| 摘要 |
Method of coating a metallic substrate (1) with thermoplastic coating material, comprising a preheating the substrate in such as way that, just prior to coating, it is at a temperature between 70 °C and 150 °C, preferably between 100 °C and 130 °C in the case of a coating containing polypropene and between 80 and 110 °C in the case of a coating containing polyethene; coextrusion, in the first coating station of a sheet (6) comprising a polyolefin covering layer and a modified polyolefin adhesion layer; coating of the substrate (1) with a molten sheet in the presence of ozone by pressing it with the adhesion layer against the surface of the substrate; transportation of the strip (9) coated on one side to a second coating station and heating the strip so that, just before coating, the strip is at a temperature between 70 °C and 130 °C, preferably between 80 °C and 120 °C, if the coating layer applied in the first coating station is polypropene and between 80 and 110 °C if the coating layer applied at that point is polyethene; coating of the substrate with a molten sheet extruded in the second coating station by pressing it against the uncoated surface of the substrate, use being made of the presence of ozone; heating of the coated substrate so that it assumes a temperature which is above the melting point of the polyolefins applied; cooling of the coated substrate. |
