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Rubber strip production line

Model XJ-75 XJ-90 XJ-120 XJ-150 Screw Diameter (mm) 75 90 120 150 Length-to-Diameter Ratio 20:1 20:1 20:1 20:1 Motor Power (kW) 30 55 110 132 Screw Speed (r/min) 30–65 30–60 30–50 30–50 Output (kg/h) 80–180 100–300 180–540 500–750 Working Principle Extrusion molding is a manufacturing process in which plasticized rubber compound, under appropriate conditions, is continuously forced through a die to produce a product with a specific cross-sectional shape. As the rubber compound moves forward along the screw, mechanical and thermal effects cause changes in its viscosity and plasticity, transforming it into a viscous fluid. Based on these changes during extrusion, the working section of the screw is generally divided into three main parts according to their functions: the feeding section, the compression section, and the extrusion section. The characteristics of each section are as follows: 1. Feeding Section: Also known as the solid conveying section, this segment extends from the feed port to the point where the rubber begins to melt. After entering the hopper, the material undergoes relative motion between the screw grooves and the inner wall of the barrel under the pushing action of the rotating screw, forming uniform rubber pellets. 2. Compression Section: Also called the plasticizing section, this part spans from the onset of melting until the rubber starts flowing. It receives the rubber pellets delivered from the feeding section, compacts them, further softens them, and expels any entrapped air back toward the feeding section. 3. Extrusion Section: Known as the metering section, this area further pressurizes and mixes the rubber conveyed from the compression section. By this stage, the rubber within the screw grooves has reached a fully fluid state. The rotation of the screw drives the flow of the rubber, ensuring uniform extrusion through the die at an appropriate rate and pressure. Cold Feed Extrusion Advantages: - Saves on hot-mixing equipment; - Facilitates mechanization and automation; - Enhances temperature and plasticity uniformity due to the intensified shearing and plasticizing action of the screw; - Improves the quality of extruded products, increasing surface smoothness and providing semi-finished products with more stable and consistent dimensions; - Exhibits reduced sensitivity to pressure fluctuations; - Offers broad applicability and high flexibility; - Lower investment and production costs compared to other methods. Currently, cold-feed extrusion is gradually replacing hot-feed extrusion for small-sized products such as wires, cables, and rubber hoses. Unlike hot-feed extrusion, cold-feed extrusion requires pre-setting temperatures in each section to specified values before heating. Typical operating temperatures are as follows: - Screw: <35°C; - Feeding section: 35–50°C; - Plasticizing section: 40–60°C; - Extrusion section: 50–70°C; - Die and die head: 80–100°C. Cold-feed extrusion commonly employs exhaust-type extruders, which remove trapped gases during the extrusion process, enhancing compactness, reducing porosity, and minimizing extrusion swell. Exhaust-Type Extrusion This type of extruder features a screw assembly comprising a feeding section, a first metering section, an exhaust section, and a second metering section. Semi-finished products produced by exhaust extruders exhibit fewer pores and greater density. Exhaust extruders are often integrated into continuous vulcanization lines alongside microwave or salt-bath vulcanization equipment, enabling the production of extruded items such as wires, cables, and sealing strips.

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Classification:

Rubber, rubber and plastic extrusion line

Business Hotline:

400-0319-386

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Rubber strip production line

Model number	XJ-75	XJ-90	XJ-120	XJ-150
Screw diameter (mm)	75	90	120	150
Length-diameter ratio	20:1	20:1	20:1	20:1
Motor power (kw)	30	55	110	132
Screw speed r/min	30-65	30-60	30-50	30-50
Yield kg/h	80-180	100-300	180-540	500-750

Working principle

Extrusion molding is a process in which the plastic material is continuously pressed out through a mouth shape to make it a product with a cross-section shape.

When the rubber material moves forward along the screw, due to the result of mechanical action and thermal action, the viscosity and plasticity of the rubber material have changed and become a viscous fluid. According to the change of the rubber material in the extrusion process, the working part of the screw is generally according to its function

The same is generally divided into feeding section, compression section and extrusion section three parts.

The features of the sections are as follows

1. Feeding section: also known as solid conveying section, this section from the feeding mouth to the melting of the rubber. After the rubber material enters the feeding port, under the action of the rotating screw, the relative motion is made between the screw groove and the inner wall of the barrel, and the uniform micelle is formed.

2. Compression section: also known as the plasticizing section, this section from the beginning of the rubber melt to the rubber to produce flow stop. The compression section receives the micelles from the feeding section, compacts and softeners them further, and discharges the air entrain in the rubber to the feeding section.

3. Press-out section: Also known as the metering section, this section compresses and transports the adhesive under further pressure for mixing. At this point, the screw grooves have created a fully fluidized state of the adhesive. The rotation of the screw facilitates the flow of the rubber, ensuring uniform delivery of both volume and pressure through the nozzle passage.

Extrude.

Cold feed extrusion

Advantages: saves heat in refining equipment, easy to achieve mechanization and automation, and because the main engine enhances the shear and plasticization of the screw, the rubber material attains uniform temperature and plasticity; improves the quality of extruded products, increases surface finish, and reduces extrusion defects.

The product has more stable and consistent size specifications; The sensitivity of cold feeding pressure is small. Wide application, flexibility; The investment and production cost of cold - feed extruder is lower.

At present, cold feeding extruder has gradually replaced hot feeding extruder in the extrusion of wire, cable, hose and other small specification products. The extrusion process of cold feeding is different from that of hot feeding. The temperature of each part should be adjusted to the specified value before heating. The common temperature of each part

As follows: screw <35℃; Feeding section 35~50℃; Plasticizing stage 40~60℃; Extrusion section 50~70℃; Nose and mouth 80~100℃. Cold feed extrusion is often used cold feed exhaust extruder, its characteristics are in the extrusion process to remove the gas in the rubber, increase

The density of the compound reduces the porosity of the compound and reduces the extrusion expansion rate of the compound.

Exhaust extruder extrusion

The screw of the extruder is composed of a feeding section, a metering section, an exhaust section and a second metering section.

The semi-finished products extruded by the exhaust extruder have fewer pores and dense products. The exhaust extruder is often combined with microwave or salt bath vulcanization equipment to form a continuous vulcanization line to produce extruded products such as wires, cables and seals.