Smoke film latex is the largest variety of natural rubber products. It is made of natural rubber latex by dilution, adding acid condensation, the rubber material is rolled by roller and then dried by tree smoke. It can be used in the production of automobile tire, rubber hose, rubber belt, rubber shoes, rubber cloth, industrial products and so on. It is widely used in large tire body and tread. In the actual production, mastering the processing characteristics and precautions of tobacco latex can further improve the quality of natural rubber products with tobacco latex as the main raw material.
1. Selection skills of cigarette emulsion
According to the reference standards of color, transparency, impurity content and mildew, the latex can be divided into 1 / 2 / 3 / 4 / 5 grade. Its quality can be judged by visual inspection of the color of the latex. Generally, the quality of golden latex is the best. No.3 cigarette film latex is divided into big No.3 cigarette adhesive and small No.3 cigarette adhesive. Big No.3 cigarette adhesive is suitable for various rubber color products because of its light color, while small No.3 cigarette adhesive is usually used for black and dark products because of its dark color.
2. Processing characteristics of tobacco latex
(1) Plasticizing: the plastic of tobacco latex is small, and it can only be used in the production of rubber products after fully plasticizing to achieve processing plasticity. The temperature during plasticizing is generally controlled at 80-120 ℃, and the plasticizer can improve the plasticizing effect. It should be noted that the amount of cigarette latex is easy to be over refined, so it is necessary to use Mooney viscosity method and rapid plastimeter method to measure the plasticity of plastic rubber in time.
(2) Mixing: before mixing, the solid components used in mixing should be crushed, dried and screened in advance. Mixing can be carried out in the open mixer or internal mixer. Two stage mixing is often used when tobacco latex is mixed in internal mixer; Liquid softener can only be added after the fillers which are easy to agglomerate in the mixing process to avoid agglomerating.
(3) Calendering: the calendering temperature should be reasonably determined according to the components and adhesion of the cigarette latex, which is generally controlled 60-90 ℃.
(4) Vulcanization: the smoke film latex is used in the production of rubber products; Continuous vulcanization can be used in the production of extruded rubber products such as sealing strip and cable sheath. It should be noted that curing reversion is easy to occur in the curing process of tobacco latex, so it is necessary to adjust the formula properly and strictly control the production process; If necessary, the reclaimed rubber can be used appropriately to reduce the cost and improve the problem of vulcanization reversion.
3. Precautions for cigarette film latex
When using tobacco latex to produce rubber products, tobacco latex must be stored in a clean, dry and ventilated place to avoid the sun and rain; Keep the transportation tools dry and clean during transportation, avoid mixing impurities, and cover them if necessary; During storage, the smoke emulsion shall not contact with solvents, Oils and substances harmful to rubber; Storage temperature should be maintained at or below 40 ℃.
At present, the market price of No.3 tobacco latex in Thailand is more than 18000 yuan / ton, and there is still room for price increase in the later stage. In this regard, rubber manufacturers can choose to use recycled rubber in raw materials to effectively reduce the cost of raw materials and power consumption. It should be noted that when tobacco latex is used in the production of light color rubber products, it is necessary to choose white latex and recycled rubber. In the process of use, tobacco latex should be fully molded and then mixed with recycled rubber. Xiaobian will continue to discuss this issue with you later.
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