Heat shrinkable tube in the production process, the expansion of this most difficult to control the process, it is the quality control is used in what way?
How control the size of the heat shrink tubing?
Some heat-shrinkable tube manufacturers in China professional practice, in this high elastic state if the material applied to the external force, its melting temperature of about 115 ~ 135 ℃ between; polyethylene starting flow temperature with the increase in irradiation dose and rise, the heat-shrinkable tube, irradiation dose is generally in 100 ~ 150kGy, due to the heat shrinkable tube base material for polyethylene multi-blend system, in order to ensure that the material is in a high elastic state, in order to obtain a higher Expansion rate and thermal contraction force.
As the temperature rises to the melting point, the uncross-linked polymer transitions from the glassy state to the viscous flow state, while the cross-linked polymer is not viscous and appears in the high elastic state, which is the effect of the three-dimensional mesh structure formed inside the material by the cross-linking reaction. At this point the corresponding starting flow temperature is approximately 180°C. The preheating temperature of the heat shrink tube should therefore be controlled at a temperature in between, i.e. around 140°C, so that the material can produce elastic deformation, i.e. once the external force is removed, the material can return to its pre-stress shape. Therefore, the prerequisite for the implementation of the expansion process is that the material is in a high elastic state, i.e. the material should be preheated before expansion to a temperature between its melt temperature and the viscous flow temperature.
How control the size of the heat shrink tubing? PVC heat-shrinkable sleeves have the special function of shrinking when exposed to heat and can be cut on behalf of the customer. It is used for the outer covering of various curtain rods, shower curtain rods, hanging rods, mop rods, broom handles, tool rods, telescopic rods, garden tools, spreader rods and other tubular items. It can also be used for marking and insulating the outer covering of copper rows, connectors and wire harnesses of low-voltage indoor busbars. High efficiency, low investment in equipment and small overall cost. It is a new generation of packaging material for the wrapping of lightings, LED pins, and the wrapping of guitars and packaging bottle mouths. It can be shrunk by heating above 98℃ and is easy to use. The products are divided into two series according to the temperature resistance of 85℃ and 105℃, specifications Φ2 – Φ200, the products comply with the EU RoHS environmental protection directive. Used for electrolytic capacitors and inductors, the products have good high temperature resistance and no secondary shrinkage, and can be printed on behalf of them. How control the size of the heat shrink tubing? PET heat-shrinkable tubing (polyester heat-shrinkable tubing) greatly exceeds pvc heat-shrinkable tubing in terms of heat resistance, electrical insulation performance and mechanical performance, and more importantly, the environmental performance of PET heat-shrinkable tubing is higher than the EU RoHs directive standard, which can reach Sony SS-00259 environmental protection standard. PET heat-shrinkable tubing is non-toxic, easy to recycle and has no toxic effects on the human body and the environment, which is more in line with environmental requirements. It does not contain Cd, Pb, Hg, CrVI, PBBs, PBBEs/PBDEs, PCBs, PCTs, PCNs and other substances banned by the environmental management, and it is the cover for electrolytic capacitors, inductors and other electronic components, high-grade rechargeable batteries, toys and medical devices. It is the outer coating of electrolytic capacitors, inductors and other electronic components, How control the size of the heat shrink tubing? high-grade rechargeable batteries, toys and medical devices, and fully meets export requirements.