Heat-shrinkable woven raffia fabric, and methods thereof

Patent metadata

Field	Value
Publication number	US-11655569-B2
Application number	US-201917056097-A
Country	US
Kind code	B2
Filing date	Jul 11, 2019
Priority date	Jul 26, 2018
Publication date	May 23, 2023
Grant date	May 23, 2023

Abstract

A method for shrink wrapping two or more articles, the method comprising: providing a heat shrinkable woven raffia fabric formed from warp and weft tapes, the warp and weft tapes comprising at least 70 wt. %, based on the total wt. % of polymers present in the warp and weft tapes, of an ethylene/alpha-olefin copolymer having a density of 0.945 g/cc or greater and a melt index (I2), as determined according to ASTM D1238 (190° C., 2.16 kg), of from 0.01 to 2.0 g/10 min; wrapping the heat shrinkable woven raffia fabric around two or more articles to form a wrapped bundle; and heating the wrapped bundle to form a shrink wrapped bundle.

First claim

We claim:

1. A method for shrink wrapping two or more articles, the method comprising:
providing a heat shrinkable woven raffia fabric formed from warp and weft tapes, wherein each warp and weft tape comprises 80 to 100 wt. %, based on the total wt. % of polymers present in the warp and weft tapes, of an ethylene/alpha-olefin copolymer having a density of 0.945 g/cc or greater and a melt index (I2), as determined according to ASTM D1238 (190° C., 2.16 kg), of from 0.01 to 2.0 g/10 min;
wrapping the heat shrinkable woven raffia fabric around two or more articles to form a wrapped bundle; and
heating the wrapped bundle to form a shrink wrapped bundle.

2. The method of claim 1 , wherein the heat shrinkable woven raffia fabric is coated with a polyolefin resin to form a coated heat shrinkable woven raffia fabric.

3. The method of claim 2 , wherein the polyolefin resin comprises a low density polyethylene, a linear low density polyethylene, polypropylene, or a blend of two or more of the low density polyethylene, the linear low density polyethylene, or the polypropylene.

4. The method of claim 2 , wherein the polyolefin resin comprises low density polyethylene.

5. The method of claim 1 , wherein the ethylene/alpha-olefin copolymer has a density of from 0.945 to 0.960 g/cc.

6. The method of claim 1 , wherein the ethylene/alpha-olefin copolymer has a melt index (I2), as determined according to ASTM D1238 (190° C., 2.16 kg) of from 0.1 to 1.5 g/10 min.

7. The method of claim 1 , wherein the ethylene/alpha-olefin copolymer has a melt index ratio (I10/I2) of 7.1 to 30.0, and I10 is determined according to ASTM D1238 (190° C., 10.0 kg).

8. The method of claim 1 , wherein the ethylene/alpha-olefin copolymer has a Vicat softening temperature of from 100° C. to 140° C.

9. The method of claim 1 , wherein the ethylene/alpha-olefin copolymer has a molecular weight distribution (Mw/Mn) from 3.0 to 6.0, where Mw is the weight average molecular weight and Mn is the number average molecular weight.

10. The method of claim 1 , wherein the wrapped bundle is heated such that the heat shrinkable woven raffia fabric reaches a temperature of from 100° C. to 165° C.

11. The method of claim 1 , wherein when the wrapped bundle is heated, the heat shrinkable woven raffia fabric has a warp direction free shrinkage at 130° C. of from 5% to 90% and a weft direction free shrinkage at 130° C. of from 5% to 90%, both as measured by ASTM D2732 test method.

12. The method of claim 11 , wherein the warp and weft tapes further comprise less than or equal to 30 wt. %, based on the total wt. % of polymers present in the warp and weft tapes, of one or more resins selected from the group consisting of a low density polyethylene having a density of about 0.916 g/cm 3 to about 0.929 g/cm 3 , a medium density polyethylene having a density of about 0.930 g/cm 3 to about 0.945 g/cm 3 , a high density polyethylene having a density of about 0.945 g/cm 3 to about 0.970 g/cm 3 , a linear low density polyethylene having a density of about 0.916 g/cm 3 to about 0.929 g/cm 3 , and a very low density polyethylene having a density of 0.860 g/cm 3 to about 0.912 g/cm 3 .

Assignees

• Dow Global Technologies Llc
• Dow Quim De Colombia S A
• Pbb Polisur Srl

Inventors

• Rodriguez Camelo Jorge Mario
• Gomes Jorge Caminero
• Valle Camila Do
• Zanetti Maximiliano
• Oliveria Marlos Giuntini De

Classifications

• D03D15/217

  natural from plants, e.g. cotton · CPC title

• D10B2321/022

  polypropylene · CPC title

• D10B2401/04

  Heat-responsive characteristics · CPC title

• D03D15/46 Primary

  Flat yarns, e.g. tapes or films · CPC title

• D03D15/283 Primary

  synthetic polymer-based, e.g. polyamide or polyester fibres (cellulose-based artificial fibres D03D15/225) · CPC title