1. What is the principle of heat shrinking?

For polyolefin materials, under the action of high energy electron beam, the linear molecular structure is transformed into a three-dimensional network structure, and crosslinking is made. The polymer materials after crosslinking have got great improvement in performance in mechanical strength, heat resistance, resistance to chemical solvents, heat oxygen aging, etc. When the crystallization polymer materials after crosslinking are heated to above the melting point, they become rubber elastomers, and under the action of external force, are expanded or stretched and rapid cooled, and the state will be preserved. When they are reheated to the temperature above the melting point, they also can be restored to the state before the action of the external force.

2. Heat Shrinkable Material Storage and Transportation

For heat shrinkable products, in the process of storage and transportation, avoid direct sunlight or ambient temperature more than 60℃, and when the environment temperature is above 60℃, some contraction of the heat shrinkable products may happens.

3. What are full cold contraction cable accessories?

Full cold contraction cable accessories, usually also called "Predilation" accessories, refer to using good elastic rubber materials (commonly using silicone rubber and ethylene propylene rubber), in the factory, being injected or molded into the parts of a variety of cable accessories and vulcanized molding, then inner diameter being expanded and the spiral plastic support bar being lined, to keep the state after expansion. Gently draw the support bar in use, and at the normal temperature, it is a new type of elastic accessories in natural contraction without fire and special tools, called cold contraction cable accessories. All the combination parts of the cable accessories adopt the cable accessories composed by cold contraction parts, and are also known as the cold contraction cable accessories.

4. What are the precautions in use of silicone-rubber electric terminal protection box?

Due to the great differences between wiring hardware fittings and wiring modes of the incoming and outgoing line of overhead transformer, lightning arrester and aerial switch, the users should provide the details about the corresponding wiring hardware fittings and wiring modes before purchasing the silicone rubber electrical terminal protection box, so that our company can provide customers with appropriate models of products.

5. What are the precautions in use of heat shrinkage busbar protection sleeve?

1. Heat shrinkable sleeve has a fixed proportion of shrinkage, and at the same time, the insulation and voltage resistance of the heat shrinkable sleeve depends on the sleeve thickness after contraction, so the type selection must be in accordance with the methods specified on the product manual, and different sizes of busbar must be of the corresponding specifications of the sleeves.

2. The copper and aluminum busbar, in the production, storage, handling, tinning process, is easy to cause surface scratch and burr. Heat shrinkable sleeve in heating shrinkage mainly relies on the huge internal stress to achieve shrinkage, and the heat shrinkable sleeve in the heating condition is softer. At this time if there is a sharp burr in the surface of copper aluminum busbar, heat shrinkable sleeve will be scratched, and heat shrinkable sleeve will be immediately cracked or after a period of time of operation. So before contraction be sure to check whether there is burr on the copper and aluminum busbar and conduct the corresponding processing, to make copper aluminum busbar surface smooth.

3. Based on the above mechanism mentioned in Item 2, before the use of continuous heat shrinkable sleeve, when cut the sleeve in accordance with the number of the specific needs, we must guarantee the notch is smooth, and cannot appear zigzag notch.

6. Are there quality system certification and test report for Changyuan cold contraction cable accessories?

Changyuan Group passed the ISO9001 Quality Management System Certification; the cable accessories passed the inspection of the Electrical Equipment Quality Inspection Center of the Ministry of Power (Wuhan High Voltage Research Institute), and conformed to GB11033-89 Standards.

7. What kind of stress control method adopted for Changyuan cold contraction cable accessories?

Our products adopt the refraction stress control method, i.e. set the high elastic stress control sleeve made from high dielectric constant (K value is around 30) materials outside the cable shielding, using its difference from the dielectric constant of the main insulation, thus to reduce the electric field intensity at the shielding mouth. The insulation resistance of the stress control sleeve with this high dielectric constant is high, the dielectric strength is big, and under the long-term electric field action and high temperature, the parameters can remain stable, the electric field distribution on the surface of the terminal is effectively improved, the terminal size is small, and the required installation space is little.