Abstract: A mechanical part has a contact surface for movement on a mating surface. The contact surface is first rough ground by using a grinding wheel of a grain size, for example, equal to or smaller than #200 and then barrel finished or buffed so as to have such a profile that is roughness spacing ranges from 5 to 100 .mu.m and more than half of its peaks are smoothly rounded.

Abstract: A stretched film of polypropylene which is excellent in transparency, substantially free of an antiblocking agent and at least uniaxially stretched and which is characterized in that it has uniformly distributed projections having a height ranging from 0.05 to 0.50 .mu. and a width ranging from 10 to 100 .mu. at least on the surface thereof as well as a method for preparing the foregoing stretched film of polypropylene which comprises the steps of forming, into a sheet, polypropylene which comprises a nucleating agent in an amount selected so that the crystallization temperature of polypropylene is increased by 1.degree.to 10.degree. C. by the addition thereof and then stretching the sheet at a temperature ranging from 140.degree. to 165.degree. C. are herein disclosed.

Abstract: A double-sided, pressure-sensitive, adhesive tape having a release paper on an adhesive surface. The release paper has a plurality of spaced-apart areas that have a lesser degree of adhesive to the adhesive surface than the remaining area of the release paper.

Abstract: This invention is directed to the formation of transparent, surface-crystallized glass bodies exhibiting very high mechanical strengths, but low frangibility, consisting essentially, in weight percent, of 2.5-5.0% Li.sub.2 O, 5-10% MgO, 3.5-12%, ZnO, 16-28% Al.sub.2 O.sub.3, and 50-70% SiO.sub.2.

Abstract: A biaxially oriented blow-molded container composed of a thermoplastic gas-barrier resin (resin B) and a thermoplastic resin (resin A) other than resin B and having excellent gas-barrier property and delamination strength. The container comprises a substantially non-oriented mouth portion composed of resin A, a portion composed of two layers of resin A and one layer of resin B which are laminated with the resin A layer and the resin B layer occurring alternately and a portion composed of three layers of resin A and two layers of resin B which are laminated with the resin A layer and the resin B layer occurring alternately. A portion having a small radius of curvature where delamination tends to occur is formed in a three-layer structure. A process for producing the container is also provided.