| 摘要 |
In this method for plastic lamination of a metal strip by means of direct extrusion, in which the metal strip is moved in its longitudinal direction, and is heated; by means of a sheet die, a film of molten, thermoplastic plastic material is deposited directly onto one side of the moving metal strip, this plastic film is pressed onto the metal strip, while being led through a gap between two rollers, by which the roller adjacent to the plastic film (laminator roller) is maintained below the melting temperature of the plastic material; if necessary the other side of the metal strip may be coated with a plastic film in similar fashion. While laminating a steel strip, the latter is heated to such a temperature that it has a temperature, in the depositing region of the liquid plastic film, which is above the melting point of the respective plastic material. Between the roller (laminator roller) which is pressing on the plastic film or a continuous belt (laminator belt) which is pressing on the plastic film, surface contact is made and this surface is maintained by synchronous moving-on of the surfaces of the plastic film and the laminator roller or laminator belt, which are in contact, via a contact time or contact length which suffice, at a belt rate of at least 50 m/min and a cooling rate of at most 400 W/m2 .degree.C, to cool down the surface layer of the plastic film to a temperature of at least approx. 20.degree.C below the melting point of the respective plastic, before contact the plastic film and the laminator roller or laminator belt is lost. In a subsequent treatment, the laminated metal strip is heated to a temperature in the region of the melting point and finally cooled rapidly to a temperature below 40_C. |
