LSR Mold for two-color/two-material injection machine

September 02, 2024

First, the characteristics of two-color/two-material injection mold.

Two-color mold: Two kinds of plastic materials in the same Injection molding machine injection molding, divided into two molding, but the product only out of the mold once. Generally, this molding process is also called double injection molding, which is usually completed by a set of molds and requires a special two-color injection molding machine. It mainly has the following characteristics:

The dynamic mold is the same, and the injection molding process is rotating and needs to be exchanged, so it must be exactly the same. (There are exceptions, the cavity may be different during molding)

After the first jet channel of the mold is injected, it cannot be left on the mold. It is best to hot runner, otherwise it can also be grabbed by manipulator. The worst is the potential gate, which can fall off automatically, otherwise the second shot of the gate on top cannot close the mold.

The product is shot twice. After the product is opened, the first shot must be left on the moving die side. In general, two-shot products are generally chosen to remain on the moving die side. Therefore, the mold needs to open and close and pull rods to achieve sequential mold opening. First, open the die side and add an ejector mechanism to the die side.

The two sets of cooling systems require in principle that the temperature of the first shot material is 60 degrees higher than the second shot, and the mold temperature is different, so it is necessary to be equipped with two sets of cooling systems.

Two, two-color/two-material injection process introduction.

Rotary core injection molding process:

In the molding process, the first part is injected with a resin in cavity 1, and then the mold is rotated 180°, the first part is injected into the second largest cavity 2 in cavity 1, and another resin is injected into the part; At the same time, the first part of the second product is injected in the cavity, which is cycled in turn.

3. Process characteristics.

At present, two-color molds are becoming more and more popular in the market. This process can make the appearance of the product more beautiful, easy to change the color, no need to spray, but the cost is expensive, high technical requirements.

(1) The two shapes of the female die are different, forming a product respectively, and the two shapes of the male die are exactly the same.

(2) The mold before and after the mold in the center rotation 180 degrees must be consistent. The inspection action must be carried out in the design process, and the requirements for the positioning and processing of the die frame are high.

(3) The total thickness of the front template plus A plate shall not be less than 170mm. Please carefully check the other reference data of this model injection molding machine, such as maximum mold thickness, minimum mold thickness, KO hole distance, etc.

(4) The water mouth of the three-plate die should be designed for automatic demoulding action, especially to pay attention to whether the demoulding action of the soft glue mouth is feasible.

(5) In the design of the second injection mold, in order to avoid the glue position of the first molding product being scratched by the second mold, a part of the design can be avoided. However, we must carefully consider the strength of each sealing position, that is, whether the plastic will deform under large injection pressure during injection molding, resulting in a possible batch front for the second injection molding.

(6) When injection molding, the product size of the first injection molding can be slightly larger, so that it can be pressed more tightly with another male mold during the second molding, so as to achieve the effect of sealing.

(7) Note: When the second injection molding, whether the flow of the plastic will impulse the first molding product, so that its glue site deformation. If possible, find ways to improve.

(8) Before plate A and B close the mold, pay attention to whether the front mold slider or inclined top will reset and crush the product first. In this way, it is necessary to find A way to reset the slider or inclined top of the front die after the closing of the A and B plates.

(9) The water transport arrangement of the two female and male molds should be as fully balanced as possible.

(10)99% of the time, the hard rubber part of the product is first injected, and then the soft rubber part of the product is injected, because the soft rubber is easy to deform.

Guangzhou S-guangyu Machinery & Equipment Co.,Ltd is a professional liquid silicone rubber(LSR) injection molding machine manufacturers in China since 2010.We have got more than one hundred patents and serve for more than thousands of customers .if you want to learn more about our machines,please visit our web www.lsrexpert-better.com or contact us:86-13902294163.

Author:

Ms. Tan

E-mail:

overseas@s-guangyu.com

Phone/WhatsApp:

13902294163