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Analysis of raw material properties of HDPE double wall bellows,
HDPE resin for double-wall bellows, how to choose HDPE resin for double wall bellows,

The general requirements for the properties of polyethylene (PE) include melt flow rate (MFR), density, flexure elastic modulus and oxidation induction time (OIT), impact strength, etc. The test items also include tensile strength, elongation at break, ash, volatiles and other oxidation induction time determines the time of oxidation damage. For the bellows requiring 50 years of use, controlling the oxidation induction time of raw materials is the key to ensure the service life of 50 years. It is clearly stipulated in GB/T19472.1-2004 that the oxidation induction time of the raw material of bellows should be ≥20min(200℃).

The elastic modulus of HDPE resin has a great impact on the ring stiffness. Materials with high elastic modulus can improve the ring stiffness of products, but also save raw materials and reduce costs under the premise of ensuring the ring stiffness. So in the production of HDPE double-wall bellows, the raw material used should have a high modulus of elasticity. The size of melt flow rate reflects the size of molecular weight. Generally speaking, the material with higher melt flow rate is conducive to processing and forming, and can improve the production efficiency. However, it can not be too large, which has a greater impact on the ring stiffness. At the same time, it must have high density and good processing performance and equipment adaptability.

HDPE pipe grade has broad or bimodal distribution of molecular weight. It has strong creep resistance and good balance of rigidity and toughness. It is very durable and has low sag when being processed. Pipes produced using this resin have good strength, rigidity and impact resistance and excellent property of SCG and RCP.

The resin should be stored in a drafty, dry warehouse and away from fire and direct sunlight. It should not be piled up in the open air. During transportation, the material should not be exposed to strong sunlight or rain and should not be transported together with sand, soil, scrap metal, coal or glass. Transportation together with toxic, corrosive and flammable substance is strictly prohibited.

Application

HDPE pipe grade can be used in the production of pressure pipes, such as pressurized water pipes, fuel gas pipelines and other industrial pipes. It can also be used for making non-pressure pipes such as double-wall corrugated pipes, hollow-wall winding pipes, silicon-core pipes, agricultural irrigation pipes and aluminumplastics compound pipes. In addition, through reactive extrusion (silane cross-linking), it can be used for producing crosslinked polyethylene pipes (PEX) for supplying cold and hot water.