CA1071086A - Laminates of polyethylene foam with an anisotropic pore structure - Google Patents
Laminates of polyethylene foam with an anisotropic pore structureInfo
- Publication number
- CA1071086A CA1071086A CA 246026 CA246026A CA1071086A CA 1071086 A CA1071086 A CA 1071086A CA 246026 CA246026 CA 246026 CA 246026 A CA246026 A CA 246026A CA 1071086 A CA1071086 A CA 1071086A
- Authority
- CA
- Canada
- Prior art keywords
- cross
- blowing agent
- layers
- polyethylene
- sheets
- 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
- 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
- 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
- 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
-
- 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
- B32B27/065—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 foam
-
- 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
- B32B27/18—Layered products comprising a layer of synthetic resin characterised by the use of special additives
-
- 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
- B32B5/00—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts
- B32B5/18—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by features of a layer of foamed material
-
- 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
- B32B7/04—Interconnection of layers
- B32B7/10—Interconnection of layers at least one layer having inter-reactive properties
-
- 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
- B32B2266/00—Composition of foam
- B32B2266/02—Organic
- B32B2266/0214—Materials belonging to B32B27/00
- B32B2266/025—Polyolefin
-
- 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
- B32B2305/00—Condition, form or state of the layers or laminate
- B32B2305/72—Cured, e.g. vulcanised, cross-linked
-
- 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
-
- 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
- B32B2605/00—Vehicles
- B32B2605/003—Interior finishings
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S264/00—Plastic and nonmetallic article shaping or treating: processes
- Y10S264/18—Cross-linking a thermoplastic linear foam during molding
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/24—Structurally defined web or sheet [e.g., overall dimension, etc.]
- Y10T428/24942—Structurally defined web or sheet [e.g., overall dimension, etc.] including components having same physical characteristic in differing degree
- Y10T428/24992—Density or compression of components
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/249921—Web or sheet containing structurally defined element or component
- Y10T428/249953—Composite having voids in a component [e.g., porous, cellular, etc.]
- Y10T428/249981—Plural void-containing components
Abstract
LAMINATES OF POLYETHYLENE FOAM WITH AN ANISOTROPIC PORE STRUCTURE
Abstract of the Disclosure A process for the production of cross-linked polyethylene foam layers which have an anisotropic pore structure in at least one internal layer, wherein at least three polyethylene sheets which contain equal quantities of peroxide as cross-linking agent and differing quantities of a chemical blowing agent are arranged as a multilayer structure in such a way that the two external layers are formed by the sheets which contain a smaller proportion of blowing agent, and the struc-ture is heated, preferably in a continuous heating furnace, so that the individual sheets are cross-linked and at the same time welded together to form a laminate which is subse-quently foamed by increasing the temperature to between 190 and 250°C.
Le A 16 242
Abstract of the Disclosure A process for the production of cross-linked polyethylene foam layers which have an anisotropic pore structure in at least one internal layer, wherein at least three polyethylene sheets which contain equal quantities of peroxide as cross-linking agent and differing quantities of a chemical blowing agent are arranged as a multilayer structure in such a way that the two external layers are formed by the sheets which contain a smaller proportion of blowing agent, and the struc-ture is heated, preferably in a continuous heating furnace, so that the individual sheets are cross-linked and at the same time welded together to form a laminate which is subse-quently foamed by increasing the temperature to between 190 and 250°C.
Le A 16 242
Description
1(~7~86 This invention relates to a process for the production of laminates from layers of cross-linked polyethylene foam, at least one of which had an anisotropic pore structure.
It is known that cross-linked polyethylene foams can be produced by a peroxidic cross-linking process in which a mix~ure of polyethylene peroxide and a chemical blowing agent is continuously extruded to form a sheet which is then cross-linked in an oven and subsequently foamed when it has reached the necessary temperature for activating the blowing agent as described in German Offenlegungsschrift No. 1,694,130 and US-Patent Specification No. 3,098,831. Foams with a closed cell and pore structure are obtained by this process. Their density is uniform across the thick-ness of a foam layer. The density of these foams is controlled by the amount of blowing agent which they contain. It is also known that foams of differing densities can be heat welded together to produce foam laminates which have a sandwich-like structure in which the different layers have different densities. These laminates have no anisotropy in their pore structure and, owing to the fact that the individual layers are subsequently welded together, there is a thin compact layer between the porous layers.
These compact layers have the disadvantage of increasing the density of the laminate and hence reducing the thermal insulation. Moreover, a certain amount of material is lost due to melting of the surface.
It has surprisingly been found that these disadvantages can be ~ overcome and, in addition, foam laminates with improved mechsnical pro-; perties can be obtained by the process according to the invention.
The present invention provides a process for the production of a laminate consisting essentially of cross-linked polyethylene foam layers which have an anisotropic pore structure in at least one internal layer, in which process at least three polyethylene sheets or layers which contain quantities of a chemical blowing agent and equal quantities of peroxide 3~ ascross-linking agent are arranged as a multilayer structure with the two ~r~
10~71086 external layers containing a smaller proportion of blowing agent relative to the amount of blowing agent in the internal layer or layers, the struc-ture is heated so that the individual sheets are cross-linked and at the same time welded together to form a laminate which is subsequently foamed by increasing the temperature.
Preferably the structure is heated to a temperature of from 190 to 250C at the foaming stage.
It is unexpectedly found that in the laminate obtained by the process according to the invention the lighter, internal layers contain cells which are elongated in a direction perpendicular to the layer, i.e. these layers have an anisotropic pore structure. The laminates are more rigid and have a higher compression strength than laminates obtained by the heat lamination of individual polyethylene foam layers.
The structure of the laminates produced according to the invention is represented schematically in Figure 1 as composed of three polyethylene foams.
Anisotropic cells elongated perpendicularly to the flat dimensions of the laminate can be seen in the middle layer. The greater the differences in density between the external layers and the middle layer, the more pronounced is this anisbbropy. By reducing the quantity of blowing agent in the external layer to zero, it is possible to produce foams which have compact external layers and an anisotropic foam core.
The process according to the invention is preferably carried out using a multiple sheet extruder to extrude discontinuously or continuously polyethylene sheets or layers which all have the same peroxide content for cross-linking but contain differing proportions of blowing agent. The blowing agent contents of the external layers, which are preferably equal to each other, are always lower than those of the internal layers.
The process of mixing the polyethylene with cross-linking and j 30 ~lowing ag~nts or concentrates of these agents in polyethylene is carried out in the extruder in ~hich the mixture is subsequently shaped at ; ~ 2 ;
., 107108~i temperatures below the decomposition point of the peroxide. The average time of stay in the extruder is about 5 minutes, so that cross-linking of the mixtures which are to be foamed is substantially suppressed at this stage.
The same result can also be obtained by extruding the individual layers separately, placing them above one another and heating them in a hot a:ir oven. While the layers are being heated, they become welded together to form a compact, multilayered laminate which undergoes cross-linking at the same time and then foams up when the decomposition temperature of the chemical blowing agent is reached.
Preferably, cross-linking mainly takes place at temperatures star~ting from 160C and the foaming processes take place at temperatures of from 190 to 250C.
Polyethylene suitable for the production of laminates in accordance with the invention include low pressure (d~V0.94 - 0.97 g/cm3) and high pressure polyethylenes (d~VO.9l to about 0.94 g/cm3), high pressure polyethylenes being preferred The peroxides used for cross-linking are suitably organic peroxides such as dicumylperoxide; 2,5-dimethyl-2,5-di-(tert.-butylperoxy)-hexane; 2,5-dimethyl-2,5-di-(tert.-butylperoxy)-hexine; tert.-butylhydro-peroxide; cumyl-tert.-butylperoxide; di-tert.-butylperoxide and bis-(tert.-butylperoxi-isopropyl)-benzene. Dicumyl peroxide is preferred.
The peroxides are used in quantities of from 0.3 to 1.5 % by weight, based on the total mixture, a degree of cross-linking of 25 to 80 % preferably being achieved.
The chemical blowing agents are preferably those which decompose at temperatures above 190C. Preferably, the blowing agent is used in a concentration of from 2.5 to 15% by weight, more preferably 7.5 to 15 %
by weight, based on the total quantity of mixture. Azodicarbonamide, disulphohydrazide and N,N'-dinitrosopentamethylenetetramine are advan-10710~36 tageously used in quantities of from 2.5 to 15 % by weight, based on the total quantity of mixture.
The process according to the invention may be carried out continuously or discontinuously.
The polyethylene foam laminates according to the invention may be used in the motor car industry, in particular for the manufacture of roof covers or wall linings in caravans.
': .
.`
~ 4 -. . .
1~71~86 Exa~le 1 Three layers lying one above the other were continuously extruded from an extruder to which a multiple sheet die was con-nected. The two external sheets consisted o~ 94.2 % by weight of polyethylene, 5 % by weight of azodicarbonamide and 0.8 % by weight of dicumyl peroxide and the middle sheet consisted of 84.2 % by weight of polyethylene, 15 % by weight of azodicarbon-amide and 0.8 % by weight of dicumyl peroxide. This compact mul-tilayer structure was introduced into a hot air oven where it was initially heated to 160C and finally to 205C. A laminate of polyethylene foam which had a density of 90 kg/m3 and iso-tropic pore structure in the two outer layers and a density of 30 kg/m3 and anisotropic pore structure in the middle layer was thereby obtained.
Le A 16 242 _ 5 _ - .. .. .: , - , - . - . -.. . .
It is known that cross-linked polyethylene foams can be produced by a peroxidic cross-linking process in which a mix~ure of polyethylene peroxide and a chemical blowing agent is continuously extruded to form a sheet which is then cross-linked in an oven and subsequently foamed when it has reached the necessary temperature for activating the blowing agent as described in German Offenlegungsschrift No. 1,694,130 and US-Patent Specification No. 3,098,831. Foams with a closed cell and pore structure are obtained by this process. Their density is uniform across the thick-ness of a foam layer. The density of these foams is controlled by the amount of blowing agent which they contain. It is also known that foams of differing densities can be heat welded together to produce foam laminates which have a sandwich-like structure in which the different layers have different densities. These laminates have no anisotropy in their pore structure and, owing to the fact that the individual layers are subsequently welded together, there is a thin compact layer between the porous layers.
These compact layers have the disadvantage of increasing the density of the laminate and hence reducing the thermal insulation. Moreover, a certain amount of material is lost due to melting of the surface.
It has surprisingly been found that these disadvantages can be ~ overcome and, in addition, foam laminates with improved mechsnical pro-; perties can be obtained by the process according to the invention.
The present invention provides a process for the production of a laminate consisting essentially of cross-linked polyethylene foam layers which have an anisotropic pore structure in at least one internal layer, in which process at least three polyethylene sheets or layers which contain quantities of a chemical blowing agent and equal quantities of peroxide 3~ ascross-linking agent are arranged as a multilayer structure with the two ~r~
10~71086 external layers containing a smaller proportion of blowing agent relative to the amount of blowing agent in the internal layer or layers, the struc-ture is heated so that the individual sheets are cross-linked and at the same time welded together to form a laminate which is subsequently foamed by increasing the temperature.
Preferably the structure is heated to a temperature of from 190 to 250C at the foaming stage.
It is unexpectedly found that in the laminate obtained by the process according to the invention the lighter, internal layers contain cells which are elongated in a direction perpendicular to the layer, i.e. these layers have an anisotropic pore structure. The laminates are more rigid and have a higher compression strength than laminates obtained by the heat lamination of individual polyethylene foam layers.
The structure of the laminates produced according to the invention is represented schematically in Figure 1 as composed of three polyethylene foams.
Anisotropic cells elongated perpendicularly to the flat dimensions of the laminate can be seen in the middle layer. The greater the differences in density between the external layers and the middle layer, the more pronounced is this anisbbropy. By reducing the quantity of blowing agent in the external layer to zero, it is possible to produce foams which have compact external layers and an anisotropic foam core.
The process according to the invention is preferably carried out using a multiple sheet extruder to extrude discontinuously or continuously polyethylene sheets or layers which all have the same peroxide content for cross-linking but contain differing proportions of blowing agent. The blowing agent contents of the external layers, which are preferably equal to each other, are always lower than those of the internal layers.
The process of mixing the polyethylene with cross-linking and j 30 ~lowing ag~nts or concentrates of these agents in polyethylene is carried out in the extruder in ~hich the mixture is subsequently shaped at ; ~ 2 ;
., 107108~i temperatures below the decomposition point of the peroxide. The average time of stay in the extruder is about 5 minutes, so that cross-linking of the mixtures which are to be foamed is substantially suppressed at this stage.
The same result can also be obtained by extruding the individual layers separately, placing them above one another and heating them in a hot a:ir oven. While the layers are being heated, they become welded together to form a compact, multilayered laminate which undergoes cross-linking at the same time and then foams up when the decomposition temperature of the chemical blowing agent is reached.
Preferably, cross-linking mainly takes place at temperatures star~ting from 160C and the foaming processes take place at temperatures of from 190 to 250C.
Polyethylene suitable for the production of laminates in accordance with the invention include low pressure (d~V0.94 - 0.97 g/cm3) and high pressure polyethylenes (d~VO.9l to about 0.94 g/cm3), high pressure polyethylenes being preferred The peroxides used for cross-linking are suitably organic peroxides such as dicumylperoxide; 2,5-dimethyl-2,5-di-(tert.-butylperoxy)-hexane; 2,5-dimethyl-2,5-di-(tert.-butylperoxy)-hexine; tert.-butylhydro-peroxide; cumyl-tert.-butylperoxide; di-tert.-butylperoxide and bis-(tert.-butylperoxi-isopropyl)-benzene. Dicumyl peroxide is preferred.
The peroxides are used in quantities of from 0.3 to 1.5 % by weight, based on the total mixture, a degree of cross-linking of 25 to 80 % preferably being achieved.
The chemical blowing agents are preferably those which decompose at temperatures above 190C. Preferably, the blowing agent is used in a concentration of from 2.5 to 15% by weight, more preferably 7.5 to 15 %
by weight, based on the total quantity of mixture. Azodicarbonamide, disulphohydrazide and N,N'-dinitrosopentamethylenetetramine are advan-10710~36 tageously used in quantities of from 2.5 to 15 % by weight, based on the total quantity of mixture.
The process according to the invention may be carried out continuously or discontinuously.
The polyethylene foam laminates according to the invention may be used in the motor car industry, in particular for the manufacture of roof covers or wall linings in caravans.
': .
.`
~ 4 -. . .
1~71~86 Exa~le 1 Three layers lying one above the other were continuously extruded from an extruder to which a multiple sheet die was con-nected. The two external sheets consisted o~ 94.2 % by weight of polyethylene, 5 % by weight of azodicarbonamide and 0.8 % by weight of dicumyl peroxide and the middle sheet consisted of 84.2 % by weight of polyethylene, 15 % by weight of azodicarbon-amide and 0.8 % by weight of dicumyl peroxide. This compact mul-tilayer structure was introduced into a hot air oven where it was initially heated to 160C and finally to 205C. A laminate of polyethylene foam which had a density of 90 kg/m3 and iso-tropic pore structure in the two outer layers and a density of 30 kg/m3 and anisotropic pore structure in the middle layer was thereby obtained.
Le A 16 242 _ 5 _ - .. .. .: , - , - . - . -.. . .
Claims (11)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A process for the production of a laminate consisting essentially of cross-linked polyethylene foam layers which have an anisotropic pore structure in at least one internal layer, in which process at least three polyethylene sheets or layers which contain quantities of a chemical blowing agent and equal quantities of peroxide as cross-linking agent are arranged as a multilayer structure with the two external layers containing a smaller proportion of blowing agent relative to the amount of blowing agent in the internal layer or layers, the structure is heated so that the individual sheets are cross-linked and at the same time welded together to form a laminate which is subsequently foamed by increasing the temperature.
2. A process as claimed in claim 1, wherein the multilayer structure is heated in a continuous heating furnace.
3. A process as claimed in claim 1, wherein the cross-linking takes place at a temperature of at least 160°C.
4. A process as claimed in claim 1, wherein the structure is heated to a temperature of from 190 to 250°C at the foaming stage.
5. A process as claimed in claim 1, wherein the polyethylene sheets or layers are extruded from a multiple sheet extruder.
6. A process as claimed in claim 1, wherein the two most external layers have equal blowing agent contents.
7. A process as claimed in claim 1, wherein the polyethylene sheets consist of high pressure polyethylene.
8. A process as claimed in claim 1, wherein the peroxide is used in a quantity of from 0.3 to 1.5% by weight, based on the total mixture.
9. A process as claimed in claim 1, wherein the polyethylene sheets are cross-linked to an extent of 25 to 80%.
10. A process as claimed in claim 1, wherein the blowing agent is used in a concentration of from 2.5 to 15% by weight, based on the total quantity of mixture.
11. A process as claimed in claim 1, wherein the blowing agent is used in a concentration of from 7.5 to 15% by weight, based on the total quantity of mixture.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19752507274 DE2507274A1 (en) | 1975-02-20 | 1975-02-20 | LAMINATE MADE OF POLYETHYLENE FOAM WITH ANISOTROPIC PORE STRUCTURE |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1071086A true CA1071086A (en) | 1980-02-05 |
Family
ID=5939365
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 246026 Expired CA1071086A (en) | 1975-02-20 | 1976-02-18 | Laminates of polyethylene foam with an anisotropic pore structure |
Country Status (15)
| Country | Link |
|---|---|
| US (1) | US4053341A (en) |
| JP (1) | JPS5952B2 (en) |
| BE (1) | BE838712A (en) |
| CA (1) | CA1071086A (en) |
| CH (1) | CH602319A5 (en) |
| CS (1) | CS190524B2 (en) |
| DE (1) | DE2507274A1 (en) |
| ES (1) | ES445311A1 (en) |
| FR (1) | FR2301372A1 (en) |
| GB (1) | GB1527162A (en) |
| IT (1) | IT1053867B (en) |
| NL (1) | NL7601646A (en) |
| PL (1) | PL101380B1 (en) |
| SE (1) | SE416388B (en) |
| SU (1) | SU651677A3 (en) |
Families Citing this family (30)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| ZA75470B (en) * | 1974-06-24 | 1976-01-28 | J Dukees | Process and apparatus for the manufacture of plastic sandwich elements |
| DE7627371U1 (en) * | 1976-09-02 | 1976-12-30 | Fa. Carl Freudenberg, 6940 Weinheim | Shoe insert |
| JPS54125877U (en) * | 1978-02-21 | 1979-09-03 | ||
| US4136226A (en) * | 1978-03-23 | 1979-01-23 | Gilman Richard L | Impact-absorbing laminate and method of manufacture thereof |
| JPS54136024A (en) * | 1978-04-10 | 1979-10-22 | Toyota Motor Corp | Ceiling panel for automobile and method of producing same |
| NO156481C (en) * | 1978-09-13 | 1987-09-30 | Bakelittfab As | PROCEDURE FOR THE MANUFACTURE OF EXPANDED PLASTIC FORM. |
| JPS5624289A (en) * | 1979-07-31 | 1981-03-07 | Furukawa Electric Co Ltd | Adiabatic pipe and its manufacture |
| DE2945285A1 (en) * | 1979-11-09 | 1981-05-21 | Dynamit Nobel Ag, 5210 Troisdorf | FLOOR MAT, ESPECIALLY FOR MOTOR VEHICLES |
| US4338466A (en) * | 1981-04-02 | 1982-07-06 | The United States Of America As Represented By The Secretary Of The Navy | Prostaglandin analogs and process of preparation thereof |
| US4606516A (en) * | 1984-05-10 | 1986-08-19 | Willison George R | Aircraft protective device |
| JPS61130041A (en) * | 1984-11-28 | 1986-06-17 | ポリプラスチックス株式会社 | Manufacture of molded shape having excellent size stability |
| US4851286A (en) * | 1986-11-18 | 1989-07-25 | United Foam Plastics | Foamed plastic cushioning materials |
| US5221570A (en) * | 1991-09-03 | 1993-06-22 | Cem Gokcen | Multilayered coextruded geomembrane |
| KR100335874B1 (en) * | 1993-07-19 | 2002-11-20 | 미츠이 다께다 케미칼 가부시키가이샤 | Insulation and its manufacturing method |
| US5929129A (en) * | 1994-09-19 | 1999-07-27 | Sentinel Products Corp. | Crosslinked foamable compositions of silane-grafted, essentially linear polyolefins blended with polypropylene |
| JP4057657B2 (en) * | 1994-09-19 | 2008-03-05 | センチネル・プロダクツ・コープ | Crosslinked foam structure of linear polyolefin and method for producing the same |
| US5932659A (en) * | 1994-09-19 | 1999-08-03 | Sentinel Products Corp. | Polymer blend |
| US5883144A (en) * | 1994-09-19 | 1999-03-16 | Sentinel Products Corp. | Silane-grafted materials for solid and foam applications |
| US5844009A (en) * | 1996-04-26 | 1998-12-01 | Sentinel Products Corp. | Cross-linked low-density polymer foam |
| CA2203595A1 (en) | 1996-04-26 | 1997-10-26 | Robert F. Hurley | Cross-linked polyolefin tape |
| US5882776A (en) * | 1996-07-09 | 1999-03-16 | Sentinel Products Corp. | Laminated foam structures with enhanced properties |
| US5876813A (en) * | 1996-07-09 | 1999-03-02 | Senitnel Products Corp | Laminated foam structures with enhanced properties |
| US5938878A (en) * | 1996-08-16 | 1999-08-17 | Sentinel Products Corp. | Polymer structures with enhanced properties |
| CA2241609C (en) * | 1997-06-26 | 2009-08-25 | Southpac Trust International, Inc. | Polymeric material having a cloth-like appearance |
| ATE243612T1 (en) | 1997-12-08 | 2003-07-15 | Dow Deutschland Inc | MULTI-LAYER FOAM, METHOD FOR THE PRODUCTION AND USE THEREOF |
| DE10123176C2 (en) * | 2001-05-12 | 2003-08-07 | Daimler Chrysler Ag | Process for producing sandwich components with a cover layer and a foam-containing core layer |
| US20040001945A1 (en) * | 2002-06-27 | 2004-01-01 | Cate Peter J. | Composite foam structure having an isotropic strength region and anisotropic strength region |
| US20040096626A1 (en) * | 2002-11-14 | 2004-05-20 | Epoli-Espumas De Polietileno Sa | Layered structures with enhanced properties |
| EP3456302B8 (en) * | 2017-09-15 | 2020-10-28 | Ontex BV | Absorbent cores and absorbent articles having anisotropic foam structures |
| EP3711736A1 (en) * | 2019-03-18 | 2020-09-23 | Ontex BVBA | Absorbent articles having an anisotropic foam acquisition layer |
Family Cites Families (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3098831A (en) * | 1959-05-01 | 1963-07-23 | Us Rubber Co | Expanded polyethylene and method of making the same |
| JPS5218232B1 (en) * | 1966-02-05 | 1977-05-20 | ||
| US3463687A (en) * | 1966-04-26 | 1969-08-26 | Gen Tire & Rubber Co | Method of producing low density rigid sheets of synthetic plastic |
| US3608006A (en) * | 1966-10-01 | 1971-09-21 | Furukawa Electric Co Ltd | Production of foamed polyolefin composite sheet |
| GB1210637A (en) * | 1969-06-21 | 1970-10-28 | Toray Industries | Thermoplastic resin foam |
| DE2365203B2 (en) * | 1973-12-31 | 1977-02-03 | Dynamit Nobel Ag, 5210 Troisdorf | PRODUCTION OF MULTI-LAYER SHEETS, PLATES, MOLDED PARTS |
| US3936565A (en) * | 1974-05-03 | 1976-02-03 | Hollowform, Inc. | Molded plastic article and method |
| US3968292A (en) * | 1974-07-22 | 1976-07-06 | Porvair Limited | Water vapor permeable sheet material |
-
1975
- 1975-02-20 DE DE19752507274 patent/DE2507274A1/en not_active Withdrawn
-
1976
- 1976-02-17 SU SU762324452A patent/SU651677A3/en active
- 1976-02-17 CH CH192976A patent/CH602319A5/xx not_active IP Right Cessation
- 1976-02-17 US US05/658,404 patent/US4053341A/en not_active Expired - Lifetime
- 1976-02-18 JP JP51016095A patent/JPS5952B2/en not_active Expired
- 1976-02-18 CA CA 246026 patent/CA1071086A/en not_active Expired
- 1976-02-18 PL PL1976187298A patent/PL101380B1/en unknown
- 1976-02-18 NL NL7601646A patent/NL7601646A/en not_active Application Discontinuation
- 1976-02-18 IT IT48155/76A patent/IT1053867B/en active
- 1976-02-19 GB GB6562/76A patent/GB1527162A/en not_active Expired
- 1976-02-19 CS CS761083A patent/CS190524B2/en unknown
- 1976-02-19 BE BE164437A patent/BE838712A/en unknown
- 1976-02-19 ES ES445311A patent/ES445311A1/en not_active Expired
- 1976-02-19 SE SE7601926A patent/SE416388B/en unknown
- 1976-02-20 FR FR7604784A patent/FR2301372A1/en not_active Withdrawn
Also Published As
| Publication number | Publication date |
|---|---|
| PL101380B1 (en) | 1978-12-30 |
| US4053341A (en) | 1977-10-11 |
| BE838712A (en) | 1976-08-19 |
| JPS5952B2 (en) | 1984-01-05 |
| SE416388B (en) | 1980-12-22 |
| ES445311A1 (en) | 1977-06-01 |
| JPS51106174A (en) | 1976-09-20 |
| CH602319A5 (en) | 1978-07-31 |
| SE7601926L (en) | 1976-08-23 |
| DE2507274A1 (en) | 1976-09-09 |
| SU651677A3 (en) | 1979-03-05 |
| AU1113476A (en) | 1977-08-25 |
| FR2301372A1 (en) | 1976-09-17 |
| NL7601646A (en) | 1976-08-24 |
| CS190524B2 (en) | 1979-05-31 |
| GB1527162A (en) | 1978-10-04 |
| IT1053867B (en) | 1981-10-10 |
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