Application and practice of injection molding process in the field of automotive plastic parts (2)


In order to ensure reliable clamping, the process clamp […]

In order to ensure reliable clamping, the process clamping force during injection molding must be less than the rated clamping force of the injection molding machine. The Z theoretical injection volume of the injection molding machine matches the clamping force tonnage of the injection molding machine. It is the nominal injection volume of the injection molding machine based on polystyrene (PS) resin before leaving the factory.
Fourth, according to the characteristics of the complex plastic parts of the automobile, the driving mode and mold clamping mechanism of the injection molding machine are designed. At present, hydraulic-mechanical or full-hydraulic hydraulic toggles or direct pressure mold clamping at the center are more commonly used in China. Institutional injection molding machine. After years of hard work, Tairui Machinery Co., Ltd. broke through the traditional constraints and developed a two-plate clamping direct pressure and compound clamping mechanical structure.
The advantage of this structure is that its mold opening stroke is much larger than that of the hydraulic toggle mold clamping structure, at least 2 times, which can meet the production requirements of large-scale automobile plastic parts (such as bumpers, dashboards, etc.). Secondly, the clamping adopts 4 composite oil cylinders to lock synchronously, and realize the stable clamping of large tonnage with small flow. The clamping force can be higher than the hydraulic toggle clamping structure of the same tonnage. Fully guarantee the precision of the molding compound surface of the large and complex plastic parts of the automobile.
Fifth, because the cavity surface of auto parts is very complicated, the injection molding machine should consider its particularity when designing, and configure some special functional programs: such as multiple core pulling functions, timing control functions, and injection molding machine supporting mold changing device functions. , Supporting the functions of pickup manipulator device, etc. These special functions have obvious advantages in the production of automotive plastic parts.
For example, in the bumper production process of this type of injection molding machine, in order to shorten the production cycle, the picking manipulator automatically takes out the large plastic parts after the mold is opened and ejected. Multiple sets of core pulls make the large plastic products stable and integral. Out, there will be no whitening or cracking. At present, we mostly use 3-axis pick-up robots in this injection molding system, and some use 6-axis pick-up robots.
Advantages of automotive plastic parts, advantages of automotive complex plastic parts:
1. The plastic can be processed and formed at one time, the processing time is short, and the accuracy is guaranteed.
2. The elastic deformation characteristics of plastic products absorb a large amount of collision energy, have a greater buffering effect on strong collisions, and protect vehicles and occupants. Plasticized dashboards and steering wheels are used in modern cars to enhance cushioning. The front and rear bumpers and the car body trim are made of plastic materials to reduce the impact of objects outside the car on the car body. Plastic also has the function of absorbing and attenuating vibration and noise, which can improve the comfort of riding.
3. The plastic has strong corrosion resistance, and it will not corrode if damaged locally.
4. By adding different fillers, plasticizers and hardeners to produce plastics with required properties to meet the requirements of different parts of the car. What's more convenient is that the color of the plastic can be adjusted to different colors through additives, saving the trouble of painting. Some plastic parts can also be electroplated.