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Cacat umum produk cetakan injeksi dan solusinya

• 2025-07-29

Cacat umum produk cetakan injeksi dan solusinya

    Diagnosis dan penyebab cacat produk umum adalah sebagai berikut.

(1) Lekukan produk

    Fenomena: depresi atau gelembung, lubang runtuh, penyusutan, rongga penyusutan, gelembung vakum, dll. Dalam produk semuanya adalah cacat produk.

    Alasannya adalah karena penahanan dan pemberian tekanan yang buruk, produk mendingin dan senyawa karet dalam rongga cetakan tidak cukup, menyebabkan penyusutan plastik yang berlebihan. Ini menghasilkan penyok, lubang runtuh, gelembung vakum, dan bayangan berongga pada permukaan produk, memberikan penampilan yang tidak rata.

(2) Produk jadi tidak memuaskan

    Fenomena: Bagian plastik yang buruk, cetakan yang tidak lengkap, dan permukaan gelembung yang tidak lengkap adalah semua cacat produk jadi yang tidak lengkap.

    Alasan utamanya adalah fluiditas material yang buruk, pemberian makan yang tidak mencukupi, aliran pengisian bahan cair yang buruk, inflasi berlebihan dan knalpot yang buruk, yang menyebabkan pengisian rongga cetakan yang tidak lengkap, menghasilkan bentuk bagian plastik yang tidak lengkap dan tidak lengkap atau pengisian rongga individu yang tidak lengkap atau pengisian cetakan yang buruk ketika ada banyak rongga.

(3) Flash Produk

    Fenomena: Flash yang berlebihan dan tepi kasar sebagian besar cacat dari gerinda produk.

    Alasannya adalah karena penjepitan yang buruk dari cetakan, obstruksi berlebihan atau celah di tepi cetakan, fluiditas plastik yang terlalu baik, dan injeksi senyawa karet yang berlebihan, produk bagian plastik memiliki sayap tipis ekstra, tepi bersisik, dll. Di sepanjang tepi.

Mould_Taizhou jiifeng Mould Co.,Ltd. (jfmoulds.com)

(4) pengelasan produk yang buruk

    Fenomena: Tanda pengelasan yang jelas dan garis fusi permukaan adalah cacat pengelasan yang buruk dalam produk.

    Alasannya adalah bahwa karena kontaminasi material, pendinginan berlebihan senyawa karet, dan penggunaan agen pelepasan cetakan yang berlebihan, kadar air dari bahan cair dan campuran berkurang, dan resin dan lampirannya tidak dapat dilihat. Alasan -alasan ini menyebabkan fusi yang buruk selama aliran material yang meleleh dan campuran, menghasilkan jahitan halus yang jelas atau garis fusi lemah di sepanjang permukaan atau di dalam produk.

(5) retak dalam produk

    Fenomena seperti menarik retak, retak atas, pecah dan retak cangkang kura -kura adalah semua cacat retakan produk.

    Alasan: Karena tekanan internal yang berlebihan dari produk, demolding yang buruk, pendinginan yang tidak merata, rasio pencampuran plastik yang tidak tepat, kinerja yang buruk, dan desain cetakan yang buruk atau pengaturan parameter yang tidak tepat seperti tekanan pin ejeksi yang berlebihan, retakan, retakan halus, retak atau retak di bawah beban dan aksi pelarut terjadi pada permukaan produk.

(6) deformasi produk

    Fenomena seperti deformasi, warping, pembengkakan permukaan, dan ketidakstabilan dimensi adalah semua cacat deformasi produk.

    Alasan karena tekanan internal yang disebabkan oleh tegangan residual, tegangan geser, ketebalan dinding yang tidak merata pada produk dan penyusutan yang tidak merata selama cetakan injeksi, bersama dengan demolding yang buruk, pendinginan yang tidak memadai, kekuatan produk yang tidak memadai, deformasi cetakan dan alasan yang tidak dapat diatasi, dengan cara yang tidak dapat dibentuk, dengan cara yang tidak dapat dibentuknya, pora yang tidak dapat diatasi, pingsan, pora yang tidak dapat diatasi, menyimpang dari lubang cetakan yang tidak dapat diikat, tidak dapat diatasi, menyimpang dari lubang cetakan yang tidak ada. Mesin cetakan injeksi, dan kondisi teknis proses yang tidak stabil, perubahan dimensi produk tidak stabil.

Komoditas mould_taichu jiifeng Mould Co.,Ltd. (jfmoulds.com)

(7) Pola perak pada produk

    Fenomena: Pola benang perak, pola awan permukaan, pola perak permukaan, dll. Semua cacat pola perak pada produk.

    The reason is that due to excessive moisture, excessive aeration or too much volatile matter in the plastic raw materials, the molten material is subjected to excessive shearing, the surface of the molten mold is poorly sealed, or it cools rapidly, mixes in impurities or decomposes and deteriorates, resulting in the appearance of silvery-white lustrous needle-like stripes or mica flaky patterns along the surface of the product.

(8) Perubahan warna produk

    Fenomena: Perbedaan warna, warna yang tidak rata, dan perubahan warna produk adalah semua cacat perubahan warna produk.

    Reason Due to poor distribution of pigments or fillers, material contamination and degradation, excessive volatile substances in materials, and decomposition of colorants and additives, plastics or pigments may change color, resulting in color differences on the surface of the products. Products with uneven color are often related to the poor thermal stability of plastics and raw materials. Uneven color in the welded part is often related to the deterioration and degradation of pigments (uneven color refers to the phenomenon where the color of the product is either darker or lighter and inconsistent with the standard color after comparison).

(9) Product corrugations

    Phenomena: Surface ripples, flow patterns, plastic surface ripples, etc. are all ripple defects of the products.

    The reason is that the molten material does not flow smoothly along the mold surface to fill the cavity, but rather flows in a semi-cured and fluctuating state along the mold cavity surface. There is a retention phenomenon of the molten material, causing ripples.

(10) The product is rough

    Phenomena: Dull surface, rough surface, mold spots, streaks, scratches, mold marks, handprints, etc. are all manifestations of rough or unsmooth products.

    The main reasons are insufficient surface finish of the mold, poor adhesion between the molten material and the mold surface, other impurities adhering to the mold or surface marks after mold maintenance and repair, improper operation, lack of cleanliness, and improper setting of parameters such as material temperature and mold temperature, which result in the product surface being not bright, having marks, not smooth, scratches and scars, mold marks, and the surface being milky white or whitish.

(11) Bubbles in the product

    Phenomenon: Defects such as internal vacuum bubbles in the product or bubbles in expanded products.

    The reason is that due to excessive inflation or poor venting in the molten material, the remaining monomers, gases and moisture inside the product form small or string cavities or vacuum bubbles.

(12) The product sticks to the mold

    Phenomena: Poor demolding, plastic part sticking to the mold and other defects.

    The reason is that due to material contamination or non-drying, poor demolding performance of the mold, overly strong filling effect, etc., the products are difficult to demold or deform or crack after demolding, or the residual direction of the products does not meet the design requirements.

(13) The products delaminate and peel off

    Phenomena: Defects such as delamination and peeling of mica flakes, and layered plastic at the gate.

    The reason is that due to improper raw material mixing ratio, improper material temperature or mold temperature, uneven plasticization, and excessive shear force when the molten material flows along the mold surface, the material peels off in thin layers, resulting in a decline in the physical properties of the product.

(14) Gate sticking to the mold

    Phenomena: Gate or sprue blockage, broken glue, broken pins, runner sticking to the mold, and sprue sticking to the mold are all gate sticking defects. In mild cases, the mold sticks; in severe cases, it gets clogged.

    The reason is that due to insufficient design of the gate opening and the slope of the gate, the limited force acting inside the gate sleeve, or insufficient cooling, the gate adheres to the gate sleeve or blocks the sprue, etc.

(15) The product is cloudy

    Phenomenon: Poor transparency, turbidity defect at the gate of the product.

    The reasons are as follows: Due to material contamination and poor drying, poor contact between the molten material and the mold surface, fine depressions on the product surface causing random light scattering or plastic decomposition, and the presence of impurities and waste materials, the mold surface is not bright, and the exhaust is not good, which can cause the transparent plastic to be poorly transparent or uneven.

(16) Spots on the product

    Phenomenon: Black spots, black lines, yellow spots, yellow lines, black stripes, brown stripes, etc. on the product are all spot defects of the product.

    Reason: Due to the decomposition of plastic or the decomposition and combustion of flammable volatile substances, air, etc. in the material under high temperature and high pressure, the burned resin is injected into the mold cavity along with the molten material, presenting various spots on the surface of the product, such as black spots, yellow spots, black stripes, brown stripes, etc., or along the surface of the product, it shows a grayish burn.

(17) Stiff lumps of the product

    Phenomenon: Defects such as cold lumps or hard lumps in the product.

    The reason is that due to the addition of cold materials or poorly plasticized rubber compounds, these unplasticized and insufficiently plasticized materials cause the plastic products to be undercooked.

(18) Glue leakage

    Phenomena: Defects such as material overflow and glue dripping from the nozzle.

    The reasons are: The temperature setting of the barrel and the nozzle is improper, the contact between the nozzle and the main gate die is poor, the clamping force is uneven or unstable, the fluidity of the plastic is too good, and the temperature of the nozzle is too high, resulting in the phenomenon of glue leakage and material overflow.

    Defects in injection molding products are the root cause of substandard product quality, and these defects are also related to the technical proficiency of injection molding operators and maintenance workers. To ensure product quality, injection molding operators are required to have rich practical experience in injection molding machines and process technologies. One should be familiar with and understand the performance of the injection machine being used, and have a comprehensive grasp and application of it. It is necessary to have a comprehensive grasp of injection molding process technology and master the entire process setting and calibration from plastic raw materials to product packaging.

    During the injection molding operation process, common product defects also have certain trends. The common practice is to accurately identify and diagnose product defects, comprehensively analyze the possible causes, and combine practical work experience to explore a set of rules. Through the setting of plastic raw materials, various temperature parameters, pressure parameters, speed parameters, stroke parameters, and time parameters, In light of specific circumstances such as molds, nozzles, melt tubes, screws, as well as lubricants and mold release agents, reasonable parameter presetting and modification should be carried out. The process technical parameters should be adjusted and corrected in combination with the actual situation. Through calibration and trial operation, product defects can be prevented and product quality can be guaranteed to be qualified.

Processing Equipment_taizhou Jiefeng Mold Co., Ltd. (jfmoulds.com)