Mechanical Processing The machining of GRP-Profiles is as simple as wood machining. The conventional machining techniques are drilling, milling, sawing, twisting, stamping and tapping.  For bores until 12mm diameter one should use a carbide drill DIN 8037 or DIN 8038. For bores above 12mm diameter we recommend the use of a diamond-studded drill. Fringes can be diminished by using a wooden pad.  Carbide- and diamond drills are good for milling GRP-Profiles, whereas carbide drills reach a higher heading speed. The usage of coolants is recommended as GRP-Profiles are bad conductors of heat.  For small amounts a metal saw is adequate. If you want to saw a bigger amount we recommend a diamond-studded saw blade. The diameter of the blades depend on the wall thickness 200 to 500mm. The usage of coolants is also recommended.  Standard equipment is adequate for small amounts, same as in metal processing. With big abouts one should use carbide equipment as used in brass- or aluminium processing. Water cooling is recommended.  For stamping we recommend the usage of tempered steel tools. The material thickness should not be more than 10mm.  Only tap if the compound is not encountering high tensile loads. It only passes one third of chunking resistance of metallic threads but has an adequate resistance when in accurate fit with adhesives.  GRP-Profiles are easy to glue with adhesives on polyurethane- and epoxy resin basis.  When riveting the bore should be slightly bigger than the rivet's diameter. The usage of adhesives for a better compound strength is recommended.  For light-loaded compounds self-tapping screws are adequate. For heavy loaded compounds machine screws are required.  Surfaces which should be varnished should first be cleaned with a solvent. As varnish we recommend a system on polyurethane basis. |
