tapi butuh beberapa hari untuk menggambar gambar 3D dan kemudian?
tapi butuh beberapa hari untuk menggambar gambar 3D dan kemudian.
Depresi atau depresi mikro pada permukaan produk cetakan injeksi adalah masalah lama dalam proses pencetakan injeksi. Penyok umumnya disebabkan oleh peningkatan tingkat penyusutan produk plastik yang disebabkan oleh peningkatan ketebalan dinding. Mereka mungkin muncul di dekat sudut tajam eksternal atau perubahan mendadak dari ketebalan dinding, seperti tonjolan, bagian belakang pengaku atau penyangga, dan terkadang di beberapa bagian yang tidak biasa. Akar penyebab penyok adalah ekspansi termal dan penyusutan dingin material, karena koefisien muai panas termoplastik cukup tinggi. Tingkat ekspansi dan penyusutan tergantung pada banyak faktor, among which the plastic properties, the maximum and minimum temperature range and the cavity packing pressure are the most important factors, and the size and shape of the injection parts, the cooling rate and uniformity are also the influencing factors. Dents and shrinkage marks on plastic products are common molding defects. Seperti yang ditunjukkan pada gambar:
tapi butuh beberapa hari untuk menggambar gambar 3D dan kemudian
1) Improper control of molding conditions
If the injection pressure is too low, the injection and holding time is too short, the injection rate is too slow, the material temperature and mold temperature are too high, the cooling of the plastic part is insufficient, the temperature during demoulding is too high, the temperature at the insert is too low or the material supply is insufficient, the surface of the plastic part will appear concave or orange peel like micro unevenness. Karena itu, it is necessary to increase the injection pressure and injection speed, increase the compression density of the melt, extend the injection and holding time, compensate the melt shrinkage and increase the injection recoil. But the packing pressure should not be too high, otherwise it will cause convex mark.
1. If the depression and shrinkage mark occur near the gate, it can be solved by extending the holding time. The cooling time of the plastic part in the mold should be extended appropriately when the plastic part is concave at the wall thickness.
2. If the local shrinkage of the melt around the insert causes depression and shrinkage mark, which is mainly caused by the low temperature of the insert, we should try to increase the temperature of the insert.
3. If the nozzle hole of the injection molding machine is too small or the nozzle is partially blocked, the local loss of injection pressure will also cause depression and shrinkage mark. Dalam kasus ini, the nozzle should be replaced or cleaned.
4. If the surface of plastic parts is depressed due to insufficient feeding, the feeding amount should be increased.
Tambahan, the cooling of plastic parts in the mold must be sufficient. Di tangan satunya, the melt temperature can be appropriately reduced by adjusting the barrel temperature; di samping itu, the setting of the mold cooling system can be changed to reduce the temperature of the cooling water, or the cooling of the concave parts can be properly strengthened on the premise of maintaining the uniform cooling of the mold surface and all parts as far as possible. Jika tidak, when the plastic part is demoulded under the condition of insufficient cooling, it is not only easy to produce shrinkage depression, but also local depression of the plastic part in the ejector due to hard demoulding.
2) Cacat cetakan
If the cross-section of runner and gate is too small, the mold filling resistance is too large, the gate setting is asymmetric, the mold filling speed is not balanced, the position of feed gate is not reasonable, and the mold exhaust affects the feeding, feeding and cooling, or the mold wear causes the pressure relief, it will lead to the surface depression and shrinkage mark of plastic parts. Karena itu, the gate and gate cross-section should be appropriately expanded according to the specific situation The gate position should be set at the symmetrical position as far as possible, and the feeding gate should be set at the thick wall of the plastic part.
If the depression and shrinkage mark occur far away from the gate, it is generally due to the poor flow of molten material in a certain part of the mold structure, which hinders the pressure transmission. Karena itu, the structure size of the gating system should be appropriately expanded, especially for the “bottleneck” which hinders the melt flow, the runner section must be increased, and it is better to extend the runner to the concave part.
For thick wall plastic parts, wing gate should be preferred. Lewat sini, for the plastic parts which are not suitable to set the gate directly on the plastic parts and are easy to produce residual deformation at the gate after molding, a wing body can be attached to the plastic parts, and then the gate can be set on the winglet. The gate on the winglet can use the reverse gate and the point gate, so as to transfer the concave defects of the plastic parts to the winglet, and then cut off the winglet after molding.
Tambahan, it is necessary to frequently check whether there is wear relief or poor exhaust of the mold, and timely replace the consumable parts in the mold or improve the exhaust condition of the mold.
3) Bahan baku tidak memenuhi persyaratan pencetakan
1. If the shrinkage rate of molding raw materials is too high or the flow performance is too poor, and the lubricant in the raw materials is insufficient or the raw materials are wet, the surface of the plastic parts will produce depressions and shrinkage marks. Karena itu, for plastic parts with high surface requirements, low shrinkage resin grade should be selected as far as possible.
2. If the underfill depression is caused by the poor flow of the molten material, an appropriate amount of lubricant can be added to the raw material to improve the fluidity of the molten material or increase the structural size of the gating system.
3. If the surface of plastic parts is depressed due to the moisture of raw materials, the raw materials should be pre dried.
4) Unreasonable shape and structure design of plastic parts
If the wall thickness of plastic parts varies greatly, the thick wall parts are prone to depression and shrinkage marks due to insufficient pressure. Karena itu, when designing the shape and structure of plastic parts, the wall thickness should be as consistent as possible. For special cases, if the wall thickness of plastic parts is different, it can be solved by adjusting the structural parameters of the gating system.
Tentang JasonMould Industrial Company Limited
Jasonmould adalah pembuat cetakan Cina dari cetakan plastik- cetakan injeksi, cetakan die casting, cetakan tiup plastik, cetakan rotasi, medis cetakan injeksi plastik, dua tembakan cetakan injeksi plastik, masukkan cetakan, overmolding, cetakan injeksi logam, cetakan injeksi mikro, cetakan injeksi bubuk, cetakan injeksi keramik, cetakan injeksi cair, cetakan injeksi husky, cetakan rumah tangga, pengecoran cetakan, alat cetakan mati, cetakan khusus, cetakan cina, perkakas prototipe cepat rapid, perkakas prototipe plastik plastic, perkakas tekan pukulan, mati dan perkakas untuk bagian ponsel / ponsel cell, bagian otomotif, penyedot debu, alat isi ulang, telepon, mesin fotokopi, komputer, speaker multimedia, dan banyak produk elektronik dan peralatan rumah tangga lainnya. Dan juga produsen produk plastik, produsen cetakan Cina- bagian-bagian yang terbuat dari plastik, tangki air plastik, bola plastik, wadah plastik, gesper plastik, jangkar plastik, gantungan plastik, sendok plastik, pemasangan pipa plastik, gelas plastik, peralatan makan plastik, gelas plastik, botol-botol plastik, nampan plastik, wadah kosmetik plastik, kotak plastik, wadah makanan plastik, kursi plastik, tutup plastik, penutupan tutup plastik, tabung plastik, pipa air plastik, kenop plastik, tabung plastik, kotak utilitas plastik, rak plastik dan sebagainya.
Kontak:
Orang: James Yuan
Perusahaan: JasonMould Industrial Company Limited
Menambahkan: Desa LongGang,Kota LongXi,Kabupaten BoLuo,Kota HuiZhou,Provinsi Guangdong, Cina
Telp: 86-752-6682869
Surel: [email protected]
Situs: https://www.jasonmolding.com/custom-injection-molding/
