| 摘要 |
<p>PURPOSE:To provide a water-impermeable film composed of a biaxially oriented film of polyethylene, etc., having specific physical properties and excellent tear strength, tensile strength and flexibility, resistant to tear in contact with soil and sand, having high slipperiness on a pipe and high abrasion resistance, heat-weldable with each other and easily storable. CONSTITUTION:A water-impermeable film made of a thermoplastic resin and having a tensile strength of >=1kg/cm, perpendicular tear strength of >=0.3kg, piercing strength of >=0.5kg and a thickness of 10-300mu. The thermoplastic resin film is a flexible polyvinyl chloride film having a thickness of 50-300mu, a biaxially oriented film of polyethylene (density: 0.90-0.96g/cc), polypropylene, ethylene-propylene copolymer, etc., having a thickness of 10-150mu, or a laminated film having a thickness of 50-300mu and produced by using a layer of uniaxially oriented fibers of polyester or polyamide resin of >=0.1 denier diameter as a substrate and laminating a film of e.g. polypropylene having a thickness of 10-100mu on the substrate layer.</p> |
