1. Key points of material selection and pretreatment
The first step of injection molding is to select the right material. According to the performance requirements of sensor structural parts, suitable plastic particles should be selected, such as high temperature resistant, high toughness or high insulation plastics. After selection, the material needs to be dried to remove moisture, prevent defects such as bubbles and silver wires during injection molding, ensure molding quality, and lay the foundation for subsequent processes.
2. Key points of mold design
The mold can be called the "heart" of injection molding. For sensor structural parts, the mold should accurately design the cavity size and shape, consider the plastic cooling shrinkage rate, reserve a reasonable margin, and ensure the dimensional accuracy of the finished product. At the same time, optimize the runner system so that the plastic melt can fill the cavity evenly and quickly, avoid short shots and uneven filling, and ensure that all parts of the structural parts are molded completely.
3. Optimization of injection molding process parameters
During injection molding, parameters such as temperature, pressure, and speed are crucial. The barrel temperature needs to be precisely controlled in sections to ensure that the plastic is fully melted and has good fluidity; the injection pressure should be moderate. Too high pressure can easily cause flash and residual stress, while too low pressure will result in insufficient filling; the injection speed affects the flow morphology of the melt and should be reasonably adjusted according to the complexity of the structural parts. Quick injection should be performed at thin walls to avoid excessive cooling and ensure the molding effect.
4. Breakthrough of Difficulties in Cooling and Demolding
The cooling process affects product quality and production efficiency. The mold cooling water channel should be reasonably designed to ensure uniform cooling and prevent deformation and warping due to uneven shrinkage. In the demolding process, the demolding mechanism, such as sliders and inclined tops, should be cleverly designed for the complex undercuts and side holes of the structural parts to ensure smooth demolding and avoid scratching the product surface and damaging the structural parts.
5. Key points for quality inspection and control
After injection molding, the sensor structural parts should be inspected for quality immediately. Use high-precision measuring tools to measure dimensional deviations, use flaw detection equipment to check internal defects, and use appearance inspection equipment to screen surface defects such as flow marks and gas marks, so as to promptly discover problems and trace them back to the process links for rectification to ensure product yield.
6. Process stability guarantee
In order to achieve stable production, regular maintenance of injection molding machines, molds and other equipment is required. Monitor process parameter fluctuations, use statistical process control (SPC) methods to adjust abnormalities in a timely manner, so that the quality of each batch of sensor structural parts is uniform and meets the high-precision assembly requirements of sensors.
7. Environmental protection and cost balance
In the injection molding process, take into account both environmental protection and cost. Use environmentally friendly and recyclable materials to reduce waste; optimize the process to reduce the scrap rate, reasonably plan the mold life, reduce costs from materials, energy, and equipment, and improve product competitiveness.
