What Need to Consider in the Mold Building?

Mold is a variety of tools used in industrial production to obtain desired products by injection molding, blow molding, extrusion, die casting or forging, smelting, stamping and other methods. In short, a mold is a tool used to make molded articles. This tool is made up of various parts, and different molds are made up of different parts. It mainly realizes the processing of the shape of the article by changing the physical state of the formed material.

 

Under the action of external force, the blank is made into a tool with a specific shape and size. The mold has a specific contour or cavity shape, and the blank can be separated according to the contour shape by using the contour shape with the cutting edge. Applying the shape of the inner cavity can make the blank obtain the corresponding three-dimensional shape. The mold generally includes two parts: a moving mold and a fixed mold, which can be separated and combined. When separating, the parts can be taken out, and when closing, the blank is injected into the mold cavity for forming. Die is a precision tool with complex shape and bears the expanding force of blank. It has high requirements on structural strength, rigidity, surface hardness, surface roughness and machining accuracy. The development level of die production is one of the important signs of mechanical manufacturing level.

 

 

Mold Manufacturing

The requirements for mold design and manufacture are: accurate size, smooth surface, reasonable structure, high production efficiency, easy automation, easy manufacture, long service life, low cost, design in line with technological requirements, and economical and reasonable. The die structure design and parameter selection must consider factors such as rigidity, guiding, unloading mechanism, positioning method, gap size, etc. Vulnerable parts on the mold should be easily replaced. For plastic mold and die casting mold, it is also necessary to consider reasonable gating system, molten plastic or metal flow state, location and direction of entering the cavity. In order to improve productivity and reduce runner casting loss, a multi-cavity mold can be used, and multiple identical or different products can be completed simultaneously in one mold. High-efficiency, high-precision and long-life dies should be used in mass production. The multi-position progressive die should be used for the stamping die, and the hard alloy insert progressive die can be used to improve the service life. In small batch production and trial production of new products, simple dies with simple structure, fast manufacturing and low cost should be adopted, such as combination dies, sheet dies, polyurethane rubber dies, etc. The mold has begun to adopt computer aided design, that is, to optimize the design of the mold through a set of computer-centered systems. This is the development direction of mold design. Die manufacturing is divided into planar blanking die and cavity die with space according to structural characteristics. The blanking die uses the size of the male die and the female die to accurately match, and some even have no clearance fit. Other forging dies, such as cold extrusion dies, die casting dies, powder metallurgy dies, plastic dies, rubber dies, etc., all belong to cavity dies and are used to form three-dimensional workpieces. The cavity mold building has dimensional requirements in the three directions of length, width and height, and is complicated in shape and difficult to manufacture. Mold production is generally one-piece and small batch production, with strict and accurate manufacturing requirements. Precision processing equipment and measuring devices are mostly used.

 

 

Service Performance

1. The density of plastic is small, which is of great significance for reducing the weight of mechanical equipment and saving energy, especially for vehicles, ships, aircraft and space spacecraft.

 

2. The absolute strength of plastic is not as high as that of metal, but the density of plastic is small, so the specific strength and specific rigidity are quite high. Especially reinforced plastics made of various high-strength fibrous, flaky and powdery metals or nonmetals as fillers have higher specific strength and specific rigidity than metals.

 

3. Most plastics have good acid, alkali, salt, water and gas resistance. Under normal conditions, they do not react with these substances.

 

4. Good electrical insulation, thermal insulation and sound insulation.

 

5.Plastic has small friction coefficient, good wear resistance, good self-lubricity, high specific strength and low transmission noise. It can work effectively in liquid medium, semi-dry or even dry friction conditions. It can be made into machine parts such as bearings, gears, cams and pulleys, and is very suitable for occasions with low rotating speed and small load.

 

6. Strong adhesion.

 

7. Good molding and coloring performance.