Extrusion molding method and device for rapidly and steplessly adjusting pipe wall thickness

Abstract

The invention discloses an extrusion moulding method and an extrusion moulding device capable of quickly regulating the wall thickness of a pipe in a stepless manner. According to the device, a mandrel and a flow dividing cone are coaxially arranged in the inner cavities of a die head body and a transition die head body; a first ventilating hole is radially formed in the outer ring of a supporting frame; a second ventilating hole is radially formed in the transition die head body; a third ventilating hole is axially formed in the bottom of the flow dividing cone; a fourth ventilating hole is axially formed in the centre of the mandrel; the second ventilating hole is connected with an air compressor through a ventilating hole; high-pressure compressed air enters the outer surface of the mandrel and the inner surface of a material blank through above ventilating channels in sequence to form a high-pressure air cushion, and the thickness of the high-pressure air cushion is changed by changing the pressure and the flow of the high-pressure compressed air, so that quick stepless regulation of the wall thickness of an extruded pipe is realized. According to the extrusion moulding method and the extrusion moulding device capable of quickly regulating the wall thickness of the pipe in the stepless manner, the wall thickness of the extruded pipe can be regulated quickly in the stepless manner without replacing the mandrel; quick, real-time and stepless regulation of the wall thickness of the extruded pipe can be realized; meanwhile, the wall thickness precision and the finish degree of an inner wall of the extruded pipe can be improved effectively; circumferential mechanical properties of the pipe are enhanced.

Description

technical field [0001] The invention relates to extrusion molding of polymer materials, in particular to an extrusion molding method and device for quickly adjusting the wall thickness of an extruded pipe without dismantling a mandrel in a die; it belongs to the technical field of polymer material processing machinery. Background technique [0002] Polymer material pipes are widely used in daily chemical, construction, petroleum and other industries. With the development of new material technology, the types and output of polymer material pipes continue to increase. At the same time, higher requirements are put forward for the performance and dimensional accuracy of polymer material pipes. requirements. At present, polymer material pipes are melted by the plasticizing system and transported to the annular gap between the die and the mandrel for processing. Usually, one set of molds corresponds to processing one polymer material and one pipe size. However, with the continuou...

AI Technical Summary

Problems solved by technology

Obviously, there are great defects in this type of adjustment method: First, in order to change the wall thickness, a pipe head must be reprocessed, and the replacement mold must go through the cooling-disassembly-heating process, which causes time, material, etc. , energy consumption, and a great waste of manpower; secondly, it is inevitable to adjust and correct the die and mandrel after replacing the new machine head, which will often cause scratches on the surface of the mold, and then affect the surface quality of the pipe; Finally, the method of replacing the machine head can only realize a jumping change from one size to another, and cannot realize stepless adjustment within a range. Especially when the pipe wall thickness accuracy is high, repeated mold trials are required. , very inefficient

Therefore, the current fixed-size processing method of polymer material pipes greatly limits the production and application of polymer materials. At present, in the field of polymer material extrusion pipe production, a method for quickly adjusting the wall thickness of pipes is urgently needed.

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