Polyethylene is made with three families of catalyst: Ziegler-Natta, Phillips chromium, and metallocene or other single-site catalysts. Between them they polymerise ethylene into all HDPE and LLDPE. LDPE is the exception: it is made at high pressure by free-radical initiators,…
ABS molds on any standard injection press once it is dried to 0.1 % moisture or less, at the melt and mold temperature its producer prints for the grade, such as a 220–260 °C melt and a 30–80 °C mold…
ABS PC plastic is a blend of polycarbonate and ABS melt-compounded into one pellet, with polycarbonate almost always the larger share. Its general-purpose grades resist heat better than ABS, mold at lower temperatures than polycarbonate, and keep more notched toughness…
Polycarbonate is the tougher, more heat-resistant and naturally clear resin; ABS is cheaper and easier to mold, and it is the standard resin for electroplating. On producer datasheets, PC’s impact lead shrinks in the cold, and the two overlap in…
To reduce linear shrinkage in polypropylene molding, raise holding pressure and hold until the gate freezes, run a colder mold and give the part more cooling time; when the press settings run out, move to a glass- or talc-filled compound…
ABS is made by polymerizing styrene and acrylonitrile in the presence of polybutadiene rubber, so that part of the styrene-acrylonitrile copolymer (SAN) grafts onto the rubber particles and the rest forms the rigid matrix around them. The three monomers come…
ABS is stiffer and more heat-resistant and holds tighter tolerances; HDPE is lighter, cheaper per kilogram and resists acids, alkalis and water. Producer datasheets contradict one common claim: injection-molding grades of HDPE are not tougher than ABS on a notched…
ABS is sold in grade families rather than a fixed number of types: general-purpose, high-impact, high-flow, heat-resistant, flame-retardant, plating, UV-stabilized, transparent and filled grades, many of them in injection and extrusion versions, plus blends with polycarbonate, nylon and other polymers.…
Polypropylene molds on a standard screw injection machine, with no drying for unfilled grades, at a melt temperature that producers put between about 200 °C and 260 °C, into a cool mold, with a fast fill and enough pack and…
Transparent ABS is ABS whose rigid matrix carries methyl methacrylate, which brings the matrix’s refractive index to that of the rubber particles so light passes through without scattering. Regular ABS keeps the two phases mismatched, so its rubber particles scatter…