The material performance of plastic pipe production lines is an important basis for quality assurance. The molecular weight and distribution range of resin have a significant impact on the performance of the product. The lower the molecular weight, the wider the distribution range, and the greater the MI (melt flow rate) reflected. High compression density. The service life of shear plasticization decreases with the decrease of pipe strength, making it more prone to quality problems such as pipe breakage and rapid aging.
Therefore, well-known domestic floor heating companies generally use high-quality imported PE-Xa special resins such as XL1800 and 8100X, with an MI (190 ℃, 21.6kg) of about 2g/10mm.
Manufacturing PE-Xa pipes with domestically produced LLDPE7042 is cheap, but the MI is too large, the molecular weight is low, and the density is low, resulting in low strength, rapid aging, and short service life. Therefore, it is easy to burst. After use, the pipeline is cut through rework, so reconnection cannot be avoided.
The resin has a high volatile component and small holes are opened on the surface or hidden areas of the pipe, with varying degrees of stress concentration, which affects the high temperature resistance of the product and shortens its service life.
Therefore, in addition to the volatile substance certification of resin processing enterprises, plastic pipe production lines will not be affected by moisture or water pollution during transportation and storage.
At the same time, attention should be paid to the order and techniques of supply to ensure the mixing time and uniformity of raw materials, generally controlled within 15 minutes, so that the resin and various additives are evenly dispersed. Ensure stable product performance and long service life.
The amount of crosslinking agent added should be accurate, and the degree of crosslinking should reach a certain height, which can meet the standard requirements and ensure the stable quality of the crosslinking agent.
If the performance of the crosslinking agent is poor, only a large amount of addition is needed to ensure the degree of crosslinking. The residual monomers after crosslinking will affect the performance and service life of the product. Therefore, good domestic underfloor heating enterprises generally adhere to the use of expensive but high-quality plastic pipe production line joint agents.
Crosslinking is the process of generating free radicals. In order to capture residual free radicals and eliminate unstable atoms after crosslinking, additional main and auxiliary antioxidants were added to control thermal aging, while also using the pipeline during the process. It can effectively prevent exposure to high temperatures. Under aging and oxidation, the performance of the material gradually decreases and its service life can be extended.
