Tokuyama Soda Kabushiki Kaisha

Shingo Kaneko

Shunichi Nakamura

Kiyoshi Sumi

Tomoyasu Kawamura

Kenji Okamura

A stretching device for stretching a tubular film includes a mandrel including a stretching section, a pair of payoff nip rolls disposed upstream of the mandrel and a pair of take-up nip rolls disposed downstream of the mandrel. The stretching section of the mandrel is comprised of a plurality of rings arranged substantially concentrically in spaced-apart relationship in the travelling direction of the tubular film. The outside diameter of a ring on the downstream side is larger than that of a ring on the upstream side. Each of the rings has a plurality of rotating members mounted rotatably, and the plurality of rotating members define an outer circumferential ring edge which is generally smoothly circular.

Stretching device for stretching tubular film

A process for the preparation of soft porous sheets, comprises forming into a sheet a composition comprising (i) 40 to 80% by weight of an inorganic filler and (ii) 60 to 20% by weight of a polyolefin type thermoplastic elastomer composition comprising at least 50% by weight of a polyolefin type thermoplastic elastomer substantially free of a polar group, in which the tensile stress at a temperature of 25.degree. C. under 100% stretching (100% modulus) is 10 to 100 Kg/cm.sup.2, the elongation at break under stretching is at least 100% and the permanent strain under 100% stretching is less than 50% and up to 50% by weight of a thermoplastic plastomer, and stretching the sheet at a temperature lower than the softening temperature of the polyolefin type thermoplastic elastomer. A porous sheet obtained according to this process has a good combination of flexibility, air permeability and water resistance.

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Houfu, Japan

Shingo Kaneko