CA1199766A - Method and apparatus for the formation of profiled thermoplastic film - Google Patents
Method and apparatus for the formation of profiled thermoplastic filmInfo
- Publication number
- CA1199766A CA1199766A CA000432563A CA432563A CA1199766A CA 1199766 A CA1199766 A CA 1199766A CA 000432563 A CA000432563 A CA 000432563A CA 432563 A CA432563 A CA 432563A CA 1199766 A CA1199766 A CA 1199766A
- Authority
- CA
- Canada
- Prior art keywords
- cooling
- film
- cooling medium
- extruded
- tubular
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
- B29C48/25—Component parts, details or accessories; Auxiliary operations
- B29C48/88—Thermal treatment of the stream of extruded material, e.g. cooling
- B29C48/911—Cooling
- B29C48/9115—Cooling of hollow articles
- B29C48/912—Cooling of hollow articles of tubular films
- B29C48/913—Cooling of hollow articles of tubular films externally
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
- B29C48/03—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor characterised by the shape of the extruded material at extrusion
- B29C48/09—Articles with cross-sections having partially or fully enclosed cavities, e.g. pipes or channels
- B29C48/10—Articles with cross-sections having partially or fully enclosed cavities, e.g. pipes or channels flexible, e.g. blown foils
Abstract
METHOD AND APPARATUS FOR THE FORMATION
OF PROFILED THERMOPLASTIC FILM
Abstract A method and apparatus for the formation of a continuous web of a tubular thermoplastic film from an extrudate of a thermoplastic polymeric material or resin, wherein the thermoplastic film has a profiled wall contour extending in the direction of the longitudinal axis of the film.
OF PROFILED THERMOPLASTIC FILM
Abstract A method and apparatus for the formation of a continuous web of a tubular thermoplastic film from an extrudate of a thermoplastic polymeric material or resin, wherein the thermoplastic film has a profiled wall contour extending in the direction of the longitudinal axis of the film.
Description
~9~
F-1785 -l-METH0D AND APPM ATUS FOR ThE FORMATION
OF PROFILE~ THERMOPLQ5TIC FIUM
The present invention relates to a method and apparatus for the forrnation of a continuous web o~ a tubular thermoplastic film ~rom an extrudake o~ a khermoplastic polymeric material or resin and, more particularly, relates to the formation of a thermoplastic ~ilm having a profiled wall contour extending in the direction of the longitudinal axis of the ~ilm.
The formation of thermoplastic tubular film through the extrusion of molten thermoplastic polymeric materials wherein the m~terials are conducted through an annular extrusion die orifice, ~mploycd for the manufacture of film, tubin~, pipes and the likeg is well known in the plastics extrusion fieldO In order to regulate the rate of cooling and solidification of the exkrudate; it has-frequently been ~ound desirable to conkact the surface o~ the molten or still heat-plaskified thermoplastic material, upon leaving the extrusion die orifice, with a stream o~ a suitable cooling medium and, as a result, to contrGl the properties and physical configurakion of the ~inished ~xtruded product.
Various commercial products, for example9 such as the extensively sold sandwich bags which are ~ormed from a thermoplastic film material, require material thickn~sses which must be heavier towards the top or opening of the bag where they are normally handled by a user in order to minimize tearing of the film and to concurrently make the bag ~eel thick and of high skrength and quality to a user. It is not necessary to provide a heavy gauge of ~ilm in the body of the bag where it is rarely handled and wherein very low mechanical stress is dev~loped~ Consequcntlv, a concept has be~n dev~loped whi~h i5 designed to ef~ect substantial savings in the required quantlties o~
polymeric material or resin without sac~ificing performance of the ~inished product by pro~iling the ~ilm thickness upon extrusion of the polymeric resin or material so as to provid~ the desired film thickness at khe top Q~ the bag while allowing ~or a thinner film thickness in F-1785 -2 ~
the body oF the bag, so that the average film thickness is, in fact;
much thinner than that which is ~elt and observed by the user of the bag.
~ retofore, various kinds of methods and apparatus have been proposed with regard to manufacturing techniques in the formation of thermoplastic film possessing profiled thicknesses; nevertheless, none of these have proven themselves in actual practice to be completely satisf`actory in a~fording the desired degree of control in the formation o~ extruded profiled thermoplastic film.
U.SO Patent No. 3,852,~6 discloses the production of an extruded plastic tubular film having circumferentially spaced thickened film sections or pro~iles extending continuously in the axlal direction o~ the film. These sections are adapted to interlock mechanically with each other so as to constitute a zipper-like fastener integrally formed with the film. The profiled sections in the film are formed through the provision of di Merent rates o~ cooling after the film has been extruded f`rom an annular die subsequen~ to the expansion of the tubular ~ilm, but while the Film is in a still hot state. As may be cl~arly ascertained, the formation of the profiled sections in the ~ilm wall is e~fected in a region having been subJected to primary cooling and inflating of the ~ilm, in which such pro~iling is rather dl~ficult to achi.eve in any satisfactorily controlled manner. Consequently, the apparatus and method disclosed in ~his patent is bounded by extensive restrictions in the ~ormation o~ precise profiled wall sections in extruded thermnplastic films.
Similarlyl interrelated ~ritish Patent Nos. 1~25099~5 and 1,2369831 each disclose processes for the production of tubular thermoplastic ~ilm which includes at least one lon~itudin~l zone wherein the wall thickness o~ the film is heavier than the thickness of the remainder o~ the ~ilm, and also describes the formation o~ bags with that processO In each o~ the British patents, the selective cooling of the extruded film is effected subsequent to the primary cooling and in~lating of the tubular plastic ~ilm, which renders the for~ation of controlled pro~iled wall structure extensively difficult, i~ not completely impossible.
~l9~ 6~i F-1785 ~3~
More recently an apparatus and method has been developed, as disclosed in U.S. Patent No. 4,209,475, which describes an apparatus for adjusting a cooling medium air ~low ~rom a cooling ring encompassing an extrusion die orifice so as to cool more extensively in selected regions o~ the film. The patented apparatus provides for a large number of adjustable deflector blades which are circumferentially arranged about the extrusion die orifice of the apparatus, and are basically designed to provide adjustment so as to compensate for errors or irregularities in the thickness o~ the plastic film produced by the extrusion die. Conceivably~ the apparatus can be employed in producing a varlation in the ~ilm thicl<ness when the extrusion die is of a precise con~iguration and, upon ef~ecting displacement of the deflector blades, is capable of producing extruded thermoplastic tubular film with a pro~iled thickness. Hbwever, the apparatus operates with relatively high air cooling speeds and flow rates and is not designed to provid0 a controlled profiled tubular fllm in a manner utilizing relatively low air cooling ~low speeds and rates as is contemplated ~y the inventive method and apparatus.
Basically, in accordance with the inventive concept, when forming extruded tubular thermoplastic film which is intended to be utilized in the formation of sandwich bag ~ilm, the cooling speed or rate is consid~rably lower than that employed with usual tubular plastic film extrusion processes, so that the amount of coolîng air which leaves the air ring is relatively small. Consequently, there is necessltated the applioation o~ a dif~erent process and apparatus which will provide fur the selective or localized cooling of the extruded tubular plastic ~ilm at a location in which the thermoplastic polymeric material or resin in the primary stage of for~ing the film is still ln a molten or heat plastified condition, and in which a separate ~lnw of a cooling medium is directed against the extrudate at speci~ic regions or zones about the periphery o~ the tubular ~ilm material being extruded so as tO ~orm one or more profile~ ~`ilm regions.
~76~
F-1785 ~4~
Essentially, the apparatus for ~orming a profiled tubular thermoplastic film, and the method which is implemented through the intermediary of the apparatus, contemplates the provision of an annular cooling ring extending ~bout the extrusion die ori~ice and which incorporates a central aperture through which the extruded plastic materlal is conveyed while still in a molten or heat-plastl~ied state, and which is adapted to direct a uniformly distributed flow o~ a cooling medium, such as air9 against the circum~erential surface o~ the extruded tubular plastic ~ilm materialJ which flow, i~ desired, may be at a relative low speed and rate of air flow. A secondary or bypass flow of the coo1ing medium is directed from the cooling ring, prior to the primary cooling medium flow against the surface o~ the extruded material, so as to impinge against one or more peripherally spaced zones on the ~ilm in order to i~part local coollng to the extruded film material withln each such zone9 to thereby cause the ~ormation o~ a thickened ~ilm wall section or profile extending in the longitudinal directisn o~ the fo~med tubular thermoplastic ~ilm. In order to control the cooling rate o~ the cooling ring9 the cooling ring incorporates an adjusting device wh:ich will va~y the extent o~ the cooling medium ~low which is uniformly provided about the perlphery o~
the extruded the~noplastic material and; additionally~ includes a rr~tering arrangernent which will rMdify or even completely inhibit the cooling medium flow thro~h the bypass so as to thereby control the extent of the profilin~ o~ the ~ilmO Eoth the unifo~n and local ~lows of the cooling mediu~ w~thin the cooling ring may be supplied ~rom a plenum encasing the oooling ring9 and which is supplied ~rom a single cooling medlurn sou~ce.
Accordingly, it is a primary ob~ect o~ the present invention to provide a method for ~o~ming a profile~ tubular thermoplastio ~ilm obtain~d through the selective looalized eooling o~ a oontinuously extruded the~moplastic polymeric m~kerial.
It is a more speeific nbjeot o~ the pxesent invention to provide a ~ethod as described hereinabove wherein local c~ollng is imparted ko an ext-ruded thermoplastie tubular film material while the ~9~
film is in a still molten or heat-plastified state subsequent to extrusion from an annular extrusion die.
Still another object of the present invention is to provide for a method of forming a profiled tubular thermoplastic film ~herein a cooling medium, such as air, ls directed at one or more localize.d zones spaced about the periphery of the film as it is being extruded from an annular extrusion die and while the film still is in a molten or heat-plastified condition, and in which the film is subsequently subiected to a uniformly distributed cooling air flow about the periphery of the film so as to, in a controlled manner7 form a precisely profiled tubular thermoplastic film~
A further object of the present invention resides in the provision of an apparatus for implementing the method as described hereinaboYe, wherein a cooling medium is supplied from a plenum so as to be uniformly distributed throughout a cooling ring, the latter of which is adapted to concurrently convey the cooling medium to localized zones on the surface of thermoplastic tubular film being extruded through an annular extrusion die orifice and while the film is in a still molten or heat~plastified condition, and subsequently to impart a uniformly distributed cooling medLum flow directed against the periphery o~ the extruded thermoplastic film so as to form a profiled wall contour on the film which extends in the longitudinal direction thereof.
A still further object of the present invention is to pro~ide an apparatus of the type described hereinabove, in which the cooling ring is adapted to provide for adjustment in the flow of the cooling mediu~ ~low which is uniformly distributed about the periphery of the extruded thermoplastic ~ilm, and including an arrangement whereby the amount of the bypass flow of cooling medium to the localized zones of the tubular film is adapted to be metered so as to allow for the formation of a controlled profiled oontour in the extruded thermoplastic film.
-5a-The present invention, then, in one aspect, resides in a method of ~orming an extruded tubular thermo~
plastic film having at least one r~gion of a thickened wall profile extending ïn the longitudinal direction of the extruded tubular f;lm; comprising extruding a molten thermoplastic polymeric material through an annular extrusion die; and passing said extruded tubular film through a cooling zone while said film is in a heat-plasti~ied condition including suhjecting said film to selectively adjustable localized cooling in the region for forming a thickened profile of variable thickness, and subsequen~ly subjecting said tubular film to a selective amount of uniform cooling about the periphery thereof, whereby said longitudinally extending thickened profiled region is formed in the wall of the tubular film.
In another aspect, the present invention resides in an apparatus ~or the forming of an extruded tubular thermoplastic film having at least one region of a thickened wall profile extending in the longitudinal direction of the extruded film, said apparatus comprising an annular extrusion die for extruding a molten thermo-plastic polymeric material to orm said film; a cooling ring having A central opening mounted in line with and downstream of said extrusion diewherein the extruded molten polymeric material passes through said central opening, said cooling ring including means for directing a flow of a cooling m dium against localized zones along the peripheral surface of said extruded material while said material is in a heat-plastified condition, and means in said cooling ring for subsequently directing a uniformly distributed flow of said cooling medium against the peripheral surace of said extruded material so as to form said thickened wall pro~ile region along the zones of said localized cooling while the ma~erial is conveyed through said cooling ring.
9~i6 Reference may now be had to the following detailed description of preferred embodiments of an apparatus pursuant to the invention for producing a proFiled tubular thermoplastic film, taken in conjunction with the accompanying drawings in whîch:
Figure 1 illustrates, in a perspective view1 a generally schematic representation o~ a cooling ring with an encompassing plenum cha~ber for supplying a cooling medium, and which is adapted to form an extruded tubular thermoplastic film having a pro~iled section pursuant to the invention;
Figure 2 shows a sectional view throug~ the cooling ring taken along line 2-2 in Flgure l;
Figure 3 shows a sectional view taken along line 3~3 in Figure
F-1785 -l-METH0D AND APPM ATUS FOR ThE FORMATION
OF PROFILE~ THERMOPLQ5TIC FIUM
The present invention relates to a method and apparatus for the forrnation of a continuous web o~ a tubular thermoplastic film ~rom an extrudake o~ a khermoplastic polymeric material or resin and, more particularly, relates to the formation of a thermoplastic ~ilm having a profiled wall contour extending in the direction of the longitudinal axis of the ~ilm.
The formation of thermoplastic tubular film through the extrusion of molten thermoplastic polymeric materials wherein the m~terials are conducted through an annular extrusion die orifice, ~mploycd for the manufacture of film, tubin~, pipes and the likeg is well known in the plastics extrusion fieldO In order to regulate the rate of cooling and solidification of the exkrudate; it has-frequently been ~ound desirable to conkact the surface o~ the molten or still heat-plaskified thermoplastic material, upon leaving the extrusion die orifice, with a stream o~ a suitable cooling medium and, as a result, to contrGl the properties and physical configurakion of the ~inished ~xtruded product.
Various commercial products, for example9 such as the extensively sold sandwich bags which are ~ormed from a thermoplastic film material, require material thickn~sses which must be heavier towards the top or opening of the bag where they are normally handled by a user in order to minimize tearing of the film and to concurrently make the bag ~eel thick and of high skrength and quality to a user. It is not necessary to provide a heavy gauge of ~ilm in the body of the bag where it is rarely handled and wherein very low mechanical stress is dev~loped~ Consequcntlv, a concept has be~n dev~loped whi~h i5 designed to ef~ect substantial savings in the required quantlties o~
polymeric material or resin without sac~ificing performance of the ~inished product by pro~iling the ~ilm thickness upon extrusion of the polymeric resin or material so as to provid~ the desired film thickness at khe top Q~ the bag while allowing ~or a thinner film thickness in F-1785 -2 ~
the body oF the bag, so that the average film thickness is, in fact;
much thinner than that which is ~elt and observed by the user of the bag.
~ retofore, various kinds of methods and apparatus have been proposed with regard to manufacturing techniques in the formation of thermoplastic film possessing profiled thicknesses; nevertheless, none of these have proven themselves in actual practice to be completely satisf`actory in a~fording the desired degree of control in the formation o~ extruded profiled thermoplastic film.
U.SO Patent No. 3,852,~6 discloses the production of an extruded plastic tubular film having circumferentially spaced thickened film sections or pro~iles extending continuously in the axlal direction o~ the film. These sections are adapted to interlock mechanically with each other so as to constitute a zipper-like fastener integrally formed with the film. The profiled sections in the film are formed through the provision of di Merent rates o~ cooling after the film has been extruded f`rom an annular die subsequen~ to the expansion of the tubular ~ilm, but while the Film is in a still hot state. As may be cl~arly ascertained, the formation of the profiled sections in the ~ilm wall is e~fected in a region having been subJected to primary cooling and inflating of the ~ilm, in which such pro~iling is rather dl~ficult to achi.eve in any satisfactorily controlled manner. Consequently, the apparatus and method disclosed in ~his patent is bounded by extensive restrictions in the ~ormation o~ precise profiled wall sections in extruded thermnplastic films.
Similarlyl interrelated ~ritish Patent Nos. 1~25099~5 and 1,2369831 each disclose processes for the production of tubular thermoplastic ~ilm which includes at least one lon~itudin~l zone wherein the wall thickness o~ the film is heavier than the thickness of the remainder o~ the ~ilm, and also describes the formation o~ bags with that processO In each o~ the British patents, the selective cooling of the extruded film is effected subsequent to the primary cooling and in~lating of the tubular plastic ~ilm, which renders the for~ation of controlled pro~iled wall structure extensively difficult, i~ not completely impossible.
~l9~ 6~i F-1785 ~3~
More recently an apparatus and method has been developed, as disclosed in U.S. Patent No. 4,209,475, which describes an apparatus for adjusting a cooling medium air ~low ~rom a cooling ring encompassing an extrusion die orifice so as to cool more extensively in selected regions o~ the film. The patented apparatus provides for a large number of adjustable deflector blades which are circumferentially arranged about the extrusion die orifice of the apparatus, and are basically designed to provide adjustment so as to compensate for errors or irregularities in the thickness o~ the plastic film produced by the extrusion die. Conceivably~ the apparatus can be employed in producing a varlation in the ~ilm thicl<ness when the extrusion die is of a precise con~iguration and, upon ef~ecting displacement of the deflector blades, is capable of producing extruded thermoplastic tubular film with a pro~iled thickness. Hbwever, the apparatus operates with relatively high air cooling speeds and flow rates and is not designed to provid0 a controlled profiled tubular fllm in a manner utilizing relatively low air cooling ~low speeds and rates as is contemplated ~y the inventive method and apparatus.
Basically, in accordance with the inventive concept, when forming extruded tubular thermoplastic film which is intended to be utilized in the formation of sandwich bag ~ilm, the cooling speed or rate is consid~rably lower than that employed with usual tubular plastic film extrusion processes, so that the amount of coolîng air which leaves the air ring is relatively small. Consequently, there is necessltated the applioation o~ a dif~erent process and apparatus which will provide fur the selective or localized cooling of the extruded tubular plastic ~ilm at a location in which the thermoplastic polymeric material or resin in the primary stage of for~ing the film is still ln a molten or heat plastified condition, and in which a separate ~lnw of a cooling medium is directed against the extrudate at speci~ic regions or zones about the periphery o~ the tubular ~ilm material being extruded so as tO ~orm one or more profile~ ~`ilm regions.
~76~
F-1785 ~4~
Essentially, the apparatus for ~orming a profiled tubular thermoplastic film, and the method which is implemented through the intermediary of the apparatus, contemplates the provision of an annular cooling ring extending ~bout the extrusion die ori~ice and which incorporates a central aperture through which the extruded plastic materlal is conveyed while still in a molten or heat-plastl~ied state, and which is adapted to direct a uniformly distributed flow o~ a cooling medium, such as air9 against the circum~erential surface o~ the extruded tubular plastic ~ilm materialJ which flow, i~ desired, may be at a relative low speed and rate of air flow. A secondary or bypass flow of the coo1ing medium is directed from the cooling ring, prior to the primary cooling medium flow against the surface o~ the extruded material, so as to impinge against one or more peripherally spaced zones on the ~ilm in order to i~part local coollng to the extruded film material withln each such zone9 to thereby cause the ~ormation o~ a thickened ~ilm wall section or profile extending in the longitudinal directisn o~ the fo~med tubular thermoplastic ~ilm. In order to control the cooling rate o~ the cooling ring9 the cooling ring incorporates an adjusting device wh:ich will va~y the extent o~ the cooling medium ~low which is uniformly provided about the perlphery o~
the extruded the~noplastic material and; additionally~ includes a rr~tering arrangernent which will rMdify or even completely inhibit the cooling medium flow thro~h the bypass so as to thereby control the extent of the profilin~ o~ the ~ilmO Eoth the unifo~n and local ~lows of the cooling mediu~ w~thin the cooling ring may be supplied ~rom a plenum encasing the oooling ring9 and which is supplied ~rom a single cooling medlurn sou~ce.
Accordingly, it is a primary ob~ect o~ the present invention to provide a method for ~o~ming a profile~ tubular thermoplastio ~ilm obtain~d through the selective looalized eooling o~ a oontinuously extruded the~moplastic polymeric m~kerial.
It is a more speeific nbjeot o~ the pxesent invention to provide a ~ethod as described hereinabove wherein local c~ollng is imparted ko an ext-ruded thermoplastie tubular film material while the ~9~
film is in a still molten or heat-plastified state subsequent to extrusion from an annular extrusion die.
Still another object of the present invention is to provide for a method of forming a profiled tubular thermoplastic film ~herein a cooling medium, such as air, ls directed at one or more localize.d zones spaced about the periphery of the film as it is being extruded from an annular extrusion die and while the film still is in a molten or heat-plastified condition, and in which the film is subsequently subiected to a uniformly distributed cooling air flow about the periphery of the film so as to, in a controlled manner7 form a precisely profiled tubular thermoplastic film~
A further object of the present invention resides in the provision of an apparatus for implementing the method as described hereinaboYe, wherein a cooling medium is supplied from a plenum so as to be uniformly distributed throughout a cooling ring, the latter of which is adapted to concurrently convey the cooling medium to localized zones on the surface of thermoplastic tubular film being extruded through an annular extrusion die orifice and while the film is in a still molten or heat~plastified condition, and subsequently to impart a uniformly distributed cooling medLum flow directed against the periphery o~ the extruded thermoplastic film so as to form a profiled wall contour on the film which extends in the longitudinal direction thereof.
A still further object of the present invention is to pro~ide an apparatus of the type described hereinabove, in which the cooling ring is adapted to provide for adjustment in the flow of the cooling mediu~ ~low which is uniformly distributed about the periphery of the extruded thermoplastic ~ilm, and including an arrangement whereby the amount of the bypass flow of cooling medium to the localized zones of the tubular film is adapted to be metered so as to allow for the formation of a controlled profiled oontour in the extruded thermoplastic film.
-5a-The present invention, then, in one aspect, resides in a method of ~orming an extruded tubular thermo~
plastic film having at least one r~gion of a thickened wall profile extending ïn the longitudinal direction of the extruded tubular f;lm; comprising extruding a molten thermoplastic polymeric material through an annular extrusion die; and passing said extruded tubular film through a cooling zone while said film is in a heat-plasti~ied condition including suhjecting said film to selectively adjustable localized cooling in the region for forming a thickened profile of variable thickness, and subsequen~ly subjecting said tubular film to a selective amount of uniform cooling about the periphery thereof, whereby said longitudinally extending thickened profiled region is formed in the wall of the tubular film.
In another aspect, the present invention resides in an apparatus ~or the forming of an extruded tubular thermoplastic film having at least one region of a thickened wall profile extending in the longitudinal direction of the extruded film, said apparatus comprising an annular extrusion die for extruding a molten thermo-plastic polymeric material to orm said film; a cooling ring having A central opening mounted in line with and downstream of said extrusion diewherein the extruded molten polymeric material passes through said central opening, said cooling ring including means for directing a flow of a cooling m dium against localized zones along the peripheral surface of said extruded material while said material is in a heat-plastified condition, and means in said cooling ring for subsequently directing a uniformly distributed flow of said cooling medium against the peripheral surace of said extruded material so as to form said thickened wall pro~ile region along the zones of said localized cooling while the ma~erial is conveyed through said cooling ring.
9~i6 Reference may now be had to the following detailed description of preferred embodiments of an apparatus pursuant to the invention for producing a proFiled tubular thermoplastic film, taken in conjunction with the accompanying drawings in whîch:
Figure 1 illustrates, in a perspective view1 a generally schematic representation o~ a cooling ring with an encompassing plenum cha~ber for supplying a cooling medium, and which is adapted to form an extruded tubular thermoplastic film having a pro~iled section pursuant to the invention;
Figure 2 shows a sectional view throug~ the cooling ring taken along line 2-2 in Flgure l;
Figure 3 shows a sectional view taken along line 3~3 in Figure
2;
Figure 4 shows a sectional view taken along line 4-4 in Figure 2, illustrating one disc member of the cooling ring;
Figure 5 i5 a vi~w similar to that o~ Figure 3 showing a somewhat modified embodiment o~ a cooling ring, Figure 6 is a ~ragmentary section taken along line 6-6 in Figure 5; and Figure 7 is a perspective view of a plastic sandwich bag made in accordance with the present invention, with the sid~s of the bag shown cut open to illustrate the prn~iled film zones.
Although the apparatus is disclosed and described herein as relating to an upwardly extruding apparatus and cooling die arrangement for the ~ormation oF a profiled tubular plastic film, it will be readily apparent to one skilled in the art that, in lieu of the film being extruded and conveyed in an upward direction, the apparatus may be operated so as to extrude and convey the tubular thermoplastic ~ilm material in a downward di~ection.
ReFerring in particular to Figure 1 o~ the drawings, th~re is shown aPparatus including an extrusion die 10 For continuously extruding a molten thermoplastic polymeric resin or material through a standard type of annular extrusion die orifice to Form a continuous thermoplastic tubular ~ilm 12. A cooling ring 14 having an annular 7~6 F-1785 ~7~
opening 16 through which the film 12 is extruded is located immedlately upstream of and about the extrusion die orifice, and is sealingly enclosed by a plenum 18 which has a cooling medium, such as air, conveyed thereto through tangentially-extending inlet ducts 20 and 22 from a suitable supply source (not shown).
As illustrated in detail in the embodiment of the apparatus o~
Figures 2 through 4 o~ the drawings, the cooling ring 14 may be constituted of a first or lower circular disc member 24 and of an upper or second disc arrangement 2~ being located in spaced relationship therewith so as to proviqe an annular passageway 28 therebetween.
The upper disc arrangement 26 includes a radially inwardly located disc portion 30 which is threadedly connected to an outer disc portion 32 by ~eans o~ cooperating threads 34 so as to provide for axial displaoe~ent or adjustment between khe disc portions 30 and 32.
The lower disc member 24 has a generally planar upper surface 36 ~ac1ng towards the passageway 28, and which includes a pair of concentrically spaced, annular raised ribs or baffles 38, 40 which provide for flow restrictions and pressure drops in the passageway 28 between the coollng ring disc portion 30 and disc member 24. Suitable spacers ~not shown) in the form of streamlined air~oils may be provided so as to interconnect disc portion 32 and disc member 24 in a fixed spatial relationship without hindering flow of cooling medium through passageway 28, whereas disc portion 30 is adapted to be adjusted towards and away ~rom the disc member 24 by rotation between the ~nterengaging thread portions 34 to thereby vary the gap size be~ween the tips o~ ba~fles 38 and 40 and the lower surface 42 o~ disc me~ber 30. This will provide ~or control over the amount o~ cooling medium flowing through the passageway 2a while providiny a pressure drop aoross th~ baf~les so as to divert a maJor portion of the cooling medium into bypass flow, as described hereinbelow.
The radially inner end 44 of the dîsc member 24 includes an upstanding peripheral wall portion 46 dimensioned to define an annular channel 48 in cooperation with the vertical peripheral end wall 50 of the disc portion 30~ to facilitate axial upward flow of the cooling medium along the outer surface of the extruded tubular thermoplastic film material conducted along surface 52 of the disc member 24 and the wall surface 50.
Formed in the surface of the disc member 24 facing away from disc arrangement 26, which as is shown in Figure 4 o~ the drawings, may be constructed o~ a solid metallic material, are essentlally rectangular cutouts 54, which are adapted to receive suitable inserts for the formation of the profiled tubular plastic film ~all, as is described in detail hereinbelow.
As is illustrated in Figure 2 of the drawing, there are shswn two of such cutouts 54 in the disc member 24 at an angular spac~ng of goo relative to each other, although one, two or even more cutouts may, as desired, be formed in the disc member 24 depending upon the number and ~pacing of profiled sections required to.be incorporated into the wall thickness of the extruded thermoplastic film. Each cutout 54 in the bottom o~ the disc member 24 is adapted to receive an insert 56 having an overall con~iguration in g~neral conformance with the dimensions o~ the associated cutout 54, with the bottom of the insert 56 being essentially ooplanar with the remaining surface of the ~ottom of disc member 24~ Suitable fasteners~ such as locking screws or the like (not shown) may be utilized to mount each insert 56 within its respective cutout 54 provided in the disc member 24~
The lnsert 56 is hollowed out so as to provide a generally rectangular cavity 58. A circular bore 60 located towards the radially outer ~nd o~ the disc member 24 communicates the cavity ~8 in the insert 56 with passageW~y~ so as to facilitate the through flow o~
cooling medium into cavity 5B from the passageway 28. The radially inner end of the cavity 58 connects with a plurality of radially inwa~dly directed and upwardly sloped small bores 62 facing in ~n arc towards the extended film which is conveyed past the sur~ace 52. Thus, a portion o~ cooling medium which is supplied to the passage~ay 28 ~rom the plenum 18 ~lows through the passageway 28 and through the axial passageway 48, whereas the remaining ~low of the cooling medium flows through the bore 60 into the cavity 58 and out through the plurality o~
small apertures or bores 62, the latter of which form a bypass passageway ~or the localized cooling of the extruded plastic material passing, and the resultant formation of the heavier or profiled wall thickness zones o~ the thermoplaskic film.
In order to meter the amount o~ cooling medium flowing into the cavity 58 and out through apertures or bores 62, the disc portion 32 is provided with a vertically adjustable metering screw 64, one being provided in axial alignment with a respective bore 60, having a tapered lower end 66 which, if desired9 can be screwed towards or away from the bore 60 so as to either restrîct or inhibît passage of cooling medium therethrough, or to increase the ~low of the oooling medium.
Referring now in detail to the embodiment of the apparatus illustrated in Figures 5 and 6 o~ the drawings, tha cooling ring structure 70 illustrated therein is similar in principle and operation to that o~ cooling ring 14 as shown in Figures 2 through 4, similar or identical parts being designated with the same re~erence numerals.
Hbwever, in this instance, the lower disc member 72 has a radlally inner end wherein the passageway 74 formed in conjunction with the upper dise portion 76 is angled radially inwardly rather than merely axially upwardly as in the preceding embodiment, with the radially inner end of the upper inner disc portion 76 being tapered down sc as to define a radially inwardly and upwardly sloping conical snd surfaoe 78~
Furthermore, in lieu of the two upstanding annular baffles ~8 and 40 as shown in the embodiment o~ Figures 2 through 4, the passage-way 28 is closed off by an annular flow restrictor ring 80, having a widened bottom portion 820 Formed within the bottom portion 82 is an annular groove 84 which communicates with the radially outer portion of passageway 28 through a series of khrough-bores 86 and~ in turn, communicates with the passageway 74 through a larger number of smaller through-bores 88. This arrangement will provide ~ar a pressure drop of the cooling air being distributed about the periphery of the extruded plastic material through passageway 74 as supplied to the passageway za from the plenum 18.
~g~6~
F~1785 -10-The bypass passageway which provides ~or the localized cooling o~ the surface o~ the the~moplastic material, as represented by ~nsert or inserts 56, is in this embodiment anal3gous in construction and function with that described in connection with the previous embod~nent, and need not be elucidated in detail herein.
Referring now to the drawing in Figure 7, this illustrates a sectional view through a plastic bag, such as a sandwich bag, which has be~n form~d ~rom an extruded tubular thermoplastic ~ilm having a prnfiled wall zones extending in the longitudinal direction o~ the extruded ~ilm.
Thus, a bag lOû includes a main body portion consisting o~
side walls 102 and 104 which are of a thinner ~ilm wall thickness, as is the gusseted bottom structure 106 o~ the ba~. In this instanoe, the ~ilm of the bag body may have a thickness o~ about 0.9 mils. The upper ends o~ the bag 108 and 110 which are usually handled during use of the bag, are ~ormed from a heavier film thickness such as~ ~or example, 1.5 mils~ which is ~ormed along the peripheral zone or zones o~ the extruded tubular ~ilm in which localized coollng has been imparted to the extrudate through the bores 62 o~ the inserts 569 to provide for the p~o~iling o~ the film. Thus, although a user will ~eel a heavier wall thickness of 1.5 mils when handling the bag at its opening end, ln actuality the average thickness of the bag is only 1.1 mlls, resulting in considerable savings o~ material.
From the fore9oln9 there may b~ ascertained that the present invention really provides a simple and lnexpensive apparatus and method o~ produoing a profiled tubular plastic film through the loealized cooling o~ the extruded ~ilm while the lstter is still in ~ molten or heat-plastl~ied state.
Figure 4 shows a sectional view taken along line 4-4 in Figure 2, illustrating one disc member of the cooling ring;
Figure 5 i5 a vi~w similar to that o~ Figure 3 showing a somewhat modified embodiment o~ a cooling ring, Figure 6 is a ~ragmentary section taken along line 6-6 in Figure 5; and Figure 7 is a perspective view of a plastic sandwich bag made in accordance with the present invention, with the sid~s of the bag shown cut open to illustrate the prn~iled film zones.
Although the apparatus is disclosed and described herein as relating to an upwardly extruding apparatus and cooling die arrangement for the ~ormation oF a profiled tubular plastic film, it will be readily apparent to one skilled in the art that, in lieu of the film being extruded and conveyed in an upward direction, the apparatus may be operated so as to extrude and convey the tubular thermoplastic ~ilm material in a downward di~ection.
ReFerring in particular to Figure 1 o~ the drawings, th~re is shown aPparatus including an extrusion die 10 For continuously extruding a molten thermoplastic polymeric resin or material through a standard type of annular extrusion die orifice to Form a continuous thermoplastic tubular ~ilm 12. A cooling ring 14 having an annular 7~6 F-1785 ~7~
opening 16 through which the film 12 is extruded is located immedlately upstream of and about the extrusion die orifice, and is sealingly enclosed by a plenum 18 which has a cooling medium, such as air, conveyed thereto through tangentially-extending inlet ducts 20 and 22 from a suitable supply source (not shown).
As illustrated in detail in the embodiment of the apparatus o~
Figures 2 through 4 o~ the drawings, the cooling ring 14 may be constituted of a first or lower circular disc member 24 and of an upper or second disc arrangement 2~ being located in spaced relationship therewith so as to proviqe an annular passageway 28 therebetween.
The upper disc arrangement 26 includes a radially inwardly located disc portion 30 which is threadedly connected to an outer disc portion 32 by ~eans o~ cooperating threads 34 so as to provide for axial displaoe~ent or adjustment between khe disc portions 30 and 32.
The lower disc member 24 has a generally planar upper surface 36 ~ac1ng towards the passageway 28, and which includes a pair of concentrically spaced, annular raised ribs or baffles 38, 40 which provide for flow restrictions and pressure drops in the passageway 28 between the coollng ring disc portion 30 and disc member 24. Suitable spacers ~not shown) in the form of streamlined air~oils may be provided so as to interconnect disc portion 32 and disc member 24 in a fixed spatial relationship without hindering flow of cooling medium through passageway 28, whereas disc portion 30 is adapted to be adjusted towards and away ~rom the disc member 24 by rotation between the ~nterengaging thread portions 34 to thereby vary the gap size be~ween the tips o~ ba~fles 38 and 40 and the lower surface 42 o~ disc me~ber 30. This will provide ~or control over the amount o~ cooling medium flowing through the passageway 2a while providiny a pressure drop aoross th~ baf~les so as to divert a maJor portion of the cooling medium into bypass flow, as described hereinbelow.
The radially inner end 44 of the dîsc member 24 includes an upstanding peripheral wall portion 46 dimensioned to define an annular channel 48 in cooperation with the vertical peripheral end wall 50 of the disc portion 30~ to facilitate axial upward flow of the cooling medium along the outer surface of the extruded tubular thermoplastic film material conducted along surface 52 of the disc member 24 and the wall surface 50.
Formed in the surface of the disc member 24 facing away from disc arrangement 26, which as is shown in Figure 4 o~ the drawings, may be constructed o~ a solid metallic material, are essentlally rectangular cutouts 54, which are adapted to receive suitable inserts for the formation of the profiled tubular plastic film ~all, as is described in detail hereinbelow.
As is illustrated in Figure 2 of the drawing, there are shswn two of such cutouts 54 in the disc member 24 at an angular spac~ng of goo relative to each other, although one, two or even more cutouts may, as desired, be formed in the disc member 24 depending upon the number and ~pacing of profiled sections required to.be incorporated into the wall thickness of the extruded thermoplastic film. Each cutout 54 in the bottom o~ the disc member 24 is adapted to receive an insert 56 having an overall con~iguration in g~neral conformance with the dimensions o~ the associated cutout 54, with the bottom of the insert 56 being essentially ooplanar with the remaining surface of the ~ottom of disc member 24~ Suitable fasteners~ such as locking screws or the like (not shown) may be utilized to mount each insert 56 within its respective cutout 54 provided in the disc member 24~
The lnsert 56 is hollowed out so as to provide a generally rectangular cavity 58. A circular bore 60 located towards the radially outer ~nd o~ the disc member 24 communicates the cavity ~8 in the insert 56 with passageW~y~ so as to facilitate the through flow o~
cooling medium into cavity 5B from the passageway 28. The radially inner end of the cavity 58 connects with a plurality of radially inwa~dly directed and upwardly sloped small bores 62 facing in ~n arc towards the extended film which is conveyed past the sur~ace 52. Thus, a portion o~ cooling medium which is supplied to the passage~ay 28 ~rom the plenum 18 ~lows through the passageway 28 and through the axial passageway 48, whereas the remaining ~low of the cooling medium flows through the bore 60 into the cavity 58 and out through the plurality o~
small apertures or bores 62, the latter of which form a bypass passageway ~or the localized cooling of the extruded plastic material passing, and the resultant formation of the heavier or profiled wall thickness zones o~ the thermoplaskic film.
In order to meter the amount o~ cooling medium flowing into the cavity 58 and out through apertures or bores 62, the disc portion 32 is provided with a vertically adjustable metering screw 64, one being provided in axial alignment with a respective bore 60, having a tapered lower end 66 which, if desired9 can be screwed towards or away from the bore 60 so as to either restrîct or inhibît passage of cooling medium therethrough, or to increase the ~low of the oooling medium.
Referring now in detail to the embodiment of the apparatus illustrated in Figures 5 and 6 o~ the drawings, tha cooling ring structure 70 illustrated therein is similar in principle and operation to that o~ cooling ring 14 as shown in Figures 2 through 4, similar or identical parts being designated with the same re~erence numerals.
Hbwever, in this instance, the lower disc member 72 has a radlally inner end wherein the passageway 74 formed in conjunction with the upper dise portion 76 is angled radially inwardly rather than merely axially upwardly as in the preceding embodiment, with the radially inner end of the upper inner disc portion 76 being tapered down sc as to define a radially inwardly and upwardly sloping conical snd surfaoe 78~
Furthermore, in lieu of the two upstanding annular baffles ~8 and 40 as shown in the embodiment o~ Figures 2 through 4, the passage-way 28 is closed off by an annular flow restrictor ring 80, having a widened bottom portion 820 Formed within the bottom portion 82 is an annular groove 84 which communicates with the radially outer portion of passageway 28 through a series of khrough-bores 86 and~ in turn, communicates with the passageway 74 through a larger number of smaller through-bores 88. This arrangement will provide ~ar a pressure drop of the cooling air being distributed about the periphery of the extruded plastic material through passageway 74 as supplied to the passageway za from the plenum 18.
~g~6~
F~1785 -10-The bypass passageway which provides ~or the localized cooling o~ the surface o~ the the~moplastic material, as represented by ~nsert or inserts 56, is in this embodiment anal3gous in construction and function with that described in connection with the previous embod~nent, and need not be elucidated in detail herein.
Referring now to the drawing in Figure 7, this illustrates a sectional view through a plastic bag, such as a sandwich bag, which has be~n form~d ~rom an extruded tubular thermoplastic ~ilm having a prnfiled wall zones extending in the longitudinal direction o~ the extruded ~ilm.
Thus, a bag lOû includes a main body portion consisting o~
side walls 102 and 104 which are of a thinner ~ilm wall thickness, as is the gusseted bottom structure 106 o~ the ba~. In this instanoe, the ~ilm of the bag body may have a thickness o~ about 0.9 mils. The upper ends o~ the bag 108 and 110 which are usually handled during use of the bag, are ~ormed from a heavier film thickness such as~ ~or example, 1.5 mils~ which is ~ormed along the peripheral zone or zones o~ the extruded tubular ~ilm in which localized coollng has been imparted to the extrudate through the bores 62 o~ the inserts 569 to provide for the p~o~iling o~ the film. Thus, although a user will ~eel a heavier wall thickness of 1.5 mils when handling the bag at its opening end, ln actuality the average thickness of the bag is only 1.1 mlls, resulting in considerable savings o~ material.
From the fore9oln9 there may b~ ascertained that the present invention really provides a simple and lnexpensive apparatus and method o~ produoing a profiled tubular plastic film through the loealized cooling o~ the extruded ~ilm while the lstter is still in ~ molten or heat-plastl~ied state.
Claims (20)
PROPERTY OR PRIVILEGE IS CLAIMED, ARE DEFINED AS FOLLOWS:
1. A method of forming an extruded tubular thermoplastic film having at least one region of a thickened wall profile extending in the longitudinal direction of the extruded tubular film; comprising extruding a molten thermoplastic polymeric material through an annular extrusion die; and passing said extruded tubular film through a cooling zone while said film is in a heat-plastified condition including subjecting said film to selectively adjustable localized cooling in the region for forming a thickened profile of variable thickness, and subsequently subjecting said tubular film to a selective amount of uniform cooling about the periphery thereof, whereby said longitudinally extending thickened profiled region is formed in the wall of the tubular film.
2. A method as claimed in claim 1, comprising imparting said localized cooling to said extruded tubular thermoplastic film at a plurality of circumferentially spaced zones so as to form a plurality of said thickened profiled regions in the film wall.
3. A method as claimed in claim 1, comprising directing a flow of a gaseous cooling medium against the outer surface of said tubular film to provide said localized cooling and the subsequent uniform cooling about the periphery of the film.
A method as claimed in claim 3, said gaseous cooling medium comprising air.
5. A method as claimed in claim 1, comprising adjusting the amount of localized cooling of said tubular film to thereby vary the thickness of the profiled region of said film.
6. A method as claimed in claim 1 or 5, comprising adjusting the amount of said subsequent uniform cooling about the periphery of said tubular film to thereby vary the thickness of said film.
7. An apparatus for the forming of an extruded tubular thermoplastic film having at least one region of a thickened wall profile extending in the longitudinal direction of the extruded film, said apparatus comprising an annular extrusion die for extruding a molten thermoplastic polymeric material to form said film; a cooling ring having a central opening mounted in line with and downstream of said extrusion die wherein the extruded molten polymeric material passes through said central opening, said cooling ring including means for directing a flow of a cooling medium against localized zones along the peripheral surface of said extruded material while said material is in a heat-plastified condition, and means in said cooling ring for subsequently directing a uniformly distributed flow of said cooling medium against the peripheral surface of said extruded material so as to form said thickened wall profile region along the zones of said localized cooling while the material is conveyed through said cooling ring. .
8. An apparatus as claimed in claim 7, comprising means for supplying said cooling medium to said cooling ring, said cooling ring including means for dividing said cooling medium into said uniformly distributed cooling medium flow about the periphery of the extruded material and a bypass flow of said cooling medium flow to the localized zones of said extruded material.
9. An apparatus as claimed in claim 8, said cooling ring comprising spaced disc members defining an annular passageway therebetween for conducting said uniformly distributed cooling medium flow about the periphery of said extruded material.
10. An apparatus as claimed in claim 9, comprising at least one insert in one of said disc members having a recess portion communicating with said annular passageway, and a plurality of apertures formed in the insert connected to said recess and having outlets facing the surfaces of the extruded material so as to provide the localized cooling medium bypass flow directed against regions about the peripheral surface of the extruded material.
11. An apparatus as claimed in claim l0, comprising means for metering the localized bypass flow of said cooling medium.
12. An apparatus as claimed in claim 11, said metering means comprising a metering screw for controlling the inflow of said cooling medium into the recess of said insert.
13. An apparatus as claimed in claim 9, wherein spacing between said disc members is adjustable to control the amount of flow of uniformly distributed cooling medium through said annular passageway to the periphery of said extended film.
14. An apparatus as claimed in claim 13, comprising annular baffle means projecting into said annular passageway to lower the outlet pressure of the uniformly distributed cooling medium flow through said passageway.
15. An apparatus as claimed in claim 14, said baffle means comprising a plurality of concentrically spaced ribs.
16. An apparatus as claimed in claim 14, said baffle means comprising a restrictor ring extending between said disc members, and a plurality of communicating radially offset inlet and outlet bores being formed in said restrictor ring.
17. An apparatus as claimed in claim 13, wherein one of said disc members includes a threaded annular portion which is adjustable relative to the opposite disc member so as to vary the passageway between said disc members.
18. An apparatus as claimed in claim 10, comprising a plurality of said inserts circumferentially spaced about said cooling ring to provide for a plurality of locally cooled zones about the periphery of said extruded material.
19. An apparatus as claimed in claim 8, said cooling medium supply means comprising a plenum encompassing said cooling ring for the circumferentially uniformly distributed inlet of said cooling medium.
20. An apparatus as claimed in claim 7, said cooling medium comprising air.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US06/407,206 US4443400A (en) | 1982-08-11 | 1982-08-11 | Method and apparatus for the formation of profiled thermoplastic film |
| US407,206 | 1982-08-11 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1199766A true CA1199766A (en) | 1986-01-28 |
Family
ID=23611084
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000432563A Expired CA1199766A (en) | 1982-08-11 | 1983-07-15 | Method and apparatus for the formation of profiled thermoplastic film |
Country Status (2)
| Country | Link |
|---|---|
| US (1) | US4443400A (en) |
| CA (1) | CA1199766A (en) |
Families Citing this family (30)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4603434A (en) * | 1983-01-03 | 1986-07-29 | Mobil Oil Corporation | Ripple lock closure for flexible bags |
| US4732727A (en) * | 1986-04-03 | 1988-03-22 | The Dow Chemical Company | Method and apparatus for producing mesh film |
| US4750874A (en) * | 1987-01-09 | 1988-06-14 | Gloucester Engineering Co., Inc. | Air cooling ring for plastic film |
| US4781880A (en) * | 1987-02-11 | 1988-11-01 | Robbins Edward S Iii | Method of forming plastic ribbed enclosure |
| US4816316A (en) * | 1987-02-11 | 1989-03-28 | Robbins Edward S Iii | Ribbed sheet |
| DE3745138C2 (en) * | 1987-12-23 | 1997-08-21 | Veit Holger Karl Prof Dr Ing | Film blowing system for the production of plastic films |
| ATE93447T1 (en) * | 1989-06-21 | 1993-09-15 | Stefan Konermann | METHOD AND DEVICE FOR PRODUCTION OF BLOWN FILM. |
| DE4001287A1 (en) * | 1990-01-18 | 1991-07-25 | Stefan Konermann | Local correction of blown film thickness using variable air flow |
| DE4115353C3 (en) * | 1991-05-10 | 1998-04-09 | Karl Veit Holger Prof Dr Ing | Film blowing system for the production of plastic films |
| US5562926A (en) * | 1991-05-10 | 1996-10-08 | Karl; Veit-Holger | Film-blowing plant for manufacturing plastic films |
| IT222712Z2 (en) * | 1991-07-23 | 1995-04-24 | Deponte Edoardo | COOLING DEVICE FOR EXTRUSION HEADS FOR TUBULAR FILMS OF PLASTIC MATERIAL |
| DE4207439B4 (en) * | 1991-12-12 | 2004-05-06 | Windmöller & Hölscher Kg | Foil blowing head for the production of tubular foils from thermoplastic |
| DE4205185A1 (en) * | 1992-02-20 | 1993-08-26 | Windmoeller & Hoelscher | BLOW HEAD FOR THE PRODUCTION OF TUBE FILMS FROM THERMOPLASTIC PLASTIC |
| US5468134A (en) * | 1993-12-01 | 1995-11-21 | Cree; Robert E. | Cooling and thickness control for extruded products |
| DE10066051B4 (en) * | 1999-09-09 | 2004-10-28 | Kdesign Gmbh | Controlling and automatically controlling thickness profile in blown film production, involves supplying additional air streams in direction of production in front of main cooling ring |
| US6439771B1 (en) | 2000-03-15 | 2002-08-27 | Webster Industries Division Chelsea Industries, Inc. | Zippered resealable closure |
| US7695263B2 (en) * | 2001-03-05 | 2010-04-13 | Windmoeller And Hoelscher Kg | Blown film die for producing tubular film |
| US6611996B2 (en) | 2001-07-02 | 2003-09-02 | Pactiv Corporation | Slider for reclosable fastener |
| US6713152B2 (en) | 2001-09-07 | 2004-03-30 | Pactiv Corporation | Fins and profiles for plastic bags |
| US7654808B2 (en) * | 2004-10-12 | 2010-02-02 | Macro Engineering and Technology, Inc. | Air ring with circumferentially adjustable air flow |
| US20060099291A1 (en) * | 2004-10-12 | 2006-05-11 | Mirek Planeta | Air ring with circumferentially adjustable air flow |
| US7220113B2 (en) * | 2005-04-11 | 2007-05-22 | Macro Engineering & Technology Inc. | Gauge distribution apparatus for plastic film |
| ES2339059T3 (en) * | 2007-10-22 | 2010-05-14 | Kdesign Gmbh | DEVICE WITH A CONTROLLABLE COOLING GAS RING WITH A RECTIFICATION UNIT AND AN ADDITIONAL COOLING GAS RING. |
| JP5634630B1 (en) * | 2014-04-14 | 2014-12-03 | 株式会社湘南貿易 | Uneven thickness adjustment type air ring |
| US9815238B2 (en) | 2014-06-30 | 2017-11-14 | Inteplast Group Corporation | Blown film with integral profiles |
| US9487334B2 (en) | 2015-03-17 | 2016-11-08 | Poly-America, L.P. | Method of forming polymeric bags |
| IT201700055831A1 (en) * | 2017-05-23 | 2018-11-23 | Syncro S R L | DEVICE AND METHOD TO ADJUST THE THICKNESS PROFILE IN BLOWN FILM PRODUCTION |
| US11072103B2 (en) | 2017-06-26 | 2021-07-27 | Inteplast Group Corporation | Extrusion system and method for blown film with integral profiles |
| US11618200B2 (en) * | 2020-03-17 | 2023-04-04 | Michael P. Bucko | External cooling air ring for blown-film extrusion |
| US11826941B1 (en) | 2022-06-28 | 2023-11-28 | Daniel R. Joseph | Air ring for blown-film extrusion apparatus |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2926384A (en) * | 1953-10-20 | 1960-03-01 | Celanese Corp | Distributor ring |
| US2952874A (en) * | 1958-05-19 | 1960-09-20 | Phillips Petroleum Co | Air ring for use in the manufacture of thermoplastic tubing |
| SE322044B (en) * | 1967-01-10 | 1970-03-23 | A Labek | |
| GB1236831A (en) * | 1968-10-18 | 1971-06-23 | British Visqueen Ltd | Plastics film bags |
| IE34177B1 (en) * | 1969-08-28 | 1975-03-05 | Voor Techno Commerciele Signal | Process for the manufacture of tubular film having at least one longitudinal lane in which the wall thickness of the film is greater than the wall thickness of the remainder of the tubular film |
| US3852386A (en) * | 1970-12-21 | 1974-12-03 | Dow Chemical Co | Manufacture of film having formed fastener means therein |
| US3835209A (en) * | 1971-11-09 | 1974-09-10 | Owens Illinois Inc | Process of extruding a foamed extrudate and controlling the thickness thereof |
| SU440038A1 (en) * | 1972-06-08 | 1974-09-15 | Предприятие П/Я В-8406 | Ring for air cooling tubular polymer film |
| JPS515021A (en) * | 1974-07-01 | 1976-01-16 | Ricoh Kk | RENZOKUYOSHIOKURISOCHINO HITSUPARIROORASOCHI |
| GB1529222A (en) * | 1976-04-13 | 1978-10-18 | Coloroll Ltd | Carrier bags |
| DE2658518C2 (en) * | 1976-12-23 | 1983-04-28 | Reifenhäuser KG, 5210 Troisdorf | Plant for the production of blown films made of thermoplastic material |
| US4209475A (en) * | 1978-10-20 | 1980-06-24 | Mobil Oil Corporation | Method and apparatus for effecting uniform film thickness |
| US4229407A (en) * | 1979-02-23 | 1980-10-21 | Baxter Travenol Laboratories, Inc. | Tear path products, method and apparatus |
| US4265853A (en) * | 1979-09-14 | 1981-05-05 | The Dow Chemical Company | Method and apparatus for forming of reinforced tube |
| US4330501A (en) * | 1980-06-30 | 1982-05-18 | Union Carbide Corporation | Method and apparatus for cooling film bubble of low strain hardening polymers |
-
1982
- 1982-08-11 US US06/407,206 patent/US4443400A/en not_active Expired - Fee Related
-
1983
- 1983-07-15 CA CA000432563A patent/CA1199766A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| US4443400A (en) | 1984-04-17 |
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