摘要 |
A process in the manufacturing of a plastic product in a mould (20) including a hot runner system (22) and at least one mould cavity (21). A pressurised fluid is injected through at least one fluid channel (23) to create a hollow space (1) in the product produced. The hot runner (22) is provided with at least one means (24) for volume adjustment for increasing and decreasing the volume. An amount of molten thermoplastics is injected while the volume of the hot runner (22) is decreased by means of the volume adjustment means (24). A pressurised fluid is injected after allowing the thermoplastics to solidify somewhat. The pressurised fluid forces molten thermoplastic material back into the hot runner (22) while the volume of the hot runner (22) is allowed to increase by means of the volume adjustment means (24). The thermoplastic material in the mould cavity (21) is allowed to solidify further after which the fluid is evacuated. |