Process for making containers

A process for thermoforming laminated hollow articles including a plurality of processing steps wherein a thermoplastic material heated to a plastic state is selectively deposited area-wise on a sheet of thermoplastic material and such resulting laminate of thermoplastic materials is positioned proximate to a female mold of a thermoforming apparatus including preferably a plug assist for a subsequent forming of laminated hollow articles.

BACKGROUND OF THE INVENTION 
This invention lies in the field of processes for thermoforming hollow 
multilayered plastic articles from a sheet of thermoplastic material. 
Many processes have been advanced for manufacturing a hollow plastic 
article formed of a plurality of layers wherein the article is provided 
with an inner wall of a plastic material having certain desired properties 
and an outer wall of a plastic material exhibiting other desired 
properties. For examples, Berger U.S. Pat. No. 3,122,598 discloses a 
process for forming decorative plastic articles using injection molding 
techniques, Sherman U.S. Pat. No 2,710,987 discloses a method and 
apparatus for forming laminated plastic articles using extrusion blow 
molding techniques, and Valyi U.S. Pat. No. 3,719,735 discloses a process 
for blow molding a laminated container from a composite parison which is 
formed by injecting a thermoplastic material over a preformed liner. 
While thermoforming techniques have been used to form hollow articles 
utilizing preformed laminated sheets comprised of one or more layers of 
plastic materials, none of such techniques have employed a combination of 
a preformed thermoplastic sheet and an extruded mass or quantity of a 
different thermoplastic material deposited thereagainst. 
Multilayered plastic containers offer various advantages, substantial 
resistance to oxygen permeation, resistance to carbon-dioxide diffusion, 
capacity for storing products under moderate pressure over extended period 
of time, and the like. 
In one prior art plastic sheet thermoforming technique, a fluid pressure 
applied within a pressure box, such as a pressure produced by compressed 
air or the like, presses a softened plastic sheet material against the 
contours of a male mold while a relatively low pressure is exerted from 
the male mold. In another prior art plastic sheet thermoforming technique, 
a vacuum from within a female mold is exerted upon one face of a softened 
plastic sheet material while atmospheric pressure (or a pressurized fluid) 
is exerted upon the opposing face thereof to shape such softened 
thermoplastic sheet material against the surface of a female mold. It is 
possible to use a combination of these two techniques. 
BRIEF SUMMARY OF THE INVENTION 
More particularly, this invention is concerned with an improved 
thermoforming technique wherein a web or sheet of one thermoplastic 
material has a mass or quantity of another thermoplastic material 
deposited thereagainst. The heat softened composite is then formed or 
shaped while in a stretchable plastic state by being drawn or pressed 
against the contours of mold die members under the influence of pressure 
differentials. The composite is first formed against the contours of a 
male mold and then is formed against the surface of a female mold. 
Multi-walled containers can thus be produced. 
This technique can be practiced using a plurality of processing stations 
wherein a thermoplastic material heated to a plastic state is selectively 
deposited area-wise on a sheet of thermoplastic material, and the 
resulting laminate composite of thermoplastic material, after being 
positioned proximate to selected female and male mold members, is 
subjected to appropriate pressure differentials in accordance with 
thermoforming principles to form a desired laminated hollow article. 
An object of the present invention is to provide a new and improved process 
for thermoforming a laminated hollow plastic article. 
Another object is to provide a technique for making multiwalled plastic 
articles from a preformed thermoplastic sheet and a measured mass or 
quantity of thermoplastic material contacted against one face thereof 
selectively. 
Another object is to provide a plastics forming technique of the type above 
indicated which can be practiced economically and which can minimize and 
even eliminate prior art plastic material recovery and recycling problems. 
Various other objects, aims, features, purposes, advantages and the like 
will become apparent from the herein provided description of this 
invention taken together with the accompanying drawings.

DETAILED DESCRIPTION 
It will be appreciated that the type of thermoplastic or thermoelastically 
deformable material employed in the present process is generally 
determined by the economics and duty to which the hollow article will 
eventually be placed. Among the many thermoplastic resins adaptable to 
thermoforming in accordance with the present invention are high-impact 
polystyrene, polybutadiene, styrene-butadiene blends or copolymers, 
styrene/acrylonitrile copolymers, styrene/butadiene/acrylonitrile graft 
copolymers, acrylonitrile copolymers with acrylic monomers (including 
"Barex", a trademark of Sohio Corporation), polyvinylchloride and related 
vinyl polymers, polyallomers, nylons, polyesters, such as polyethylene 
terephthalate, formaldehyde polymers, polyolefins such as polyethylene and 
polypropylene, nitrocellulose, cellulose acetate, cellulose propionate, 
cellulose acetate, acetate butyrate, polymethyl methacrylate, ethyl 
cellulose, benzyl cellulose, ester-esters of cellulose, and the like. 
Production of a multilayered container of this invention is exemplified in 
the embodiment shown in FIGS. 1-8. Referring to FIG. 1, a quantity of 
thermoplastic heated to a plastic condition is deposited from extruder 25 
on a preformed sheet 13 of a (preferably different) thermoplastic. Sheet 
13 is supported in a flattened configuration on flat surfaced working 
table 15 centrally over the head 17 of a reciprocatable cylindrical piston 
19. Head 17 is here maintained in a level configuration with the surface 
of table 15. A forming ring or chase 21 is mounted by clamp assemblies 23 
over and against sheet 13. Clamp assemblies 23 thus also hold sheet 13 in 
a fixed relationship to other elements, such as chase 21. Chase 21 has a 
circular central bore 27 defined therein and bore 27 is oriented generally 
coaxially with piston 19 and head 17 thereof. Chase 21 and table 15 are 
each internally heated by electric resistance heaters 27 and 29, 
respectively. Piston 19 is likewise heated by electric resistance heater 
33. Herein, any conventional heating means may be used such as a 
circulating heat exchange fluid, a combination of electrical and fluidic 
heating, or the like, as desired. Heaters 27, 29 and 33 permit one to heat 
and maintain sheet 13 at some predetermined temperature. Instead of 
directly depositing quantity 11 on sheet 13 from extruder 25, one can, if 
desired, deposit quantity 11 on a suitably sized, preferably heated, 
transport tray or the like located adjacent to an extruder. Then quantity 
11 is transportable on such tray for deposition on or against the sheet 
member 13. 
Once quantity 11 is deposited on sheet 13, a shoe 35 is positioned at chase 
21 (see FIG. 2). Shoe 35 has a diameter only slightly smaller than the 
bore 37 of chase 21 so as to provide a minimum clearance therebetween and 
thereby result in little and preferably no loss of material from quantity 
11 between shoe 35 and chase 21. Shoe 35 is internally heated by electric 
resistance heater 43 or the like as desired. The back face of shoe 35 is 
joined to the forward (lower) end of rod 39 which in turn is a part of 
fluid cylinder assembly 41. The arrangement between shoe 35, rod 39 and 
cylinder assembly 41 is such that, when rod 39 is extended by fluid 
pressure applied in cylinder assembly 41, shoe 35 is compressed against 
quantity 11 so as to shape and conform quantity 11 into a disc-like 
configuration adjacent to one face of sheet 13 within chase 21 below shoe 
35. A clamping flange 11a, extending radially outward of the disc-like 
configuration is formed therewith. 
Next, the shoe 35 is removed from quantity 11 and bore 37 by retracting rod 
39 by cylinder assembly 41. Then, at a subsequent station, a cylinder 
assembly 41 moves a female die plate 47 (see FIG. 3) which is provided 
with a rim 48 for face to face engagement with the periphery 49 of chase 
21 and which is further provided with a central recess 53 whose diameter 
is equal to that of bore 37. Plate 47 is internally heated by electric 
resistance heaters 47a. Thus, bore 37 and recess 53 combine to define a 
female mold cavity. Plate 47 is maintained against chase 21 by rod 39' 
which is axially pressurized by fluid pressure applied in cylinder 
assembly 41'. With plate 47 thus positioned and held, piston 19' is raised 
against the composite of sheet 13 and shaped quantity 11 by a rod and 
fluid cylinder assembly (not detailed, but similar to rod 39' and cylinder 
41'). The resulting preform 55 comprised of the composite of sheet 13 and 
quantity 11 has the cross-sectional configuration shown in FIG. 3. 
Now, piston 19' is lowered, plate 47 is raised, clamp assemblies 23 are 
released, and chase 21 is removed from sheet 13 and associated preform 55. 
The sheet 13 and the associated preform 55 are then moved to a different 
flat surfaced working table 57 (see FIG. 4), and such are centrally 
positioned over the somewhat raised (relative to the surface of table 57) 
head 59 of a reciprocatable cylindrical pistion 61 whose diameter is 
somewhat less than the diameter of piston 19'. Then, a pair of mating 
forming plates 63 are brought into operative association circumferentially 
about the sides of preform 55 with the piston 61 centrally disposed 
therewithin in preparation of the following stretching operation as best 
seen in FIG. 5. 
A pair of mating blow mold halves 69 are brought into operative association 
over and about and in adjacent axial aligned relationship to, the forming 
plates 63, and halves 69 are mechanically locked together in place 
conventionally (not detailed, but see FIG. 4). 
A plate 69a abuting against engaged mold halves 69 is moved axially 
downwardly thereagainst by a fluid cylinder assembly (not detailed, but 
conventional) so that the preform 55 is clamped between working table 
surface 57a and plates 63 against the clamping flange 11a. If desired, 
plates 63 can have thread molds defined therein spirally about their neck 
region so as to provide the capability to later mold threads by swaging 
into the stretched preform 79 during the stretched preform 79 formation as 
described below, being formed by a swaging operation (see FIG. 5). Table 
57, piston 61, and plates 63 are, respectively, each internally heated by 
electric resistance heaters 71, 72, and 73, or by other heating means as 
desired. 
Next, referring to FIG. 5, with the plates 63 thus in place, cooperatively 
with the mold halves 69, piston 61 is raised against the preform 55 (as 
shown in FIG. 4) by a rod 81 and a fluid cylinder assembly (not detaled, 
but similar to cylinder 41). The resulting stretched preform 79 comprised 
of stretched sheet 13 and associated stretched quantity 11 has the cross 
sectional configuration shown in FIG. 5. Circumferentially about rod 81, 
and in longitudinally adjacent but spaced relationship to the bottom of 
piston 61, is a sleeve 85 which reciprocates with rod 81. Sleeve 85 has a 
longitudinally extending channel 89 defined therein, and the outside 
diameter of sleeve 85 is such that sleeve 85 maintains a relationship with 
plates 63 such that the developing stretched preform 79 remains clamped 
therebetween sealingly. As the stretched preform 79 develops, pressurized 
fluid (e.g. air or the like) in mold halves 69 between stretched preform 
79 and mold halves 69 is vented to the atmosphere by vent holes (not 
detailed). 
When the stretched preform 79 reaches for example approximately the 
relative size development shown in FIG. 5, compressed gas, such as air or 
the like illustrated by the arrows shown is admitted to channel 89 which 
results in internal expansion or inflation of the stretched preform 79 
using a pressure sufficient to cause the outer wall portions thereof to 
move outwards and engage the adjacent interior mold wall surfaces of mold 
halves 69 and thereby assume the configuration illustrated in FIG. 6 and 
identified by the numeral 91; such configuration is actually that of the 
walls of a finished container 91 produced by such practice of this 
invention. 
At this general time, in the operational sequence, the interior pressure of 
container 91 is reduced via channel 89 to a minimum level sufficient to 
maintain the container 91 shape, and mold halves 69 are disengaged and 
removed from container 91. Concurrently, piston 61 is raised in the 
interior of container 91 until the head 59 thereof rests against and 
supports the inside bottom surface of container 91, all as illustrated in 
FIG. 7. The sleeve 85 is maintained in a stationary supporting engagement 
with the neck region of container 91 in cooperation with the plates 63 by 
sliding the rod 81 axially and longitudinally relative to the preferably 
tapered sleeve 85 as piston 61 is so raised thereby swage forming threads. 
Container 91 is then allowed to cool in ambient air until container 91 has 
cooled at least sufficiently to be self-supporting. 
Finally, piston 61 and sleeve 85 are retracted from the interior of 
container 91, so that the head 59 of piston 61 is flush approximately with 
the surface of table 57 (not detailed). Then, with the plates 63 still 
grasping the neck of container 91, a trim die 45 or the like is drawn 
transversely across the mouth of container 91 as illustrated in FIG. 8. 
Trimming is an optional step not required to practice thermoforming, 
stretching and blow molding by the practice of this invention. Trimming 
can be accomplished by other means. Sometimes, as in a container having a 
flanged top without a thread finish, trimming may not be performed. 
Referring now to FIGS. 9 and 10, there is seen a thermoforming apparatus 
generally indicated as 10, illustrating the practice of the process of the 
present invention. Apparatus 10 includes a preforming section 12 and a 
forming section 14. It will be understood by one skilled in the art that 
the apparatus 10 is provided with the conventional motor and timing 
subassemblies, including conventional instrumentation, timing circuits, 
safety features, and the like, for automatic and continuous operation of 
the apparatus 10; however, such parts and subassemblies are not shown and 
detailed in the interest of clarity. The preforming section 12 includes 
supply roller assembly 16; heating station 18; operation station A (also 
designated 20); operating station B (also designated 22; and operating 
station C (also designated 24). The forming section 14 includes molding 
station D (also designated 20) and cooling station E (also designated 28). 
The supply roller assembly 16 includes a shaft 30 journalled for rotation 
on supports 32 positioned on a foundation F. On the shaft 30, is mounted a 
core (not detailed) on which is convolutely wound a roll 31 of a sheet or 
strip of thermoplastic material 34 selected for the specific properties to 
be imparted to the inside wall of a product. The heating station 18 is 
here provided with a source of actinic electromagnetic radiation, such as 
an infra-red lamp or lamps 36, as a means for uniformly heating and 
thereby softening the sheet of thermoplastic material 34 in the region 
thereat prior to sheet indexing sequentially in a stop and go manner into 
subsequent stations A, B and C, respectively, of the preforming section 
12. For some modes of operation, the heating station 18 is preferred; 
however, it is contemplated that for other operating modes and conditions, 
the heat of the molten thermoplastic material 68 being deposited on the 
sheet of thermoplastic material 34 at station A could be sufficient to 
heat area-wise the underlying sheet of thermoplastic material 34 to a 
temperature at which said sheet may be thermoformed in accordance with the 
present invention thereby eliminating the necessity of using such heating 
station 18. A sheet support assembly including drums 38 (paired) mounted 
on shafts 40 (paired) journalled for rotation in support trunnions 42 is 
positioned on foundation F. An endless chain belt 44 is mounted about the 
drums 38 to support the sheet of thermoplastic material 34 during passage 
thereof through the stations A, B and C. Belt 44 is provided with 
longitudinally equally spaced, upstanding pin-type retaining elements 46 
associated with links (not detailed) forming the chain belt 44 to ensure 
positive indexing movements of the sheet 34 through the preforming section 
12 of thermoforming apparatus 10. Clamping means (not detailed) may be 
used over drums 38 to prevent slippage of sheet 34 over belt 44. 
Referring now to FIG. 11, in conjunction with FIG. 9, station A is seen to 
be provided with an extrusion assembly 50, a placement assembly 52, and a 
support assembly 54. The extrusion assembly 50 includes a barrel 56 having 
a cylindrically-shaped chamber 58 in which an extruder screw 60 is 
centrally disposed for moving a plastic material therethrough, as known to 
one skilled in the art. The extrusion assembly 50 includes an L-shaped 
extrusion nozzle 62 which is suitably threaded into the forward end region 
of barrel 56 and which extends downwardly to a mouth 51 located above the 
thermoplastic sheet 34. The mouth of the nozzle 62 is machined to engage 
sealingly a gate plate 64 having defined therein an orifice 66 for 
controlling the time when, the amount of a quantity 68 heated 
thermoplastic plastic material is selectively deposited on a predetermined 
location of the sheet 34. The gate plate 64 is mounted for reciprocal 
movements across the mouth 51 responsive to movements of a rod member 72 
which is reciprocally moved by fluid cylinder assembly 70. Nozzle 62 can 
have any convenient construction. 
The placement assembly 52 includes a chase 74 mounted to cylinder rods 76 
(not detailed in FIG. 11) associated with fluid cylinder assemblies 78. 
The chase 74 is provided to establish a selective area portion (here 
illustratively a circular area) on the thermoplastic sheet 34 on which the 
quantity 68 of second thermoplastic plastic material is deposited from 
mouth 51 in a thermoplastic state. The chase 74 is provided internally 
with a suitable passageway network 80 for the circulation therethrough of 
a heat transfer fluid to control the temperature of chase 74 to aid in 
regulating the temperature desired for quantity 68 and sheet 34 in station 
A prior to indexing the sheet 34 to the next station B. 
The support assembly 54 includes a support shoe 82 which has a flat upper 
face 83 and which is provided internally with a passageway network 84 for 
the circulation therethrough of a heat transfer fluid to control the 
temperature of sheet 34 and quantity 68 in station A, any convenient 
controlled heating means may be employed as those skilled in the art will 
appreciate. The back or bottom face of the support shoe 82 is mounted to a 
rod 88 for reciprocal movements towards and away from the back or bottom 
face of sheet 34. Rod 88, in turn, is associated with fluid cylinder 
assembly 86. 
Referring now to FIG. 12 in conjunction with FIG. 9, station B is seen to 
be provided with a guiding assembly 90, a shaping assembly 92, and a 
support assembly 94. The guiding assembly 90 of station B is similar in 
structure and function to the placement assembly 52 of station A, and 
includes a chase 96 with a passageway network 98 for circulating 
therethrough of a heat transfer fluid for temperature control. The chase 
96 is reciprocally mounted to fluid cylinder assemblies 100 by respective 
cylinder rods 102 for movements towards and away from the upper face of 
sheet 34. 
The shaping assembly 92 includes a stamper foot 104 which has a flat lower 
face 105 and which is provided internally with a passageway network 106 
for the circulation therethrough of a heat transfer fluid to control the 
temperature of quantity 68. Stamper foot 104 is mounted for reciprocal 
movements towards and away from quantity 68 to a rod 110 which, in turn, 
joins fluid cylinder assembly 108. The peripheral configuration of the 
stamper foot 104 conforms closely to the inner configuration of the chase 
96 to minimize any seepage of the second thermoplastic material from 
quantity 68 therebetween. The chase 96, and the foot 104, together with 
associated components coact to form the quantity 68 into a disc shaped 
body in the embodiment shown. However, the contacting surface of the 
stamper foot may be, if desired, specially configured to distribute the 
second thermoplastic material in a quantity 68 in some selected (or 
uneven) manner, dependent on the shape or configuration desired in a 
product article with regard to the eventual distribution of thermoplastic 
materials therein. 
The support assembly 94 includes a support shoe 112 internally provided 
with a suitable passageway network 114 for the circulation of heat 
transfer fluid therethrough for temperature control; any suitable 
controlled heating means may be employed, as those skilled in the art will 
readily appreciate. The back or bottom face of the support shoe 112 is 
mounted to a rod 118 for reciprocal movements towards and away from the 
back or bottom face of sheet 34. Rod 118, in turn, is associated with 
fluid cylinder assembly 116. 
Referring now to FIG. 13 in conjunction with FIG. 9, station C is seen to 
be provided with an initial molding assembly 128 which includes a forming 
die assembly 122 and a forming plate assembly 124. The forming die 
assembly 122 includes a female forming die 126 mounted for reciprocal 
movements towards and away from the upper surface of the composite of 
sheet 34 and quantity 68 to the end of a rod 130 which, in turn, connects 
with a fluid cylinder assembly 120. 
The forming plate assembly 124 includes a male forming plate 132 mounted 
for reciprocal movements to a fluid cylinder assembly 134 by an 
interconnecting cylinder rod 136. Plate 132 is adapted to be matingly 
received within die 126 with the composite of sheet 34 and quantity 68 
formed therebetween. Each of the forming die 126 and forming plate 132 are 
provided with a passageway network 138 and 140, respectively, for 
circulating therethrough a heat transfer fluid for temperature control; 
any convenient controlled heating means may be employed as those skilled 
in the art will readily appreciate. 
The forming portion 14 of the apparatus 10 (see FIGS. 9 and 10) is 
comprised of a blowing station 26 (Station D) and the cooling station 28 
(Station E) circumferentially equally spaced about and mounted on a rotary 
table assembly 150, including a rotary table 152. 
Referring now to FIG. 14 in conjunction with FIG. 9, the blowing station 
126 is seen to include mating blow mold halves 154 mounted for reciprocal 
horizontal separating and joining movements to a vertically movable platen 
156 in a conventional manner known to one skilled in the art. Beneath the 
mold halves 154, there are disposed thread forming plates 158 mounted to 
fluid cylinder assemblies 160 by interconnecting cylinder rods 162. 
Each operating piston of the rotary table 152 includes a piston 164 
disposed within a chamber 166 defined in the rotary table 152. Each piston 
164 is positioned therein for vertical movements by a centrally apertured 
cap plate 168 which is threadably mounted about its periphery to table 152 
and through which a central sleeve portion 190 of each piston 164 is 
slidably extensible and retractable to a limited extent. Conduits 170 and 
172 are defined in the rotary table 152 and are each in fluid 
communication with a different portion of the chamber 166 on either side 
of the piston 164. The piston 164 is formed with an axially disposed 
cylindrical passageway 174 defined therein within which an extendible and 
retractable core pin 176 is positioned for reciprocal movements. The core 
pin 176 is provided with an axial channel 178 and orifices 180 radially 
connected therewith to permit the introduction of a fluidic expansion 
medium into the interior of a preform, as hereinafter more fully 
described. The end of the core pin 176 is provided with a conically-sided 
support element 182 which here has a flattened head portion 183. 
From the upper surface of the piston 164, there is axially affixed a 
cylindrical sleeve 190 on which is mounted a top plate 192. 
Circumferentially about sleeve 190 and in slidable engagement therewith is 
positioned a plate 194 which has a circumferential cutting edge abutment 
195. Between plate 194 and plage 192 an elastomeric body 196 is 
positioned. Plate 194 is adapted to abut against a shoulder (not detailed) 
formed on sleeve 190 so that downward movement of plate 194 relative to 
sleeve 190 is limited thereby. When sleeve 190 is lowered, plate 168 
limits travel of plate 194 and body 196 is impressed and radially 
expanded. Thus, in a non-operative or relaxed mode, the resilient, 
elastomeric body 196 assumes a substantially cylindrical shape. When body 
196 is compressed by the downward movement of plate 196, the body 196 is 
forced radially outwardly against the thermoplastic materials of preform 
210 to cause such thermoplastic materials to be forced radially outwardly 
against the thread plates 158 thereby to form a threaded neck portion 198 
of the formed container 200. 
Referring now to FIG. 15 in conjunction with FIG. 9, the cooling station 28 
(Station E) is seen to be similar to station 26 described above, except 
that here the mold components 154 and 158 and their associated components 
constituting the system for forming a hollow article remain at station 26 
(Station D). At each such station 28 (Station E) there is provided a 
conically sided, flat ended support element 206 which is suspended from an 
overhead fluid cylinder assembly 208 for reciprocal movements by means of 
an interconnecting rod 204 to and from the bottom portion of an article 
200 being fabricated. As illustrated in FIG. 10, four holding stations 28 
are provided on the rotary table assembly 150. 
A Station F, generally designated as 209, is provided for the removal of 
each formed container (or article) 200 onto a conveyor assembly (not 
shown) for subsequent inspection, filling, packaging, or the like of such 
formed container 200. 
In operation, sheet 34 is unwound from the roll 31 in response to the 
movement of the chain 44 in accordance with the operational cycle of the 
apparatus 10 determined, inter alia, by such factors the size and 
thickness of the article being formed, the types of thermoplastic 
materials being used, and the like. The sheet 34 is heated to a formable 
plastic state during passage under the heat source 36. The heated sheet 34 
is indexed to Station A whereat the chase 74 is lowered into contact with 
the sheet 34 by the action of the fluid cylinder assemblies 78. 
Simultaneously (or before or after, as desired), the support shoe 82 is 
raised to a contacting position with the underside of sheet 34 by 
actuation of the fluid cylinder assembly 86. Extrusion of the second 
thermoplastic material is initiated by moving orifice 66 of the gate 64 
into co-axial alignment with the extrusion nozzle 62 with the screw 60 of 
the extrusion assembly 50 moving plastic forward in a manner known to one 
skilled in the art. After deposition of a preselected quantity 68 of 
thermoplastic material, the gate 64 is displaced in response to actuation 
of the fluid cylinder 70 to arrest the flow of plastic material. The chase 
74 and support shoe 82 are returned to their respective initial positions 
and the sheet 34, carrying quantity 68, is indexed to Station B. 
At Station B, referring to FIG. 12, the support shoe 112 is raised in 
response to the actuation of the fluid cylinder assembly 116 to a point 
whereat the support shoe 112 is in contact with the underside of the sheet 
34. The chase 96 is lowered into a contacting relationship with the sheet 
34 in response to the actuation of the fluid cylinder assemblies 100 
whereupon the stamper foot 104 is lowered by actuation of the fluid 
cylinder assembly 108 to a position whereat the foot 104 causes the 
thermoplastic material 68 to be distributed over the select portion of the 
sheet 34 within chase 96 thereby to form quantity 68 into a disc shape in 
the embodiment shown. After a predetermined time period, the stamper foot 
104 is raised by fluid cylinder assembly 100, the support shoe 112 is 
lowered by cylinder assembly 116 and the chase 96 is moved vertically 
upwardly to respective starting positions by respective actuations of 
fluid cylinder assemblies 100 after which the sheet 34 carrying quantity 
68 is indexed to Station C. 
At Station C, referring to FIG. 13, the forming die 126 is moved vertically 
downwardly in response to fluid cylinder assembly 120 with the forming 
plate 132 being raised by actuation of fluid cylinder assembly 134 thereby 
forming the composite sheet 34 and quantity 68 into a preform 210. After a 
predetermined time interval, the forming die 126 and the forming plate 132 
are each returned to their respective starting positions by actuation of 
fluid cylinders 120 and 134, respectively, and the sheet 34 carrying 
preform 210 integrally therewith is indexed to Station D. 
At Station D, referring to FIG. 14, after such indexing of the preform 210 
into position, the die halves 154 and the thread plates 158 are moved into 
operative association. Pressurized fluid (e.g. air) is introduced into 
conduit 170, and thus into the portion of the chamber 166 above the piston 
164, causing the piston 164 to be moved vertically downwards together with 
the associated sleeve 190 and the plate 192 resulting in a movement of 
resilient material 196 outwardly against the preform 210 thereby causing a 
portion of the preform 210 to be forced radially against the thread dies 
158. Thereafter, the blow pin 176 is moved vertically upwardly, such as 
disclosed in my copending application U.S. Ser. No. 583,427, filed June 3, 
1975, now U.S. Pat. No. 4,085,177, assigned to the same assignee as the 
present invention, together with the introduction of a pressurized fluid 
through the passageway 178 and orifices 180 formed in the blow pin 176, 
thereby causing preform 210 to expand into the configuration shown in FIG. 
14 identified as container 200. Pressurization is maintained for a 
predetermined time interval, after which pressurization is reduced to a 
level to support the blown container 200 against collapsing or further 
extension after separation and removal of the mold halves 154 and thread 
plates 158. After blowing, a compressed fluid is introduced into conduit 
172 with conduit 170 being vented to the atmosphere to cause the piston 
164 to return to an initial position whereby the resilient material 196 is 
returned to an uncompressed state and thereby assumes a substantially 
cylindrical configuration. The thread plates 158 are thereafter retracted 
by actuation of cylinders 160, and the mold halves 132 are separated and 
returned to an initial position whereupon the rotary table 152 is indexed 
sixty degrees. It is to be noted that sheet 34 is cut at an angle 
represented by line 218 in FIG. 2 by an assembly (not shown) during the 
processing functions of Station D to permit portions of the sheet 34 to 
revolve on the table 152 until final trimming and removal of the container 
200 whereupon the residual material is removed and passed to subsequent 
processing operations (not shown) for reclamation of such residual 
thermoplastic materials. 
At Station E, referring to FIG. 15 the end support element 206 is lowered 
into contacting relationship with the bottom of the container 200 by 
actuation of the fluid cylinder assembly 208 with such contacting 
relationship being maintained through three subsequent indexes of 
apparatus 10 operation. At the last Station F, the hollow article 200 may 
be alternately trimmed from the residual material by increasing the 
pressure in conduit 172 to cause the piston 164 to be raised to an extent 
that the upper portion thereof is above the level of the rotary table 152 
at which point trim dies 212, referring to FIG. 15, are caused to be moved 
against each other by fluid cylinder assemblies 214 operatively associated 
with cylinder rods 216. 
It will be understood by those skilled in the art that other methods and 
apparatus may be used to trim the product article either as part of the 
hereinabove described apparatus or downstream of product removal station 
209. 
It will be understood by those skilled in the art that a plurality of 
Stations A and B may be successively provided to form a complete laminate 
structure (not shown) of more than two thermoplastic materials prior to 
formation therefrom of a preform at Station C. 
The rotatable forming assembly 150, it is contemplated, may be used to form 
single layered hollow articles from a single heated sheet of thermoplastic 
materials. 
As hereinabove mentioned, the latent heat of the molten thermoplastic 
material quantity 68 is preferably generally sufficient to heat the 
underlying sheet 34 to a temperature for thermoforming (i.e., by the time 
such area reaches the molding station), thereby optionally eliminating any 
requirement for heating such underlying sheet prior to selective 
deposition. 
FIGS. 16 and 17 illustrate the appearance of a container at various 
successive stages in its production by the practice of the process of this 
invention. The appearance at the end of each of stations A, B and C, 
respectively, is labeled; a single forming operation is achieved in each 
such station, as shown. In station D, however, three separate stages of 
forming may be discerned. Thus, here in an initial forming stage D1, the 
preform 210 is positioned between the thread forming plates 158 and the 
body 196. After radial expansion of body 196, threads 211 are formed as is 
a dome 213 in preform 210. Then, core pin 176 moves upwardly thereby 
advancing support element 182 to produce an axially elongated parison-like 
body 220 in an intermediate forming state D2. Next, as the core pin 176 
nears the end of its upward thrust of movement, the axial channel 178 is 
pressurized with a compressed fluid, such as air or the like, which 
expands and stretches the parison-like body 220 outwardly into engagement 
with the blow mold halves 154. When support element 182 reaches the top of 
its travel path in spaced relationship to the adjacent here overlying blow 
mold halves 154, the space therebetween is filled by the thickness of the 
bottom portion of the container 200 being formed, and the container 200 
side walls are engaged with and formed by blow mold halves, thus 
completing a final forming stage D3. 
At this point in production, the mold halves 154 are removed and the 
container 200 with residual thermoplastic material still attached thereto 
at the neck region thereof is indexed to station E where the end support 
element 206 is brought into supporting spaced adjacent relationship with 
support element 182, as explained above, with the bottom portion of 
container 200 therebetween. This relationship is maintained during the 
next three indexing locations about rotary table 152, thus, station E can 
be considered to comprise a total of four indexed locations 
circumferentially spaced about table 152. The appearance of container 200 
in this formation stage is shown in FIGS. 16 and 17. 
Finally, the container 200 enters station F where container is cut from 
scrap portions of sheet 34 and quantity 68 (here not detailed), thereby 
completing a forming operation. 
From the preceding description, it is appreciated that the process of the 
present invention involves the thermoforming of a hollow article from a 
substrate sheet of thermoplastic material. A moldable quantity of a 
thermoplastic material is deposited in a heated thermoplastic state on an 
area of a substrate sheet. Such quantity is shaped on the substrate sheet 
to form a composite region of predetermined perimeter dimensions and 
thickness dimensions on such substrate sheet. Typically, the starting 
substrate sheet has opposed, spaced, parallel faces, and the region of the 
shaped, deposited thermoplastic material likewise has typically opposed, 
spaced, parallel faces, but variations in such thickness characteristics 
are possible, and the actual average respective thicknesses of starting 
substrate sheet and shaped layer of deposited thermoplastic material can 
vary over very large ranges. Present preferences involve the use of 
starting substrate sheet members having thicknesses ranging from about 
0.020 to 0.080 inches and the use of starting shaped layers of 
thermoplastic material on such a starting substrate sheet member ranging 
from about 0.100 to 0.500 inches, but it will be understood that such 
ranges are for illustration purposes only, that thicker and thinner valves 
can be employed if desired, and that no limitations on the teachings 
herein are to be implied or inferred therefrom. Processing temperatures 
and pressures vary greatly, depending upon many significant variables, 
such as the particular thermoplastics employed, their thicknesses, 
container thicknesses desired and the like, so that it does not appear 
possible to provide exact statements of temperatures and pressures for the 
practice of the present invention. 
After a composite of starting sheet substrate and shaped layer thereon has 
been prepared, such is introduced into a thermoforming operation resulting 
in a multilayed hollow article from such composite. Preferably, such 
article has an inner layer of one thermoplastic material and an outer 
layer of another thermoplastic material. 
More specifically, after the initial depositing and shaping, a composite 
section comprised of preformed sheet and shaped, deposited layer is first 
compression molded between mating female and male mold means to form a 
cavity therein whose exterior surface portions are continuously comprised 
of first thermoplastic material and whose interior surface portions are 
continuously comprised of said second thermoplastic material. Also, the 
cavity is characterized further by having continuously adjacent the 
perimeter of its mouth wall portions which extend perpendicularly relative 
to the cross-sectional area defined by said mouth. Compression molding is 
accomplished with the composite section being maintained in a moldable 
plastic state. A cavity or cavities so produced may be used as such, if 
desired, as a container or containers (as the case may be). Alternatively, 
further processing may be, and preferably is, undertaken. 
Thus, such perpendicularly extending wall portions of such a compression 
molded composite section are continuously circumferentially clamped 
between radially opposed respective interior and exterior clamping means 
located adjacent the perimeter of said mouth. A mandrel means is then 
advanced into said mouth through said interior clamping means and into 
engagement with said interior surface portions to stretch and to form said 
so compression molded composite section into a continuously multi-walled 
cross-sectionally generally uniformly shaped close-ended elongated body. 
The said first and said second thermoplastic materials are maintained in 
respective moldable plastic states. Such a body or bodies can be used as 
such, if desired, as a container or containers (as the case may be). 
Alternatively, further processing may be, and preferably is undertaken. 
Thus, into the interior of such an elongated body, with said 
perpendicularly extending wall portions remaining so clamped, a 
pressurized fluid is charged whose pressure is sufficient to expand the 
walls of such elongated body outwardly into continuous engagement with 
such exterior surface portions thereof with a concurrently circumscribing 
mold means having a predetermined molding surface defined therein. The 
first and the second thermoplastic materials are maintained in respective 
moldable plastic states. A multi-walled plastic container is thus made 
which thereafter is cooled and preferably trimmed. 
As is apparent from the foregoing specification, the present invention is 
susceptible of being embodied with various alterations and modifications 
which may differ particularly from those that have been described in the 
preceding specification and description. For this reason, it is to be 
fully understood that all of the foregoing is intended to be merely 
illustrative and is not to be construed or interpreted as being 
restrictive or otherwise limiting of the present invention, excepting as 
it is set forth in the hereto-appended claims.