed by way
of description and not limitation with respect to the upright
orientation of the preform assemblies and components illustrated in
the drawings. Directional words such as "radial" and
"circumferential" are employed by way of description and not
limitation with respect to the axis of the preform neck or finish
ring as appropriate.) Neck 32 typically is cylindrical. A flange 30
extends radially outwardly from the open end of neck 28 remote from
body 26. Neck 28 and flange 30 surround the open mouth of preform
22. A pair of axially spaced circumferential channels 34, 36 extend
around the outer surface of neck 32, which preferably is
cylindrical in geometry. In the embodiment of FIGS. 1-5, channels
34,36 are in planes that are parallel to each other and
perpendicular to the axis of the preform neck, with upper channel
34 being spaced from flange 30. Channels 34,36 provide gripping
abutment areas for ejecting or stripping the preform from its
forming mold.
[0014] Finish ring 24 is circumferentially continuous (FIG. 5).
Finish ring 24 includes an annular cylindrical wall 38 having one
or more external threads or thread segments 40. In the preferred
embodiment of ring 24 illustrated in the drawings, a
circumferential bead 42 extends around the outer surface of wall 38
beneath threads 40 for cooperating with a tamper-indicating
mechanism on a closure secured to the finish of the final
container. A capping flange 44 extends radially outwardly from the
lower end of wall 38, giving finish ring 24 a generally L-shaped
lateral cross section (FIG. 4) in the illustrated embodiments of
the invention. Finish ring 24 is secured over the external surface
of preform neck 28, covering channels 34, 36 in the embodiment of
FIGS. 1-5.
[0015] FIGS. 6-9 illustrate a preform assembly 50 in accordance
with a second exemplary but presently preferred embodiment of the
invention. Reference numerals in FIGS. 6-9 that are identical to
those employed in FIGS. 1-5 indicate identical or similar
components. Preform assembly 50 includes a preform 52 having a
separate finish ring 24 externally secured thereto. Preform 52
includes body 26 having a cylindrical neck 54 molded integrally
with body 26. A flange 30 extends radially outwardly from the upper
end of neck 54 remote from body 26 and surrounding the preform
mouth 32 (FIG. 9). A pair of external circumferential channels 56,
58 extend in spaced parallel planes around the outer surface of
cylindrical neck 54, with channel 56 being adjacent to and
immediately beneath flange 30 and channel 58 being adjacent to the
juncture of neck 54 with body 26. At least one axial channel 60
extends along the outer surface of neck 54 interconnecting channels
56,58. In the illustrated preferred embodiment of the invention,
there are four axial channels 60 (FIG. 9) circumferentially spaced
around the outer surface of neck 54 at 90.degree. spacing from each
other. When finish ring 24 is assembled to preform neck 54, lower
channel 58 is wholly or partially uncovered, as best seen in FIG.
6. Channels 56, 58 assist in removing preform 52 from its forming
mold, as with channels 34,36 in the embodiment of FIGS. 1-5.
Furthermore, circumferential channels 56, 58 cooperate with
interconnecting axial channels 60 to provide for drainage of any
liquid that may enter between the lower surface of flange 30 and
the upper edge of finish ring 24 during filling of the final
container.
[0016] Preforms 22, 52 may be of any suitable plastic construction,
such as monolayer PET or multilayer construction of PET layers
alternating with layers of barrier resin such as ethylene vinyl
alcohol (EVOH) or nylon. Preforms 22, 52 may be injection molded or
compression molded. Likewise, finish ring 24 may be of injection or
compression molded plastic construction. By providing finish ring
24 separate from preforms 22,52, the finish ring 24 may be of any
desired material construction, either the same as or more
preferably different from the material construction of the preform.
For example, finish ring 24 can be of PET, post consumer resin
(PCR), process regrind (REG), polypropylene (PP), polyethylene (PE)
or polyethylene naphthalate (PEN) construction. Where finish ring
24 is of polyester construction (e.g., PET or PEN), the finish ring
may be wholly or partially crystallized as molded. This may be
accomplished by employing fast-crystallizing materials or suitably
setting process conditions for manufacture of the finish ring, such
as high mold temperature, slow mold cooling, heated areas in the
mold cavity, etc. The finish ring alternatively may be wholly or
partially crystallized in a post-molding operation. In other words,
the material and conditions of fabrication of finish ring 24 may be
selected separately from the material and manufacturing conditions
of preforms 22, 52 to achieve desired operating characteristics at
the finish area of the preform and the final container.
Furthermore, the preforms can be molded with thin wall sections
without having to accommodate flow of material into a thicker
finish area, which reduces material cost and mold cycle time.
Finish ring 24 is secured to the neck 28 of the preform 22 by
interference fit (e.g., press fit or shrink fit), adhesive or
welding. One presently preferred implementation of the invention
involves interference press fit of finish ring 24 onto the neck of
the preform. The preform neck and/or the finish ring can be
provided with suitable means for preventing rotation of the ring on
the neck.
[0017] There have thus been disclosed a preform assembly and a
method of manufacture that fully satisfy all of the objects and
aims previously set forth. The invention has been disclosed in
conjunction with two exemplary presently preferred embodiments
thereof, and a number of modifications and variations have been
discussed. Other modifications and variations will readily suggest
themselves to persons of ordinary skill in the art. The invention
is intended to embrace all such modifications and variations as
fall within the spirit and broad scope of the appended claims.
* * * * *