Abstract: Irradiated polypropylene articles of non-crystalline mesomorphous polypropylene and a method for preparing the articles are provided. The articles are irradiated with a sterilizing dosage of ionizing radiation. The irradiated articles such as films and blown microfiber webs are substantially undegraded after storage periods of as long as six months.

Abstract: Method of preparing a tape having a backing bearing on at least one major surface thereof a plurality of ribs disposed substantially longitudinally thereon, and further bearing on at least one major surface thereof a layer of adhesive. The ribs are joined to the backing such that the contact angle between the ribs and the surface of the backing ranges from about 10.degree. to about 160.degree.. At least 50% of the cross-section of the ribs must project from the rib-bearing surface of the tape. It is preferred that the adhesive be a pressure-sensitive adhesive. The tape of this invention can be prepared by means of coextrusion techniques.