GB1603128A - Tubular plastics film - Google Patents
Tubular plastics film Download PDFInfo
- Publication number
- GB1603128A GB1603128A GB23059/78A GB2305978A GB1603128A GB 1603128 A GB1603128 A GB 1603128A GB 23059/78 A GB23059/78 A GB 23059/78A GB 2305978 A GB2305978 A GB 2305978A GB 1603128 A GB1603128 A GB 1603128A
- Authority
- GB
- United Kingdom
- Prior art keywords
- density polyethylene
- film
- plastics film
- die
- high density
- 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
- 229920003023 plastic Polymers 0.000 title claims description 40
- 239000004033 plastic Substances 0.000 title claims description 40
- 229920001903 high density polyethylene Polymers 0.000 claims description 32
- 239000004700 high-density polyethylene Substances 0.000 claims description 32
- 229920002397 thermoplastic olefin Polymers 0.000 claims description 22
- 229920001684 low density polyethylene Polymers 0.000 claims description 20
- 239000004702 low-density polyethylene Substances 0.000 claims description 20
- 238000000034 method Methods 0.000 claims description 20
- 229920001971 elastomer Polymers 0.000 claims description 18
- 239000000806 elastomer Substances 0.000 claims description 18
- 230000008569 process Effects 0.000 claims description 17
- 239000003570 air Substances 0.000 claims description 11
- 238000004519 manufacturing process Methods 0.000 claims description 11
- 238000001125 extrusion Methods 0.000 claims description 8
- 239000012080 ambient air Substances 0.000 claims description 7
- 230000035699 permeability Effects 0.000 claims description 4
- 238000004659 sterilization and disinfection Methods 0.000 claims description 4
- 239000004698 Polyethylene Substances 0.000 claims description 3
- 239000003000 extruded plastic Substances 0.000 claims description 3
- -1 polyethylene Polymers 0.000 claims description 3
- 229920000573 polyethylene Polymers 0.000 claims description 3
- 239000000470 constituent Substances 0.000 claims description 2
- 229920000642 polymer Polymers 0.000 description 3
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 description 2
- 239000005977 Ethylene Substances 0.000 description 2
- 229920000098 polyolefin Polymers 0.000 description 2
- 239000005022 packaging material Substances 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B27/00—Layered products comprising a layer of synthetic resin
- B32B27/32—Layered products comprising a layer of synthetic resin comprising polyolefins
-
- 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
-
- 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
-
- 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
- B29C48/14—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor characterised by the particular extruding conditions, e.g. in a modified atmosphere or by using vibration
- B29C48/147—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor characterised by the particular extruding conditions, e.g. in a modified atmosphere or by using vibration after the die nozzle
- B29C48/1472—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor characterised by the particular extruding conditions, e.g. in a modified atmosphere or by using vibration after the die nozzle at the die nozzle exit zone
-
- 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
- B29C48/16—Articles comprising two or more components, e.g. co-extruded layers
- B29C48/18—Articles comprising two or more components, e.g. co-extruded layers the components being layers
- B29C48/21—Articles comprising two or more components, e.g. co-extruded layers the components being layers the layers being joined at their surfaces
-
- 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
- B29C48/30—Extrusion nozzles or dies
- B29C48/32—Extrusion nozzles or dies with annular openings, e.g. for forming tubular articles
- B29C48/335—Multiple annular extrusion nozzles in coaxial arrangement, e.g. for making multi-layered tubular articles
-
- 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
- B29C48/30—Extrusion nozzles or dies
- B29C48/32—Extrusion nozzles or dies with annular openings, e.g. for forming tubular articles
- B29C48/335—Multiple annular extrusion nozzles in coaxial arrangement, e.g. for making multi-layered tubular articles
- B29C48/337—Multiple annular extrusion nozzles in coaxial arrangement, e.g. for making multi-layered tubular articles the components merging at a common location
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B1/00—Layered products having a non-planar shape
- B32B1/08—Tubular products
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B27/00—Layered products comprising a layer of synthetic resin
- B32B27/06—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material
- B32B27/08—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material of synthetic resin
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B7/00—Layered products characterised by the relation between layers; Layered products characterised by the relative orientation of features between layers, or by the relative values of a measurable parameter between layers, i.e. products comprising layers having different physical, chemical or physicochemical properties; Layered products characterised by the interconnection of layers
- B32B7/02—Physical, chemical or physicochemical properties
-
- 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
- B29C2791/00—Shaping characteristics in general
- B29C2791/004—Shaping under special conditions
- B29C2791/007—Using fluid under pressure
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2323/00—Polyalkenes
- B32B2323/04—Polyethylene
- B32B2323/043—HDPE, i.e. high density polyethylene
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2323/00—Polyalkenes
- B32B2323/04—Polyethylene
- B32B2323/046—LDPE, i.e. low density polyethylene
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2439/00—Containers; Receptacles
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Extrusion Moulding Of Plastics Or The Like (AREA)
Description
(54) IMPROVEMENTS IN OR RELATING TO
TUBULAR PLASTICS FILM
(71) We, LAMIPAK INDUSTRIES
PTE LIMITED, a company incorporated under the laws of the Republic of Singapore of 209 Kallang Bahru, Singapore 12 do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:
This invention relates to tubular plastics films, in particular, to polyolefin films, and to a process for the preparation thereof.
Tubular polyolefin films manufactured by extrusion have found widespread use as packaging materials and in many other applications. Such films are commonly formed using low density polyethylene and more recently using high density polyethylene polymers.
While films manufactured from low density polyethylene have advantageous properties with respect to their printability and the ease of stacking of packages and bags produced therefrom, they suffer from a low mechanical strength for a given film thickness, exhibit a poor suitability with respect to thermal sterilisation and packages and bags produced from such films are not easily opened. In addition, such films have a high gaseous permeability, which in some circumstances is undesired.
On the other hand films manufactured from high density polyethylene have a low gaseous permeability, poor printability and packages and bags produced therefrom are not easily stacked. However, such films do have a high mechanical strength for a given film thickness, are suitable for thermal sterilisation and packages and bags produced therefrom are easily opened.
According to one respect of the present invention there is provided a tubular plastics film (as herein defined) comprising a first axially extending circumferential layer comprising high density polyethylene (as herein defined) and a second axially extending circumferential layer comprising a further thermoplastic polyolefin (which is other than high density polyethylene).
The term "tubular film", as used herein, is intended to mean a cylinder-like structure having walls of a substantially uniform and relatively small thickness. The term "high density polyethylene", as used herein, is intended to mean a polymer made by low-pressure polymerisation, and comprising monomeric units derived wholly or predominantly from ethylene. High density polyethylene generally has a high density of not less than about 0.950 x 103 kg.m
In a preferred embodiment, the films according to the present invention consist of two layers, one of which consists of high density polyethylene. In general, the high density polyethylene layer will be the inner layer. The further thermoplastic polyolefin in the films according to the invention advantageously consists of low density polyethylene as herein defined).
The term "low density polyethylene", is used herein to designate a polymer usually made by high pressure polymerisation and comprising monomeric units derived wholly or predominantly from ethylene. Low pressure polyethylene generally has a density of not more than about 0.925 x 10 3 kg. m The films according to the present invention generally have a thickness of from about 10 to 60,us. In films of the preferred embodiment consisting of two layers, the first high density polyethylene layer conveniently has a thickness of from 7 to 42 iim, and the second layer of low density polyethylene conveniently has a thickness of from 3 to 18 calm.
The films according to the present invention may conveniently be produced by co-extrusion.
Thus, according to a further aspect of the present invention there is provided a pro cess for the manufacture of a tubular plastics film which comprises extruding high density polyethylene (as herein defined) through a slit-shaped annular die orifice at a temperature above the softening point of said high density polyethylene and simultaneously extruding a further thermoplastic polyolefin through the same or a concentric slit-shaped annular die orifice at a temperature above the softening point of said further thermoplastic polyolefin so as to produce a tubular plastics film of the invention.
The process according to the invention is preferably effected using low density polyethylene as the further thermoplastic polyolefin.
The coextrusion of the process according to the invention is advantageously effected by extrusion through the same die orifice.
By this technique the individual plastics components of the films are introduced separately into the die block and are brought together at or before the die orifice so as to form the different layers on extrusion. The extrusion is normally effected through an annular die orifice. In this case, air at a pressure higher than the ambient air pressure may, if desired, be introduced into the zone bounded by the extruded plastics film and the die so as to expand, and thereby thin, the plastics film while the latter Is at a temperature higher than the softening point of its components.
According to a further aspect of the present invention there is provided apparatus for manufacturing a tubular plastics film which comprises means for separately introducing high density polyethylene (as herein defined) and a further thermoplastic polyolefin into a die block provided with one or more slit-shaped annular die orifices and means for extruding from said die orifices a tubular plastics tilm of the invention.
Embodiments of the process according to the present invention will hereinafter be particularly described with reference to the accompanying drawing which shows an apparatus for manufacturing a tubular plastics film according to the invention.
In the process illustrated in the Figure, high density polyethylene (HPDE) elastomer is fed to the die block 1 by the screw extruder 2. Simultaneously, low density polyethylene (LDPE) elastomer is also fed to the die block by the screw extruder 3. The screw extruders and the die block are heated by the heaters 4 to a temperature sufficient to ensure that the elastomers emerge from the annular die orifice 5 at a temperature above their respective softening points. The die block 1 incorporates a cylindrical passage for the elastomers terminating in the die orifice 5, such that the LDP elastomer forms an outer layer surrounding an inner layer of HDPE elastomer. The die orifice 5 is annular and is formed by the die ring 6.
and the mandrel 7. Thus, the elastomers emerge from the die block in the form of a tube having two layers, the outer layer consisting of LDPE and the inner layer
HDPE.
A passage 8 is provided in the die block, which passage passes through the mandrel, whereby air may be introduced at a pressure greater than the ambient air pressure into the zone bounded by the elastomer film emerging from the die orifice and the mandrel. As the film emerging from the die orifice is still soft, the increased air pressure within the film causes the film to expand and thus its thickness may be readily controlled.
By the time the tube-like film reaches the line 9, it has cooled to a temperature below the softening point of its constituent elastomers and thereafter no further expansion of the film occurs. The blown film then passes over the guide rollers 10 to the pinch rollers 11. The blown film thus forms a "bubble" 12 serving to maintain the air pressure in the zone above the die orifice above ambient air pressure. The air ring 13 helps in maintaining the desired form of the bubble 12. After passing over idler and tensioning rollers the finished film tube may be collected on wind-up rollers 14.
The plastics films according to the invention have improved properties as a result of the combination of the good Properties of high density polyethylene and the further thermoplastic polyolefin employed in their manufacture. Thus films accordingto the invention formed from high density polyethylene and low density polyethylene exhibit, particularly when the low density polyethylene layer is the outer layer, a high mechanical strength for a given film thickness, have good printability and low gaseous permeability, are suitable for thermal sterilisation and packages produced therefrom are easily opened and are readily stacked.
WHAT WE CLAIM IS:
1. A tubular plastics film (as herein defined) comprising a first axially extending circumferential layer comprisinz high densi- ty polyethylene (as herein defined) and a second axially extending circumferential layer comprising a further thermoplastic polyolefin (which is other than high density polyethylene).
2. A Plastics film as claimed in claim 1 wherein the further thermoplastic polyolefin comprises low density polyethylene (as herein defined).
3. A plastics film as claimed in either of claims 1 and 2 consisting of two layers.
4. A plastics film as claimed in any of the preceding claims having a thickness of from 10 to 60 ,um.
5. A plastics film as claimed in claim 3
**WARNING** end of DESC field may overlap start of CLMS **.
Claims (16)
1. A tubular plastics film (as herein defined) comprising a first axially extending circumferential layer comprisinz high densi- ty polyethylene (as herein defined) and a second axially extending circumferential layer comprising a further thermoplastic polyolefin (which is other than high density polyethylene).
2. A Plastics film as claimed in claim 1 wherein the further thermoplastic polyolefin comprises low density polyethylene (as herein defined).
3. A plastics film as claimed in either of claims 1 and 2 consisting of two layers.
4. A plastics film as claimed in any of the preceding claims having a thickness of from 10 to 60 ,um.
5. A plastics film as claimed in claim 3
wherein the high density polyethylene layer has a thickness of from 7 to 42 ;ism, and the further thermoplastic polyolefin layer has a thickness of from 3 to 18 ,um.
6. A tubular plastics film as claimed in claim 1 substantially as herein described.
7. A tubular plastics film substantially as herein described with reference to the accompanying drawings.
8. A process for the manufacture of a tubular plastics film which comprises extruding high density polyethylene (as herein defined) through a slit-shaped annular die orifice at a temperature above the softening point of said high density polyethylene and simultaneously extruding a further thermoplastic polyolefin through the same or a concentric slit-shaped annular die orifice at a temperature above the softening point of said further thermoplastic polyolefin so as to produce a tubular plastics film as claimed in claim 1.
9. A process as claimed in claim 8 wherein the further thermoplastic olefin comprises low density polyethylene (as herein defined).
10. A process as claimed in either of claims 8 and 10 wherein the high density polyethylene and the further thermoplastic polyolefin are extruded through the same die orifice.
11. A process as claimed in any of claims 8 to 10 wherein air at a pressure higher than the ambient air pressure is introduced into the zone bounded by the extruded plastics film and the die so as to expand and thereby thin the plastics film while the temperature of said plastics film is above the softening point of its components.
12. A process as claimed in claim 8 substantially as herein described.
13. A process for the manufacture of a plastics film substantially as herein described with reference to the accompanying drawings.
14. A plastics film whenever prepared by a process as claimed in any of claims 8 to 13.
15. Apparatus for manufacturing a plastics film as defined in claim 1 which comprises means for separately introducing high density polyethylene 5as herein defined) and a further thermoplastic polyolefin into a die block provided with one or more slit-shaped annular die orifices and means for extruding from said die orifices a tubular plastics film as defined in claim 1.
16. Apparatus as defined in claim 15 substantially as herein described with reference to the accompanying drawings.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB23059/78A GB1603128A (en) | 1978-05-26 | 1978-05-26 | Tubular plastics film |
| MY58/83A MY8300058A (en) | 1978-05-26 | 1983-12-30 | Improvements in or relating to tubular plastics film |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB23059/78A GB1603128A (en) | 1978-05-26 | 1978-05-26 | Tubular plastics film |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB1603128A true GB1603128A (en) | 1981-11-18 |
Family
ID=10189445
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB23059/78A Expired GB1603128A (en) | 1978-05-26 | 1978-05-26 | Tubular plastics film |
Country Status (2)
| Country | Link |
|---|---|
| GB (1) | GB1603128A (en) |
| MY (1) | MY8300058A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1986002044A1 (en) * | 1984-09-28 | 1986-04-10 | Travenol European Research And Development Centre | Polyolefin film for steam sterilizable flexible containers |
| US4622199A (en) * | 1985-06-11 | 1986-11-11 | Owens-Illinois, Inc. | Process for extruding high molecular weight, high density linear ethylene polymers to form heavy tubular members |
-
1978
- 1978-05-26 GB GB23059/78A patent/GB1603128A/en not_active Expired
-
1983
- 1983-12-30 MY MY58/83A patent/MY8300058A/en unknown
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1986002044A1 (en) * | 1984-09-28 | 1986-04-10 | Travenol European Research And Development Centre | Polyolefin film for steam sterilizable flexible containers |
| US4622199A (en) * | 1985-06-11 | 1986-11-11 | Owens-Illinois, Inc. | Process for extruding high molecular weight, high density linear ethylene polymers to form heavy tubular members |
Also Published As
| Publication number | Publication date |
|---|---|
| MY8300058A (en) | 1983-12-31 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4151318A (en) | Laminar thermoplastic film constructions | |
| US4244914A (en) | Process for preparing gas-, vapor- and odor-proof coupled and coextruded multilayer articles of thermoplastic material and closed-surface bodies comprising the same | |
| US4379117A (en) | Method for preparing a film of vinylidene chloride polymer | |
| US3337665A (en) | Method for the production of thermoplastic film | |
| US4112181A (en) | Method for preparing a film of vinylidene chloride polymer | |
| US4048428A (en) | Method for preparing a film of vinylidene chloride polymer | |
| US3985849A (en) | Preparation of biaxially oriented polyvinyl alcohol film | |
| GB1486849A (en) | Process for producing a laminate containing oriented nylon film | |
| GB2028716A (en) | Laminar thermoplastic film constructions | |
| US4284458A (en) | Method for producing laminated film | |
| US4254175A (en) | Multilayer thermoplastic film laminate | |
| US6413346B1 (en) | Production of stretch plastic film | |
| US4289727A (en) | Method for extrusion of tubular films | |
| CA1191007A (en) | Oriented multi-layer films having a different orientation distribution between layers and process for forming same | |
| EP0095995B1 (en) | Process for the manufacture of polyester film | |
| CA1224610A (en) | Method and apparatus for forming a laminated film containing different polymer layers | |
| EP0287246B1 (en) | Method of manufacturing polybutylene terephthalate resin films | |
| US4615858A (en) | Method and apparatus producing decorative melt fracture patterns on polymeric products | |
| US4034055A (en) | Tubular film of polyethylene terephthalate and process for the production thereof | |
| JPS63193821A (en) | Manufacture of film from semicrystalline molten polymer through coextrusion blow molding of tube | |
| GB1603128A (en) | Tubular plastics film | |
| US4076568A (en) | Process for the preparation of a multilayer film | |
| US4164529A (en) | Process for preparing tubular film of hydrolyzed ethylene-vinyl acetate copolymer | |
| US3862868A (en) | Filament reinforced film | |
| EP0285291B1 (en) | Method of manufacturing polyacetal resin film |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PS | Patent sealed [section 19, patents act 1949] | ||
| PCNP | Patent ceased through non-payment of renewal fee |