Injection molded parts processing crack problem how to do?

In the production of plastic products, injection molding is a common molding method. However, in the actual operation process, often encountered a variety of problems, one of the more common is the product surface cracking phenomenon. This phenomenon not only affects the appearance of the product, but also may cause damage to the function of the product. Therefore, it is particularly important to understand and master the effective way to solve this problem.

To understand why cracking occurs, you need to first understand the injection molding process and its material properties. Plastic parts in the injection molding, raw material particles are melted at high temperatures and injected into the mold cavity, cooling and curing into the desired shape. In this process, due to the non-uniformity of the material, improper temperature control, uneven pressure distribution and other factors, may lead to plastic parts in the molding process or after the molding of the stress, and thus produce cracks.

How to prevent and solve this phenomenon of injection molded parts processing? The following are a few key steps:

1. Material selection and processing: the selection of appropriate plastic raw materials is critical, different plastic materials have different melting point, fluidity and shrinkage, these characteristics directly affect the molding quality and subsequent use of performance. In addition, appropriate drying treatment of raw materials to avoid excessive moisture content caused by internal porosity and stress concentration.

2. Optimize mold design: Reasonable mold design can effectively disperse pressure and reduce the risk of stress concentration. For example, measures such as increasing rounded transitions, reasonable setting of gates and air vents can ensure smooth material flow and reduce gas and pressure trapping, thus reducing the possibility of defects.

3. Temperature and Pressure Control: Accurate temperature and pressure control is one of the key factors in guaranteeing product quality. Too low a temperature may result in poor material flow and incomplete filling; too high a temperature may cause material degradation. Similarly, proper adjustment of injection pressure and holding pressure ensures that the plastic fills the mold cavity and cools uniformly.

4. Post-processing: For cracking problems that have already occurred, some post-processing techniques can be used to mitigate their effects. For example, annealing can reduce or even eliminate microcracks by releasing residual stresses within the plastic through a slow heating and cooling process.

5. Detection and analysis: When cracking problems occur, detection and cause analysis should be carried out immediately. Using scanning electron microscope (SEM), differential scanning calorimeter (DSC) and other precision equipment for microscopic observation and composition analysis of plastic parts, to find out the root cause of the problem and develop targeted solutions.

6. Production process monitoring: Through real-time monitoring systems, such as sensor technology and intelligent control software applications, the parameters in the production process can be continuously monitored and adjusted to detect and react to abnormalities in a timely manner.