Oil-resistant and anti-static calendering rubber material and cloth-wrapped V-belt calendering process adopting oil-resistant and anti-static calendering rubber material

Abstract

The invention relates to the field of V belts, in particular to an oil-resistant anti-static calendering rubber material and a cloth-wrapped V belt calendering process adopting the oil-resistant anti-static calendering rubber material. The invention has the following characteristics: firstly, the chloroprene rubber adhesive is selected as a main rubber system, and the cis-butadiene rubber 9000 is accurately blended, so that the intrinsic oil resistance and elastic balance of the base material are enhanced; 2, a multi-element system of double carbon black reinforcement and special conductive carbon black is constructed, and the synergism of conductivity and strength is realized under the condition of low addition amount; and thirdly, a composite anti-aging, vulcanizing and bonding system is designed, and a segmented mixing and precise calendering process is matched, so that the performance of the formula is fully exerted and is adapted to industrialization, and the comprehensive targets of oil resistance, static electricity resistance, high strength and easiness in calendering are finally realized.

Description

Technical Field

[0001] This invention relates to the field of V-belts, specifically to an oil-resistant and anti-static calendering compound and a fabric-covered V-belt calendering process using the oil-resistant and anti-static calendering compound. Background Technology

[0002] As a core component of mechanical transmission systems, fabric V-belts are widely used in oily, dusty, and flammable / explosive environments such as petrochemicals, coal mining, and metallurgical forging. In these scenarios, the V-belt does not swell or fail when impregnated with the base adhesive, and its antistatic properties prevent static electricity buildup that could lead to safety accidents. The calendering performance determines the quality of the adhesive coating on the canvas, thus influencing molding quality and production efficiency. Currently, the industry focuses on calendering adhesive formulations and calendering technologies for oil-resistant and antistatic fabric-coated V-belts.

[0003] The first type is the formulation of antistatic wrapped V-belt base adhesive, which uses natural rubber, styrene-butadiene rubber, etc. as the base, combined with ordinary carbon black (such as N330, N550, etc.) and calcium carbonate as fillers. The purpose is to improve the mechanical strength and wear resistance of the rubber, and to increase the conductivity of the conductive carbon black. The calendering process can be controlled. The drawback is that the oil resistance is poor and it is prone to swelling failure mode when exposed to oil stains.

[0004] The second type uses chloroprene rubber as the main rubber compound, with 10%-15% natural rubber added to reduce costs. The reinforcement system uses a single carbon black N330 or N660 (total addition 30%-40%), and conductivity is achieved by adding 10%-20% conductive carbon black. The vulcanization system uses zinc oxide + stearic acid activation, combined with DM as a single accelerator, and sulfur vulcanization. This formula has oil resistance and conductivity, but the calendering process is slow and inefficient. After calendering, the rubber compound delaminates and adheres to the canvas, affecting quality. The only solution is to crush the rubber compound, dissolve it with rubber solvent oil and toluene, and then impregnate it to coat the canvas surface with the rubber paste, allowing the V-belt to achieve oil resistance and antistatic properties.

[0005] The existing process requires the use of large amounts of rubber solvent oil and toluene to dissolve the rubber compound, which poses safety hazards and exceeds environmental standards. Furthermore, in the impregnation process of canvas and rubber paste, the solvent oil and toluene in the rubber paste evaporate, which also leads to exceeding environmental standards and wasting costs.

[0006] Meanwhile, existing technologies have poor calendering performance and unstable molding quality: with existing formulas, the calendering process is prone to sticking to the rollers and wrinkling of the film surface, requiring frequent cleaning of the rollers and resulting in insufficient production efficiency; at the same time, the existing formulas have low bonding strength between the calendered film and the skeleton layer, and delamination is prone to occur after vulcanization. Summary of the Invention

[0007] This invention aims to provide a fabric-covered V-belt calendering process using oil-resistant and anti-static calendering compound, the specific solution of which is as follows: An oil-resistant and anti-static calendering compound, comprising the following materials in parts by weight: Chloroprene rubber 85-95 Butadiene rubber 5-15 Carbon Black N660 5-10 Carbon black N330 10-40 Conductive carbon black KF-80 5-10 Calcium carbonate 15-30 Environmentally friendly aromatic oil E370 5-15 Additive MgO 3-7 Indirect method for zinc oxide 3-7.

[0008] It also includes a processing and bonding system comprising the following materials in parts by weight: stearic acid 2-4 and adhesive RC3-7.

[0009] It also includes an anti-aging protection system, which comprises the following parts by weight of materials: Anti-aging agent 2246 1-3 Anti-aging agent MB 1-3 Anti-aging agent ODA 1-3 Microcrystalline wax 1-3.

[0010] It also includes a vulcanization accelerator system, which comprises the following materials in parts by weight: Accelerator DM 0.5-1.5 Accelerator CBS 0.5-1.5 Anti-scorching agent 0.2-1.0.

[0011] It also includes 0.5-1.5% oil-extruded sulfur as a vulcanizing agent.

[0012] A fabric-covered V-belt calendering process using oil-resistant and anti-static calendering compound includes the following steps: (1) Apply adhesive to the front of the canvas: 1.1 Raw material pretreatment: After the canvas is dried, it is fixed in width and fed into the calender by the traction device. At this time, the side that needs to be glued faces the glue feeding area between the rollers. 1.2 Rubber compound penetration and extrusion: After the oil-resistant and anti-static calendered rubber compound is preheated by the screw extruder, the rubber compound is added into the feeding gap between the upper roller and the middle roller. The rollers rotate at a preset speed ratio, and the oil-resistant and anti-static calendered rubber compound is rolled into a thin layer by extrusion and shearing force and forcibly penetrated into the gap between the warp and weft fibers on the front of the canvas. 1.3 Temperature control and shaping: The roller temperature is controlled at 80-100℃; a uniform adhesive layer is formed on the front side of the canvas after gluing, and the adhesive and fiber form a mechanical interlocking structure.

[0013] 1.4 Cooling and Temporary Storage: After the front side of the canvas is coated with adhesive, it is cooled and shaped by cooling rollers; (2) Apply adhesive to the reverse side of the canvas: 2.1 Secondary positioning of canvas: The canvas with glue applied to the front is fed back into the second calender. The direction of the canvas is adjusted by the traction steering device so that the un-glueed reverse side faces the feeding area. At the same time, it is ensured that the canvas is flat and wrinkle-free, and the glued side does not directly contact the feeding roller. 2.2 Reverse side gluing operation: Similar to the first side gluing, after the oil-resistant and anti-static calendered rubber material is preheated by the screw extruder, the rubber material is added into the feeding gap between the upper roller and the middle roller, and the extrusion and shearing process is repeated. The extrusion pressure of the rollers penetrates the rubber material into the fiber gaps on the reverse side of the canvas, forming a rubber layer with the same thickness as the front side. 2.3 Final shaping process: The canvas with double-sided adhesive is cooled, its thickness is measured, and it is rolled up to become a semi-finished product of adhesive tape for V-belts.

[0014] In step 1.2, the temperature of the screw extruder's feed port, plasticizing section, and extruder head section is controlled at 80-100℃.

[0015] In step 1.2, the preset speed ratio is 0.92 for the upper roller and 0.88 for the lower roller.

[0016] In step 2.1, the temperature of the screw extruder's feed port, plasticizing section, and extruder head section is controlled at 70-90℃.

[0017] This invention has the following features: First, it uses chloroprene rubber as the main rubber system and precisely blends it with butadiene rubber 9000 to enhance the intrinsic oil resistance and elasticity balance of the base material; second, it constructs a multi-element system of "double carbon black reinforcement + special conductive carbon black" to achieve synergistic conductivity and strength at low addition levels; third, it designs a composite anti-aging, vulcanization and bonding system, combined with segmented mixing and precise calendering processes, to ensure that the formulation performance is fully utilized and adapted to industrial applications, ultimately achieving the comprehensive goal of "oil resistance, antistatic properties, high strength, and easy calendering".

[0018] This invention has the following advantages: ① Address the safety hazards and environmental compliance issues related to the presence of rubber solvent oil and toluene in the rubber compound pulping process; ②Solve the environmental protection standards for rubber solvent oil and toluene in the impregnation process and the cost waste after volatilization; ③ A new oil-resistant and anti-static calendering formula was developed, using chloroprene rubber as the main rubber and high-structure, high-specific-surface-area conductive carbon black KF-80 as filler, giving the rubber compound excellent physical properties such as oil resistance, heat resistance, and antistatic properties. This solves the problems of poor calendering performance and unstable molding quality. By optimizing the rubber blending ratio and adjusting the plasticizer with environmentally friendly aromatic oil, combined with optimization of calendering process parameters, the Mooney viscosity (ML1+4 100℃) of the rubber compound is controlled at 40-60, and the calendering speed is increased to 12-15 m / min; the thickness deviation of the calendered sheet is ≤0.1mm, with no defects such as sticking to the roller or bubbles, and the adhesion strength between the sheet and the skeleton layer is ≥5N / mm.

[0019] ④ A calendering and rubbing process using a neoprene rubber formulation was developed to replace the impregnation process. Detailed Implementation

[0020] The formula and effects of this invention are as follows:

[0021] Adhesive bonding process details: The three-roll calender used for applying adhesive to both sides of the canvas achieves uniform adhesive penetration and consistent adhesion on both sides of the canvas through two independent single-sided adhesive application processes.

[0022] The working principle is based on the basic extrusion and shearing mechanism of a three-roll calender. The basic structure consists of three parallel rollers (I-type arrangement) with independent temperature and speed control. It is also equipped with two independent canvas traction and positioning systems and a rubber feeding device. The roller gap adjustment accuracy can reach 0.01mm, allowing for adaptation to the process parameters of applying rubber to both sides of the canvas. It supports secondary feeding and positioning of the canvas, ensuring that when the first rubber-applied side is facing up / down, the second rubber-applied side can precisely fit the roller gap, preventing secondary crushing damage to the already rubber-applied surface.

[0023] 1. Process Steps 1.1 Apply adhesive to the front of the canvas: Raw material pretreatment: After the canvas is dried, it is fixed in width and then fed into the calender by the traction device. At this time, the side that needs to be rubbed with glue faces the glue feeding area between the rollers.

[0024] Rubber compound penetration and extrusion: After the oil-resistant and anti-static calendered rubber compound is preheated by a ∮150 screw extruder (the temperature of the screw extruder feed port, plasticizing, and extruder head section is controlled at 80-100℃), the rubber compound is added into the feeding gap between the upper and middle rollers. The rollers rotate at a preset speed ratio (upper roller speed ratio 0.92, lower roller speed ratio 0.88). The extrusion and shearing forces are used to roll the oil-resistant and anti-static calendered rubber compound into a thin layer and force it to penetrate into the gaps between the warp and weft fibers on the front of the canvas.

[0025] Temperature control shaping: The roller temperature is controlled at 80-100℃. The purpose of this temperature is to reduce the viscosity of the adhesive, improve the penetration, and prevent the adhesive from scorching. After the adhesive is applied, a uniform adhesive layer is formed on the front of the canvas, and the adhesive and the fiber form a mechanical interlocking structure.

[0026] Cooling and temporary storage: After the front side is coated with adhesive, the canvas is cooled and shaped by cooling rollers to prevent the adhesive from sticking together. Then it is rolled up and temporarily stored or directly sent to the secondary positioning device.

[0027] 2. Apply adhesive to the reverse side of the canvas: Secondary positioning of canvas: The canvas with glue applied to the front is fed back into the second calender. The direction of the canvas is adjusted by the traction steering device so that the un-glueed reverse side faces the feeding area. At the same time, it is ensured that the canvas is flat and wrinkle-free, and the glued side does not come into direct contact with the feeding roller.

[0028] Reverse side coating process: Similar to the first side coating, the oil-resistant and anti-static calendered rubber compound is preheated by a ∮150 screw extruder (the temperature of the screw extruder feed port, plasticizing, and extruder head section is controlled at 70-90℃). The rubber compound is then added to the feeding gap between the upper and middle rollers, and the extrusion and shearing process is repeated. The extrusion pressure of the rollers penetrates the rubber compound into the fiber gaps on the reverse side of the canvas, forming a rubber layer with the same thickness as the front side.

[0029] Final shaping process: The canvas, after being coated with adhesive on both sides, is cooled, its thickness is measured, and it is rolled up to become a semi-finished product of adhesive tape for V-belts.

[0030] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An oil-resistant and anti-static calendering compound, characterized in that, The following materials are included by mass: Neoprene 85-95 Butadiene rubber 5-15 Carbon black N660 5-10 Carbon black N330 10-40 Conductive carbon black KF-80 5-10 Calcium carbonate 15-30 Environmentally friendly aromatic oil E370 5-15 Auxiliary MgO 3-7 Indirect method zinc oxide 3-7.

2. An oil resistant antistatic extension stock as in claim 1, characterized in that Also included is a processing and bonding system, which includes the following materials by mass:

3. An oil resistant antistatic extension stock as in claim 1, wherein Stearic acid 2-4 and bonding agent RC 3-7. Also included is an antioxidant protection system, which includes the following materials by mass: Antioxidant 2246 1-3 Antioxidant MB 1-3 Antioxidant ODA 1-3 4. An oil resistant antistatic extension stock as in claim 1, wherein Microcrystalline wax 1-3. Also included is a vulcanization promoting system, which includes the following materials by mass: Promoter DM 0.5-1.5 Promoter CBS 0.5-1.5 5. An oil resistant antistatic extension stock as in claim 1, characterized in that: Anti-scorching agent 0.2-1.

0.

6. A process for calendering of the oil resistant antistatic pressure sensitive adhesive of claims 1-5, characterized in that, Also included is oil-extended sulfur 0.5-1.5 as a vulcanizing agent. The following steps are included: (1) Canvas front side wiping: 1.1 Raw material pretreatment, the canvas is dried and then subjected to width setting treatment, and is fed into the calendering machine by a traction device, at which time the front side requiring wiping is directed towards the rubber feeding area between the rollers; 1.2 Rubber penetration and extrusion: the oil-resistant and anti-static calendering rubber is preheated by a screw extruder, the rubber is fed into the feeding gap between the upper roller and the middle roller, the rollers are rotated at a preset speed ratio, and the oil-resistant and anti-static calendering rubber is rolled into a thin layer by using extrusion force and shear force, and is forced to penetrate into the warp and weft fiber gaps of the canvas front side; 1.3 Temperature control and shaping: the roller temperature is controlled at 80-100℃; the canvas front side after wiping forms a uniform rubber layer, and the rubber and the fibers form a mechanical engagement structure; 1.4 Cooling and temporary storage: the canvas after front side wiping is cooled and shaped by a cooling roller; (2) Canvas back side wiping: 2.1 Second positioning of the canvas: the canvas whose front side has been wiped is fed into the second calendering machine again, the direction of the canvas is adjusted by a traction and turning device, so that the back side not yet wiped is directed towards the feeding area, while ensuring that the canvas is flat and wrinkle-free, and the wiped side does not directly contact the feeding roller; 2.2 Back side wiping operation: similarly to the first side wiping, the oil-resistant and anti-static calendering rubber is preheated by a screw extruder, the rubber is fed into the feeding gap between the upper roller and the middle roller, and the extrusion and shearing process is repeated, the extrusion force of the roller penetrates the rubber into the fiber gaps of the canvas back side, and forms a rubber layer with the same thickness as the front side; 7. A cover fabric V-belt calendering process as claimed in claim 6, characterized in that: 2.3 Final shaping treatment: the canvas after double side wiping is cooled, thickness is detected, and is wound into a roll, becoming a rubber cloth semi-finished product for V-belts.

8. A cover fabric V-belt calendering process as claimed in claim 6, characterized in that: The feeding port, plasticizing, and extruder head section temperature of the screw extruder in step 1.2 are controlled at 80-100℃.

9. A cover fabric V-belt calendering process as claimed in claim 6, characterized in that: The preset speed ratio in step 1.2 is an upper roller speed ratio of 0.92 and a lower roller speed ratio of 0.

88. The feeding port, plasticizing, and extruder head section temperature of the screw extruder in step 2.1 are controlled at 70-90℃.

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