Extruder nozzle and a method for producing plastic products
AssigneeMarie Iacconi
InventorSven Lindqvist
Life of this patent
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Abstract
In order to homogenize and to obtain a uniform temperature distribution in a plastics substance, which is to be extruded between an inner and an outer component, in a nozzle, the substance is made to pass a bearing structure comprising a number of rolling bearings, where the balls serve as kneading bodies. The inner and the outer components of the orifice rotate in opposite directions, which will orientate the molecular chains in the surface zones of the extruded products at an angle to the direction of extrusion. In this manner the structure of the product is enhanced, while simultaneously the kneading operation reduces the risk of impurities in the plastics compound causing weak spots in the product.
Claims7
An extruder nozzle for producing a thin-walled tubular product from a pressurized plastics substance extruded through a circular clearance opening formed by a rotating outer component and a counter-rotating inner component, and including a shaft for mounting said inner component,
- a tubular casing for mounting said outer component and enclosing said shaft with an annular axial allowance,
- a bearing structure comprising a number of rolling bearings arranged axially behind each other within said annular allowance,
- a fixed central column with a conduit for supplying said pressurized plastics substance to said nozzle and communicating with the end of said annular allowance remote from said clearance opening,
- a connection passage between said clearance opening and the adjacent end of said annular allowance, whereby the plastics substance on its way to said clearance opening is forced to pass through at least some of said rolling bearings,
- a housing rotatably journaled on said central column and forming an extension of the casing mounting said outer component, and
- a power source mounted upon said housing and drivingly connected by gearing means enclosed in said housing for rotating said shaft and said casing together with said inner and outer components in opposite directions by means of planetary gears mounted on said central column.
Dependencies are inferred from the claim text.