PC mempunyai prestasi yang sangat baik, ketelusan yang tinggi, ketahanan hentaman yang baik, rintangan merayap, suhu yang luas. Ciri-ciri proses PC adalah: kepekaan kelikatan lebur terhadap kadar ricih adalah kecil, tetapi mempunyai kepekaan yang besar terhadap suhu, tiada titik lebur yang jelas, kelikatan cair yang tinggi, hidrolisis mudah resin pada suhu tinggi dan produk mudah retak. Memandangkan ciri-ciri ini, kita harus memberi perhatian khusus kepada perlakuan yang berbeza: untuk meningkatkan kecairan leburan, we should not increase the injection pressure but also adopt the method of increasing the injection temperature. The runner and gate of the mould are required to be short and thick to reduce the pressure loss of the fluid and to have a higher injection pressure. Before forming and processing, the resin should be dried sufficiently to keep its moisture content below 0.02%. Sebagai tambahan, heat preservation measures should be taken to prevent moisture absorption during the process. Not only the reasonable product design is needed, but also the molding process should be correctly mastered, such as increasing the mold temperature and post-treatment of the products, dan lain-lain. can reduce or eliminate the internal stress. Adjust the process parameters according to the different conditions of the product.
Here is the forming process
1. Injection temperature must be integrated with the shape, size and mold structure of the product. The performance and requirements of the products can only be made after considering the conditions. Secara amnya, the temperature of the molding is between 270-320 ℃, jika suhu bahan lebih tinggi daripada 340 ℃, PC akan reput, the product color will become darker, and the surface will show defects such as silver wire, jalur gelap, black spot and bubble, and the physical and mechanical properties also decrease significantly.
2. Injection pressure has a certain influence on the physical and mechanical properties, internal stress and molding shrinkage of PC products, which has a great influence on the appearance and demoulding performance of the products. Low or too high injection pressure will cause some defects of the products. Secara amnya, the injection pressure is controlled between 80-120MPa, and for products with thin wall, proses yang panjang, complex shape and small gate, In order to overcome the resistance of melt flow and fill the cavity in time, the higher injection pressure (120-145cangkang penutup keselamatan) is selected. Oleh itu, the products with complete and smooth surface are obtained.
3. The pressure maintaining pressure, the pressure holding time and the length of the holding time have a great influence on the internal stress of PC products. The pressure maintaining pressure is too small, and the small shrinkage effect is easy to appear vacuum bubble or concave surface, too much pressure retaining pressure, and the large internal stress is easily produced around the gate. In the actual processing, the method of high material temperature and low pressure keeping is often used to solve. The selection of pressure holding time should be determined by the thickness of the product, the size of the gate and the mold temperature. Secara amnya, the small and thin products do not need a long holding time. Sebaliknya, the pressure holding time of the large and thick products should be longer. The length of pressure holding time can be determined by the test of gate sealing time.
4. The injection speed has no obvious influence on the performance of PC products. Kecuali berdinding nipis, pintu pagar kecil, lubang dalam dan produk proses panjang, kelajuan sederhana atau pemprosesan perlahan biasanya diterima pakai, preferably multi-stage injection, and the slow fast slow multi-stage injection method is generally adopted.
5. The mold temperature can be controlled at 80-100 ℃, and the shape of the products with complex shape, thin and high requirements can also be increased to 100-120 ℃, tetapi ia tidak boleh melebihi suhu ubah bentuk panas acuan.
6. Screw speed and back pressure are characterized by high viscosity of PC melt, which can be beneficial to plasticizing, exhaust and maintenance of plastic machine, to prevent screw overload. The speed requirement of screw should not be too high. Secara amnya, it is appropriate to control the screw speed at 30-60r/min, while the back pressure should be controlled between 10-15% tekanan suntikan.
7. PC should strictly control the use of mold release agent in the process of injection molding, and the use of recycled materials should not exceed three times, and the usage should be about 20%. Requirements for the molding machine for PC products: the maximum injection volume (including runner, pintu gerbang, dan lain-lain.) of the products shall not be greater than 70-80% of the nominal injection quantity. The screw shall be of single head thread equal pitch and gradient compression screw with check ring. The length diameter ratio of screw l/d is 15-20, and the geometric compression ratio c/r is 2-3.
Mengenai JasonMould Industrial Company Limited
Jasonmould adalah Pembuat acuan China dari acuan plastik- acuan suntikan, acuan pemutus mati, acuan plastik, acuan putaran, perubatan pengacuan suntikan plastik, dua pukulan pengacuan suntikan plastik, masukkan acuan, terlalu banyak, pengacuan suntikan logam, pengacuan suntikan mikro, pengacuan suntikan serbuk, pengacuan suntikan seramik, pengacuan suntikan cecair, acuan suntikan husky, acuan isi rumah, acuan pemutus, alat acuan mati, acuan khas, acuan cina, perkakas prototaip pantas, perkakas prototaip plastik, perkakas penebuk, mati dan perkakas untuk bahagian telefon bimbit / telefon bimbit, bahagian automotif, pembersih vakum, alat yang boleh dicas semula, telefon, mesin penyalin, komputer, pembesar suara multimedia, dan banyak produk elektronik dan perkakas rumah yang lain. Dan juga pengeluar produk plastik, pengeluar acuan China- bahagian plastik, tangki air plastik, bola plastik, bekas plastik, gesper plastik, sauh plastik, penyangkut plastik, sudu plastik, pemasangan paip plastik, plastik jatuh, pinggan mangkuk plastik, cawan plastik, botol plastik, dulang plastik, bekas kosmetik plastik, sarung plastik, bekas makanan plastik, kerusi plastik, penutup plastik, penutup penutup plastik, tiub plastik, paip air plastik, tombol plastik, tiub plastik, kotak utiliti plastik, rak plastik dan sebagainya.
Hubungi:
Orang: James Yuan
Syarikat: JasonMould Industrial Company Limited
Tambah: Kampung LongGang,Bandar LongXi,Daerah BoLuo,Bandar HuiZhou,Wilayah GuangDong, China
Tel: 86-752-6682869
E-mel: [email protected]
Tapak: https://www.jasonmolding.com/custom-injection-molding/
