CA1142311A - Apparatus for the preparation of hollow plastic articles - Google Patents

Abstract

Abstract of the Disclosure The invention relates to an apparatus for forming objects of moldable organic plastic material requiring pro-longed tempering cycles to obtain conditions suitable for orientation. In accordance with the invention, there is provided an improvement which consists of including a multiplicity of tempering molds in spaced relationship to each other for retaining and tempering parisons prior to orientation and blowing. With this improvement, the tempering molds receive and release the parisons seriatim, and the overall cycle of the apparatus is substantially un-affected by the number of the tempering molds.

Description

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ThiS Application is a division of Applicantion Ser. No.
328,841, filed May 31, 1979.

BACKGROUND OF THE INVENTION

This invention relates to the art of blow rnolding from a parison of articles of organic plastic material susceptible to the improvement of their properti~s by orientation and has for its principal objects the provision Or an apparatus which is characterized by a more rapid operating cycle with less effect upon the temperature of the parison, carrying ouk the steps of parison production, stretch orientation and circumrerential orientation in a slngle uninterrupted~ yet completely controlled sequence, and the pro~ision of improved, oriented hollow articles.
The art teaches various rnethods and apparatus ror obtaining blow molded articles of organic plastic material from a parison~ such as in U.S. Patent 3,349,155 and Re. 27,104~
; Generallyg these methods are characterized by forming a parison in a parison mold on a blow core, placing said rormed parison and blow core into a blow mold and expanding said parison in the blow mold by rneans of fluid pressure.
While the blow molding operation tends to impart orientation to the article, such orientation is predominantly circurnferential, i.e., not bi-axial. Also~ the degree Or such orientation is dir~icult to control. It is thererore ~,, L~60 7 `, .
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dl~icult to obtain t~e advantageous properties in the article that bl-a~ial orientation is capa~le of proYiding, It is known th~t the control Or ~rientati~on depends largel~
upon the control o~ the temperature of the parison ~ust prior to orientation. It ls ~ound tha$ such te~perature control is best o~tained by enclosing the article prior to the orientlng step ln heating ~eans that i~part temperatures, preferably by contact with the corresponding surfaces of the par~son, to the regions o~ the par~son corresponding-to the degree o~
de~ormation that is intended for such regions.
Ho~eYer, art devices that o~tain the desirable ~i~a~ial orientation are often cumbersome and slo~ and inconYenient to operate. Also, Production rates with such de~ices are rar r~m opti~um.
SUMMARY OF THE INYENTION
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In accordance ~lth the present in~entionS an apparatus is pro~ided ror the prep~rat~on o~ hollow articles ~aintaining suhstantial}y consistent temperature control of the articles prior to orientation and/or prior to final e~pansion, while 20` also ohtaining an i~proYed, conrolled in~ection blow molding or stretc~ blo~ ~olding sequence with a rapid operating cycle whic~ has less effect upon the temperature o~ the parison.
; The apparatus of the present invention also obtains nu~erous other slgnificant advantages ~hich will he ~ore readily apparent ~r~m the ensuing specification, The apparatus of the present invention co~prises; a reciproca~le first core, preferably axially reciprocable, and a temperature controlled ~irst mold, preferably laterally reciprocable; ~eans ~or providing a parison on sa~d ~irst core;
means including said ~irst core to place said parison in said .

; ~-260 flrst mold, means ~or separatin~ sa1d parison ~rom said first core while retaining ~aid parison in said flrst mold to ad~ust the temperature thereof; a ~econd core and ~ second mold ln spaced relationship to said first core and ~irst ~old, respectively, preferably in lateral spaced relationship, wherein said second core is reclprocable, preferably axially and laterally reciprocable, and whereln said second ~old ls stationary; means for transferri~g said parison to said second core and second mold; and means ~o expand said par~son on said second core in said second ~old to pro~ide a finished article.
Preferably, the apparatus includes an article r~oval plug for removing the finished article in lntegral, spaced relationship to said second core, preferably in lateral spaced relation3hip, so that when the second core engages ~he parison in the first mold, the removal plug engages the finished article in the second mold.
In accordance with the apparatus of the present invention, the parison walls may be caused ko establish lntimate surface contact with the walls Or the first mold, such as by forcing said parison in the first mold to conform to the shape of the ` first mold, such as by expansion The parison shape may be chosen so as to permit the insertion therein of the second core into intimate surface contact with the inside of the par~son.
The parlson is therefore in full surface contact wlth the first mold for ad~ustment of the temperature ~ t~e pari~$onl and possibly also in full surface contact with the second core.
The temperatures of the first mold, of the second core~ or of both, may be controlled to provide optimum conditions in the parlson for orientation thereof.
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Alternatively, the pari~on may b~ stripped ~rom the flrst core into the first ~old without substant~ally deforming the parison, in which case the shape Or the ~irst ~old is substantially the same as that o~ the parison t~ insure.adequate surface contact between the two. At times, the parison may be placed within a heated cavity that does not correspond to the shape o~ the par~son, such heated cavity taking the place of the first mold. This heated cavity is the equivalent of the first mold in the present context-and it will be included within the term "first mold" throughout the present specification.
In view of the plural cores and molds used in the present in~ention and the high degree of temperature control which can be exercised over the parison, the present invention readily obtains a multi-axially oriented article by axially stretching the temperature adjusted parison at a predetermined rate in the second ~old by means of the second core and ~y expanding the parison to form the finished article. ~urthermore, the ~ovement parameters of the components of the present apparatus provide a highly efficient and smooth operation.
If it is desired to produce a multi-layered parison and a multi-layered ~inal article, the first core may be provided with a layer o~ one plastic and a subsequent layer may then be pressure molded therearound in accordance wlth.my U.S. Patent Nos. 3,349,155, 3,717,544 and 3,719,735, It should be understood, therefore, that where the general description that follows refers simply to parisons, the method and apparatus of the present invention are applicable to multi-layered as well as single-layered parisons.

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Thu~, a multi-axially oriented article may be readily obtained in accordance with the apparatus of the present inventlon by providing means for axially stretching the temperature ad~usted p~rison at a predetermined rate and by the expansion of the same, such as by an a~ially reciprocable portion of the second core that is actuated by means capable of ad~usting the speed of reciprocation.
It can ~e seen that the apparatus of the present invention efficiently and conveniently obtains uniform temperature control O of the parison so that the resultant article is characterized by highly improved properties, while o~taining a high production rate. It is known that orientation substantially improves the signiricant properties o~ plastics~ as clarity~ impact resistanceg strength, resistance~to permeation, etc. ~mong the plastics that can be so improYed are polystyrene, polyvinyl chloride, polyolefins, as polyethylene and polypropylene, polyesters~ polycarbonates, polyamides~ acrylics, fluorocarbon resins, acrylonitrile, and ~ethacrylonitrile polymers. The improved temperature control o~ the present 'O invention enables one to obtain improved properties and controlled multi-axial orientation in a simple and e~peditio~s manner.
Accordingly, it is a princlpal object of the present invention to provide an apparatus for the preparation of hollow articles ~rom moldable organic plastic material which enables accurate te~perature control and a rapid and expeditiolls operating cycle.
It is a ~urther ob~ect of the present invention to eonveniently and expeditiously provide improved articles which are multi-axially oriented under conditions o~ close control 3~

of temperature and deformation rate.
It is a still further object of the present invention to provide an apparatus as aforesaid which provides products possessing reproducibly uniform properties due to orientation.
In accordance with a particular em~odiment of the invention there is provided an apparatus ~or forming objects o~ moldable organic plastics material req~liring prolonged tempering cycles to obtain conditions suitable for orientation.
The apparatus includes a ~ultiplicity of tempering molds in spaced relationship to each other for retaining and tempering parisons prior to the orientation and blowing. The tempering molds are arranged to receive and release the parisons seriatim in operation in such a manner that the overall operating cycle of the apparatus is substantially unaffected by the number of the tempering molds. The apparatus includes a first core and means for providing a parison on the first core ~y injection molding in an injection mol~. ~lso provided are means including the first core to place and leave the parison directly from the injection!mold in a first one of the temper-ing molds including means for relatively removing a first of the tempering molds and the first core into alignment with each other. Also provided are means for transferring the parison from the first core to the first tempering mold and means for relatively moving the first core and first temper-ing mold out of alignment with each other. A second core and blow mold engageable therewith are provided in spaced relationship to the first core, and means are provided for transferring the tempered parison at the end of the tempering cycle to the second core and blow mold. Means are also provided for expanding the tempered parison on the second core in the blow mold.

Other objects and advantages of the present invention will be apparent to those skiLled in the art from the description which follows with reference to the accompany-ing drawings.
BRIEF DESCRIPTION OF T~E DRAWINGS
Figure 1 is an elevation, partly in section, illus-trating the apparatus of the present invention, Figure lA shows a core modification in the apparatus of Figure 1.
Figures 2 and 3 are views similar to Figure 1 with additional portions in phantom showing a sequence of operations according to an embodiment of the present invention.
Figure 4 is a partial view similar to Figures 1-3 showing a modification of the apparatus of the present invention.
Figure 5 is a schematic elevation similar to Figure 1 showing a plurality of cores and molds.
Figures SA and 5B are schematic top views of the second cores showing a variation of the embodiment of Figure 5.
Figure 6 is a schematic view showing a plurality of first cores in a variation of the apparatus of the present invention, DETAILED DESCRIPTION OF T~IE PRh~FERRED EMBOVIMENTS
Referrlng to the drawings in more detail, Flgures 1, 2 and 3 illustrate an apparatus in accordance with one embodiment of the present invention. In this embodiment, the parison is provided by an injection moldlng process, however, the invention is not limited thereto and includes other known molding processes that are capable of producing parisons such - 6a -3~' as compression moldlngi casting, e~trusion with or without secondary operation, and the like. Figure 1 depicts a parison die la, having outer walls 11 which may be separable, depending upon the shape of the parison and which are adapted to form the - outer surface of the parison~ and having an end wall 12 shaped to form the end ~all of the parison. The parison die 10 may be temperature controlled, such as.by heating or cooling elements lOa contained therein whlch are connected to appropriate heat transfer sources ~not shown) whereby such temperat~re control may be arranged in se~eral zones to obtain different temperatures in different regions of the.parison. The end wall 12 Or the parison die-has an injection open~ng 13 registering wi~t~ an injection nozzle 14 through which the or~anic plastic material is in~ected into the parison die.
The parison die 10 is shown as split for.conYenience ln opening to release the formed parison; however, it should be understood that the invention is not limited thereto, as one_piece dies suitably designed for release of the parison are enco~passed herein.
As indicated hereinaboYe, the plastics contemplated in accordance with the present invention are the molda~le organic plastic materials and preferably those whose properties are impro~ed by orientation, such as the pol~ole~i~ns~ polyethylene, polypropylene and copolymers thereof, polyvlnyl chlorlde, polystyrene and other sty~eni~c.resins, acrylonitrile, methacrylonitrlle, polyv.inylidene chloride~ polycarbonates, polyesters, polyamides, fluorocarbon resins, etc.
The formation of the parison in accordance with the embodiment illus*rated ln Figures 1, ~ and 3 takes.place a~ter a first core 15 ~prererably a blow core) lllustrated ln Figure 1, and set ~orth ln phantom in ~igures 2-3 3 and die 10 are brought in$o engagement by suitable mechanical ~eans such as the motive means ~hown schematically in ~lgure l. In the embodiment shown in Figures 1, 2 and 33 core 15 ls a~lally reciprocable in the direction o~ the arrow into and out of engagement with die 10. Upon co~pletion of inJectlon through nozzle 14, a parison 16, having substantially the configu~ation represented in Figure ~, ls fo~ned.
Side wall 17 and an end 18 of core 15, walls 11 and 12 cf parison die 10, and the neck mold 20 constitute a die cavity in which the parison is formed. Core 15 may be temperature controlled in one or ~ore æones, such as by internal heat exchange c~rcuits known in the art contained therein~ whlch are connected to an appropriate heat transfer or power source ~not shown). Core 15 is carried by platen 19. This assembly further include6 a neck mold 20 in which the neck of the parlson is for~ed and which re~ains enga~ed with the parison wh~le the latter remains on blow core 15 after disengagement ~rom the parison die, which neck mold may be independently te~perature controlled. The neck mold may possess threads 21 for defining a threaded opening in t~e final ~olded ob~ect. The neck mold 20 may be split and opened into two portions by suitable mechanical means such as the motlve means shown schematically ln Figure 1, to release the parison, or, if the conriguration of the neck permits, may be Or one piece construction and, thus, separable ~rom the parison as a unit.
During separation of the parison die 10 and the core 15, the parison 16 is sufriciently retalned thereon by means of neck mold 20, or by other ~eans, such as an undercut, lf necessary. Upon separatlon, the parison assumes the position , . . .

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deplcted in Flgure 1 and shown in phant~m ln Fi~ure 3.
First mold 22, which is a conditioning, i.e.~ t~pering mold and may be a pre-forming mold~ and core 15 are brought into alignment so as to Ju~tapose first mold 22 and parison 16, illustrated, as noted earlier in phantom in Figure ~. As i shown, f1rst mold 22 is laterally reciprocable by suita~le mechanlcal means, such as the motive means shown schematically in ~i~ure 1, wikh the first mold movlng in the directi~n of the arrow into and out of ali~nment with core 15. ~old 22 is , 10 temperature controlled., frequently in multiple zones which may be disposed along the length thereor, as by heating or cooling ele~ent~ 22a which are-connected to appropriate heat transfer : sources (not shown). It is possi~le, although not preferred, to align first mold 22 and parison 16 by lateral or circular reciprocation of core 15.
.~ Referring to Figure 3, upon the alignment of ~irst mold 22 and core 15 bearing parison 16, core 15 and parison 16 are then placed within first mold 22, for exa~ple, ~y the axial reciprocation of core 15. Other means of engaging parisons ~ 20 and ~olds may be used and are .~ell known, such as those r disclosed:.in U.S. Patent Nos. 2,853,736 and 2,974,362. The parison is then releas~a from first core 15 into first-mold 22, as by stripping it axially which ~ay be facilitated, if desired, by partially expanding the parison. The partial expansion is . carried out by arranging for the mold cavity Or ~old 22 to be i a small fraction of an inch larger than the parison and by applying fluid pressure through channel 27 on the inside of . the parison thereby expanding the parison into conformance ~ith . thé cavlty:Df mold 22. Passage 27 is provided within core 15 ~o and may terminate at a valve-like, closeable portion Or the .; .

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, core well kno~n in the art. Separatlon o~ the pari~on fr~m core 15 may then be facllitated by air-pressure stripping of the parison ~rom the core, with remoYal of the core ~rom the parison lea~ing the parison in mold 22~ It should be noted that such e~pansion is not always necessary, but is often help~ul as in the example shown. I~ des~i~ed~ an e it channel ~not shown) ~ay be provided on mold 22 to permit the removal Or air -~rom the mold cavity as the parison enters facilltating the esta~llshment of contact of the parison with the mold walls.
The temperature of first mold 22 is controlled by heating ... .
or cooling means 22a connected to appropr~ate heat trans~er sources (not shown), or by electric heaters~ to optlmize the parison temperature for subse~uent operations ln a manner to be descri~ed below. Naturally any suita~le heating or cooling means may be used in any Or the heating or cooling coils descri~ed hereln~ such as a passage containing heat transfer fluid ~aintained at a suitable temperature, electric resistance heaters or radlant heat sources.
,., Fi~ure 3 illustrates the pressure ~olded parison 16 as conformed to the shape of the mold ca~ity in first mold 22, for e~ample, by the e~ertion of fluid pressure~ wlth the partially e~panded parison labeled 29. At ti~es the shape of partially expanded parison 29 may be made such that a second core, e.g.
stretch-bIow core 30, may be inserted into substant1ally . .
complete surface contact therein, as shown ln Figure 2, ~,f~ per~itting heat exchange throughout, by contact o~ the second core and the parison In such an instance, the said shape should exhibit no undercuts or re~erse cur~es on the inside surrace, for e~ample, due to an outward taper oYer its inside surface.
; 30 Ho~eYer, the parison shape does not alNays permit this, ~or , ... . . .

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. example, in ~ome cases of long, narr~-necked pari~ons, in which cases it may be neces~ary to ~orego contact heating the inslde Or the parisons~
A~ter completion of the transfer of the parison lnto first mold 22, that mold and first~core 15 are separated a~ by moving the first core plus first neck mold axially in the direction of the arrow~ usually accompanied ~y the application Or air pressure at the inside Or the parison by ~eans o~ the ~irst core~ and the parison 29 thus transferred is retained in ~o first mold 22. Core 15 and neck mold 20 are then returned to the starting position as illustrated in ~lgure l~ and ~irst mold.22 containing the parison 29 which may be partially expanded~ is shifted laterally into the position illustrated in . Figures 1 and 2.
Parison 29, which is retained within first ~old 22, is : thereby.transferred into alignment with a second core 3Q which is carrled b~ platen 31 and which may be proY~ded ~th .temperature control ~eans, and which may:ha~e an externa}
configuration shaped to conform to the internal configuration -20 of the parison 2~. Whenever axial stretching of the parison is desired, core 30 will include a-stretch and ~lo~ assembly which c~mprises a mandrel extension 32 which is reciprocable as-indicated by the arro~ in ~igure 1 to axially e~tend the parison 29. An actuating means is shown which comprises a push rod 34 ~hich en~ages extension 32, and which is connected to a piston 35 housed within a cylinder 36.~hich ~ay7 for example, be responsive to hydraulic pressure e~erted by a pump, not shown. By controlling the ~low of fluid into cylinder 36, the speed of piston 35 and thererore of the moYable portion o~ core 30 may be controlled to stretch the ' ~

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Y~260 ~3~

parison at the ~peed best suited for the te~perat~re of the parisvn. Such actuating ~eans ls merely illustrati~e o~ one ~anner of operatlon, as other actuating means kn~wn in the art can be employed herein. If a highly oriented article is not desired, the a ial extension operation may be dispensed with~
For the final formlng sequence, the parison is separated from first mold 22 by retaining it at the neck region on core 30 and, at times, also on.a neck ~old 37 which operates ln the s~e ~anner as neck ~old 20. In the absence of neck mold 37, one may retain parison 29 on core 30 by close fit of core 30 ~ithin the neck of the parison, or5 as shown in Fi~ure lA, by proY:lding an e~pandable sleeve 30a made of an elastomer or the like at the neck region of core 30 arranged to grip the neck of the parison internally, whereby such a sleeve ~ay ~e caused to e~pand by air pressure brou~ht to it ~rom the core, as-through fl~id passageway 38.
: Core 30 is situated in spaced relationship to core 15, and first mold 22 is situated in spaced relationship to second mold 23, to enable both cores to engage a respecti~e ~old when core 15 is aligned with mold 22 as shown in Figure 3. This facil~tates the concurrent pursuit of ~oth the temperin~ and final forming processes with separate parisons. ~urtherj and with regard to the transfer of parison 29 to core 30, it should be noted that par~son die 10 is spaced from first mold 22, as illustrated in Figures 1 and 2, so that core 15 may engage wlth die 10 to form another parison while core 30 engages with first mold 22 and also while a third core 41 e~ects the fully e~panded article 40. The abillty to c~ncurrently conduct the various-operations Or the process outlined.herein co~prises one Or the n~table advantages of the invention. The simultaneDus y~260 ~
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~ormation, transfer~ or ~nal e~pansion and finished article removal of a plurality of parts-is envlsioned, as the apparatus illustrated ln the accompanying figures can be further modified to provide additional intermediate ~olds and cores, such as mold 22 and core 30.
A fl1l~d passageway 38 is pro~ided and terminates at the end surface Or that portion o~ the core 30 which does not ~oYe during the movement of extension 32. Fluid passagewày 38 also connects to a source of fluid under pressure, not sho~n. ~~
0 Accordingly, fluid ~ay enter the space inside parison 22 during final expansion, discussed hereina~ter, once passageway 38 is opened by movement of the extension 32 and correspondingly of the movable portion Or core 30. I~ the transfer of the parison out of first mold 22 is to be facilitated by gripping the - parison from the inside as shown in Figure lA, elastic sleeve 30ais pressurized fr~m its inside surface ~y means of pressure air through secondary passageway 38a causing the sleeve to expand against the inner half of the parison neck.
In the instance where core 30 may be made to conform to ~0 the lnner contour of parison 29, it can be seen that core 30 may be heated or cooled. Thus, the ~emperature o~ parison 29 may be ad~usted ~y heat exchange between ~oth the inner and outer sur~aces o~ parison 29 and the corresponding mold and -core surfaces.
The parison 29 is thereby rapidly and ~niformly prepared for further processing, such as axial extenslon and final e~pansion. This is a considerable advantage since it avoids the proble~ of parison cooling during a multl-step process.
Whenever core 30 may be made to conform to the shape of parison 2~, the heat transfer conditions ~ay be ~urther lmproved . . .
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over the ones prevailing if only the outer surface of parison 29 is in heat transfer relation with a corresponding mold element. Naturally, the conventional temperature regulators that are used to control the heating means of core 30 and mold 22 are able to do so individually, in several zones within the assembly, corresponding to ~he desired temperature profile.
In the interest of a rapid operating cycle, it is particularly advantageous to first rapidly alter the heat con-tent of parison 16 by heat exchange with core 15 and mold 10 to result in a heat content desired ~or subsequent operations, but almost always at the cost of an unequal distribution of temperature in said parison. This must be followed by sub-stantially equalizing the temperature distribution across the wall thickness of said parison by heat exchange with mold 22 and, whenever made to conform with the inner wall of the parison, with core 30, to avoid a layer-wise pattern of properties in the finished article corresponding to the known relationship between such properties and the deformation temperatures. This procedure is described in more detail in my U. S. Patent 4,116,606. Thus, for example, one can form parison 16 by injection molding, rapidly cool said parison by heat exchange with core 15 and mold 10 which will result in a rapid cycle, but will also produce said unequal temperature distribution, followed by substan-tia]ly equalizing the cross-sectional temperature distribu-tion of said parison, all in a controlled manner, to impose thereon the temperature profile desired for orientation.
Naturally, the parison remains in mold 22 until the necessary desired temperature distribution adjustment is obtained.
Alternatively, in accordance with the present invention, a y 26Q
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pre-Yormed pari~on ~ay be placed in ~old 10, heated rapidly ln mold 10 by heat e~change wlth mold 10 and core 15, which is also apt to produce-said unequal temperature distribution3 and further treated in ~o1d 22 by heat exchange wlth ~old 2~ and core 30 to substantially equalize the t~mperature distrl~utlon of said parison. Tbe foregoing provides the considera~le advantages of enabling the attainment of a predetermined te~perature profile of khe parison resulting in opt~mu~
conditions for orientation without e~cessiYe d~ell tlme in the LO ~olds. The parison mold is freed for further use ~hile the first ~old is completing the conditloning of the parison, resulting in an e~pedltious processing cycle, Referring to Figure 2, the transfer Or parison 29 to finishing mold 23 is conducted by core 30 which is in engagement with first mold 22 and parison 29. Core 3V with parison 29 thereon is separated from ~irst mold 22, ~hich may be split to release parison 29~ by moYing core 30 a~ially by suitable mechanical ~eans such as the motiYe means shown schematically in Figure l. Upon release, core 30 with parlson ~o ` 29 thereon returns to the position illustrated in ~igure 1 and depicted in phant~m in Figure 3.
In accordance with the apparatus of the present inYention, the second mold 23 is in lateral spaced relatlonship to said first mold 22, witll the second mold ~eing fi~ed, The fixed or stationary positlon of the second mold represents a significant advantage of the apparatus of the present lnvention. It permits the placement of the parison ~uch more rapldly and hence with less effect upon its temperature. Also, second mold 23, if it is a multi-impression mold (which is often the case) is apt to ~0 weigh several tons. The mo~ement of such a mass ~lth great .

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speed requlres elaborate, expensive and not altogether efficacious means~to control acceleration and deceleratlon o~
the movement; ~herRas~ the parison with the core asse~bly weighs but a few pounds and may be moved s~lftly by s~ple ~eans3 e.g., cushioned-end air cy~inders.
As can be seen in F~gures l and 2, a third core or article removal plug 41 for removlng the finished article ls in integral, lateral spaced relatlonshlp to second core 30, with ~oth the second and third cores being carried on platen 31. Therefore, o when the second core engages parison 29 in second ~old 22, the re~oval plug 41 engages the finished article 40 in the second mold 23. As shown by the arrows, the second and third cores are i axially and laterally reciprocable so that the ~econd core transfers parison 29 from mold 22 to ~old 23 by a combinatior of a~ial, lateral and axial movements. Simultaneously~ third core 41 removes the finished article from mold 23~ which may ` be split and separable to facilitate the extraction o~ the finished article, and transfers same to an ejection station located laterally of mold 23 ~not shown~ for remoYal of the finished article while core 30 engages mold 23.
Core 30 carrying parison 29 is then receiYed in mold 23 with the temperature Or parison 29 having been ad~usted as described abo~e. Parison 29 is usually axially e~tended to the bottom of mold 23 by the advancement Or the movable portion of mandrel 32 by ~neans o~ push rod 34 at a predetermined rate.
Thus, the present invention may controlla~ly stretch the parison longitudinally before final blowing and thereby produce orientation ln the axial direction as ~ell as the orientation subse~uently produced by blowing. It can be seen that the S0 temperature of the parison preparatory to stretching and blowing . ~

~ 260 may be properly and conveniently controlled by the respectiYe ~olds and core. -While stretching occurs, passageway 38 is kept open to provide pressure equalization or the lnside of the parison with the atmosphere to prevent collapse o~ the parison due to the vacuum created inside it as its inside volume increases during stretching.
After completion Or a~ial e~tension, the parison-is fully expanded to conform to the configuration ~r -rinishlng, i.e., second mold 23, to ~orm the final:ob~ect 40 w~1ch, in the embodiment illustrated hereinl is an open-ended container.
Naturally, a wide variety of shapes may be prepared as the commercially known shapes which may be a bottle, a ~ar or a cup-shape. ~ull e~pansion is accomplished by supplying fluid I under pressure through passageway 38 into the interior of i a~ially extended parison 29, or at times and at various rates, into the interior of the pari~on while it is ~eing extended.
After full e~pansion is co~pleted, second core 30 and second mold 23 containing final ob~ect 40 are separated as descri~ed hereinabove wlth reference to first core 15 and first mold 22. The second core is moved axially, laterally and axially, which positions the second core in the rirst mold 22 ~ and at the same ti~e positions removal core 41 in finished ; article 40 Ior removal of sa~e a~ter the finished article has cooled-suf~iciently for that purpose.
In the embodlment illustrated herein, finishlng ~old 23 is longitudinally split into two sections labeled 42 and 43~ whlch may reciprocate in and out of CoJamUniCatiOn by an actuating .
meansj not sho~n, such as for example a hydraul~c cylinder.
Thus? sections 4? and 43 may be parted an amount suff`icient to permit the removal of article 4~ ~y core 41 which may ~e lnserted y~260 3~

into the neck thereof with a tight fit. Prlor to such opentng of mold 23 and removal~ fluid pre~sure ~ay.he applied through passaKeway 46 to continue the blowing process,-lf desired~ in cases requiring continued contact of article 4~ ~ith second mold 23 for the purpose Or extended cooling Alternatively, passageway 46 may be utilized to contlnue to supply cooling air to the inside Or the finished article~ or to apply suction to .
the inside of the rinished article to aid in ~etaining same thereon.
L0 Thus, it can be seen that the present invention improYes the in~ection blow molding process and carries out the steps of parison production, stretch orientation and circumferential orientation in a single uninterrupted and completely controlled sequence. The parison is injected or provided in a ~irst station and is moved axially .~rom the first stat~on on a first core. The parison is then transferred ~y the first core lnto a first or ~empering ~old which is shi~ted laterally into alignment with the first core ~or that purpose. -The first mold is then shifted laterally with t~e parison therein into a ~20 second station wherein a second core is inserted into the parison and the second core with parison thereon is mo~ed a~ially away from the first ~old. The second core ~lth parison thereon is then shifted ~nto alignment with the second mold and inserted therein for final processing into a rinished article, with the finished article being e~ected by a third or e~ection core.
The apparatus and process of the present invention is simple, convenient and progressive in nature. The parison moves from the-in~ection ~old-to first core; from.first core to tempering mold; from tempering ~old to a second core which may ' ; ~ Y-2~0 ~;23~

be a stretch-blow co~e; from second core to finis~lng mold and out; or prefera~ly ~rom finlshlng mold ~o a third e~ection core and out. The moYement-of components is qulte s~mple and convenient and e~pedltious, with the large3 ~u~ky finishing mold being stationary.
The temperature ad~ustment of the parison a~rorded by the present inYention has been found to proYide an oriented product ha~ing consistently good propert~es. The-parison ls ~n~ected into a comparatively cool mold and lert there for a ~ery short time, long enough to remoYe the amount of heat fro~ the parison that corresponds to the condition ~est suited ~or orientation.
( The parlson is then transferred into a tempering ~old which imparts the optimum orientation temperature distribution to the given plastic article, staying ln that mold long enough to equali~e the temperat~re across the wall thickness o~ the parison which nat~rally arri~es from the ln~ectlon ~old ~lth a poor cross-sectional temperature profile After tempering, the parison, now having the right temperature profile wlth good cross-sectional distri~ution, is transferred into a cool finishing ~old in which it is stretched at a controlled rate and blown. The steps of injection plus dwell in the in~ection mo}d;
o~ tempering and Or stretch-blo~ing with coollng oYerlap; and of article removal, occur at the same t~e allo~ing ~or ef~icient ~achine utillzation. Also, the c~ponent ~ovements allow ~or s~ooth operation.
Naturally, ~any ~ariations ~y ~e Included. In~ected or blown necks may be ~ade. The stretch f~nction ~ay ~e omitted~
ln which case a ~ery ef~lcient in~ection blo~ ~olding operation is provlded. Instead Or te~pering, the second station ~y be ~30 used as a first blow station and the third station ~y ~e used --lg--` Y~260 .

as a second ~low statlon in order to di~de the co~ling dwell betNeen the two. This may ~e desirable in the case o~ thlck- -~alled articles. In fact, additional cooling stat~ons ~ay be added.
In one modification, the parlson ~ay be ~or~ed earlier at a time and location of its own-and stored ~efore ~eing ~or~ed into the final art~cle. In addition to in~ectlon molding, numerous methods are known that ~ay be employed to proYide thermoplastics in the shape of a parison, such as tube e~trusion with welding of one open end, dipping, deposltion, thermo~orming and the like. Thus, the previously ~ormed parison may be transported to-and placed upon a first hlo~ core which cooperates with a heating means to raise the te~perature of the parison suf~iciently to enable it to undergo deformation.
Secondary operations often need t~ be per~ormed:upon the hollo~ article made in accordance with the present invention.
Among-these is the application of a ~ase cup to the articles haYing a domed bottom as is frequently the case ~lth hottles that have to withstand appreciable internal pressure, e g., car~onated beverage bottles. These base cups are usually plastic dish-like ob~ects ~ith a ~lat ~ott~m, the-ins~de o~
the dish often being glued to the conve~ bottom o~ the bottle so as to render it capable of standing upon a fiat sur~ace, These base cups are usually applied in a special deYice to which hottles that have been previously made are randomly presented In accordance wlth the improvement illustrated by the modlfication Or ~igure 4, it is possible to dispense ~ith such a separate device and instead to integrate the base cup applicator--into the apparatus itself. In accordance with the embodi~ent o~ ~igure 4, a base cup applicator is proY~ded for .

; Y~26Q
~ 3 ~

applying a ~ase c~p to the hase of the finlshed artlcle, with the applicator being located in lateral spaced relatlonship to the 3econd mold so that ~hen the second core and parison engage the second mold ~Fi~re 3~ the applicakor carry~ng a hase cup engages the base of the finished artlcle on the removal plug.
. As shown in ~lgure ll, base C~lp appllcator 50 is carried by a suita~le platen 51 ~hich may be mova~le ln the direction of the arrow by suita~le motiYe ~eans. The applicator includes a sleeYe portion 52 and a bottom base cup carrier 53. In 10 operation, carrier 53 is loaded ~ith a base cup 54 by conventional ~eans, not shown. The ~a~e cups ~ay ~e provided ~ith adhesive 55 at predeter~ined, spaced locations for adhering to the bottom o~ the flnished article. The ~ase cups carr~ed by applicator 50 are then engaged with the base of the finished article 40 with slee~e 52 surrounding the finished article to keep same from buckling.outwards. Air pressure ~ay ~e supplied ~ lnside the finsihed article by passageway 46 in core-41.
: Pressure is then app~ied to carrier 53 in the direction of the arrow pressing c~p 54 firmly against the ~ase of the bottle 40.
Upon co~pletion Or the requisite setting times for the adhesive 55, if used, the applicator is removed ~rom the finished article 40 now equipped wlth a base cup 54, and the article is stripped from the plug 41.
It is well known that in in~ection molding it is desirable to minimize the length over which molten plastic is ~ade to flow and also to group individual cavities in in~ection multi-cavity molds so as to minimize the platen space which helps accuracy in ~olding due.to the reduced hazard of deflectlng the support-struc-ture-of-the mold under-the great ~orces of in~ection. As shown in the schematic diagrams of ~igures 5, ~26~

5A and 5B ~hich utllize an apparatus according to F~g~res 1,

2 and 33 an apparatus ls provlded including a plurality of ri~st cores in spaced relationship to each other carried by a co~mon carr~ing ~eans9 a plurality of ~irst molds ln spaced relatlonship to each other carried ~y a co~on carrying means, a plurallty of second cores in spaced-relationship to each other carried by a common carrying means, and a plurallty of second molds in spaced relationshlp to each other carried ~y a com~on carrying means,-wherein a plurality of the rin~shed articles are made simultaneou51y. Naturally, the molds may be split for convenience of article or parison remo~al. As sh~n in Figure 5, the ca~ities 111 i~ multiple parison mold 110 are arranged in a row cooperating with flrst cores carried on common carrying means or support plate 119. The parison die 110 cooperates with injection unit 114 through-whlch ~olten plastic is inJected through channel 113 distributed hy runner 113a.
The spacing between cavities 111 corresponds to t~e dimensions of the parisons. Accordingly, the spacing of the second cores 130 carried ~y common carrylng ~eans or platen 131 must correspond to t~at of the cavities 111 if the parisons made in cavities 111 are to be t,ransferred in the manner shown in Figures 1, 2 and 3. The parisons are then transferred through the processing cycle in ~ manner arter Figures 1~ 2 and 3 utilizing a plurality of ~irst molds 122 and a plurality of second molds 123.
Holl~w articles to be made fr~m parisons are frequently much larger than the parisons and hence cannot be acc~mmodated with the same center spacing as the parisons. For example, the parison for a large ~ottle may have a diameter of approx~mately l-1/2 inches~ while the bottle made fr~m the .
' -22- -y 260 parison ~ay measure 4 inches ln di~eter. In accordance ~ith the ~bodi~ent of ~lgures 5A and ~B, which represents a schematlc top ~iew of the second cores in t~o dl~ferent pos~tions, means are provided ~or ~o~ing said second cores aw~y ~r~ and towards each other in a predeterm~ned relationshlp, The apparatus accord~ng to ~igures 5A and 5B accommodates the larger cenker spacing of the finished article while preserving the cG~pact arrangement in-the parison mold as in ~igure 5, Two rows 131' and 131 " of second cores 130' are pro~ded to ~ate with t~o o corresponding ro~ ~r parisons (not shown~. ~eans are provided to spread the two rows-of second cores, such as spreader bars 150 connected to any suita~le moti~e means, in the direction o~ the arrows. Thus, once the parisons carried by second cores 130' complete the tempering cycle tn the ~irst molds Cthe posit~on - sho~n in ~igure 5A~ and the parisons are separated therefr~m, the spreader bars 150 are ~oved to spread the second cores 130' to t~e center lines of the ~inishing cavities of the second ~olds Cto the position shown in ~igure 5B~. After stretchlng and blowing in the second molds, the second cores are removed 'o fr~ the hollow articles and ~oved together again to the center llnes of the first molds to resume the ne~t c~cle.
Figure 6 sho~s a further impro~e~ent a-imed at handling parisons ~ade o~ plastics that require a prolonged tempering cycle prior to bi-axial orientation by stretch~ng and blowing.
Among these plastics, polypropylene being the ~o~t pro~inent, I tempering cycles in terms of Minutes are called for, in contrast to tempering cycles measured in seconds that are needed in connection with other ~aterials~ The problem in connection ~ith an apparatus ~or this type of material is to introduce an extended tempering cycle ~ithout at the sa~e t~me V~260 2~3~

prolonging the actual operating cycle o~ the deyice and wlthout constructing e~tremely ~ulky and inefflcient heating apparatu~.
Flgure 6 sche~atleally show~ an apparatus ~ich acco~plishes the~regoing ~y including a plurality o~ ~rst ~olds ~oYable into posItions spaced ~rom the cores rOr e~tended ad~ustment of the temperature of the parison In the em~od~ment s~own ln Figure 6~ a multi-tier arrangement is provided-~n t~e tempering station sho~ing a plurallty of ~irst ~olds 222~ In operation accord~ng to Figures l, 2 and 3, ~en a mold -222 ~lth the .
LO paris-on reaches the tempering station it is side~sh~fted ~y : conventional motive ~eans to neighboring position A. In a ne~t cycle, it may ~e ~rther side-shi~ted into an ad~oining position A', and so on, whereby the n~mber of such side positions will depend upon the actual tempering c~cle desired, ~s illustrated in Figure 6, upon reaching positlon A'~ the tempering mold is ~oved to a lo~er tier, l.e., into position B " , from ~hence it is moved further into position B', and ~r~
there to position B, ~rom whlch positlon it is elevated into the original upper tier, l.e., into the position at which ~o ~old 222 had originally entered the tempering cycle. Positions A, A', etc-. and B, ~', etc. may o~ course be arranged at either side, or ~oth sides of the tempering station. It can be readily seen that by means of th~s simple side-shift and elevator device, the parisons may ~e given any e~tended te~pering desired without- impeding the overall operating cycle of the ~achine.
Thus, the ~achine output will remain the same re~ardless of the tempering dwell provided that a sufficient nu~ber o~ tempering ~olds are used. Nat~rally, all ~olds in circulation ~ay be c~nnected to a s~urce of energy, for-e~ample, in the case Or electric heatingj electric power may reach each mold over a -24~

y~260 sllding connector cooperating with suitable cor~entional bus bars.
In accordance with the embodiment Or Figure 6 9 the parisons arriving in the flrst or tempering mold are not removed therefrom ~y the second cores, but prior thereto, the first ~old is side-shifted to give an extended tempering cycle ~hlle keeping the parisons under controlled temperature conditlons.
The length o~ ~ime for this d~ell will depend ~pon the nurn~er of ~olds that are in c:lrculation. The re~oval of the tempered parison may occ~r at position B, Instead of the preferred de~ice for using a multipllcity temper~ng ~nolds as above described, it is conceivable to move a ~ultiplicity of first molds along different paths~ for e~ple, in a circle, which may be ~ertical or horlzontal~
However, care must be taken to keep the parisons in a vertical posltion to a~oid their distortion and to keep the molds in contact with temperature control units.
In summary, in accordance with the embodiment of Figure 6, an apparatus is provided for form~ng ob~ects of moldable 2~ plastic material requiring prolonged tempering cycles to obtain conditions suitable for orientation, said apparatus including a multiplicity of tempering molds for retaining parisons prior to orientation, whereby the tempering molds receive and release the parisons seriatim and whereby the overall cycle of the apparatus is substantially unaffected by the nurnber Or the tempering molds. Preferably, the apparatus is o~ the type sho~n in Figures 1, 2 and 3.
As indicated hereinabove, in connection wlth the discussion of Figure 4, secondary operations can if desired be perfor~ed at the e~ector station. ~ne illustration of these secondary .

-25_ Yæ6o

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operations is the attac~ent o~ a base cup 54 to the fini~hed artlcle 40 by means of a base cup applicator 50, Naturally, other secondary operations may readlly be perfo~ed at the e~ector station as sho~n in ~y previous ~S. Patent~ 3,336,425 and 3,587,133, for e~ample, one ~ay ~111 the finisbed artlcle ~ whlle said article is confined by ~eans oi the base cup appllcator 50 or other suitable means to confine the ~alls o~
the flnlshed art.lcle while said article ls belng filled,. This procedure ~ill enable one to readily hot rill the finished article and, if destred, maintain the filled article conflned until cooled suf~iciently to handle.
This ln~ention may be embodied ln other forms or carried out in other ways without departlng fro~ the spirlt or essentl~l characteristics thereof. The present em~odiment is therefore to be considered a~ in all respects illustrative and not restrictive, the scope of the lnvention being indicated by the appended clai~s, and all changes ~hich cvme within the meaning and range of eq~i~alenc~ are intended to ~e em~raced therein.

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Claims (10)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:-

1. An apparatus for forming objects of moldable organic plastics material requiring prolonged tempering cycles to obtain conditions suitable for orientation, in-cluding a multiplicity of tempering molds in spaced relation-ship to each other for retaining and tempering parisons prior to orientation and blowing, the tempering molds being arranged to receive and release said parisons seriatim in operation, in such a manner that the overall operating cycle of said apparatus is substantially unaffected by the number of said tempering molds, including a first core, means for providing a parison on said first core by in-jection molding in an injection mold, means including said first core to place and leave said parison directly from said injection mold in a first one of said tempering molds including means for relatively moving a first of said tempering molds and said first core into alignment with each other, means for transferring said parison from said first core to said first tempering mold and means for relatively moving said first core and first tempering mold out of alignment with each other, a second core and blow mold engageable therewith in spaced relationship to said first core, means for trans-ferring said tempered parison at the end of said tempering cycle to said second core and blow mold, and means for expanding said tempered parison on said second core in said blow mold.

2. An apparatus according to claim 1 including means engageable with each one of said tempering molds for placing and leaving parisons in said tempering molds to be tempered therein.

3. An apparatus according to claim 1 including means for placing and leaving parisons to be tempered in said tempering molds seriatim at a first station and means for moving said parisons from said first station to a second station.

4. An apparatus according to claim 3 including means for preparing said parison spaced from and in alignment with said first station, wherein said second stations are situated to the side of said alignment.

5. An apparatus according to claim 3 wherein said means to move said parisons from said first station to said second station is operative to side shift said parisons to a neighboring position.

6. An apparatus according to claim 5 including a plurality of said neighboring positions corresponding to the actual tempering cycle desired.

7. An apparatus according to claim 3 including means to maintain said parisons under controlled temperature conditions in said tempering molds.

8. An apparatus according to claim 3 wherein said par-isons are in a multi-tier arrangement.

9. An apparatus according to claim 1 including means for moving said first tempering mold into and out of align-ment with said first core.

10. An apparatus according to claim 9 wherein said first core is axially reciprocable into and out of engagement with said injection mold and said first tempering mold is laterally reciprocable into and out of alignment with said first core between said first core and said injection mold.