Patent DE1130144B successfully refreshed from Google Patents.
Patent EP0108513A1 successfully refreshed from Google Patents.
EP0108513A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Molecularly orientating plastics material
Assignee: PLG Research Ltd
•
Filing: 1983-10-10
•
Granted: —
•
Expires: 2003-10-10
Abstract
Abstract It is known to form an integral plastics material mesh structure by punching a square or rectangular pattern of holes in a starting material sheet, and then stretching. Particularly when the material is stretched biaxially, irregularities occur across the structure. In order to avoid such irregularities, the strand-forming zones 3,7 are formed with depressions 13,14 with the sheet at ambient temperature, prior to stretching. This is found to greatly improve the regularity, as well as increasing through-put speeds and decreasing power requirements, particularly with polypropylene.
Inventors
- 👤 Frank Brian Mercer
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 06:13
CPC Classifications
B; B29; B29D; B29D28/00; B29C; B29C59/00; B29C59/02; Y; Y10; Y10S; Y10S264/00; Y10S264/81
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
83 words
A method of stretching plastics material 1 having holes or mesh openings 2, to form orientated strands 8, 1 3 from strand-forming zones 5, 6 of the plastics material, and including forming depressions 3, 4 in at least some of the strand-forming zones 5, 6 without material removed, prior to stretching the respective strand-forming zones 5, 6, characterized in that the depressions 3, 4 are formed when the plastics material is at a temperature below the lower limit of its melting range .
Claim 2
Independent Claim
83 words
A method of stretching plastics material 1 having holes or mesh openings 2, to form orientated strands 8, 1 3 from strand-forming zones 5, 6 of the plastics material, and including forming depressions 3, 4 in at least some of the strand-forming zones 5, 6 without material removed, prior to stretching the respective strand-forming zones 5, 6, characterized in that the depressions 3, 4 are formed when the plastics material is at a temperature below the lower limit of its melting range .
Claim 3
Dependent Claim
18 words
The method of Claim 1, wherein the depressions 3, 4 are formed at or close to ambient temperature.
Claim 4
Dependent Claim
42 words
The method of Claim 1 or 2, wherein the depressions 3, 4 are formed by a tool 26 whose cross-section taken parallel to the stretching direction is substantially constant across the width of the tool 26 and which presents opposite, inclined faces.
Claim 5
Dependent Claim
37 words
The method of Claim 3, wherein the depressions 3, 4 are wedge-shaped, the apex of the wedge extending substantially at right angles to the direction in which the respective strand-forming zones 5, 6 are to be stretched.
Claim 6
Independent Claim
52 words
The method of any one of the preceding Claims, wherein the depressions 3, 4 are bounded by steps substantially at right angles to the faces of the plastics material 1, the steps extending substantially at right angles to the direction in which the respective strand-forming zones 5, 6 are to be stretched.
Claim 7
Independent Claim
40 words
The method of any one of the preceding Claims, wherein a plurality of depressions 3 or 4, spaced apart in the direction of stretching the respective strand-forming zone 5 or 6, are formed in a strand-forming zone 5 or 6.
Claim 8
Independent Claim
57 words
The method of any one of the preceding Claims, wherein the plastics material is biaxially-stretched in a continuously-operating plant, one stretch being effected in the machine direction and the other stretch being effected in the transverse direction, and the depressions being formed in at least those strand-forming zones 6 which will stretch in the transverse stretching direction.
Claim 9
Independent Claim
48 words
The method of any one of the preceding Claims. wherein the starting material 1 is formed by punching holes 2 in a plastics material sheet, the depressions 3, 4 being formed generally at the same time as the punching in an adjacent part of the starting material 1.
Claim 10
Independent Claim
67 words
The method of any one of the preceding Claims, wherein the depth of a depression 3, 4 on one face only of the plastics material 1, or the combined depth if there are registering depressions 3, 4 on opposite faces of the plastics material 1, expressed as a percentage of the thickness of the undepressed zones of the plastics material, is about 40% or less than 40%.
Claim 11
Dependent Claim
15 words
The method of Claim 9, wherein the percentage is about 25% or less than 25%.
Claim 12
Dependent Claim
17 words
The method of Claim 9 or 10, wherein the percentage is about 10% or more than 10%.
Claim 13
Independent Claim
29 words
The method of any one of the preceding Claims. wherein there are registering depressions 3, 4 on opposite faces of the plastics material, and of substantially the same depth.
Claim 14
Independent Claim
38 words
The method of any one of the preceding Claims, wherein, in the side edges of the respective strand-forming zones 5,6 in which said depressions 3,4 are to be formed, said holes or mesh openings 2 define wedge-shaped indents.
Claim 15
Dependent Claim
28 words
The method of Claim 13, wherein said holes 2 are radiussed squares with a diagonal parallel to the direction in which the respective strand-forming zones 5,6 are stretched.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.