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2020
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What are the specifications for flexible tubes? Introduction to the classification of flexible tube raw materials
Author:
Hoses are important components in modern industry and are used in many places, commonly in bathrooms.
Hoses are important components in modern industry and are used in many places, commonly in bathrooms. Although they are common items, many people don't understand their specifications and nature. What are the specifications of hoses? What are the main classifications of hose materials? Let's give a brief introduction below.
Introduction to Hose Material Classification:
PVC hoses (sanitary grade plastic hoses, plastic hoses, plastic corrugated hoses, sanitary grade hoses, imported hoses) were widely used in water supply pipe systems and gas transmission pipe systems. However, in recent years, the market share of PVC pipe systems in the field of gas transmission has been almost zero, and the usage in water supply systems has also slightly decreased. However, the use of PVC hoses in pressureless pipe systems such as drainage, sewage, and waste disposal systems has steadily increased, mainly because the production of PVC raw materials is less dependent on crude oil than other thermoplastic plastics, making its production cost relatively low.
Hoses (plastic corrugated hoses, imported hoses) can be designed with solid walls or structural walls, and their connections mainly use solvent bonding. Depending on whether plasticizers are used, they can be divided into hard polyvinyl chloride (which has relatively high corrosion resistance and high-temperature performance, and the cost is also relatively high.
Although PE pipe systems do not have a cost advantage (relatively high raw material prices), they have been rapidly promoted and popularized. This is mainly due to the fast, convenient, and reliable connection method of PE hoses, namely, hot melt connection. Teflon hoses, due to the characteristics of the melting temperature range and melt viscosity of PE hoses (sanitary grade plastic hoses, plastic hoses, polyethylene hoses, sanitary grade hoses, imported hoses), determine that PE hoses have good weldability, so that the strength of the PE hot melt connection joint reaches or even exceeds the strength of the hose itself. In addition, the use of PE electrofusion fittings can also make the repair work of the PE pipe system simple and easy, thus improving the reliability of the pipe.
PP hoses (sanitary grade plastic hoses, plastic hoses, polypropylene hoses, sanitary grade hoses, imported hoses) have been used in pipe production since the 1970s. According to the different polymer structures, PP materials can be divided into three categories: PP-H (homopolymer polypropylene), PP-B (block copolymer polypropylene), and PP-R (random copolymer polypropylene).
PP-R pipe systems are an important part of building cold and hot water pipe systems. There was once a boom in promoting PP-R plastic pipe systems in China, but unfortunately, due to the interference of counterfeit and substandard products, the market for PP-R pipes did not achieve good sustained development. Instead, it left the market with a bad impression of "plastic pipes are not durable," so that many building designers, developers, and users of water supply pipe systems have lost confidence in plastic pipes. From a technical point of view, the reasons for the failure of substandard products are multifaceted. On the one hand, qualified raw materials were not used. In the early stages of plastic pipe development, practitioners did not have a thorough understanding of the long-term performance and strength of raw materials, nor did they have a deep understanding of the evaluation methods of raw materials; on the other hand, the system connection had problems, because the modulus of PP-R pipes is relatively large among plastic hoses, so excess stress is easily generated at the joints, especially at the steel-plastic transition joints, which often leak after a period of hot and cold water circulation.
