Process for producing polyvinyl alcohol articles
The present invention relates to novel polyvinyl alcohol non-woven films and fabrics which have been modified so as to have a breathable coalesced lower porosity surface polyvinyl alcohol layer attached to a fibrous polyvinyl alcohol layer by a transition layer. The fabrics are useful as clothing or wraps for inert articles.
1. A non-woven breathable polyvinyl alcohol article comprising
three polyvinyl alcohol layers each formed from a common fibrous polyvinyl alcohol material, the article comprising:
a first layer consisting of the fibrous polyvinyl alcohol material as coalesced to have a reduced porosity relative to the fibrous polyvinyl alcohol material, and that is more susceptible to thermal transfer than the fibrous polyvinyl alcohol material;
a second layer consisting of the fibrous polyvinyl alcohol material in an unmodified state and having a higher porosity than the first layer; and
a transition layer interposed between the second layer of fibrous polyvinyl alcohol and the first layer and formed during modification of the fibrous polyvinyl alcohol to make the first layer, wherein the transition layer comprises a mixture of the fibrous polyvinyl alcohol and coalesced polyvinyl alcohol;
wherein the article comprises polyvinyl alcohol from the fibrous polyvinyl alcohol material extending throughout the first layer and transition layer.
2. The article of claim 1 comprising a further polyvinyl alcohol surface layer formed from a modified portion of the second layer of the fibrous polyvinyl alcohol opposite the first layer, wherein the further surface layer is coalesced and has a reduced porosity relative to the second layer of the fibrous polyvinyl alcohol.
3. The article of claim 1 wherein the first layer is formed with steam.
4. The article of claim 1 further comprising a thermoplastic polymer layer attached to the film along the second fibrous polyvinyl alcohol layer, wherein the thermoplastic polymer layer is formed from a material different from that of the fibrous polyvinyl alcohol.
5. The article of claim 4 wherein the thermoplastic polymer layer is a polyolefin.
6. The article of claim 1 having a degree of polymerization of 700 to 1500.
7. The article of claim 1 wherein the film comprises a water repelling composition disposed on the first surface layer.
8. The article of claim 1 wherein the film comprises an antimicrobial composition disposed on the first surface layer.
9. The article of claim 1 wherein the polyvinyl alcohol is cross-linked.
10. The article of claim 1 wherein the first surface layer is substantially non porous.
11. The article of claim 1 wherein the polyvinyl alcohol has acetyl groups.
12. Clothing comprising the article of claim 1 .
13. The clothing of claim 12 wherein the article contains a plasticizer.
14. The clothing of claim 12 including an antimicrobial coating.
15. The clothing of claim 14 which comprises medical clothing.
16. The clothing of claim 12 wherein the polyvinyl alcohol is spun laced.
17. The article of claim 1 which is film.
18. The article of claim 1 which is a fabric.