Today we are going to talk about an old-fashioned topic, that is, the production process of Heat Shrinkable Tube. This article is mainly divided into five chapters to introduce: 1. Raw material formula mixing; 2. Extrusion; 3. Irradiation crosslinking ; 4. Expansion molding, cooling; 5. Printing, packaging into trays and boxing.
The first step, the mixing of masterbatch and additives: the matching of chemical formula, using advanced special masterbatch production line, weighing all kinds of polyolefin substrates and various functional auxiliary materials according to the formula ratio, and then mixing, the mixed The material is put into a twin-screw extruder and granulated to produce a polyolefin functional masterbatch. Effectively ensure that the final products of various formulations have balanced physical, chemical, electrical and other characteristics.
The second part, extrusion: according to the shape and diameter of the Heat Shrinkable Tube, it can be processed and produced by single-screw extrusion and injection molding:
(1) Extrusion molding: mainly used for extrusion molding of heat-shrinkable tubing, such as single-wall heat-shrinkable tubing, double-wall adhesive heat-shrinkable tubing, medium-thick-wall heat-shrinkable tubing, high-pressure busbar Products such as shrink tubes are all processed by single-screw extrusion.
(2) Injection molding: mainly used to produce heat-shrinkable special-shaped parts, such as heat-shrinkable sealing caps, heat-shrinkable umbrella skirts, heat-shrinkable fingertips, etc., are all produced by injection molding.
On the basis of technology introduction, mastering advanced processing and forming technology, we can provide tubular products with various wall thicknesses, various colors, and multi-layer structures, and ensure that the dimensions of the pipes are highly accurate and the surface quality is excellent.
The third part, radiation cross-linking: the product formed by extrusion or injection molding still has a linear molecular structure, and the product does not have a "memory function", and the performance of temperature resistance, aging resistance, and wear resistance is not enough. At this time, it is necessary to The molecular structure of the formed product is changed. The commonly used method is radiation cross-linking modification "electron accelerator radiation cross-linking". At this time, the molecule changes from a linear molecular structure to a network structure. Extruded products have a "memory effect" after cross-linking, which greatly enhances the temperature resistance, mechanical properties, and chemical properties of the Heat Shrinkable Tube. Melting, aging resistance, wear resistance, chemical corrosion resistance, etc. Using advanced transmission control technology, tension control technology and the most mature radiation technology in China, the company has formed a unique high-efficiency and low-cost radiation cross-linking process to ensure that high efficiency, high quality and low cost of radiation cross-linking are realized at the same time .
The fourth part, expansion: the pipe after irradiation and cross-linking can be preheated to a higher temperature and expanded by external force to increase the diameter of the pipe, and then quickly cooled to room temperature, so that the shape of the pipe after expansion is finalized The main principle of this process is that the activity of the high-fraction segment of the pipe after irradiation crosslinking has a great relationship with the temperature. In a certain high temperature range, the segment is activated, and the resistance of the segment to stretch and other behaviors is very small. , the entire Heat Shrinkable Tube is like an elastic net, which can be stretched by external force, so when heated to this temperature range, the tube can be easily expanded. When the temperature drops rapidly, usually by using a cold water bath, this activation phenomenon will be lost, and the resistance of the chain segment to stretch and bend is very large, and the internal stress of retraction is not enough to overcome this resistance. Therefore, in the natural state, it is maintained after expansion. shape. Expansion production technology is the most important step in the production of Heat Shrinkable Tube, which requires precise control of each step in the production process to ensure that the parameters of the final product, such as size, longitudinal shrinkage rate, and wall deviation rate, meet customer requirements. High quality heat shrinkable tubing.
The fifth step is to detect the inner diameter and wall thickness of the Heat Shrinkable Tube. The inner diameter is generally detected with a plug gauge. The wall thickness is mainly to check whether there is a partial wall, and then print and package to complete the production of the Heat Shrinkable Tube.
Shenzhen Huiyunhai Tech.Co., Ltd.
