EP0095299A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Plastics film and bags and sacks therefrom
Assignee: Stiksack Sts SA
•
Filing: 1983-05-16
•
Granted: —
•
Expires: 2003-05-16
Abstract
Abstract A thermoplastics bag whose wall includes first and second layers each formed by melt extrusion from a synthetic thermoplastics material, one of said layers comprising a blend of linear low density ethylene polymer and at least one of (a) a second ethylene polymer which has a higher density and is selected from ethylene homopolymers and copolymers of ethylene and at least one other a-olefin and (b) polypropylene, and the other of said layers comprising linear low density ethylene polymer; at least one of said layers providing a face of the wall and at least a part of the surface of the outer face of the wall having a higher coefficient of friction than the inner face. Also a multilayer film suitable for use in the manufacture of the bag.
Inventors
- 👤 Michael Anthony Cowan
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-26 12:10
CPC Classifications
B; B32; B32B; B32B27/00; B32B27/06; B32B27/08; B32B7/00; B32B7/02; B32B7/022; B32B27/32; B32B27/322; B32B3/00; B32B3/02; B32B3/04; B32B38/00; B32B38/0008; B32B38/0012; B32B7/04; B32B7/10; C; C09; C09D; C09D123/00; C09D123/02; C09D123/04; C09D123/06; C09J; C09J123/00; C09J123/02; C09J123/04; C09J123/08; C09J123/0807; C09J123/0815; B32B2307/00; B32B2307/70; B32B2307/72; B32B2310/00; B32B2310/027; B32B2323/00; B32B2323/04; B32B2323/046; B32B2439/00; B32B2439/02; B32B2439/06; C08; C08L; C08L2666/00; C08L2666/02; C08L2666/04
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
126 words
A thermoplastics bag or sack at least one of the walls of which includes first and second layers each formed by melt extrusion from a synthetic thermoplastics material, and wherein one of said layers comprises a blend of linear low density ethylene polymer and at least one of (a) a second ethylene polymer which has a higher density and is selected from ethylene homopolymers and copolymers of ethylene and at least one other α-olefin and (b) polypropylene, and the other of said layers comprises linear low density ethylene polymer; at least one of said layers provides a face of the wall and at least a part of the surface of the outer face of the wall has a higher coefficient of friction than the inner face.
Claim 2
Dependent Claim
126 words
A thermoplastics bag or sack at least one of the walls of which includes first and second layers each formed by melt extrusion from a synthetic thermoplastics material, and wherein one of said layers comprises a blend of linear low density ethylene polymer and at least one of (a) a second ethylene polymer which has a higher density and is selected from ethylene homopolymers and copolymers of ethylene and at least one other α-olefin and (b) polypropylene, and the other of said layers comprises linear low density ethylene polymer; at least one of said layers provides a face of the wall and at least a part of the surface of the outer face of the wall has a higher coefficient of friction than the inner face.
Claim 3
Dependent Claim
19 words
A bag or sack as claimed in claim 1 in which the layers of the wall are fused together.
Claim 4
Dependent Claim
19 words
A bag or sack as claimed in claim 2 in which the wall is formed from coextruded plastics film.
Claim 5
Dependent Claim
25 words
A bag or sack as claimed in any one of claims 1 to 3 in which said other of said layers is the outer layer.
Claim 6
Dependent Claim
41 words
A bag or sack as claimed in any one of claims 1 to 4 in which said linear low density ethylene polymer of said other of said layers has a density in the range 0.916 to 0.925 g / cm3 .
Claim 7
Dependent Claim
41 words
A bag or sack as claimed in any one of claims 1 to 4 in which said linear low density ethylene polymer of said other of said layers has a density in the range 0.918 to 0.922 g /cm 3 .
Claim 8
Dependent Claim
38 words
A bag or sack as claimed in any one of claims 1 to 6 in which the coefficient of friction of the outer face of the wall is at least 0.8 as determined by ASTM D-1894 (static test).
Claim 9
Dependent Claim
26 words
A bag or sack as claimed in claim 7 in which the coefficient of friction of the outer face of the wall is at least 0.85.
Claim 10
Dependent Claim
26 words
A bag or sack as claimed in claim 8 in which the coefficient of friction of the outer face of the wall is at least 0.87.
Claim 11
Dependent Claim
25 words
A bag or sack as claimed in any one of claims 1 to 9 in which said one of said layers forms the innermost layer.
Claim 12
Dependent Claim
40 words
A bag or sack as claimed in any one of claims 1 to 10 in which the linear low density ethylene polymer employed in the blend is a copolymer of ethylene and an α-olefin having more than 4 carbon atoms.
Claim 13
Dependent Claim
34 words
A bag or sack as claimed in any one of claims 1 to 11 in which the blend comprises linear low density ethylene polymer and a second ethylene polymer which has a higher density.
Claim 14
Dependent Claim
25 words
A bag or sack as claimed in claim 12 in which said second polymer has a density in the range 0.930 to 0.935 g/cm 3.
Claim 15
Dependent Claim
31 words
A bag or sack as claimed in claim 11, 12 or 13 in which the blend has a density in the range of about 0.914 to about 0.937 gjcm 3 .
Claim 16
Dependent Claim
28 words
A bag or sack as claimed in claim 14 in which the blend has a density in the range of about 0.920 to about 0.935 g/cm 3 .
Claim 17
Dependent Claim
29 words
A bag or sack as claimed in claim 15 in which the blend has a density in the range of about 0.923 to about 0.930 g / cm3 .
Claim 18
Dependent Claim
38 words
A bag or sack as claimed in any one of claims 1 to 16 in which the inner face of the wall has a coefficient of friction, as determined by ASTM D-1894 (static test) of less than 0.5.
Claim 19
Dependent Claim
19 words
A bag or sack as claimed in any one of claims 1 to 17 which is a valve bag.
Claim 20
Dependent Claim
19 words
A bag or sack as claimed in claim 1, substantially as hereinbefore described with particular reference to the Example.
Claim 21
Dependent Claim
125 words
A multi-layer film comprising a laminate having at least two layers each of which is formed by melt extrusion from a synthetic thermoplastics material, and wherein a first one of said layers comprises a blend of linear low density ethylene polymer and at least one of (a) a second ethylene polymer which has a higher density and is selected from ethylene homopolymers and copolymers of ethylene and at least one other o(.-olefin and (b) polypropylene and a second one of said layers comprises linear low density ethylene polymer, at least one of said layers provides a face of said film and at least a part of the surface of one face has a higher surface coefficient of friction than the other face of the film.
Claim 22
Dependent Claim
125 words
A multi-layer film comprising a laminate having at least two layers each of which is formed by melt extrusion from a synthetic thermoplastics material, and wherein a first one of said layers comprises a blend of linear low density ethylene polymer and at least one of (a) a second ethylene polymer which has a higher density and is selected from ethylene homopolymers and copolymers of ethylene and at least one other o(.-olefin and (b) polypropylene and a second one of said layers comprises linear low density ethylene polymer, at least one of said layers provides a face of said film and at least a part of the surface of one face has a higher surface coefficient of friction than the other face of the film.
Claim 23
Dependent Claim
14 words
A multi-layer film as claimed in claim 20 which has been formed by coextrusion.
Claim 24
Dependent Claim
14 words
A multi-layer film as claimed in claim 21 which has been formed by blow-extrusion.
Claim 25
Dependent Claim
25 words
A multi-layer film as claimed in any one of claims 20 to 22 wherein said first and second layers provide the faces of the film.
Claim 26
Dependent Claim
37 words
A multi-layer film as claimed in any one of claims 20 to 23 wherein in the layer which comprises linear low density ethylene polymer, said polymer has a density as specified in claim 5 or claim 6.
Claim 27
Dependent Claim
37 words
A multi-layer film as claimed in any one of claims 20 to 24 in which the layer which comprises linear low density ethylene polymer provides the face of the film having the higher surface coefficient of friction.
Claim 28
Dependent Claim
25 words
A multi-layer film as claimed in claim 25 in which said coefficient of friction is as specified in any one of claims 7 to 9.
Claim 29
Dependent Claim
28 words
A multi-layer film as claimed in any one of claims 20 to 26 in which the blend is as defined in any one of claims 11 to 16.
Claim 30
Dependent Claim
28 words
A multi-layer film as claimed in claim 25, claim 26 or claim 27 in which the layer which comprises the blend forms the other face of the film.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.