| 摘要 |
<p>PURPOSE:To provide a screw protector high in strength, light in weight, inexpensive to produce and particularly capable of being buried in the ground after use by a method wherein the synthetic resin such as powdery or fibrous polyolefin and pulp are mixed together and processed into the form of a nonwoven fabric and the resulting material is molded in a metal die under pressure into a molding having an internal or external thread part. CONSTITUTION:10-50 pts.wt. of the synthetic resin such as powdery or fibrous polyolefin and 50-90 pts.wt. of pulp are mixed together and processed into the form of a nonwoven fabric by a wet or dry process and the resulting material is molded in a metal die under pressure into a cylindrical body 1 having an internally threaded part 2 on its inner peripheral surface. The wet process comprises mixing the material dispersively in water, shaping, dehydrating and drying the resulting mixture into the material having a thickness of about 10mm and introducing the material into a metal die to mold the same into a threaded cylindrical body 1 at a temperature of 200-220 deg.C and at a pressure of 100-250Kg/cm<2>. The dry process comprises pressing the material into the form of a nonwoven fabric having a suitable thickness and this material is introduced into a metal die for molding.</p> |
