Trimming is a common process in rubber products production. Trimming methods include: manual trimming method, grinding method, cutting method, freezing trimming method, no flapping mold forming method, etc. Each manufacturer can choose the appropriate trimming method according to the quality requirements of products and their own production conditions.

Artificial trimming

Manual trimming is an ancient trimming method, which includes cutting rubber edges by hand with punches; Use scissors, scraping and other knives to remove glue edge. The quality and speed of rubber products trimmed by hand will also vary from person to person, and the geometry of finished products must meet the requirements of product drawings, without scratches, scratches and deformation. Before dressing, it is necessary to know the dressing parts and technical requirements, master the correct dressing methods and correct use of tools.

In the production of rubber parts, trimming operations are mostly manual operations in different forms. Because the manual operation of trimming production efficiency is low, often in the production task concentration, to mobilize many people to trim. In this way, not only the order of work is affected, but also the quality of products can not be guaranteed. For this reason, more effective process measures (such as non-flapping molding dies) or various edging equipment should be considered for edging.

Mechanical trimming

It mainly includes punching cutting, grinding wheel edging and round knife edging, which is suitable for special products with low precision requirements. It is currently the leading dressing method.

1) Mechanical cutting repair edge with pressure machinery and die, punching knife, remove the rubber edge of the product. This method applies to the product and its rubber edge can be placed on the die or punching knife bottom plate model products, such as bottle stopper, leather bowl, etc.. On the high rate of glue, hardness of small products usually choose impact method impact cutting, so that can be reduced because the product is more elastic to form a knife cutting back part of uneven, side depression; And for products with lower glue content and higher hardness, can directly adopt the method of cutting die. In addition, blanking is divided into cold cutting and hot cutting, cold cutting refers to blanking at room temperature, the demand for equipment blanking pressure is higher, blanking quality is better; Eager refers to the high temperature when cutting should avoid high temperature touch products too long, affect the quality of the product.

2) Mechanical cutting trimming is suitable for trimming of products with larger shape scale, using cutting tools. One side cutting machinery is a special machine, different kinds of products using different kinds of cutter. For example, the tire after vulcanization appearance of air and exhaust line parts have different lengths of rubber strip, it is necessary to use grooves with rubber strip under the condition of tire rotation.

3) Mechanical grinding trimming of rubber products with inner holes and outer circles, usually using grinding fangzi. The cutting tool of grinding is the grinding wheel of certain thickness of particles. The precision of grinding trimming is low, and the grinding surface is rough. It can clamp the remaining sand particles, which affects the application effect.

4) Low-temperature shot blasting edge repair precision products with high quality demand, such as O-ring, small leather bowl, etc., can choose this method of edge repair. Products with liquid nitrogen or dry ice quickly cooled to brittleness temperature below, and then high-speed spraying metal pellets or plastic pellets will fly to break off, the end of the edge repair.

5) Low temperature brush grinding edge repair it is with two nylon brush rotating around the horizontal axis of the frozen rubber products to remove the rubber edge brush.

6) low temperature drum it was among the first to choose frozen beveling method, using drum shift impact force and the friction force between products, that have been frozen products under the flash to the embrittlement temperature cracking and drop, the shape of the drum is usually octagonal, to increase the products in the lighting strike force in the drum, the drum speed wants moderate, abrasive agent can progress power. Such as electrolytic capacitor rubber plug trimming technology is the selection of low temperature drum dressing.

7) Low temperature oscillation trimming is also known as oscillation frozen trimming. Products do spiral oscillation in the circular sealing box, and there is a strong impact effect between products and products and abrasive agent, resulting in the fragmentation of frozen embrittlement glue edge. Low temperature oscillation trimming is better than low temperature drum trimming, low damage rate and high production power.

8) Low-temperature swing, vibration trimming is suitable for small or miniature products or miniature silica gel products rich in metal skeleton, and abrasive agent to repair the product holes, corners and grooves in the glue edge.

Frozen trimming

The principle of the special frozen trimming machine is to use liquid nitrogen (LN2) to make the burrs of finished products brittle at low temperature, and use specific frozen particles (pellets) to hit the burrs to quickly remove the burrs. Freezing trimming equipment with high production efficiency, low labor intensity, good trimming quality and high degree of automation is especially suitable for pure rubber parts. Widely applicable products, has become the mainstream process standard. However, such equipment is expensive and expensive to run.

No fly-edge die

The use of non-flying edge mold for production, repair work becomes simple and easy (flying edge a tear off, so this mold is also called tearing edge die). No flying edge mold forming method, can completely omit the trimming process, improve product quality and performance, reduce labor intensity and production costs and other characteristics, has broad prospects for development.