![]() ![]() RJ Mould is capable of manufacturing the perform molds with one cavity up to ninety-six cavities. And the mold price is relatively cheaper. Type Two: It is without valve gate, but shut-off is still independently for each cavity, the finished perform is with some short tail at the bottom. Type One: It is the first-class perform mold, due to it is adopted with valve gate, and shut-off independently for each cavity, so the finished perform is without any tail at the bottom. Our factory manufactures dozens sets of preform injection mold annually, and all molds are exported to our international customers. When the mold temperature is low and even, the cooling speed shall be too fast with few crystallization and transparent products.RJ Mould is professional in making all kinds of PET preform moulds, we are very capable to provide Preform Design, Mold Design and Mold Manufacturing for our customer. (2) If we don’t control the mold temperature or the metal temperature properly, it’s easy to produce “white fog” and become opaque. Otherwise, it’s easy to form “bridging” at discharging chute which will influence the plasticizing. (1) Recycled material cannot be too much. If the machine stops less than 15 minutes, we only need to make air injection If the machine stops more than 15 minutes, we should not start the machine again until we use viscosity PE to clean the machine and make the feed cylinder’s temperature drop to PE temperature. Try to avoid the temperature above 300 Celsius degree. It should avoid overlong detention time to prevent from the molecular weight declining. In order to avoid wearing, the packing pressure shall be as low as possible. ![]() The material injection is usually completed in 4 seconds. But if injecting too fast, the shear rate would be so high that the material would become fragile easily. ![]() Generally, injection speed must be fast, in order to prevent premature solidification. The temperature is ranging from 270 Celsius degree to 295 Celsius degree and the enhanced GF – PET’s temperature can be set from 290 Celsius degree to 315 Celsius degree, etc. It can be measured by the air injection method. There is enough exhausting effect for it so as not to appear local overheating or chipping, but the vent’s depth is generally not more than 0.03 mm, otherwise, it is easy to produce flashing. Insulation board’s thickness is about 12 mm, and can bear high pressure. It is better to have an insulation board between mold and injection molding machine template. We generally use hot runner mold to design PET bottle preform. PET can only be stable for a short time after the melting point, and the melting point is so high, which needs to choose the injection system which has more temperature-control periods and less friction heat when plasticizing, and the product’s (the material which contains water) actual weight cannot be less than two-thirds of the amount of machine injection. The proportion of recycled material is generally not more than 25%, and the recycled material needs to be completely dried. ![]() We can use air injection method to examine whether the material is completely dry or not. Therefore, we need to dry the material at 150 Celsius degree for more than 4 hours and 3 to 4 hours at 170 Celsius degree before processing. When the water content exceeds the limit, the molecular weight of the PET will drop during the processing, so the product will be colored and become crisp. The aggregate is very sensitive to water when it’s at a high temperature. Plastic dryingĭue to PET macromolecule contains an aliphatic base, it has certain hydrophilicity. Therefore, we change the rheological property mainly from the pressure. PET has a good rheological property in molten condition and pressure has more effects on viscosity than temperature does. PET injection molding parts are mostly used in the bottle preform products At present, GF-PET is used by most clients. The chemical name of PET is poly terephthalic acid alcohol ester, also called polyester. The injection techniques of poly terephthalic acid alcohol ester (PET) The injection techniques of poly terephthalic acid alcohol ester (PET). ![]()
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