ntroduction to Silicone Processing Technology and Production Process

ntroduction to Silicone Processing Technology and Production Process

Process introduction

First, the basic process

A wide range of silicone products, but the production process is basically the same. The basic process of silicone products with general solid silicone and raw silicone as raw materials includes six basic processes of plasticizing, kneading, calendering, pressing, forming and vulcanizing. Of course, raw material preparation, finished product finishing, inspection and packaging and other basic processes are indispensable. The process of silicone processing is mainly to solve the plastic and elastic properties of this contradictory process. Through a variety of means of technology, making the elastic silicone into a plastic plastic with plastic, and then add a variety of compounding agent made of semi-finished products, and then through the vulcanization of plastic semi-finished products into a high elasticity, physical and mechanical properties of silicone products The

Second, raw material preparation

1. The main raw material of silicone products is raw silicone as the basic material, and raw silicone is grown in tropical and subtropical silicone trees through the artificial cut bark collected.

2. Various compounding agents are auxiliary materials that are added to improve the performance of silicone products.

3. Fiber materials are (cotton, linen, wool and all kinds of man-made fibers, synthetic fibers and metal materials, steel wire) is used as silicone products, skeleton materials to enhance the mechanical strength, limiting product variants. Ingredients must be accurately weighed according to the recipe during the preparation of the raw material. In order to make the raw silicone and the compounding agent can be mixed with each other, the need for processing of materials. Raw silicone to be in the 60 - 70 ℃ drying room after drying soft and then cut silicone, broken into small pieces, with a mixture of block. Such as paraffin, stearic acid, rosin, etc. to be crushed. If the powder contains the mechanical impurities or coarse particles need to be filtered to remove the liquid such as pine tar, the ancient Malone need to heat, melt, evaporate moisture, filter impurities, with the agent to be dry or easy to agglomerate, if the mixture can not be dispersed Bubble when producing even vulcanization can affect product quality

Third, plastic refining

Raw silicone is flexible and lacks the plastic properties necessary for processing and is therefore not easy to process. In order to improve its plasticity, it is necessary to plasticize the raw silicone, so that when the mixing agent is easy to evenly dispersed in the raw silicone, while in the rolling, forming process also helps to improve the permeability of silicone infiltration into the fabric And molding fluidity. The process of plasticizing the long-chain molecules of raw silicone is called plasticizing. There are two kinds of plastic molding and plasticization. Mechanical plasticizing is the effect of mechanical squeezing and friction by the plasticizer at very low temperatures to shorten the degradation of long chain silicone molecules from high elasticity to plastic. Thermoforming is the introduction of hot compressed air into the raw silicone in the role of heat and oxygen to shorten the degradation of long-chain molecules in order to obtain plasticity.

Four, mixing

In order to adapt to a variety of different conditions of use, to obtain a variety of different performance, but also to improve the performance of silicone products and reduce costs must be added in the raw silicone with a different agent. Mixing is the plastic blend of raw silicone and mix agent, placed in the mixing machine through the mechanical mixing effect with the agent completely and evenly dispersed in the raw silicone in a process. Mixing is the silicone products in the production process of an important process, if the mixing is not uniform can not give full play to the role of silicone and the role of the product performance. It is known as the silicone products are commonly used as a commodity for sale buyers can use the compound directly into the molding, vulcanization made of the required silicone products The According to the different recipe? There are a number of different grades and varieties of different properties. Offer choice.

Five, forming

In the production process of silicone products using calendering machine or extruder preformed in a variety of shapes, different sizes of the process? Called molding. There are methods of forming

1. calendering

Suitable for the manufacture of simple sheet, plate products. It is the compound by pressing the press pressed into a certain shape, a certain size of the film method is called rolling forming. Some silicone products? Such as tires, tape, hose and other textile fiber materials must be coated with a layer of thin plastic in the plastic coating is also called glue or rub glue? The The coating process is also done on the calender. The purpose of the fiber material to be dried and dipped before calendering is to reduce the moisture content of the fibrous material to avoid evaporation of the water. And to improve the temperature of the fiber material to ensure the quality of the calendering process. Dipping is the necessary process before hanging glue in order to improve the bonding properties of fiber materials and silicone.

2. Press out

Used for more complex silicone products? Like tire tread, hose, wire surface coating needs to be made by extrusion molding method. It is a plastic with a certain plastic into the extruder hopper under the extrusion of the screw through a variety of mouth type is also called a model for continuous modeling of a method. Before the silicone material must be preheated to make the compound soft, easy to squeeze out to get the surface smooth, accurate size silicone products.

3. Molding

Can you use the molding method to create some of the complex shape, such as leather cups, seals silicone products? With the molding of the yin and yang mold will be placed in the mold in the mold heating.

Sixth, vulcanization

The process of converting plastic silicone into elastomer is called vulcanization. It is a method in which a certain amount of vulcanizing agent such as sulfur, vulcanization accelerator or the like is added to the semi-finished product made of raw silicone and heated in a vulcanization tank at a prescribed temperature. The linear molecules of the raw silicone are cross-linked into a three-dimensional network structure by generating a "sulfur bridge" so that the plastic compound becomes a highly elastic vulcanizate. As the cross-linking key is mainly composed of sulfur so called "vulcanization." With the rapid development of synthetic silicone vulcanizing agent is now a lot of varieties in addition to sulfur and organic polysulfide, peroxide, metal oxide and so on. So all can make the linear structure of plastic silicone into a three-dimensional network structure of the elastic silicone process is called vulcanization in the silicone material from the "bridge" role of the material are called "vulcanizing agent." Vulcanized elasticity Silicone is called vulcanized silicone, also known as soft silicone, commonly known as "silicone." Vulcanization is one of the most important silicone processing process Silicone products must be vulcanized to obtain the desired performance. The vulcanized silicone is of little value in its use, but is it less than sulfur The curing time is not enough to achieve the best state and sulfur sulfide time is over, the performance of a significant decline in silicone properties are reduced. So the production process must be strictly controlled curing time? To ensure that the vulcanized silicone products have the best performance and longest service life.