method of molding flexible polymeric envelopes , the mold useful therefor , and the products that are produced by such a method . the essence of this process is the ability to injection mold the polymeric envelopes , cure or dry them on the mold core , and in spite of the small opening left by the molding process as compared to the size of the large core , eject the molded product without splitting or tearing the product in the process of demolding using gas injection to expand the molded product .