Gas-assisted extrusion equipment

Abstract

The invention discloses gas-assisted extrusion equipment. The gas-assisted extrusion equipment comprises an extruder and an extruder head which is matched and connected with the extruder, wherein the extruder comprises a material cylinder; the inside of the material cylinder is provided with a screw rod; the screw rod is capable of rotating in the material cylinder and comprises main threads and accessory threads which are arranged in intervals with the main threads; the height of each main thread is greater than that of each accessory thread; the extruder head comprises a gas input controlling device and an extrusion opening die; a gas inlet hole is formed in the extrusion opening die; the gas inlet hole is connected with the gas input controlling device; the gas in the gas input controlling device enters the extrusion opening die through the gas inlet hole; a gas layer is formed between the inner wall side of the extrusion opening die and a molten plastic body. Through the gas-assisted extrusion equipment, the molten plastic body can be fully stirred and pushed to a discharging die opening, the requirement on the rotation torsion of the screw rod can be reduced, the whole life of the gas-assisted extrusion equipment is prolonged, and the production efficiency is improved.

Description

technical field [0001] The invention relates to the field of plastic thermal processing equipment, in particular to a gas-assisted extrusion equipment. Background technique [0002] Extrusion equipment heats the plastic to make it into a viscous flow state. Under pressure, it passes through a die with a certain shape to become a continuous body with a cross-section similar to the shape of the die, and then cools to make it have a certain geometric shape. The plastic of different sizes changes from a viscous fluid state to a high elastic state, and finally cools and shapes into a glass state to obtain the desired product. After years of development, the extrusion equipment has been derived from the original single-screw, twin-screw, multi-screw, and even no screw. The extruder (main machine) can be matched with various plastic molding auxiliary machines such as pipe, film, handle material, monofilament, flat wire, packing belt, extruded net, plate (sheet), profiled material,...

AI Technical Summary

Problems solved by technology

The thread of the screw directly affects the effect of pushing out the molten plastic body. The higher the tooth height of the thread (that is, 1 / 2 of the difference between the major diameter and the minor diameter of the thread), the better the stirring effect, and the greater the rotational torque required. If the tooth height is too low, it will affect the speed of pushing out the molten plastic body, and even reverse glue will cause the blockage of the barrel

In addition, due to the resistance between the extrusion die and the extrusion melt, the existing extrusion molding technology generally has the problem of extrusion swell, that is, the cross-sectional size of the extruded product is larger than the size of the extrusion die, and the extrusion swell This greatly increases the difficulty in the design of the extrusion die, which affects the accuracy of the product. At the same time, due to the high viscosity of the molten plastic material, a large die pressure is required to overcome the resistance of the inner wall of the die to the extrudate during extrusion, resulting in a pressure drop in the die. Large, so that the internal stress of the extruded product increases, resulting in increased deformation, but also increases energy consumption, affecting the quality of plastic products

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