HDPE Pipe flower pattern causes: because the melt flow in the cylinder, the cylinder wall and the internal flow rate between the difference, when leaving the die, the whole melt and no resistance, the gap between the two becomes zero. It is the relative movement of the layers of the change, causing the mold at the melt flow of intense oscillation, leading to the occurrence of such phenomena!
1, add auxiliaries: like organic silicone additives (silicone plastic additives) or Fu Fu polymer additives (PPA).
2, the appropriate increase in temperature can also improve the melt flow!
Squeeze HDPE pipe, and sometimes because of temperature, and sometimes because of the type of raw material problems and more or less patterns, but sometimes it is to increase the temperature, change the plastic model or how much. There have been tested on the membrane head of the air ring overhead, or that elevation.
3, choose the rest assured HDPE pipe first to determine the appropriate material. In the past, the pipes used for water supply were mainly cast iron pipes. Outside the main sand cast iron pipe, indoor use of galvanized cast iron pipe, which can be divided into cold (electric) galvanized and hot galvanized two. Galvanized pipe as a water pipe, the use of a few years later, the tube produces a lot of rust, the outflow of yellow water not only pollution sanitary ware, and mixed with non-smooth wall breeding bacteria, rust caused by high levels of heavy metals in water, serious harm to human health. More importantly, the performance of such a superior HDPE pipe, the price is not expensive.
HDPE is a thermoplastic polyolefin produced by copolymerization of ethylene. Although HDPE was introduced in 1956, but this plastic has not yet reached a mature level. This common material is also constantly developing its new uses and markets. The thermoplastic resin. The appearance of the original HDPE was milky white, in a slight cross-section was a certain degree of translucent. PE has excellent resistance to most of the characteristics of life and industrial chemicals. Certain types of chemicals can produce chemical corrosion, such as corrosive oxidants (concentrated nitric acid), aromatic hydrocarbons (xylene) and halogenated hydrocarbons (carbon tetrachloride). The polymer is non-hygroscopic and has good water vapor resistance
PE can be manufactured with a wide range of different processing methods. Including extrusion such as sheet extrusion, film extrusion, pipe or profile extrusion, blow molding, injection molding and rotomoulding.
HDPE pipe is the traditional steel pipe, PVC drinking water pipe replacement products.
HDPE pipe must bear a certain pressure, usually to use a large molecular weight, mechanical properties of PE resin, such as HDPE resin. LDPE resin has low tensile strength, poor pressure resistance, poor rigidity, poor dimensional stability during molding, and difficulty in connection, and is not suitable as a material for water supply pressure pipes. However, due to its higher health indicators, LDPE, especially LLDPE resin has become a common material for the production of drinking water pipes. LDPE, LLDPE resin melt viscosity is small, good mobility, easy processing, and thus its melt index selection range is also wide, usually MI in the 0.3-3g / 10min between.