Under the action of external force, the mold makes the blank become a tool with a specific shape and size. It is widely used in punching, die forging, cold heading, extrusion, powder metallurgy parts pressing, pressure casting, and compression molding or injection molding of engineering plastics, rubber, ceramics and other products. The mold has a specific contour or inner cavity shape, and the contour shape with a cutting edge can be used to separate the blank according to the contour shape (punching). The shape of the cavity can be used to obtain the corresponding three-dimensional shape of the blank.
The mold generally includes two parts: a movable mold and a fixed mold (or a convex mold and a concave mold), which can be separated or combined. The parts are taken out when they are separated, and the blanks are injected into the mold cavity to form when they are closed. The mold is a precision tool with a complex shape and can withstand the expansion force of the blank. It has high requirements for structural strength, rigidity, surface hardness, surface roughness and processing accuracy. The development level of mold production is one of the important signs of the level of mechanical manufacturing.
Types of molds
There are many types of molds, which can be divided into: ①Metal processing molds according to the processing object and processing technology. ②Process non-metal and powder metallurgy molds. Including plastic molds (such as injection molds, compression molds and extrusion molds, etc.), rubber molds and powder metallurgy molds. According to the structural characteristics, the mold can be divided into a flat punching mold and a cavity mold with space. Molds are generally single-piece, small batch production.
The composition of the mold
In addition to the mold itself, it also needs a mold base, a mold base, a guide device, and a part ejection device. These components are generally made of general-purpose type. Mold companies need to be bigger and more refined. They must determine product positioning and market positioning according to market demand, technology, capital, equipment and other conditions. These practices are especially worthy of learning and reference by small mold companies, and focus on gradually forming their own technical advantages and products. Advantage. Therefore, my country’s mold companies must actively strive to learn from the experience of these advanced foreign companies for better development in the future.
Classification of molds
According to the different materials to be molded, molds can be divided into hardware molds, plastic molds, and their special molds.
Hardware molds are further divided into: including stamping molds (such as punching molds, bending molds, deep drawing molds, turning molds, shrinkage molds, undulating molds, bulging molds, plastic molds, etc.), forging molds (such as die forging molds, Upsetting die, etc.), extrusion die, extrusion die, die-casting die, forging die, etc.;
Non-metallic molds are also divided into: plastic molds and inorganic non-metallic molds. According to the different materials of the mold itself, the mold can be divided into: sand mold, metal mold, vacuum mold, paraffin mold and so on. Among them, with the rapid development of polymer plastics, plastic molds are closely related to people’s lives. Plastic molds can generally be divided into: injection molding molds, extrusion molding molds, gas-assisted molding molds, and so on.