Method of making a thermally stable acoustical insulation microfiber web
AssigneeMinnesota Mining and Manufacturing Company
InventorsMichael D. Swan, Ruth A. Ebbens
Life of this patent
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Abstract
There is provided a thermally stabilized polypropylene melt-blown microfiber acoustical insulation web which has a resistance to thermal degradation at a temperature of 135.degree. C. for at least 10 days. The polypropylene has a thermal stabilizer uniformly distributed within the melt-blown microfiber polymer which polymer when produced is subject to thermal and/or catalytic degradation in the absence of significant levels of thermal stabilizer or antioxidant.
Claims3
A method of forming a thermally stable acoustical insulation microfiber web for the attenuation of sound comprising the sequential steps of:
- a) supplying a feedstream polypropylene polymer, copolymer or blend having a weight average molecular weight of at least 150,000;
- b) extruding the molten feedstream while degrading the feedstream;
- c) homogeneously blending into the degraded feedstream a thermal stabilizer or antioxidant;
- d) forming the blend into melt-blown microfibers having a thermal stability of at least 10 days at 135.degree. C. having a weight average molecular weight of less than 150,000.
Dependencies are inferred from the claim text.