PC/ABS polycarbonate and acrylonitrile-butadiene-styrene copolymers and mixtures Typical applications: computer and commercial machine housings, electrical equipment, lawn gardening machines, automotive parts dashboards, interior finishes, and wheel covers. Injection Molding Process Conditions : Drying: Drying before processing is a must. Humidity should be less than 0.04%. Recommended drying conditions are 90~110C for 2~4 hours.
In order to ensure that designed mold and injection moulding machine have a good match, it is necessary to check relevant data between these two, thereby design mold and select appropriate injection moulding machine model.
To form a qualified product requires a perfect fit between injection moulding process, injection moulding machine and injection molding mold. If there is a problem on either side, it is impossible to produce a qualified product. Table below lists some common injection moulding defects and suggestions for your reference.
When designing plastic mold, after mold structure is determined, various parts of mold can be designed in detail, that is size of each template and part, cavity and core size are determined. This will involve major design parameters such as material shrinkage. Therefore, size of each part of cavity can be determined only by specifically grasping shrinkage rate of shaped plastic. Even if selected mold structure is correct, if parameters used are not correct, it is impossible to produce a qualified plastic part.
Cracking, including filament cracks on the surface of part, microcracking, whitening, cracking, and damage caused by sticking of part, sticking of flow path. Cracking is divided into split cracking and application cracking according to cracking time.. There are mainly following reasons:
In industrial and municipal pipeline systems, demand for plastic bends is increasing. 90° pipe joint is a key component of pipeline. Especially in pressure pipeline, quality of pipe joints is more important, and it is difficult to obtain a high-quality and high-precision 90° pipe joint in production. Numerical simulation of shrinkage of pipe joint under different injection process parameters is carried out, and influence of injection process parameters on molding shrinkage of 90° pipe joint is obtained. Finally, three-dimensional inspection method is applied to high-precision detection of plastic parts to obtain shrinkage distribution.
Injection moulding is an engineering technique that involves transforming plastic into a product that is useful and maintains its original properties. Important process conditions for injection moulding are temperature, pressure and corresponding individual time of action that affect plasticizing flow and cooling.
Injection moulding process parameters mainly include baking temperature and time, injection amount, metering stroke (pre-plastic stroke), residual material amount, anti-delay amount, screw rotation speed, back pressure, injection speed and pressure, holding pressure and time, barrel temperature, mold temperature, cooling time, opening and closing speed and pressure, ejection speed, gas-assisted blowing pressure and time.
1. Material is wrong.2. Mold cavity size NG (shrinkage rate error, processing error)3. Mold cavity size is OK, unreasonable mold structure (number or position of gate, mold has no heating system or heating failure, uneven cooling), unreasonable product structure (deep cavity, thin wall, uneven wall thickness), unreasonable process parameters (holding pressure, sequence valve), injection molding machine (small tonnage, insufficient injection pressure)
According to research data from Research and Markets, global market value of plastic injection molding parts is currently US$325 billion. It is expected that market value will reach US$478.72 billion in 2025 and compound annual growth rate will be 5.7% in 2019-2025. Driven by rapid development of Asian economy, advancement of process efficiency and new resin materials, plastic injection molding parts are widely used in more complex applications, which presents great opportunities and challenges for product designers and engineers. A significant advantage of plastic injection molding is ability to produce very large quantities of product at a lower unit cost relative to development cost (tool). However, these same large-volume production requires a good plastic mold design.