Injection molding introduction

Injection molding introduction

【Date】:2013-12-31 【Hit】:4884

1 what is the injection molding

The injection molding (Injection Molding) refers to, heat melting the material by thehigh pressure into the mold cavity, after cooling after curing, are molded method.The method is suitable for mass production of complex shaped parts, is an important processing methods.

Injection molding process can be divided into the following 6 stages.

1 clamping

2 injection

3 pressure

The 4 cooling

5 open

Out of 6 products

The process repeatedly, can continuously produce products.

Injection molding machine 2

Injection molding machine can be divided into clamping device and injection device.

The main function is to realize the clamping device of mold opening and closing and crest products. Clamping device can be divided as connecting rod type shown by oil pressure clamping and direct implementation of direct pressure.

The injection device is injected into the device mould of the resin material is heatedto melt after. As shown in the resin into the cylinder from the head, through the rotation of the screw front melt conveying to the barrel. In the process, the heateris heated under the action of the resin material in the heating barrel, screw shear stress under the effect of resin into a molten state, will be equivalent to the molding and the sprue, runner up in front of the molten resin in the barrel (calledmeasurement), screw continuous forward the materials into the die cavity.

When the molten resin flow in the mold, must move speed control screw (injection speed), pressure and mold cavity filled with the resin (and pressure) control.When the screw position, injection pressure reaches a certain value we will be able to speed control switch to control pressure.

3 die

The so-called mold (Mold) refers to, be of a certain shape of products resinmaterial into metal model. Although it is not marked, the fact is that in order tocontrol the mould temperature, in the mold and the refrigerant (water or oil)through the cooling hole, a heater device.

Has become the material melt into the mainstream, the runner, gate into the mold cavity. After the cooling period after opening the mold, molding machine on theejection device will put the ejector stroke, the product launch.

The 4 forming product

Forming product is main runner molten resin flowing, which shunts and products to guide the molten resin into the mold cavity. If a molding can only get a product, the production efficiency is not high. If we use the shunt multiple cavity connectedtogether, can also produce a number of products.

At this point, if the runner to the length of the cavity no equal words, resin cannotat the same time into the mold cavity, the product size, appearance, physicaldifference. Therefore, we will usually divided channel length is equal.

The use of the 5 feed back

Molding of sprue and runner are not products, sometimes discarded or crushedas a molding material again use. We will call it a feed back.

Feed back is generally not as a molding material is used alone, is usually used after mixing with the new. This is because after after a one-time molding,mechanical properties, fluidity of the resin, color and other properties will change.The new material control in 30% the following general and mixing ratio of feed back,if using the ratio of feed back is too high, may make the inherent properties of the material decreased, even using the control volume feed back below 30%, we alsomust according to the product quality requirements, strength, mold structure,molding shape so, the correct amount to determine the feed back. Especially thefilling grade material, paying particular attention to this point.

The specific characteristics of using the back material, please refer to thecharacteristics of regenerated resin database.

The 6 forming conditions

Forming condition is, in order to obtain a molded product required, and barrel temperature, injection speed, mold temperature and combination of molding machine set into many different molding conditions. Size in appearance, according to the formed product get the forming condition, changes in mechanical propertiesand so on, we must rely on the technology and experience to find out the optimum molding conditions.

Forming conditions we recommend the company materials standard. Please click on the name of the resin.

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