Cross-linked low-density polymer foam
AssigneeSentinel Products Corp.
InventorsRobert F. Hurley, John D. Bambara, Michael Bambara, Richard Bambara
Life of this patent
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Abstract
The invention relates to physically-blown low density polyethylene (LDPE) foams that are blends of an LDPE resin and a silane-grafted single-site initiated polyolefin resin. The LDPE resin generally has a density between about 0.91 and about 0.93 g/cm.sup.3 and a melt index greater than 1, and the silane-grafted single-site initiated polyolefin resin generally is a copolymer of ethylene and a C.sub.3 -C.sub.20 alpha-olefin that has a density between about 0.86 and about 0.96 g/cm.sup.3 and a molecular weight distribution between about 1.5 and about 3.5.
Claims39
A physically-blown foam comprising a polymer blend of a low-density polyethylene resin and at least one silane-grafted single-site initiated polyolefin resin.
A method of making a physically-blown silane-grafted foam comprising the steps of:
- providing a blend of a low-density polyethylene resin and at least one silane-grafted single-site initiated polyolefin resin, the blend further comprising a physical-foaming agent;
- extruding the blend;
- and
- expanding the blend to form the foam.
A physically-blown foam comprising a polymer blend of a low-density polyethylene resin and at least one silane-grafted single-site initiated polyolefin resin wherein the foam has a tensile strength between 20 and 250 psi, a 25% compression resistance between 3 and 200, and a density between 1.0 and 10 pounds per cubic foot.
A method of reducing cell size of a physically-blown foam comprising a low-density polyethylene resin, the method comprising the step of:
- blending a low-density polyethylene resin and at least one silane-grafted single-site initiated polyolefin resin and a physical-foaming agent;
- extruding the blend;
- and
- expanding the blend to form the foam,
- wherein the cell size of the physically-blown foam is reduced by 60 to 70 percent upon addition of the silane-grafted single-site initiated polyolefin resin to the low-density
Dependencies are inferred from the claim text.