2000 KN Vertical Epoxy Resin Injection Molding Machine For Silicone Kitchenware Parts

2000 KN Force Vertical Epoxy Resin Injection Molding Machine For Kitchenware

Rubber product production process

1. Basic process

Along with the rapid development of modern industry, especially the chemical industry, there are many kinds of rubber products, but the production process is basically the same. The product is made of general solid rubber (raw rubber), and its production process mainly includes:

Raw material preparation→Mastication→Kneading→forming→vulcanization→dressing→inspection

2. Raw material preparation

The main materials of rubber products are raw rubber, compounding agent, fiber material and metal material. Raw rubber is the basic material; compounding agent is auxiliary material added to improve certain properties of rubber products; fiber material (cotton, hemp, wool and various rayon, synthetic fiber) and metal material (steel wire, copper wire) It is used as a skeleton material for rubber products to enhance mechanical strength and limit product modification.

In the preparation of raw materials, the ingredients must be weighed according to the formula. In order to allow the raw rubber and the compounding agent to be uniformly mixed with each other, some materials need to be processed:

1. Basic process

Along with the rapid development of modern industry, especially the chemical industry, there are many kinds of rubber products, but the production process is basically the same. The product is made of general solid rubber (raw rubber), and its production process mainly includes:

Raw material preparation → Mastication → Mixing → Forming → Vulcanization → Resting → Inspection

2. Raw material preparation

The main materials of rubber products are raw rubber, compounding agent, fiber material and metal material. Raw rubber is the basic material; compounding agent is auxiliary material added to improve certain properties of rubber products; fiber material (cotton, hemp, wool and various rayon, synthetic fiber) and metal material (steel wire, copper wire) It is used as a skeleton material for rubber products to enhance mechanical strength and limit product modification.

In the preparation of raw materials, the ingredients must be weighed according to the formula. In order to allow the raw rubber and the compounding agent to be uniformly mixed with each other, some materials need to be processed:

The raw rubber should be softened in a 60--70 ° C drying room, then cut into pieces and broken into small pieces;

Bulk compounding agents such as paraffin, stearic acid, rosin, etc. are to be crushed;

If the powdery compounding agent contains mechanical impurities or coarse particles, it needs to be removed by screening;

Liquid compounding agents (pine tar, coumarone) need to heat, melt, evaporate water, and filter impurities;

The compounding agent should be dried, otherwise it will be easy to agglomerate and mix and disperse when it is not uniformly dispersed, and bubbles will be generated during vulcanization, thereby affecting product quality;

3. Mastication

Raw rubber is elastic and lacks the necessary properties (plasticity) during processing, so it is not easy to process. In order to improve its plasticity, the raw rubber is plasticized; thus, the compounding agent is easily dispersed uniformly in the raw rubber during the kneading; at the same time, it also contributes to the improvement of the permeability of the rubber during the calendering and molding process (infiltration) Inside the fiber fabric) and molding fluidity. The process of degrading the long-chain molecules of raw rubber to form plasticity is called mastication. There are two kinds of raw plastic mastication methods: mechanical mastication and thermoplastic refining. Mechanical mastication is the process of shortening the degradation of long-chain rubber molecules and changing from a highly elastic state to a plastic state by the mechanical extrusion and friction of the plasticizer at a relatively low temperature. Thermoplasticing is the introduction of hot compressed air into the raw rubber. Under the action of heat and oxygen, the degradation of long-chain molecules is shortened, thereby obtaining plasticity.

4. Mixing

In order to adapt to various use conditions, obtain various properties, and also to improve the performance of rubber products and reduce costs, it is necessary to add different compounding agents to the raw rubber. Mixing is a process in which the raw rubber after mastication is mixed with a compounding agent, placed in a rubber mixing machine, and mechanically mixed to completely and uniformly disperse the compounding agent in the raw rubber. Mixing is an important process in the production of rubber products. If the mixing is not uniform, the effects of rubber and compounding agents cannot be fully exerted, which affects the performance of the products. The rubber compound obtained after mixing is called rubber compound. It is a semi-finished material for manufacturing various rubber products. It is commonly known as rubber compound. It is usually sold as a commodity. The purchaser can directly form and vulcanize the rubber material. Rubber products needed. Depending on the formula, the mix has a range of different grades and varieties with different properties.

5. Molding

In the production process of rubber products, a variety of various shapes and different sizes of processes are preliminarily formed by a calender or an extruder, which is called forming. The molding methods are:

Calendering is suitable for the manufacture of simple sheet and plate products. It is a method of pressing a rubber compound into a certain shape and a certain size by a calender, which is called calender molding. Some textile products (such as tires, tapes, hoses, etc.) used in textile fiber materials must be coated with a thin layer of glue (also called glue or glue on the fiber), and the glue coating process is generally completed on the calender. The fiber material needs to be dried and dipped before calendering. The purpose of drying is to reduce the water content of the fiber material (to avoid evaporation of water and foam) and to increase the temperature of the fiber material to ensure the quality of the calendering process. Dipping is a necessary process before hanging glue, in order to improve the bonding properties of fiber materials and rubber compounds.

Extrusion molding For more complex rubber products, such as tire tread, hose, and wire surface coating, it needs to be manufactured by extrusion molding. It puts the rubber compound with certain plasticity into the hopper of the extruder, and extrudes it through a variety of mouth shapes (also called prototypes) under the extrusion of the screw. Previously, the compound had to be preheated to make the rubber soft and easy to extrude, resulting in a rubber product with a smooth surface and accurate dimensions.

Molding It is also possible to manufacture certain rubber products with complicated shapes (such as cups and seals) by molding. The molded materials are placed in the mold by means of molded male and female molds.

6. Sulfuration

The process of converting plastic rubber into elastic rubber is called vulcanization. It is to add a certain amount of vulcanizing agent (such as sulfur, vulcanization accelerator, etc.) to the semi-finished product made of raw rubber (in the vulcanization tank), in the specified Heating and heat preservation at a temperature, the linear molecules of the raw rubber are cross-linked to form a network structure by forming a "sulfur bridge", so that the plastic compound becomes a vulcanizate having high elasticity. Since the cross-linking bond is mainly composed of sulfur, it is called "vulcanization". With the rapid development of synthetic rubber, there are many varieties of vulcanizing agents, in addition to sulfur, organic polysulfides, peroxides, and metal oxides. Wait. Therefore, the process of converting the plastic rubber of the linear structure into the elastic rubber of the three-dimensional network structure is called vulcanization, and any substance capable of "bridge" in the rubber material is called "vulcanizing agent".

Vulcanized elastic rubber is called vulcanized rubber, also known as soft rubber. It is commonly called "rubber". Vulcanization is one of the most important processes in rubber processing. Various rubber products must be vulcanized to obtain the desired performance. Unvulcanized rubber has no use value in use, but under-sulfur (not enough degree of vulcanization, insufficient vulcanization time, failure to achieve optimum conditions) and persulfurization (more than vulcanization time, significant performance degradation) Rubber performance is degraded. Therefore, the vulcanization time must be strictly controlled during the production process to ensure the best performance and longest service life of the vulcanized rubber products.