What is a heat-shrinkable tube? A heat-shrinkable tube? It may be described directly in this way. There is no comparability and it is difficult to guess. The development of heat-shrinkable pipes has penetrated into all aspects of life.
Plastics are widely used in people's daily life. Polyethylene materials are aggregates of linear molecules formed by polymerization of ethylene monomers. They can be seen everywhere in the market, but they do not have thermal shrinkage properties. They are used no matter what kind of film or pipe they are in stores.
X-rays are usually invisible light emitted by matter when it undergoes microscopic changes. It has a wide range of applications in military, medical, scientific, industrial and agricultural fields. In this paper, the preparation of a magical thermal shrinkage material by using radiation is described.
The so-called heat-shrinkable material is that the material shrinks and deforms after being heated. When it is cold, it is a thick tube. When heated, it can shrink into a thin tube and stick to the surface of the object attached to it, so as to ensure the insulation of the object or the anti-corrosion of the metal surface. If the material is a film, the packaging food with this film shrinks and wraps the food tightly once heated, so as to isolate the food air and play a fresh-keeping role.
Why does this material have such magical properties? It is necessary to discuss the structure of materials.
Ordinary polyethylene pipes do not have thermal shrinkage. Polyethylene is synthesized by the polymerization of ethylene monomer. The molecular formula of ethylene monomer is H2C=CH2. Under the conditions of polymerization, the double bonds of each ethylene monomer molecule are opened, and the polyethylene which is synthesized by several molecules is linear. The polyethylene plastics we usually see are made up of linear molecules which are aggregated by ethylene monomers.
Heat shrinkable tubes, but polyethylene plastics under the action of radiation, linear molecules will produce chemical bonds, that is, radiation crosslinking, the greater the radiation dose, the greater the degree of crosslinking. Radiation crosslinking results in the transformation of polyethylene plastics from linear structure to reticular structure, i.e. three-dimensional structure. The new material has a wonderful "memory effect". For example, the pipe can be enlarged and then cooled to form a thick pipe, which can be restored to the original diameter of the plastic pipe before expansion as long as it is heated again, so it is called "memory effect" material.
Tubes made of heat shrinkable polyethylene materials can be conveniently used to protect the joints of cables and optical cables, and the protection of metal pipe poles, etc. Heat-shrinkable materials can be used not only to produce radial shrinkage heat-shrinkable tubes, but also to prepare bi-directional shrinkage plastic film, which can be used in packaging, protection of goods and so on. Magic heat shrinkable materials will bring more extensive applications to people's life, industry and agriculture in the future.
High-temperature heat-shrinkable pipe, as its name implies, is a high-temperature-resistant heat-shrinkable pipe. Usually, the heat-resistant grade of our common heat-shrinkable pipe is between 105 degrees Celsius and 150 degrees Celsius. In the heat-shrinkable industry, high-temperature heat-shrinkable pipe with temperature resistance greater than or equal to 150 degrees Celsius is called heat-resistant heat-shrinkable pipe.
Generally speaking, high temperature shrinkable pipes have the advantages of high temperature resistance, high mechanical strength and good chemical resistance. High temperature shrinkable pipes are widely used in cable insulation protection, insulation treatment or stress relief at the end or connection, wire processing coating and insulation protection, solder joint protection, coating of electronic components, insulation protection of resistors and capacitors, anti-rust and anti-corrosion treatment of metal products. Wire marking or color marking, etc.
According to the temperature grade and service environment, high temperature shrinkable tubes can be divided into: 150 temperature shrinkable tubes, EPDM heat shrinkable tubes, diesel heat shrinkable tubes and so on; 175 heat shrinkable tubes, such as PVDF heat shrinkable tubes; 200 temperature heat shrinkable tubes, such as silicone rubber, fluororubber heat shrinkable tubes; 260 degree heat shrinkable tubes, currently the highest heat-resistant grade heat shrinkable tubes in the heat shrinkable industry, namely Teflon heat shrinkable tubes.
High temperature heat shrinkable tube with temperature resistance of 150:
It should be noted that the temperature of heat-resistant shrinkable pipe is the temperature of long-term operation of casing, not the temperature of short-term. In fact, if it is only temporary high temperature resistance in a short period of time, the ordinary 125 heat-shrinkable tube can meet the requirements. Our ordinary 125 heat-shrinkable tube can withstand temperature up to 168 hours in 175 working environment after testing.
With its excellent performance, high temperature heat shrinkable pipes are not only used as special materials in aerospace, advanced technology and military technology departments, but also used in various sectors of national economy. Their applications have been extended to metal smelting, construction, electronic and electrical, textile, automobile, machinery, chemical and light industry, etc. With the improvement of the production level of domestic silicone and other raw materials, there will be tremendous reserves. Development space.