You must collect or have the following information before making a choice: mold dimension (width, height, thickness), weight and special design; types and amount of the plastic (single or multiple plastic materials); dimensions and weight of injection molding product (length, width, height, thickness); molding requirements, such as quality condition, production speed and so on.
Because injection molding machine has very many kinds, so at first to correctly judge the product should be what kind of injection molding machine, or a series of production, such as is the general thermoplastic plastic bakelite raw materials or PET raw material and so on, is monochrome, two-color, multicolor, sandwich or mixed color, etc.In addition, some products need high stability , high precision, energy saving, high pressure or rapid manufacturing , and other conditions, production must also choose the appropriate series.
1.The mold width and height must be less than or at least less than the internal spur of large column.
2.The mold width and height must in the mold plate size range.
3.The mold thickness should be between the thickness of plastic injection molding machine.
4.The mold width and height must be fit with the minimum mold size recommended by the plastic injection molding machine.
Mould schedule at least should be greater than the height of the finished product in the direction of switch mode more than twice, and contains the length of the vertical gating (sprue); travel need enough to finished product out.
The product and plastic determine the tonnage of “clamping force”.
When the raw materials inject into the mold cavity in a high pressure, it will create a bulging force, so the clamping unit of the plastic injection molding machine should provide sufficient “clamping force” so that the mold was not subject to distraction. The need of clamping force is calculated as follows:
Clamping force = projected area of product in the direction of opening and closing mould (cm2) ×the number of mold cavity×in-mold pressure (kg/cm2);
Projected area of product in the direction of opening and closing mould is generated by the product appearance size.
In-mold pressure is different with different materials, generally take 350-400 kg/cm2.
The machine clamping force is usually greater than 1.17 times of the bulging force.
So far has been preliminary decision model of the specifications of the unit, and an approximate model tonnage, then must be the following steps,to make sure which one screw diameter of the injection unit is required.
By finished product weight and cavity number needed to "shoot dosage" and select the appropriate "screw diameter".
Calculation of the finished weight cavity should be considered (one module and a few holes);for stability's sake, injection amount is more than 1.35 times the weight of the finished product, i.e. the finished weight for injection amount to less than 75%.
Made of plastic to judge "screw compression ratio" and "injection pressure" and other conditions.
Ningbo KEBIDA Machinery Equipment Co., Ltd is one of the Chinese leading innovators for plastic molding machine's researching and developing. It provides various plastic injection molding machines and plastic molding auxiliary machines, you can get what you want in Ningbo KEBIDA Machinery Equipment Co., Ltd .
