Low-viscosity, low-smoke and flame-retardant high-speed elevator balance compensating chain PVC sheath material and preparation method thereof

Abstract

The invention provides a formula of a low-viscosity, low-smoke and flame-retardant high-speed elevator balance compensating chain PVC sheath material, which is adapted to a rapid moulding technology and meets an environment-friendly requirement, and a preparation method thereof. The raw material formula of the low-viscosity, low-smoke and flame-retardant high-speed elevator balance compensating chain PVC sheath material comprises the following components in parts by weight: 100-150 parts of PVC resin, 60-120 parts of a plasticizer, 4-8 parts of a stabilizer, 2-8 parts of a lubricant, 30-60 parts of a flame retardant, 5-15 parts of a smoke suppressant, 5-20 parts of a viscosity reducer and 0.3-1.0 part of a pigment. The preparation method comprises the following steps: mixing the PVC resin to 70-80 DEG C in a kneading machine, then adding a certain amount of an auxiliary agent, continuing mixing, and discharging after the temperature of a mixed material reaches 85-95 DEG C; sending the mixed material into a cooling stirrer, and cooling to 40-50 DEG C; finally, placing in a conical twin-screw extruder, and performing extrusion granulation at the extruding temperature of 130-170 DEG C to obtain a low-viscosity, low-smoke and flame-retardant elastic PVC material. The special low-viscosity, low-smoke and flame-retardant high-speed elevator balance compensating chain PVC sheath material prepared by the preparation method provided by the invention can be applied to the rapid moulding technology of an elevator balance compensating chain sheath, has relatively good appearance, high toughness, high heat aging resistance and high heat stability, and has low viscosity, low smoke performance and flame retardance.

Description

Technical field [0001] The invention relates to a preparation technology of a polymer composite material, in particular to a low-viscosity, low-smoke flame-retardant high-speed elevator balance compensation chain sheath material and a preparation method thereof. Background technique [0002] With the continuous emergence of high-rise buildings, the amount of elevators has grown exponentially. Elevator balance compensation chain is an important safety component that keeps the elevator lifting process running smoothly. The elevator balance compensation chain is composed of a special electric welded anchor chain and an outer coating composite material. In order to ensure that the elevator balance compensation chain reduces frictional noise and is stable during operation, the elevator balance compensation chain must be wrapped with a certain elastic polymer material. jacket. At present, the PVC elastomer-coated elevator balance chain is usually produced by a "two-step" extrusion pr...

AI Technical Summary

Problems solved by technology

At present, PVC elastomer-coated elevator balance chains are usually produced by a "two-step" extrusion process, that is, the first step is pre-coating, and a right-angle machine head is used to coat the surface of the iron chain and the gap between the chain rings with a certain thickness of PVC. The rubber material is then cooled rapidly to freeze the internal high-elastic deformation; the second step is coating, which rapidly heats the pre-coating material at high temperature to melt the surface, and then performs secondary coating through the right-angle head. This method has high production efficiency Low

Some companies have also tried to improve the above two-step molding process, such as using two extruders to perform two coatings on the same production line, but because the first coating speed is fast, the second coating speed is slow , the two speeds are difficult to coordinate, and the overall speed is not significantly improved. If the coating speed is increased, uneven elastic recovery will appear after the material exits the mold. After the product is cooled, the surface will appear uneven, and the product size will fluctuate significantly.

Since the PVC sheathing material of elevator balance compensation chain is mostly prepared by mixing PVC and elastomer, its viscoelasticity is relatively large. During the rapid extrusion process, due to the existence of the iron chain, the material is subjected to complex shearing in different directions, and the large Molecular orientation, after the material flows out of the die, the molecular chain is disoriented. Due to the different orientation degrees of different parts, the elastic recovery is inconsistent, which further aggravates the fluctuation of the product size, which brings difficulties to the realization of rapid prototyping.

In order to meet the requirements of rapid prototyping technology and environmental protection, the present invention provides a low-viscosity, low-smoke, flame-retardant, high-speed elevator balance compensation chain PVC sheath material and its preparation method. The produced PVC thermoplastic elastomer contains a large amount of plasticizer, its flame retardancy is poor, and thick smoke is generated during the combustion process, which contains a large amount of toxic and harmful gases (such as carbon monoxide, benzene, hydrogen chloride, etc.), so it is inhibit Smoke flame retardancy is also very important

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