Reparos em plástico

501-25-51 Body Repairs - General Information 501-25-51 DESCRIPTION AND OPERATION E122807 E122808 NOTE: The identification of the type of plastic is necessary for the plastic welding process in order to determine the correct welding rod (welding material) to use. If an identifier is missing or cannot be made out, the following easy to perform tests will help: Visual Inspection Visual inspections mainly serve to identify PUR and GRP materials. Thermoplastic components are often painted and are therefore difficult to identify. Identification characteristics: ‡ When PUR cracks or similar damage occurs, pores of foam can be seen. ‡ GRP can be recognized by the glass fiber structure on the inside. Mechanical test: The plastic group can be determined by a sound test: ‡ Degree of hardness - the higher-pitched the sound, the harder the plastic. ‡ Elasticity - the more muffled the sound, the higher the elasticity of the plastic. Sanding test In this a place is chosen which will not be visible later, and the finger belt sander is used to sand the plastic. The plastic group can be determined using the pattern of the dust: ‡ Thermosets produce a white dust. ‡ Thermoplastics smear and do not produce dust. Float test in water: Take a small piece of plastic from the component to be repaired and test whether it floats on water (PP-EPDM, HD-PE, PP) or sinks (PVC/U, PVC/P, ABC, PC). Nature of the surface The surface of plastics can be categorized as rigid (PVC-U, PVC-P) and waxy (PP/EPDM, HD/PE, PP). Adherence test using welding rod Heat a welding rod that is identified with the type of material and the plastic component using the hot air gun. Press the welding rod onto the plastic component to be welded. When the welding rod cools down, if it remains stuck to the component or can only be removed with great difficulty, then it can be assumed that the two are made of the same plastic. When pulling away from PP/EPDM, HD/PE and PP, this can lead to strings. CAUTION: Danger of poisoning! When burned, most plastics release vapors harmful to health. Ventilate the room well and use respiratory protection. Where possible work using an extraction system. Burning test Every plastic has a characteristic behavior and smell when burned. Using a knife, cut off a small piece from the component to be repaired, remove any dirt and paint residues and set light to the small chip. Now observe the burning behavior. Compare the color, type and smell of the smoke with the results from the following table. Short Plastic recognition using a descrip- burning test WLRQ ABS Blackish smoke, the material drips like a candle when burning and smells like wax. PA No smoke, draws filaments, smells like burnt horn.