Patent ID: 9023260
Filing Date: 2015-05-05
Classification: B29C,B29L,Y10T

Abstract:
1. A method for producing a molded part with a rotationally symmetrical or at least partially annular cross-section, the method comprising the steps of injecting a plasticized polymeric mass (PM) containing fibers (F) through at least two injection openings (O 1 , O 2 , O 3 ) into at least one annular cavity (K) of a molding tool to form a screw part having a base body shaped as a hollow cylinder with an internal thread and an external thread thereon and defining a longitudinal axis, and once the polymeric mass (PM) has solidified into the screw part, the screw part is removed from the molding tool, wherein the plasticized polymer mass (PM) has a fiber content by volume in a range of 2.5 through 60 percent, wherein the fibers (F) have an average length in a range of 0.1 through 1.5 mm, and wherein the polymer mass (PM) fills the cavity (K) by simultaneously flowing out of each of the injection openings (O 1 , O 2 , O 3 ) in an axial direction (X-X) of the molded part and toward two sides in a circumferential direction so that that the fibers (F) are aligned during injection predominantly in both main stress directions of axial tension (Z) and torsion (T) throughout the screw part, the fibers including a first proportion being aligned in a circumferential direction at right angles to the longitudinal axis being less than fifty percent of all of the fibers, the fibers also including a second proportion of the fibers being aligned in a direction parallel to the longitudinal axis and being less than fifty percent of all of the fibers.