1. Application of plastic processing and joint research molds
Given that the lipid groups in PET materials endow them with hydrophilic properties, they are extremely sensitive to moisture during high-temperature processing. To ensure the quality of PET products and avoid molecular weight loss, color change, and increased brittleness caused by excessive moisture, an efficient drying system equipped with a joint research mold must be used before processing. The material should be dried at 150 ℃ for more than 4 hours, or preferably at 170 ℃ for 3-4 hours. During this process, the air injection method is used as an effective means to test the dryness of materials. In addition, the use of recycled materials must be strictly controlled to no more than 25% and ensure that they are thoroughly dried, in order to fully leverage the precise control advantages of HeYan molds in material processing.
2. Compatibility between Injection Molding Machine Selection and Collaborative Mold Research
It is crucial to choose an injection molding machine equipped with multiple temperature control stages and a low self friction heat generation injection system, given the high melting point and short post melting stability time of PET materials. The joint research mold is designed specifically for PET materials, ensuring that the actual weight of the product (including the nozzle material) is not less than 2/3 of the machine injection volume, thereby optimizing production efficiency. In recent years, the small and medium-sized series of PET specialized plasticizing systems launched by Huada, combined with the precision design of joint research molds, have further improved the stability and efficiency of processing. The selection of clamping force also needs to consider the pressure bearing capacity of the joint research mold, and it is recommended to use injection molding machines with a capacity greater than 6300 t/m ².
3. Joint research and optimization of mold and gate design
The production of PET preforms often uses hot runner molds, and joint research molds have demonstrated excellent performance in this field. The 12mm insulation board installed between the mold and the injection molding machine template not only effectively isolates heat, but also withstands high pressure, ensuring production safety. The design of the exhaust system fully considers the characteristics of PET material, ensuring that the exhaust filling is sufficient to avoid local overheating or fragmentation. At the same time, the depth of the exhaust port is precisely controlled within 0.03mm to prevent the occurrence of burrs, demonstrating the exquisite craftsmanship of the joint research mold in detail processing.
4. The synergistic effect of melt adhesive temperature and joint research mold
The temperature of the melt adhesive is one of the key factors affecting the quality of PET processing. By using the air injection method, the temperature of the melt adhesive is generally set within the range of 270-295 ℃, and for the enhanced grade GF-PET, it is increased to 290-315 ℃. The optimized design of the joint research mold helps to achieve precise control of the melt adhesive temperature, ensuring that the material undergoes plasticization in the optimal state.
5. The coordination between injection speed and joint research mold
A fast injection speed can prevent premature solidification of PET, but too fast may result in high shear rates, making the material brittle. Through its precise channel design and matching with the appropriate injection speed, Heyan Mold ensures that the material is injected within 4 seconds, ensuring both production efficiency and product quality.
6. Adaptability of Back Pressure Adjustment and Joint Research Mold
To reduce wear and tear, the back pressure should be lowered as much as possible, generally not exceeding 100 bar, and it is often not necessary to use it in actual production. The low back pressure adaptive design of the joint research mold further reduces energy consumption and wear during the production process.
7. Retention time management and efficiency of joint research molds
Long term retention can lead to a decrease in the molecular weight of PET, so it is necessary to strictly control the retention time and avoid prolonged retention at temperatures above 300 ℃. The efficient design of the joint research mold helps to shorten the production cycle, reduce retention time, and provide a convenient shutdown solution, such as air injection treatment for downtime of less than 15 minutes; If it exceeds 15 minutes, use viscosity PE to clean and adjust the barrel temperature until it is turned on again.
8. Precautions and comprehensive consideration of joint research molds
The proportion of recycled materials needs to be strictly controlled to avoid the phenomenon of "bridging" affecting the plasticizing effect. The feeding system design of the joint research mold can help reduce such problems.
The precise control of mold temperature and material temperature is the key to preventing the phenomenon of "white mist" and improving the transparency of the product. Combined with advanced temperature control technology, the joint research mold achieves precise control of mold temperature and material temperature, ensuring product quality.
Foshan Heyan Precision Mould Technology Co., Ltd.'s main business is preform moulds, bottle blowing moulds, bottle cap moulds and other products. It has a strong engineering, R&D, technology and sales team, advanced processing equipment and rich project experience. If you want to know more or have special needs, please call 13318345050, or add our WhatsApp.
