CA1200357A - Extruding laminated sheet with alteration of stream dimensions in die - Google Patents
Extruding laminated sheet with alteration of stream dimensions in dieInfo
- Publication number
- CA1200357A CA1200357A CA000938525A CA938525A CA1200357A CA 1200357 A CA1200357 A CA 1200357A CA 000938525 A CA000938525 A CA 000938525A CA 938525 A CA938525 A CA 938525A CA 1200357 A CA1200357 A CA 1200357A
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- streams
- axis
- stream
- passageway
- exit
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Abstract
A method is described whereby plastic film or sheet having a plurality of layers is formed by deforming a flowing stream having layers of diverse thermoplastic material wherein the cross-sectional configuration of the plurality of flowing streams is altered by reducing the dimension of the stream in a direction generally perpendicular to the interfaces between the individual streams and by increasing the dimension of the stream in a direction transverse to the direction of flow and generally parallel to the said interface to provide a sheet or film having a laminar structure.
Description
~'7 ~693-1000 This invention relates to a method and apparatus for the preparation of multilayer laminates from -thermoplastic materials.
In accordance with themethod of this invention improv~
ed laminates are readily prepared by pro~iding a pluralit~
of adjacent streams of thermoplastic material in conticJuous relationship to each other, altering the cross~sectional configuration of the plurality of streams by reducing the dimension of the stream perpendicular to interfaces between the individual streams and increasing the dimension in a direction transverse to the direction of flow and generally parallel to the interfaces of the streams.
The method of the invention is advantageously carried out with the apparatus of this invention which comprises in cooperative combination a housing defining a paSSaCJeway, the passageway having an en-trance and an exit, the entrance having a first axis and a second axis, the exit having a first axis and a second axis , the first axes of the entrance and the exit ~ being coplanar and the second axes of the entrance and the exit being coplanar, the first and second axes of the entrance and the exi-t being disposea generally normal to each other, the first axis of the entrance being the major axis and the second axis th.e minor axis, the fi.rst axis of the exit being the minor a.xis and the second axis of the exit being the major axis, the passageway being so constructed and arranged so as t~ permit streamlineflowof a fluid therein and the length of the first axis of the major entrance being substantially great-er than that of the first axis of the exit.
Case 10,706-F -1 ~2~3~7 As will be described in detail hereinafter, the invention provides a method of preparing a sheet of thermo-plastic resinous materials by extruding in an extrusion appa-ratus wherein the materials are arranged as a pluralit~ of laminae having major surfaces generally parallel to the major surfaces of the resultant sheet. The steps of the method com-prise; (a) providing by extruding in an extrusion apparatus a plurality of closel~ adjacent flowing streams of diverse : thermoplastic materials in a heat plastified condition in con-tiguous relationship to each other, each stream having gener-ally planar surfaces which are generally parallel, (b) altering the cross-sectional configuration of th~ plurality of flowing streams by reducing the dimension of the stream in a direction generally perpendicular to interfaces between the individual streams, and (c) inc~easing the dimension of the stream in a direction transverse to the direction of flow and generally parallel to the interface of the streams to form a sheet-like configuration having a plurality of layers wherein the layer interfaces are in generally parallel relationship to each other and to major surfaces of the sheet-like configuration.
In a different aspect, the invention described herein provides a method for preparing a sheet of thermoplastic resinous materials wherein the materials are arranged as a plurality of laminae, the sheet and the laminae having major surfaces which are generally parallel to the major surface of the resultant sheet. The steps of the method comprise:
extruding at least a first heat plastified synthetic resinous material and a second heat plastified synthetic resinous material to provide first and second heat plastified resinous streams, each stream being of diverse material; subdividing ~; .~ . .
- la -'''. ' 3~;7 the first and second streams into first and second substreams, interdigitating the first and second substrearns to form a stream having an elongate cross-sectional configura~ion, the configura~ion having a first side, a second side, a first edge and a second edge, the substreams having generally planar interfaces and the substreams extending from the first side to the second side of the cross-sectional configuration; deforming the stream by forcing the edge portions into generally adjacent relationship and the side portions into remote relationship, thereby forming a stream having a generally elongat~
cross-sectional configuration having sides corresponding to the edges of the interdigitated substreams and edges corrasponding to the sides of the interdigitated substreams, subsequently ¦ extruding, and; cooling the deformed stream to form a laminate sheet of synthetic resinous thermoplastic materials having major surfaces generally parallel to the major surfaces of the extruded stream.
Thus, in accordance with a broad aspect of the invention, there is provided a method of preparing a sheet of thermoplastic resinous materials wherein the materials are arranged as a plurality of laminae having major surfaces generally parallel to the major surfaces oE the resultant sheet, characterized by (a) providing a plurality of closely adjacent streams of diverse thermoplastic materials in a heat plastified condition in contiguous relationship to each other, (b) altering the cross-sectional configuration of the plurality of streams by reducing the dimension of the streams in a direction generally perpendicu~ar to interfaces between the individual streams and (c) increasing the dimension of the streams in a direction transverse to the direction of flow and . . .
- lb -~Z~
gene~ally parallel to the interface of the streams to form a sheet-like configuration.
In accordance with another broad aspect of the inven-tion there is provided apparatus for preparing laminates of thermoplastic resinous materials characterized hy a housing defining at least one cavity therein and adapted to receive at least a first and second heat plastified thermoplastic stream, means to distri.bute the streams into a plurality of smaller streams, the smaller streams being in generally alternate arrangement with smaller streams from the first stream being in alternating arrangement with the smaller streams from the . second stream, the housing defining a passageway, the passage-way having an entrance and an exit, the entrance having a first axis and a second axis, the exit having a first axis and a second axis, the first axes of the entrance and the exit being coplanar and the second axes of the entrance and the exit being I coplanar, the first and second axes of the entrance and the exit being disposed generally normal to each other, the first axis of the entrance being the major axis and the second axis - 20 the minor axis~ the first axis of the exit being the minor axis and the second axis of the exit being the major axis, the passageway being constructed and arranged to permit streamline flow of a fluid therein and the length of the first axis of the major entrance being substantially greater than that of the first axis of the exit.
In accordance with another broad aspect of the inven-tion there is provided an extrusion apparatus for extruding laminated plastic products; said extrusion apparatus including an extrusion die defining a flow path for fluid products and 1 30 having a thin elongated discharge orifice comprising, a first -- lc .~
ii7 i conduit passageway having one end adapted to be connected to a first extruder, a second conduit passageway having one end adapted to be connected to a second extruder; said first and second conduit passageways communicating with said flow path;
whereby materials flowing from said first and second conduit passageways are laminarly joined under pressure before extru-sion through said discharge orifice; said flow path having a divergent portion toward said discharge orifice, whereby said laminarly joined extruded materials are lateral].y extended prior to discharge from said discharge orifice.
The invention will become more apparent from the following specification when taken in connection with the drawing wherein:
- ld ` .~
~2~(~3S7 Figure 1 is a schematic representation of a simplified appara~us in accordance with the invention showing an enlarged section of the product thereo~;
Figure 2 is a sectional view through a distribution manifold of ~he appara~us of Figure l;
Figure 3 shows a view of a distribution block employed in the manifold;
Figure 4 is a schematic isome~ric representa~ion of a transition piece as utilized in the appara~us of Figure l;
Figure 5 is an alternate configuration of a transition piece;
Figure 6 is an alternate embodiment of a manifold and Figure 7 is a view of a portion of a feed port block for use in the manifold of Figure 6.
In Figure 1 there is illustrated an apparatus in accordance with the inven~ion generally designated by ~he ref-erence numeral 10. The apparatus comprises ~n cooperative combination a first extruder 11, a second extruder 12, a dis-tribution manifold 13, in full communication with the extruder 11 by means of the eonduit 15 and in communication with the extruder 12 by means of the conduit 16. A transition piece 17 having an inlet or first opening ~8 and a second or outlet open-ing 19 is in communication with the discharge of the manifold 13. A laminated film 20 issues from the discharge opening 19 Adjacent ~he opening 19 are cooling means 22 which reduce the temperature of the laminate film or sheet 20 to a temperature below the thermoplastic temperature thereof. The film or sheet 20 is wound onto a takeup means or roll 23. An enlarged portion of 20a of the film 20 is shown d~pic~ing a plurality of laminae 25 and 26 of material from the extruders 11 and 12 9 respectively.
In accordance with themethod of this invention improv~
ed laminates are readily prepared by pro~iding a pluralit~
of adjacent streams of thermoplastic material in conticJuous relationship to each other, altering the cross~sectional configuration of the plurality of streams by reducing the dimension of the stream perpendicular to interfaces between the individual streams and increasing the dimension in a direction transverse to the direction of flow and generally parallel to the interfaces of the streams.
The method of the invention is advantageously carried out with the apparatus of this invention which comprises in cooperative combination a housing defining a paSSaCJeway, the passageway having an en-trance and an exit, the entrance having a first axis and a second axis, the exit having a first axis and a second axis , the first axes of the entrance and the exit ~ being coplanar and the second axes of the entrance and the exit being coplanar, the first and second axes of the entrance and the exi-t being disposea generally normal to each other, the first axis of the entrance being the major axis and the second axis th.e minor axis, the fi.rst axis of the exit being the minor a.xis and the second axis of the exit being the major axis, the passageway being so constructed and arranged so as t~ permit streamlineflowof a fluid therein and the length of the first axis of the major entrance being substantially great-er than that of the first axis of the exit.
Case 10,706-F -1 ~2~3~7 As will be described in detail hereinafter, the invention provides a method of preparing a sheet of thermo-plastic resinous materials by extruding in an extrusion appa-ratus wherein the materials are arranged as a pluralit~ of laminae having major surfaces generally parallel to the major surfaces of the resultant sheet. The steps of the method com-prise; (a) providing by extruding in an extrusion apparatus a plurality of closel~ adjacent flowing streams of diverse : thermoplastic materials in a heat plastified condition in con-tiguous relationship to each other, each stream having gener-ally planar surfaces which are generally parallel, (b) altering the cross-sectional configuration of th~ plurality of flowing streams by reducing the dimension of the stream in a direction generally perpendicular to interfaces between the individual streams, and (c) inc~easing the dimension of the stream in a direction transverse to the direction of flow and generally parallel to the interface of the streams to form a sheet-like configuration having a plurality of layers wherein the layer interfaces are in generally parallel relationship to each other and to major surfaces of the sheet-like configuration.
In a different aspect, the invention described herein provides a method for preparing a sheet of thermoplastic resinous materials wherein the materials are arranged as a plurality of laminae, the sheet and the laminae having major surfaces which are generally parallel to the major surface of the resultant sheet. The steps of the method comprise:
extruding at least a first heat plastified synthetic resinous material and a second heat plastified synthetic resinous material to provide first and second heat plastified resinous streams, each stream being of diverse material; subdividing ~; .~ . .
- la -'''. ' 3~;7 the first and second streams into first and second substreams, interdigitating the first and second substrearns to form a stream having an elongate cross-sectional configura~ion, the configura~ion having a first side, a second side, a first edge and a second edge, the substreams having generally planar interfaces and the substreams extending from the first side to the second side of the cross-sectional configuration; deforming the stream by forcing the edge portions into generally adjacent relationship and the side portions into remote relationship, thereby forming a stream having a generally elongat~
cross-sectional configuration having sides corresponding to the edges of the interdigitated substreams and edges corrasponding to the sides of the interdigitated substreams, subsequently ¦ extruding, and; cooling the deformed stream to form a laminate sheet of synthetic resinous thermoplastic materials having major surfaces generally parallel to the major surfaces of the extruded stream.
Thus, in accordance with a broad aspect of the invention, there is provided a method of preparing a sheet of thermoplastic resinous materials wherein the materials are arranged as a plurality of laminae having major surfaces generally parallel to the major surfaces oE the resultant sheet, characterized by (a) providing a plurality of closely adjacent streams of diverse thermoplastic materials in a heat plastified condition in contiguous relationship to each other, (b) altering the cross-sectional configuration of the plurality of streams by reducing the dimension of the streams in a direction generally perpendicu~ar to interfaces between the individual streams and (c) increasing the dimension of the streams in a direction transverse to the direction of flow and . . .
- lb -~Z~
gene~ally parallel to the interface of the streams to form a sheet-like configuration.
In accordance with another broad aspect of the inven-tion there is provided apparatus for preparing laminates of thermoplastic resinous materials characterized hy a housing defining at least one cavity therein and adapted to receive at least a first and second heat plastified thermoplastic stream, means to distri.bute the streams into a plurality of smaller streams, the smaller streams being in generally alternate arrangement with smaller streams from the first stream being in alternating arrangement with the smaller streams from the . second stream, the housing defining a passageway, the passage-way having an entrance and an exit, the entrance having a first axis and a second axis, the exit having a first axis and a second axis, the first axes of the entrance and the exit being coplanar and the second axes of the entrance and the exit being I coplanar, the first and second axes of the entrance and the exit being disposed generally normal to each other, the first axis of the entrance being the major axis and the second axis - 20 the minor axis~ the first axis of the exit being the minor axis and the second axis of the exit being the major axis, the passageway being constructed and arranged to permit streamline flow of a fluid therein and the length of the first axis of the major entrance being substantially greater than that of the first axis of the exit.
In accordance with another broad aspect of the inven-tion there is provided an extrusion apparatus for extruding laminated plastic products; said extrusion apparatus including an extrusion die defining a flow path for fluid products and 1 30 having a thin elongated discharge orifice comprising, a first -- lc .~
ii7 i conduit passageway having one end adapted to be connected to a first extruder, a second conduit passageway having one end adapted to be connected to a second extruder; said first and second conduit passageways communicating with said flow path;
whereby materials flowing from said first and second conduit passageways are laminarly joined under pressure before extru-sion through said discharge orifice; said flow path having a divergent portion toward said discharge orifice, whereby said laminarly joined extruded materials are lateral].y extended prior to discharge from said discharge orifice.
The invention will become more apparent from the following specification when taken in connection with the drawing wherein:
- ld ` .~
~2~(~3S7 Figure 1 is a schematic representation of a simplified appara~us in accordance with the invention showing an enlarged section of the product thereo~;
Figure 2 is a sectional view through a distribution manifold of ~he appara~us of Figure l;
Figure 3 shows a view of a distribution block employed in the manifold;
Figure 4 is a schematic isome~ric representa~ion of a transition piece as utilized in the appara~us of Figure l;
Figure 5 is an alternate configuration of a transition piece;
Figure 6 is an alternate embodiment of a manifold and Figure 7 is a view of a portion of a feed port block for use in the manifold of Figure 6.
In Figure 1 there is illustrated an apparatus in accordance with the inven~ion generally designated by ~he ref-erence numeral 10. The apparatus comprises ~n cooperative combination a first extruder 11, a second extruder 12, a dis-tribution manifold 13, in full communication with the extruder 11 by means of the eonduit 15 and in communication with the extruder 12 by means of the conduit 16. A transition piece 17 having an inlet or first opening ~8 and a second or outlet open-ing 19 is in communication with the discharge of the manifold 13. A laminated film 20 issues from the discharge opening 19 Adjacent ~he opening 19 are cooling means 22 which reduce the temperature of the laminate film or sheet 20 to a temperature below the thermoplastic temperature thereof. The film or sheet 20 is wound onto a takeup means or roll 23. An enlarged portion of 20a of the film 20 is shown d~pic~ing a plurality of laminae 25 and 26 of material from the extruders 11 and 12 9 respectively.
2~
In Figure 2 there is illustraked a sectlonal view o~
the mani~old 13. The manifold 13 comprises a ~irst maJor passageway 30 in communica~ion with the conduit 15, a second major passageway 31 in communlcation with the condu.it 16 ~not shown), an extrusion slot or orifice 33, and a diskribution block 35. The distribution block 35 defines a plurality o~
passageways 36 and a plurality o~ passagewa~s 37, The passage-ways 36 provide communication between the ~irst major passage-way 30 and the exkr~sion ori~ice 33. The passageways 37 provide commun~cation between th~ second ma~or passageway 31 and the exkrusion ori~ice 33. The passageways 36 and 37 are so ¢ons-: tructed and arranged that the~ alternate in the distribution block and provide interdigi~ated ætreams o~ the material ~lowing from the ~irst and second ma~or passageway~ 31 to ~he extrusion ori~ices 33.
, , ~ In Fig~re 3 a front par~ial view of the distribution i block 35 is ~hown illus~rating the relationship between the ~ passagewa~s or channels 36 and 37 illus~ra~ing th~ interdl~ltated ;` discharge o~ the thermoplastic materials, In Figure 4 there is lllustrated an isomekric repre-sentation of a transition piece 17 having an inlet opening 18 and an outlet opening 19. A passageway 40 provides full communi-cation between the inlet and outlet opening and permits stream-line ~low o~ a liquid ~rom the opening 18 to the opening 19 without rotation of the ~low lamina, The ~nlet openlng 18 has a ~irst or maJor axis a and a second or minor axis b. The out-~ let opening 19 has a ~irst axis a' and a second axis b'. The ,~ ~ axes a and a' are generally coplanar and the axes b and b' are ~,` generally coplanar. The transition piece o~ Flgure 4 is an exponential transition piece o~ constank cross-sectional area
In Figure 2 there is illustraked a sectlonal view o~
the mani~old 13. The manifold 13 comprises a ~irst maJor passageway 30 in communica~ion with the conduit 15, a second major passageway 31 in communlcation with the condu.it 16 ~not shown), an extrusion slot or orifice 33, and a diskribution block 35. The distribution block 35 defines a plurality o~
passageways 36 and a plurality o~ passagewa~s 37, The passage-ways 36 provide communication between the ~irst major passage-way 30 and the exkr~sion ori~ice 33. The passageways 37 provide commun~cation between th~ second ma~or passageway 31 and the exkrusion ori~ice 33. The passageways 36 and 37 are so ¢ons-: tructed and arranged that the~ alternate in the distribution block and provide interdigi~ated ætreams o~ the material ~lowing from the ~irst and second ma~or passageway~ 31 to ~he extrusion ori~ices 33.
, , ~ In Fig~re 3 a front par~ial view of the distribution i block 35 is ~hown illus~rating the relationship between the ~ passagewa~s or channels 36 and 37 illus~ra~ing th~ interdl~ltated ;` discharge o~ the thermoplastic materials, In Figure 4 there is lllustrated an isomekric repre-sentation of a transition piece 17 having an inlet opening 18 and an outlet opening 19. A passageway 40 provides full communi-cation between the inlet and outlet opening and permits stream-line ~low o~ a liquid ~rom the opening 18 to the opening 19 without rotation of the ~low lamina, The ~nlet openlng 18 has a ~irst or maJor axis a and a second or minor axis b. The out-~ let opening 19 has a ~irst axis a' and a second axis b'. The ,~ ~ axes a and a' are generally coplanar and the axes b and b' are ~,` generally coplanar. The transition piece o~ Flgure 4 is an exponential transition piece o~ constank cross-sectional area
-3-, 10,706-F
.;
[)3S~7 wherein its length is arbitrarlly selected and the central portlon has a square cross-section having a length 1~ b and h are the deslred width and hei~ht of one of the openings. The equation of the outline of ~he trans~tion section such as is seen in Figure 1 if a z axis is assumed to run vertically is z~ h (h) / . The equation .~or a line drawn cen~rally khrou~h the conduit and correspondlng to the outline in a plane 90 ~o the observed plane of Figure 1 is~ y= ~h (~) . The exponen tlal transltion section is particularly advantageou~ and bene-ficlal if uni~orm flow rate within the transitlon piece ls to be maintained For many purpo~es a kransition piece such as is illustrated in Flgure 5 is adequate. A transition piece of Figure 5 generally designated b~ the re~erence numeral 45 com-prises a hou~ing 46 de~ining an inlet passage 47J an outlet passage 48 and an internal interconnectlng channel 49 so cons-tru¢ted and arranged ~o as to permit sub~tantially streamlined flow of material entering the passageway 47 and being discharged ~rom the opening 48.
In Flgure 6 there is illustrated an alternate con~i~u ration of a manif'old generally designated by ~he reference numer-al 55 The manifold 55 comprises a housing or body 56 hav~n~
deflned thereLn an exkrusion orifice 57, ~irst, second and third ma~or passageways 58~ 59 and 60 respectively, which are in communication with thermoplastic material supply conduits 61, 62, and 63J respectively. A distribution block 65 is dlsposed within ~he body 56 and defines a plurality of passageways 66 providing communicatlon between the first ma~or passageway 58 and the extrusion aperature 57, a plurality o~ passagewa~s 67 providing commu~ication between the ma~or pas~ag~way 59 and the extrusion opening 57, a plurality o~ passageways 68 prov-ld-10,706-F
~Lz~Q3~tj7 ing communication between the third maJor passageway 60 and the extrusion orifice 67. The passagewa~s 66, 67 and 68 are alternately arranged in the distri'~ution block 65.
In Figure 7 a front view of a portion o~ the distri-bution block 65 is shown depicting the relationshlp between the passageways 66, 67 and 68, Each o~ the passageways terminate in an opening ~ubstantially commensurate with the width of the extrusion passage 57. The embod~ment of Figure 6 is particularly advanta~eous when it is desired ~o prepare a laminate having three ¢omponents and a plurality of layers.
In operation o~ the apparatus ~n-accordance wlth the invention thermoplast~c re~nous materlal in a hea~ plastified condition is extru~ed from the extruders ll and 12, passed into the mani~old 13 to the pas~ageways 30 and 31 respecti~ely. The heat plastified material from the passageway 30 flows to the extrusion orifice 33 by way of passageway 36. ~he material ~rom the extruder 12 ~lows into a pa~sageway 31 a~d is discharged lnto the passageway 33 in interdigitating relationship with the materlal ~rom the extruder ll. Thus a striped sheet or stream is formed wherein the diverse mater-lals extend from one major ~ur~ace to the opposlte ma~or surface. On passing into the tran~ition section the extruded sheet in ef~ect is squeezed or reduced ~in width) and expanded in a direction corresponding to its thickness u~til on emerging ~rom the outlet the portion o~ the sheet originally representing the edge is now a ma~or surface or the width and that which had heretofore been the thickness of the sheet is now the width. As the transition ~` piece permits linear or streamline flow, the various component~
~ are repositioned in such a manner that a num~er of thi~ layers ' 3 o~ material in the form o~ a compo~ite sheet are obtained with-10~706-F
'~`
.:
~ ` -out the necessity o~ employing a plurality o~ slot dies. The relative thickness of the various layers is readily controlled by varying the quantity of ma~erial provided to the manifold by the extruders, Thus it is possible to have the various materials present in the deslred proportion. Due to the realtive-ly large size Or the various ~eed por~s def~ned in the distribu-- tion block3 control of the thickness of the varlous layers is readily accomplished without the necessity o~ maintaining the extremely high dimensional tolerances that are necessary when conventional ~ilm and sheetlng dies are utilized to prepare laminates, The embodiment o~ Figures 6 and 7 are readily utll-ized by employing the required number o~ streams of thermo-plastic resinous material to provide the desired laminate.
Employing an apparatus generally ~imilar to the appara-tus 10 of Figure 1, equal quantities o~ polyskyrene and poly-methyl methacrylate are extruded at a rate o~ about 15 pounds (6,8 kgs) per hour into a sheet about 4 inches (10 cm) in wldth and about 1/8 inch (3.2 mm~ ln thickne~s. The sheet consi~ted of 125 layers alternately o~ polystyrene and polym~thyl methacry~
~ late, On microscopic examination) the layers were determined to be substantlall~ parallel to the sur~aces o~ the sheet and o~ uniform thickness. The resultant sheet was more ~lexible and had higher impact resistance than a like sheet of polystyrene or polymethyl methacrylate.
~5 The foregoing example is repeated employing polystyrene in combination with a gr~ntlnted nylo~. Slmilar results were obtained. Beneficial laminates are also prepared ln accordance with the inventlon employing, for example, polypropylene~
polyvinylchloride, polypropylene-polystyrene, ethyl cellulose-polystyrene, polyethylene-polystyrene, polypropylene-polyethylene 10,706-~
' ~2~5i7 and polyvinylchloride copolymer of vinyl chloride and vlnylidenechloride. As is evident the relative thicknesses o~ the like material are proportional to the amount o~ material issuing ~rom the appropriate passageway or ~eed port in the die. Thus, by varying the dimensions o~ the feed ports, heavier or thicker layers may be employed at desired locations within the ~ilm.
, , : 30
.;
[)3S~7 wherein its length is arbitrarlly selected and the central portlon has a square cross-section having a length 1~ b and h are the deslred width and hei~ht of one of the openings. The equation of the outline of ~he trans~tion section such as is seen in Figure 1 if a z axis is assumed to run vertically is z~ h (h) / . The equation .~or a line drawn cen~rally khrou~h the conduit and correspondlng to the outline in a plane 90 ~o the observed plane of Figure 1 is~ y= ~h (~) . The exponen tlal transltion section is particularly advantageou~ and bene-ficlal if uni~orm flow rate within the transitlon piece ls to be maintained For many purpo~es a kransition piece such as is illustrated in Flgure 5 is adequate. A transition piece of Figure 5 generally designated b~ the re~erence numeral 45 com-prises a hou~ing 46 de~ining an inlet passage 47J an outlet passage 48 and an internal interconnectlng channel 49 so cons-tru¢ted and arranged ~o as to permit sub~tantially streamlined flow of material entering the passageway 47 and being discharged ~rom the opening 48.
In Flgure 6 there is illustrated an alternate con~i~u ration of a manif'old generally designated by ~he reference numer-al 55 The manifold 55 comprises a housing or body 56 hav~n~
deflned thereLn an exkrusion orifice 57, ~irst, second and third ma~or passageways 58~ 59 and 60 respectively, which are in communication with thermoplastic material supply conduits 61, 62, and 63J respectively. A distribution block 65 is dlsposed within ~he body 56 and defines a plurality of passageways 66 providing communicatlon between the first ma~or passageway 58 and the extrusion aperature 57, a plurality o~ passagewa~s 67 providing commu~ication between the ma~or pas~ag~way 59 and the extrusion opening 57, a plurality o~ passageways 68 prov-ld-10,706-F
~Lz~Q3~tj7 ing communication between the third maJor passageway 60 and the extrusion orifice 67. The passagewa~s 66, 67 and 68 are alternately arranged in the distri'~ution block 65.
In Figure 7 a front view of a portion o~ the distri-bution block 65 is shown depicting the relationshlp between the passageways 66, 67 and 68, Each o~ the passageways terminate in an opening ~ubstantially commensurate with the width of the extrusion passage 57. The embod~ment of Figure 6 is particularly advanta~eous when it is desired ~o prepare a laminate having three ¢omponents and a plurality of layers.
In operation o~ the apparatus ~n-accordance wlth the invention thermoplast~c re~nous materlal in a hea~ plastified condition is extru~ed from the extruders ll and 12, passed into the mani~old 13 to the pas~ageways 30 and 31 respecti~ely. The heat plastified material from the passageway 30 flows to the extrusion orifice 33 by way of passageway 36. ~he material ~rom the extruder 12 ~lows into a pa~sageway 31 a~d is discharged lnto the passageway 33 in interdigitating relationship with the materlal ~rom the extruder ll. Thus a striped sheet or stream is formed wherein the diverse mater-lals extend from one major ~ur~ace to the opposlte ma~or surface. On passing into the tran~ition section the extruded sheet in ef~ect is squeezed or reduced ~in width) and expanded in a direction corresponding to its thickness u~til on emerging ~rom the outlet the portion o~ the sheet originally representing the edge is now a ma~or surface or the width and that which had heretofore been the thickness of the sheet is now the width. As the transition ~` piece permits linear or streamline flow, the various component~
~ are repositioned in such a manner that a num~er of thi~ layers ' 3 o~ material in the form o~ a compo~ite sheet are obtained with-10~706-F
'~`
.:
~ ` -out the necessity o~ employing a plurality o~ slot dies. The relative thickness of the various layers is readily controlled by varying the quantity of ma~erial provided to the manifold by the extruders, Thus it is possible to have the various materials present in the deslred proportion. Due to the realtive-ly large size Or the various ~eed por~s def~ned in the distribu-- tion block3 control of the thickness of the varlous layers is readily accomplished without the necessity o~ maintaining the extremely high dimensional tolerances that are necessary when conventional ~ilm and sheetlng dies are utilized to prepare laminates, The embodiment o~ Figures 6 and 7 are readily utll-ized by employing the required number o~ streams of thermo-plastic resinous material to provide the desired laminate.
Employing an apparatus generally ~imilar to the appara-tus 10 of Figure 1, equal quantities o~ polyskyrene and poly-methyl methacrylate are extruded at a rate o~ about 15 pounds (6,8 kgs) per hour into a sheet about 4 inches (10 cm) in wldth and about 1/8 inch (3.2 mm~ ln thickne~s. The sheet consi~ted of 125 layers alternately o~ polystyrene and polym~thyl methacry~
~ late, On microscopic examination) the layers were determined to be substantlall~ parallel to the sur~aces o~ the sheet and o~ uniform thickness. The resultant sheet was more ~lexible and had higher impact resistance than a like sheet of polystyrene or polymethyl methacrylate.
~5 The foregoing example is repeated employing polystyrene in combination with a gr~ntlnted nylo~. Slmilar results were obtained. Beneficial laminates are also prepared ln accordance with the inventlon employing, for example, polypropylene~
polyvinylchloride, polypropylene-polystyrene, ethyl cellulose-polystyrene, polyethylene-polystyrene, polypropylene-polyethylene 10,706-~
' ~2~5i7 and polyvinylchloride copolymer of vinyl chloride and vlnylidenechloride. As is evident the relative thicknesses o~ the like material are proportional to the amount o~ material issuing ~rom the appropriate passageway or ~eed port in the die. Thus, by varying the dimensions o~ the feed ports, heavier or thicker layers may be employed at desired locations within the ~ilm.
, , : 30
Claims (9)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A method of preparing a sheet of thermoplastic resinous materials wherein the materials are arranged as a plurality of laminae having major surfaces generally parallel to the major surfaces of the resultant sheet, characterized by (a) providing a plurality of closely adjacent rectangular streams of diverse thermoplastic materials-in a heat plastified condition in contiguous relationship to each other, (b) altering the cross--sectional configuration of the plurality of streams by reducing the dimension of the streams in a direction perpendicular to interfaces between the individual streams and (c) increasing the dimension of the streams in a direction transverse to the direc-tion of flow and parallel to the interface of the streams to form a sheet-like configuration.
2. The method of Claim 1 wherein the reducing and increasing of the dimensions of the stream is performed while keeping the cross-section of the stream of generally constant area.
3. The method of Claims 1 or 2 wherein the composite stream comprising a plurality of laminae is subsequently cooled below the thermoplastic temperature of the components thereof.
4. Apparatus for preparing laminates of thermoplastic resinous materials characterized by a housing defining at least one cavity therein and adapted to receive at least a first and second heat plastified thermoplastic stream, means to distribute the streams into a plurality of smaller streams, the smaller streams being in generally alternate arrangement with smaller streams from the first stream being in alternating arrangement with the smaller streams from the second stream, the housing defining a passageway, the passageway having an entrance and an exit, the entrance having a first axis and a second axis, the exit having a first axis and a second axis, the first axes of the entrance and the exit being coplanar and the second axes of the entrance and the exit being coplanar, the first and second axes of the entrance and the exit being disposed generally normal to each other, the first axis of the entrance being the major axis and the second axis the minor axis, the first axis of the exit being the minor axis and the second axis of the exit being the major axis, the passageway being constructed and arranged to permit streamline flow of a fluid therein and the length of the first axis of the major entrance being substantially greater than that of the first axis of the exit.
5. The apparatus of Claim 4 wherein the means to provide a plurality of streams comprises a housing having defined therein a first passageway and a second passageway, the first passageway so constructed and arranged so as to receive a first thermoplastic stream, the second passageway so constructed and arranged so as to be adapted to receive a second thermoplastic stream, the housing defining an exit aperture and a plurality of minor passageways selectively providing communication between the first passageway and the extrusion orifice and the second passageway and the extrusion orifice, the minor passageways being disposed in generally side by side arrangement.
6. An extrusion apparatus for extruding laminated plastic products; said extrusion apparatus including an extru-sion die defining a flow path for fluid products and having a thin elongated discharge orifice comprising, a first conduit passageway having one end adapted to be connected to a first extruder, a second conduit passageway having one end adapted to be connected to a second extruder; said first and second conduit passageways communicating with said flow path; whereby materials flowing from said first and second conduit passage-ways are laminarly joined under pressure before extrusion through said discharge orifice; said flow path having a diver-gent portion toward said discharge orifice, whereby said laminarly joined extruded materials are laterally extended prior to discharge from said discharge orifice.
7. A method of preparing a sheet of thermoplastic resinous materials wherein the materials are arranged as a plurality of laminae having major surfaces generally parallel to the major surfaces of the resultant sheet, characterized by (a) providing a plurality of closely adjacent streams of diverse thermoplastic materials in a heat plastified condition in contiguous relationship to each other, (b) altering the cross-sectional configuration of the plurality of streams by reducing the dimension of the streams in a direction generally perpendicular to interfaces between the individual streams and (c) increasing the dimension of the streams in a direction transverse to the direction of flow and generally parallel to the interface of the streams to form a sheet-like configur-ation.
8. The method of Claim 7 wherein the reducing and increasing of the dimensions of the stream is performed while keeping the cross-section of the stream of generally constant area.
9. The method of Claims 7 or 8 wherein the composite stream comprising a plurality of laminae is subsequently cooled below the thermoplastic temperature of the components thereof.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000938525A CA1200357A (en) | 1965-08-18 | 1965-08-18 | Extruding laminated sheet with alteration of stream dimensions in die |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000938525A CA1200357A (en) | 1965-08-18 | 1965-08-18 | Extruding laminated sheet with alteration of stream dimensions in die |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1200357A true CA1200357A (en) | 1986-02-11 |
Family
ID=4142313
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000938525A Expired CA1200357A (en) | 1965-08-18 | 1965-08-18 | Extruding laminated sheet with alteration of stream dimensions in die |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1200357A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5882774A (en) | 1993-12-21 | 1999-03-16 | Minnesota Mining And Manufacturing Company | Optical film |
| US6018419A (en) * | 1995-06-26 | 2000-01-25 | 3M Intellectual Properties Company | Diffuse reflectors |
| US6096375A (en) | 1993-12-21 | 2000-08-01 | 3M Innovative Properties Company | Optical polarizer |
| US7852560B2 (en) | 1993-12-21 | 2010-12-14 | 3M Innovative Properties Company | Display incorporating reflective polarizer |
-
1965
- 1965-08-18 CA CA000938525A patent/CA1200357A/en not_active Expired
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5882774A (en) | 1993-12-21 | 1999-03-16 | Minnesota Mining And Manufacturing Company | Optical film |
| US6096375A (en) | 1993-12-21 | 2000-08-01 | 3M Innovative Properties Company | Optical polarizer |
| US6613421B2 (en) | 1993-12-21 | 2003-09-02 | 3M Innovative Properties Company | Optical film |
| US7852560B2 (en) | 1993-12-21 | 2010-12-14 | 3M Innovative Properties Company | Display incorporating reflective polarizer |
| US6018419A (en) * | 1995-06-26 | 2000-01-25 | 3M Intellectual Properties Company | Diffuse reflectors |
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