| 摘要 |
An extrusion apparatus is used for extruding material through a nozzle (10) for forming a product In the nozzle (10), the material is pressed around rods (9) so that tubular cavities (13) are formed in the wall of the product. The rods (9) are hollow and the apparatus comprises channels (14) connected to the hollow rods (9) to enable flow in the tubular cavities (13). |
