| 摘要 |
This novel process extrudes a profile (4) in one or more thermoplastics or rubbers. The profile cross section varies along its length. It is especially suitable as a seal for motor vehicles. The extruder (1) has an extrusion head (2) and suitable channel (3). In the new process, additional plastic or rubber material is injected into the head or channel, controlling flow-rate, injection pressure and injection interval. Control of addition, achieves required variation in cross section. The added material adheres with the thermoplastic or rubber of the profile, in creating the local modifications in cross section. Also claimed is coextrusion equipment as described. It includes a piston screw injection unit (5), controllable as described. This makes a side connection to the extrusion head or channel. |
