Sustainable Polymer Films
Sustainable film compositions and articles including recycled elastomer. The compositions comprise one or more virgin polymers. Optionally, the films may also include one or more compatibilizers having compatibility with the polymers and a thermoplastic elastomer (TPE) such as a block copolymer with a hard block and a soft block. Multi- or mono-layer films are possible. The films are useful for packaging films or component films for consumer products.
1 . A method for forming a sustainable thermoplastic film, the method comprising:
forming a mixture by supplying a virgin polymer comprising polyolefin and a post-industrial-recycled material (PIR) to a feed section of an extruder, wherein the PIR comprises a thermoplastic, elastomeric-polymer and a spunbond component;
melt processing the mixture within the extruder and extruding the mixture through a die to form the film, wherein the film has a thickness of 100 micrometers or less.
2 . The method of claim 1 wherein the thermoplastic, elastomeric-polymer is a styrenic, thermoplastic block-copolymer.
3 . The method of claim 1 wherein the polyolefin is polyethylene, polypropylene, and copolymers of ethylene or propylene with other vinyl comonomers.
4 . The method of claim 3 wherein the polyolefin is selected from a group of low density polyethylene, linear low density polyethylene, high density polyethylene, polypropylene, ethylene propylene copolymers, ethylene-co-vinyl acatate (EVA), ethylene-co-methyl acrylate (EMA), ethylene-co-acrylic acid (EAA), ethylene-co-methacrylic acid (EMAA).
5 . The method of claim 1 wherein the thermoplastic, elastomeric-polymer is selected from the group consisting of a polystyrene/poly(ethylenebutylene)/polystyrene) block copolymer; a linear tri-block copolymer based on styrene, ethylene/butylene and polystyrene; a styrene-butadiene-styrene block copolymer, a styrene-isoprene-styrene block copolymer, polyurethane, polyolefin elastomers and a combination thereof.
6 . The method claim 1 wherein the thermoplastic elastomeric-polymer has an average molecular weight of from about 65,000 g/mol to about 100,000 g/mol.
7 . The method of claim 1 wherein the mixture comprises 10 percent to 90 percent PIR.
8 . The method of claim 1 wherein the mixture comprises 20 percent to 80 percent PIR.
9 . The method of claim 1 wherein the step of melt processing is performed at temperatures ranging from 160° C. to 240° C.
10 . A sustainable thermoplastic film comprising:
30 to 70 parts by weight of 100 percent virgin polyolefin; and
the remaining parts by weight of a post-industrial-recycled material (PIR), wherein the PIR comprises a styrenic, thermoplastic block-copolymer, and wherein the film thickness is 100 micrometers or less.
11 . The film of claim 10 wherein the polyolefin is selected from a group of low density polyethylene, linear low density polyethylene, high density polyethylene, polypropylene, ethylene propylene copolymers, ethylene-co-vinyl acatate (EVA), ethylene-co-methyl acrylate (EMA), ethylene-co-acrylic acid (EAA), ethylene-co-methacrylic acid (EMAA).
12 . The film of claim 10 comprising 50 parts by weight of the 100 percent virgin polyolefin, wherein the 100 percent virgin polyolefin consists of polypropylene.
13 . The film of claim 10 having 70 parts by weight of the 100 percent virgin polyolefin, wherein the 100 percent virgin polyolefin consists of polyethylene.
14 . The film of claim 10 wherein the 100 percent virgin polyolefin further comprises a copolymer.
15 . An absorbent article comprising: a liquid permeable topsheet, a liquid impermeable backsheet, and an absorbent core positioned between the backsheet and the topsheet, and wherein the backsheet comprises the film of claim 10 .
16 . The film of claim 10 wherein the 100 percent virgin polyolefin comprises polypropylene or polyethylene.
17 . A multi-layer film comprising a core layer and a first skin layer, wherein the core layer is the film of claim 10 and the first skin layer is a virgin polymer.
18 . The film of claim 16 further comprising a second skin layer of a virgin polymer, wherein the core layer is disposed between the first skin layer and the second skin layer.
19 . The film of claim 17 further comprising a first middle layer disposed between the first skin layer and the core layer, and a second middle layer disposed between the second skin layer and the core layer.
20 . The film of claim 18 wherein a ratio between the core layer and the first and second skin layers is 10% to 80% core layer, and 10% to 90% of the first skin layer and the second skin layer combined.