Reparos em plástico

501-25-50 Body Repairs - General Information 501-25-50 DESCRIPTION AND OPERATION Plastic Repairs General The proportion of plastics used in vehicle construction continues to rise. Up to now damaged plastic components often had to be replaced. These days, plastic repairs are becoming more and more widely accepted because of the increasing cost of spare parts. NOTE: Plastic adhesives are chemical products and are subject to the safety instructions of the manufacturer. In repair work, the material properties of plastics are highly significant. There are two main groups: ‡ Thermoplastics. ‡ Thermosets. NOTE: Elastomers make up a third group of plastics. These are not mentioned below because they have no plastics repair applications. Thermoplastics Heat causes thermoplastics (also called TP polymers) to transform from the solid state into the thermoelastic state and then into the thermoplastic state. When thermoplastics are cooled, they return to solid state. Brief Plastic descrip- WLRQ ABS Acrylonitrile butadiene styrene copolymer PA Polyamide 3& Polycarbonate 33 Polypropylene PP/EPDM Polypropylene/ethylene propylene diene copolymer PC/PBT Polycarbonate/polybutylene tereph- WKDODWH Hard PVC Polyvinylchloride / soft PVC Thermosets Thermosets (also called TS polymers) are much harder and more brittle than thermoplastics. Their strength remains largely unchanged when they are heated. Thermosets are destroyed when heated above the critical temperature. Also, the original state will no longer be restored on cooling. Brief Plastic descrip- WLRQ *53 Glass reinforced plastic 385 Close-meshed cross-linked poly- urethane 385 Wide-meshed cross-linked poly- urethane Plastic identification Normally the appropriate identifier is marked on the plastic components used in vehicle construction. The capital letter sequences used for this are standardized in DIN EN ISO 1043-1 and DIN ISO 1629 (for rubber) and can be looked up in the tables which they contain. In addition the string of characters provides information about the exact mixture ratio and the proportion of certain fillers. Examples of the identification of plastics E122806