How to choose a second-hand injection molding machine

How to choose a second-hand injection molding machine

The important factors that usually affect the selection of injection molding machine include mold, product, plastiki, mahitaji ya ukingo, na kadhalika. Kwa hiyo, the following information must be collected or obtained before making a selection: 1. Mold size (upana, urefu, unene) , uzito, muundo maalum, na kadhalika.; 2. The type and quantity of plastic used (malighafi moja au plastiki nyingi); 3. The appearance size (urefu, upana, urefu, unene) and weight of the injection molded product; 4. Molding requirements, such as Quality conditions, kasi ya uzalishaji, na kadhalika. After obtaining the above information, you can follow the steps below to choose a suitable plastic injection molding machine:

1. Choose the right type:

Since there are many types of second-hand injection molding machines, it is necessary to correctly judge which type of injection molding machine or which series the product should be produced at the beginning, such as general thermoplastic or bakelite raw materials Or PET raw materials, na kadhalika., are single-color, double-color, rangi nyingi, interlayer au rangi iliyochanganywa, na kadhalika.

Zaidi ya hayo, some products require high stability (kitanzi kilichofungwa), usahihi wa juu, ultra-high injection rate, high injection pressure or rapid production (kitanzi anuwai), na kadhalika., na safu inayofaa lazima ichaguliwe pia kwa uzalishaji.

2. Can fit the sindano mold:

Tambua ikiwa “big column inner distance”, “mold thickness”, “minimum mold size” na “mold plate size” of the machine are appropriate according to the mold size, so as to confirm whether the mold can be placed.

Kumbuka: ①The width and height of the mold must be smaller than or at least one side is smaller than the inner distance of the large column; ②The width and height of the mold should preferably be within the size range of the mold plate; ③The thickness of the mold should be between the mold thickness of the injection molding machine; ④The width and height of the mold must meet the minimum mold size recommended by the injection molding machine, and it is not acceptable if it is too small.

3. Take out injection molding products:

Tambua ikiwa “kiharusi cha kufungua mold” na “mold ejection stroke” zinatosha kwa bidhaa iliyomalizika kutolewa na ukungu na bidhaa iliyomalizika.

①The mold opening stroke must be at least twice the height of the finished product in the direction of opening and closing the mold, and must include the length of the vertical sprue;

②The ejection stroke must be sufficient to eject the finished product.

4. Can lock the plastic solution:

Tani ya “nguvu ya kubana” imedhamiriwa na bidhaa na plastiki.

When the raw material is injected into the mold cavity at high pressure, it will generate a force to support the mold. Kwa hiyo, kitengo cha kubana cha mashine ya ukingo wa sindano lazima itoe ya kutosha “nguvu ya kubana” to keep the mold from being stretched. The calculation of the clamping force requirement is as follows:

① Obtain the projected area of ​​the finished product in the direction of the opening and closing mold from the appearance size of the finished product; /cm2); ③The pressure in the mold varies with the raw material, na malighafi ya jumla ni 350 ~ 400kg / cm2; more than double. So far, uainishaji wa kitengo cha kubana umedhamiriwa awali, na tani ya mfano imedhamiriwa takribani. Kisha, the following steps must be carried out to confirm which injection unit has a more suitable screw diameter.

5. Shot to fill the injection mold cavity:

Tambua inayohitajika “injection volume” and select the appropriate “kipenyo cha screw” based on the weight of the finished product and the number of mold cavities.

To calculate the weight of the finished product, the number of mold cavities (one mold with several cavities) needs to be considered;

For the sake of stability, kiasi cha sindano lazima iwe zaidi ya 1.35 mara uzito wa bidhaa iliyomalizika, hiyo ni, uzito wa bidhaa iliyokamilishwa lazima iwe ndani 75% ya kiasi cha sindano.

6. Injection parameters of injection molding machine:

The conditions such as “uwiano wa compression ya screw” na “shinikizo la sindano” are judged by the plastic. Some engineering plastics require a higher injection pressure and a suitable screw compression ratio design to have a better molding effect. Kwa hiyo, in order to make the finished product injection better, the injection pressure and compression ratio must also be considered when selecting the screw. . Kwa ujumla, a smaller diameter screw provides higher injection pressure.

7. Kasi ya sindano of injection molding machine:

Confirmation of “kasi ya sindano”. Some finished products require high injection rate and fast injection to form stably, such as ultra-thin products. Kwa kesi hii, it may be necessary to confirm whether the injection rate and injection speed of the machine are sufficient , whether it needs to be equipped with pressure accumulator, closed loop control and other devices. Kwa ujumla, chini ya hali sawa, the screw that can provide higher injection pressure usually has a lower injection rate, and on the contrary, the screw that can provide lower injection pressure usually has a higher injection rate.

Kwa hiyo, when selecting the diameter of the screw, kiasi cha sindano, shinikizo la sindano na kiwango cha sindano (kasi ya sindano) need to be considered and traded off. Zaidi ya hayo, multi-loop design can also be used to shorten the molding time with synchronous compound actions.

Ikiwa una maswali yoyote juu ya sindano ukingo ,plz jisikie huru kuuliza Timu ya FLYSE,tutakupa huduma bora!