Rubber Molds

What are the structural forms of the pressure-filled molding die?

1 Open-type filling die Open-type filling die is characterized by no direct positioning between the upper and lower stencils. If positioning is required, positioning of the mutual position is achieved by positioning mechanisms such as locating pins. The structure of the open filling die is only closed when the end faces of the upper and lower molds are completely closed. The cavity is always open during the entire closed mold stroke, so it is easy to discharge the gas in the cavity, but the rubber loss is more, generally 10%~15%. The smaller the product, the larger the amount of lost glue, thus causing the lack of glue. And the possibility of producing waste is also great. In addition, the biggest disadvantage is that the rubber is not subjected to pressure and compactness during pressing, and the physical and mechanical properties of the product are not high.

2 The closed filling die is characterized in that the upper and lower templates are directly guided and positioned in the extended portion of the mold cavity. The upper mold has a convex portion extending into the continuation portion of the cavity. After the point A of the convex portion of the upper mold is in contact with the point B at the upper end of the continuation portion, the cavity is closed, so it is called closed type. The advantage of this mold structure is that the pressure of the press is almost always applied to the rubber, so the quality of the product is good, and the rubber is difficult to flow out of the mold cavity: the phenomenon of partial underpressure and filling of the mold can be avoided, and the obtained product can be obtained. The density of the parts is very high. However, this mold structure has the disadvantage of poor exhaust performance. In addition, from the mold manufacturing, the mold structure is more precise than the open filling mold, and the edge of the upper and lower stencils is prone to wear during use.

In the molding production, such molds require that the mold compound must be weighed strictly, and each press must be made into a quantitative mold to ensure the quality of the product parts.

What is a filling die?

Firstly, the mold is opened, and the quantitative rubber or preformed semi-finished product is directly filled into the mold cavity, and then the mold is closed, and the rubber product parts are obtained through a flat vulcanizing machine or a vertical vulcanization tank for pressurization, heating and vulcanization. The mold is called a filling type rubber mold, and is simply referred to as a filling mold or a stamper.

What types of rubber molds are there?

In the general production process, the commonly used rubber molds can be roughly classified into the following main types.

1 vulcanization equipment classification: flat mold; injection mold; injection mold; mobile mold; extrusion mold.

2 mold structure classification: filling mold (open, closed, semi-closed); injection molding; injection molding; extrusion mold; multi-cavity mold; hinge mold; combined mold;

What are the requirements for a qualified vulcanization mold?

As a molded production of rubber products, the requirements for its molds are as follows:

1 can ensure that the product has the correct contour and size.

2 requires a certain degree of smoothness, cavity surface, rough Chengdu should meet the quality requirements of the surface of the product. Reasonable parting surface to ensure that the quality of the product is easy for the colleague to trim the rubber edge.

3 The overall structure of the mold should be reasonable, the positioning is reliable, and the operation of loading, clamping, and taking products is simple.

4 Improve the life of the mold as much as possible.

5 Under the condition of ensuring sufficient strength, the weight of the mold should be reduced as much as possible.

6 Under the premise of ensuring product quality, the mold should be as easy to process as possible.

7 There is a suitable flow tank for easy venting and draining excess glue.

8 The working area of the mold requires reasonable design and is suitable for the selected vulcanizing press. The height of the mold is proportional to the size of the shape of the body to meet the needs of the forming of the part.

What is a rubber vulcanization mold

The mold is a tool (tool) for vulcanization and shaping of model rubber products. It has a certain plasticity material. After pre-forming a certain shape or weighing the predetermined quality, it is filled or suitable for injection into the mold cavity and pressurized. After heat vulcanization, the desired shape and size of the article can be obtained.

Whether the structure of the mold is reasonable or not directly affects the operation, production efficiency and various technical indexes of the product parts in the molding production, and also directly affects the service life of the mold itself.