Mold information

Methods to Prevent Forming Shrinkage Error in Mould Design of Dustbin Mould


If the manufacturing precision of the Dustbin Mould is […]

If the manufacturing precision of the Dustbin Mould is well controlled, the matching of the mould size and the drawing size may not necessarily meet the requirements of product size and performance. In addition to data control during mould manufacturing and injection moulding, perfect products should be injected. More relevant experience is needed in the design and manufacture of dustbin mould. According to the characteristics, sizes and shapes of different materials, the pre-design evaluation and analysis were made, and the post-test evaluation was carried out.

As the shrinkage rate will change with the change of injection pressure, the cavity pressure of single cavity mould should be as consistent as possible, and the cavity pressure difference of multi-cavity mould should be very small. For single-chamber multi-gate or multi-chamber multi-gate cases, the same injection pressure must be used to make the chamber pressure consistent. Therefore, the position balance of the gate must be ensured. Before the pressure balance of the gate, the runner should keep balance.

As the temperature of the dustbin mould has a great influence on the shrinkage rate of the mould, it also directly affects the mechanical properties of the injection-moulded products and also causes various forming defects such as surface blooming of the products, so it is necessary to maintain the temperature of the mould. The mould is within the specified temperature range and the mould temperature is kept changing with time. The temperature difference between the cavities of the multi-cavity mould shall not be changed. Therefore, the temperature control measures of heating or cooling must be taken in the design of the dustbin mould. In order to minimize the temperature difference between mould cavities, attention must be paid to the design of a temperature control cooling circuit. In the mould cavity and core temperature control circuit, there are mainly two connection modes of series cooling and parallel cooling.

Here, it is necessary to pay special attention to the fact that the material design of nylon plus fibre must be completed before the product evaluation and analysis in the manufacture of garbage can mould. The shrinkage rate of nylon material is relatively large, the wall thickness and shape of the product, and glueing have great influence on the precision and shrinkage rate of the product. In-mould design, design work and preventive measures must be done according to experience values.