The purpose of this research is to design disc cutter for cutting poly propylene random co-polymer (PPR) and high density polypropylene (HDP) extrudates. Analytical methods and software including like Catia and ANSYS are used to design the tool and analyze the effect of load on the cutter. In designing the disc Cutter, using the digital logic method of material selection, the optimum material, carbon steel 19573 with the least cost, locally obtainable, manufacturable and with hardness 63.42HRC is selected. The desired optimum combination of hardness and toughness of the cutter is obtained using hardening temperature 10200C, tempering temperature 2000C, and tempering time 120min which finally gives a hardness value of 63.42HRC. The strength and quality of cut edge are tested by cutting hard plastic PPR pipe with maximum thickness of 12.9mm. By the same setup of the cutter used in the factory the prototype disc cutter serves and its failure rate improves from cutting 150 to 250 PPR pipe pieces which was recognized by the industry. The research results can be used to design the cutter disk and fabricate a cutter with enough strength to cut different thickness of PPR pipes without breakage, reducing unwanted additional cost.

Keywords : Disc Cutter, Bevel Angle, Tool Stress, Hardness, and Tool Contact Area.