The processing of GRP profiles is simple and similar to woodworking. The most common processing techniques are drilling, milling, sawing, turning, punching and thread cutting.
A simple carbide drill according to DIN 8037 or DIN 8038 can be usedfor drill holes up to 12 mm in diameter. If possible, a diamond-tipped drill bit should be used for drill holes over 12 mm in diameter. To minimise fraying at the drill exit, a wooden underlay should be used.
Drilling speed 60-80 m/min. Diamond-set drill 300 to 1200 m/min
Carbide or diamond milling cutters are well suited for milling GRP. A higher feed rate can be achieved with carbide cutters. It is advisable to use coolant, as GRP profiles are poor heat conductors.
Cutting speed 100 to 400 m/min
A conventional metal saw is sufficient for sawing smaller quantities. For larger volumes, however, the use of a diamond-tipped saw blade is recommended. The diameter of the saw blades should be between 200 - 500 mm, depending on the wall thickness. Extraction is recommended for dry processing.
Cutting speed 1800 to 3600 m/min.
When turning smaller quantities, standard equipment such as that used for conventional metalworking is sufficient. For larger quantities, however, carbide tools such as those used for brass or aluminium machining should be used. Water cooling is always advisable.
Cutting speed as for brass or aluminium.
Hardened steel tools should be usedfor punching. However, the material thickness of the workpiece to be processed should not be greater than 10 mm.
Max. Material thickness for punching = 10 mm
Threads should only be cut if the connection is not subjected to excessive tensile stress. The pull-out strength is around a third of that of metallic threads, but sufficient strength for many applications can be achieved with an exact fit and the use of adhesive.
Tubular and trapezoidal threads enable better force transmission than metric threads
GRP can be bonded easily and firmly with polyurethane and epoxy resin-based adhesives. However, the instructions given should be observed.
Follow the manufacturer's guidelines when applying the adhesive.
When riveting, the hole should be slightly larger than the rivet diameter. The use of adhesives to increase the bond strength is recommended.
Self-tapping screws are sufficient for lightly loaded connections. Machine screws should be used for joints that are subject to heavy loads. The use of adhesives to increase the bond strength is also recommended when screwing.
The surface to be painted should be thoroughly cleaned and degreased with a solvent before applying the paint. We recommend a polyurethane-based paint system.
The best painting results are achieved with 2-component PUR paints.