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Teknologi Pintu Acuan Suntikan

• 2025-07-23

Teknologi Pintu Acuan Suntikan

Sistem gating

Kereta Mould_Taizhou Jiefeng acuan co, Ltd. (jfmoulds.com)

Apabila merancang acuan, pemilihan kedudukan pintu dan bentuk pintu memainkan peranan penting dalam ekonomi pengeluaran suntikan.

1.1 Sistem gating untuk menyambungkan bahagian suntikan suntikan

1.1.1 Runner Cold

Untuk acuan pelari sejuk, kedua -dua bahagian suntikan yang dibentuk dan pintu disejukkan di dalam acuan dan pada masa yang sama dikeluarkan dalam setiap kitaran pencetakan.

Titik utama reka bentuk pelari sejuk adalah untuk memastikan pengisian seragam semua rongga acuan. Oleh itu, hanya apabila jarak dari semua rongga ke titik masuk gam pusat adalah sama, proses pengisian dijamin menjadi seragam.

Jika kawasan keratan rentas rod suapan (juga dikenali sebagai lengan pelari) terlalu kecil, tekanan suntikan yang sangat tinggi diperlukan untuk mengisi bahagian suntikan yang dibentuk. Tekanan suntikan yang tinggi boleh menyebabkan tekanan dalaman, yang membawa kepada retak produk.

Sebaik sahaja tekanan suntikan terlalu tinggi, tekanan di dalam rongga juga akan meningkat. Sekiranya elaun daya pengapit mesin pengacuan suntikan tidak mencukupi, bahagian suntikan suntikan akan berkembang.

Kawasan keratan rentas saluran lencongan boleh dianggap sebagai fungsi berat produk, dan nilai rujukannya diperoleh daripada pengalaman praktikal.

Diameter pelari hendaklah sekurang -kurangnya tidak kurang daripada ketebalan dinding maksimum bahagian suntikan yang dibentuk.

Komoditi Mould_Taizhou Jiefeng acuan co, Ltd. (jfmoulds.com)

1.1.2 Pelari acuan tiga plat

Kelebihan acuan tiga plat adalah bahawa bahagian suntikan yang dibentuk dan pelari boleh diambil dari dua permukaan perpisahan yang berbeza. Ini mengurangkan langkah tambahan, iaitu memisahkan pintu dari bahagian suntikan yang dibentuk.

Acuan tiga papan boleh mengisi produk melalui satu atau lebih bukaan. Ini bermakna terdapat kebebasan yang lebih besar dalam reka bentuk berbanding dengan acuan dua plat. Sistem penembusan acuan tiga plat direalisasikan oleh pintu titik pecah.

Apabila acuan dibuka, batang lukisan atau lukisan cangkuk yang disuntik dengan acuan membetulkan pelari pada acuan tetap. Oleh itu, spout itu ditarik dari produk. Terdapat mekanisme yang serupa dengan pin ejektor pada bahagian acuan tetap untuk mengeluarkan saluran aliran. Satu kelebihan acuan tiga plat ialah jarak antara rongga boleh menjadi sangat padat.

Harus diingat bahawa kawasan keratan rentas saluran perpecahan perlu dipadankan dengan berat produk, dan saluran perpecahan harus seimbang. Oleh kerana dua permukaan perpisahan perlu dibuka, salah satu permukaan boleh ditangguhkan dalam pembukaan, contohnya.

Jika boleh, tunggu sehingga teras keluar bahagian suntikan yang dibentuk atau teras benang diputar dan ditarik sebelum membukanya.

Pembukaan tiga plat, iaitu templat, plat tengah dan plat ejector, kebanyakannya didorong oleh mesin pencetakan suntikan. Kunci sisi atau tarik rod menentukan strok. Silinder pneumatik atau hidraulik juga sering digunakan untuk membuka kerja. Kelebihan mereka ialah kedudukan pembukaan setiap plat boleh dikawal oleh masa.

Batang pelari sering menyebabkan kerosakan pengeluaran. Dengan lancar menghilangkannya dari bahagian -bahagian yang rosak kuno, mereka perlu digunakan

Manipulator kepala pengambilan bahan. Selepas pengaturcaraan, tangan mekanikal boleh menghantar kepala material secara langsung ke penghancur.

1.2 Sistem gating dikekalkan dalam acuan

1.2.1 Saluran Aliran Adiabatik

Acuan untuk mengekalkan sistem gating, dengan kawasan keratan rentas yang agak tebal saluran aliran, dapat mengekalkan saluran aliran teras (paip penebat)

Keadaan cair plastik dalam acuan sistem gating pengekalan; Jenis lain ialah sistem pelari panas yang memerlukan pemanasan elektrik.

Acuan tunggal-rongga secara langsung menyuntik produk melalui pelari utama, rongga pra-deposit atau pintu yang dipanaskan. Acuan pelbagai rongga memerlukan sistem gating.

Early molds only used cold runners. Later, a large-capacity gating system formed on the second formwork was added. These channels (also known as "skeletons") remain in the mold. Only thick channels can be insulated, and such molds are called insulated channel molds.

When the mold malfunctions or the material and color are changed, the second template is opened and the runner is removed.

Adiabatic channels are often used for high-speed injection molded parts. The molding cycle of different systems does not exceed 15 seconds.

Typical applications include yogurt cartons, threaded bottle caps, disposable tableware, disposable syringes, pens and planting POTS.

1.2.2 Hot runner

(1) Advantages of hot runners

Hot runner is theoretically an extension of the injection molding unit. It should keep the plastic in the mold cavity in a molten state, guide and heat the molten plastic until it reaches the cavity, while maintaining very little temperature and pressure loss. The hot runner meets the aforementioned requirements.

The greatest advantage of hot runner technology is that there is no waste during the injection molding process and the quality of the injection port is good. There will be no phenomenon of material head sticking together when opening the mold during the production process.

Another advantage is that it is convenient to select the gate position for balanced filling of injection molded parts. Feeding from the center of the bottom of the product is balanced filling, which is suitable for all cylindrical products, such as cups, buckets or similar products.

When the depth of the injection molded part is irregular, all the surfaces of the product can be projected onto a plane, and then another one can be drawn

A circle that accommodates all product areas. If the glue is injected at the center of the circle, it can ensure the balanced filling of the injection molded part.

Eliminating the intermittent runner channels on the parting surface enables the application of brand-new ideas in mold design. The mold can become more compact and the number of cavities can be significantly increased. Molds with 128 or more cavities are not uncommon.

(2) Internal heating type hot runner

Internal heating hot runner molds represent the rise of hot runner technology, but they are rarely used nowadays. One drawback of the internal heating system is that the process of changing colors or materials is very complicated.

The original concept of hot runner technology started from the adiabatic runner concept and developed an internal heat diversion and intake system to prevent plastic solidification in the mold runner. Therefore, the heating system is installed at the center of the diversion channel.

High-temperature raw materials will not overflow from the solidified cold material

It is an important condition for the system's sealing performance. More serious defects will occur during color and material changes. Streaks will appear on injection molded parts because the raw material particles will degrade on the surface of the insulation layer. To avoid these problems, every time the color or material is changed, the entire system needs to be disassembled to remove the raw materials in the distribution pipeline, which is a rather complex process.

The heating system is installed at the center of the flow channel. As a heating element

The simple heating jacket regulates the temperature with the help of sensors. The heating sleeves are almost all self-insulating, so the heat transferred to the mold is very little. This ensures that the thermal expansion is very small, thereby enhancing the sealing capacity of the mold.

Internal heating systems should be given priority for processing semi-crystalline thermoplastics, such as polyethylene (PE), polypropylene (PP), or polyamide(PA).

(3) External heating type hot runner

In the external hot runner, heat is transferred from the outside of the mold to the distributor plate. At this point, the molten plastic in the diversion channel does not come into contact with the heating element.

Wind the heating coil

Most heating elements adopt preformed wound heating coils. First, process grooves on both sides of the diverter plate, then insert the wound heating ring into the grooves, and finally seal it with two-component thermal conductive adhesive. Sometimes, the heating ring is only covered with a thin iron plate. Winding the heating ring can make the heat in the gating system evenly distributed.

Cylindrical heating jacket

As an alternative solution, a simple heating sleeve can be used near the flow channel holes on the split plate. The processing of these holes needs to achieve the best dimensional fit with the heating sleeve to ensure smooth heat transfer.

Simple heating sleeves are usually used in combination with thermal conductive adhesive to ensure good heat conduction and make the replacement of simple heating sleeves more convenient. At present, heating jackets are only used for simple molds.