The quality of car lights is very important to driving safety, so the laws and regulations of various countries in the world have strict requirements on car lights. The design of car lights must not only meet the safety requirements of regulations, but also meet some other requirements. For example, the appearance must be integrated with the appearance of the entire car, beautiful and practical, and meet the requirements of aerodynamics. And passengers feel comfortable and convenient. Therefore, the design technology of car lights is also changing with the development of the automobile industry.

Automobile lights are generally composed of a base and a lamp shell. The material of the base is usually a thermosetting material-BMC (bulk molding compound). The lamp shell can be processed by PMMA, PP, ABS and other materials, usually two-color or three-color. In the production process of two-color car lights, special attention should be paid to the injection part of the two-color injection molding machine. The center distance of the two screws corresponds to the center distance of the two-color mold. In addition, the following important points need to be paid attention to:

1. The influencing elements of the stable forming of car lights

• Control unit response: too long switching point, noise interference, unstable command output, unstable temperature;
• The noise of the hydraulic system: unstable pressure, valve positioning quality, hysteresis, changes in tubing damping;
• Differences in mechanical systems: oil seal leakage, damping, friction differences, screw check valve positioning, and check effect;
• Uneven plasticization: differences in plasticization quality;
• Mold temperature control.

2. Common problems in car taillight design

• The screw does not feed when idling;
• The torque required by the screw is too large to rotate;
• The plastic has not completely melted;
• Screw measurement is unstable;
• Uneven plastic mixing;
• There are bubbles in the molded product;
• Easy to turn yellow in the molded product;
• The screw is easy to corrode, wear, and has a short service life.

3. Key points of screw design

• The screw is the heart component of the injection molding machine, responsible for the transportation, melting, mixing, metering and other functions of plastic raw materials. Therefore, the plastic plasticizing screw is closely related to the quality of the molded product.
• The main purpose of the improved screw is to: uniformly mix; improve the plasticizing ability;