Introduction
During the production of automotive interior components, occasional bright spots may appear due to the poor compatibility between silicone and polypropylene during injection molding. This issue not only affects the aesthetic quality of the products but also potentially reduces customer satisfaction. To effectively address this problem, the R&D team at Chongqing Baozhuan New Materials has conducted in-depth research and developed a new type of silicone masterbatch, BZPP308, specifically optimized to tackle the bright spot issue.
Main Factors Influencing the Bright Spot Phenomenon
1. Formulation Design
- Flowability: The higher the flowability of the formulation system, the more it helps to mitigate the bright spot phenomenon.
- Silicone Masterbatch Addition: The larger the amount of silicone masterbatch added, the greater the probability of bright spots occurring.
- Dispersion: Better dispersion of the silicone masterbatch within the formulation system is more favorable for reducing the bright spot phenomenon.
Schematic diagram of typical structure of silicone
2. Molding Process
- Injection Speed and Pressure: An increase in injection speed and pressure can lead to an increase in the area affected by bright spots and a higher likelihood of defects.
- Injection Temperature: A lower injection temperature can also exacerbate the bright spot phenomenon.
3. Molding Die
- Mold Venting: Poor mold venting increases the likelihood of bright spots.
- Surface Texture: Fine-grained textures are far more prone to bright spots than coarse ones.
Solution with the New Silicone Masterbatch BZPP308
1. Improvement in Bright Spots
- Under conditions of adding 5% silicone masterbatch, the bright streaks were compared using low-temperature and high-speed injection molding processes. Test results showed that after incorporating BZPP308, the bright spots were significantly improved, leading to a marked enhancement in surface quality.
Comparison of bright spot flow marks using low temperature and high speed injection molding processes with 5% silicone masterbatch addition
2. Scratch Resistance Performance
- Comparative scratch resistance data:
3. Mechanical Properties
- Comparative mechanical properties under the same conditions:
| Test Item | BZPP301 | BZPP308 | Si-MB from company1 | Si-MB from company2 |
| Izod impact performance (23℃,kJ/m²) | 36.7 | 37.3 | 36.1 | 35.9 |
| Melt Index(g/10min) | 16.7 | 16.9 | 16.2 | 17.3 |
| Stress whitening resistance(△L) | 0.53 | 0.49 | 0.76 | 0.65 |
| Surface stickiness | No | No | No | No |
*The above formula system is PP+EPDM+T20, the silicone masterbatch addition amount is 2%
Conclusion
By utilizing the new silicone masterbatch BZPP308, not only can the bright spot issues during the injection molding process be effectively addressed, but the scratch resistance and mechanical properties of the materials can also be significantly enhanced. This solution greatly improves the aesthetic quality and overall performance of automotive interior components, meeting the market demand for high-quality materials. Chongqing Baozhuan New Materials will continue to develop more efficient and environmentally friendly solutions, providing customers with superior products and services.
For any inquiries or needs, feel free to contact us at any time.
Chongqing Baozhuan New Material Technology Co.,Ltd has a team of senior R & D, marketing and sale in the polymer industry, focusing on the innovative R & D, production and sales of high-end additives.
The main products are silicone masterbatch, silicone powder, flame retardant, flame retardant synergist, light stabilizer, rheological agent, laser marking additives, compatilizing dispersant, lubricating dispersant, adsorbent,etc.Official website Address:https://www.additivebz.com/
