Posted 20 March 2007 - 16:43

As far as I am aware "Precious Resin" is really only a polymer resin which is injection molded into pen barrels. Resin is the base material for all polymers (read Plastics), and comes in many many formulae which can be tailored for the specific application.I would be failry surprised if Glock made the frame for their wonderful pistols out of strictly Nylon 66 (aka PA66 in Europe, PA standing for Poly Acetal). I am not sure that PA66 is glass or mineral filled which is what gives polymers the tensile strengths that they now exhibit.Zytel, which is mentioned in the original post above, is, depending on the grade a glass filled polymer which has amazing tensile strength. The interesting thing here is that we are not talking about tensile strength, or compressive strength, which most nylons have inherently. When a pen is dropped and is broken across the barrel it is subject to shear stresses, and would require shear strength to combat this. Additionally, for crushing loads the pen would have to have sufficient hoop strength to resist.Looking at a Glock the material would appear to me to be glass filled (mineral filled would be out of the question due to its hydrophobic tendencies and the resultant loss of strength). The finish of a material does not totally depend on what the fillers are, albeit some glass filled products like the Glock do have a characteristic silvery mottled appearance. This can be offset via processing parameters in the molding process to leave the item with a resin rich surface. Typically this is done by increasing the mold temperature to bring the resin to the surface, not unlike boiling cream. There is a definite decrease in strength in the resin rich surface though and could incude stress cracking if subject to stress (either mechanical or thermal).That said, and it was a mouthful, MB could mold the pens in Zytel for increased strength and still acheive the nice polish that we have come to expect. The downside would be the material costs would increase, and they would not be able to use regrind as much to use up runners etc from the molding process. Regrind is typical in injection molding and when done with filled resins it decreases the size of the filler strands with each regrind, and makes it more and more difficult to keep the filler in the polymer and not at the surface. Additionally, each regrind would decrease the strength of the material.Cheers,SGDon't ask how I know this.