XJ-90 Rubber Cold Feed Extruder And EPDM Rubber Strip Production Line

1. Mixing System
   • The production process begins with the mixing of raw materials. The mixing equipment is crucial for ensuring a homogeneous blend of EPDM rubber, fillers (such as carbon black, silica), vulcanizing agents (like sulfur), and other additives. High - speed mixers are often used to achieve a proper dispersion of the components. For example, the Banbury mixer is a popular choice. It has two counter - rotating rotors that knead the rubber compound thoroughly. The mixing temperature and time are carefully controlled to optimize the properties of the rubber mixture.
2. Extrusion Unit
   • After the mixing stage, the rubber compound is fed into the extrusion unit. The extruder is the heart of this part of the production line. It consists of a screw conveyor that pushes the rubber through a die to form the desired shape of the rubber strip. The die can be customized according to the specific cross - sectional shape of the strip required, such as circular, rectangular, or T - shaped. The extrusion temperature and pressure are adjusted to ensure a smooth and consistent output. The screw speed also affects the extrusion rate and the quality of the extruded strip. For instance, a screw with a higher pitch can move the rubber compound through the extruder more quickly, but it may require more power and precise temperature control.
3. Vulcanization Equipment
   • Vulcanization is a critical step in the production of EPDM rubber strips. It is the process that cross - links the rubber molecules to improve its strength, elasticity, and resistance to heat and chemicals. There are different methods of vulcanization used in the production line. One common method is continuous vulcanization in a hot air oven. The extruded rubber strip passes through a heated chamber where it is exposed to a specific temperature and time profile. Another option is microwave vulcanization, which offers faster and more efficient cross - linking. The vulcanization conditions (temperature, time, and pressure) are carefully calibrated to achieve the desired degree of cross - linking and physical properties of the rubber strip.
4. Cutting and Winding Equipment
   • Once the vulcanized rubber strip is produced, it needs to be cut to the appropriate length. Automatic cutting machines are used to ensure accurate and consistent lengths. These machines can be programmed to cut the strip at specific intervals according to customer requirements. After cutting, the rubber strips are usually wound onto reels for easy storage and transportation. The winding process should be carried out smoothly to avoid any damage or distortion of the strips. Some advanced winding machines have tension - control systems to ensure that the strips are wound evenly and tightly.

1. Raw Material Preparation
   • The first step involves gathering and preparing the raw materials. The EPDM rubber in the form of pellets or bales is weighed according to the recipe. Fillers and additives are also measured precisely. This step requires strict quality control to ensure that the correct proportions of each component are used, as any deviation can affect the final properties of the rubber strip.
2. Mixing
   • As mentioned earlier, the raw materials are mixed in the mixing system. The mixing process typically takes a certain amount of time, usually ranging from 5 to 15 minutes depending on the complexity of the recipe and the volume of the batch. The temperature of the mixer may increase during this process due to the friction of the moving parts and the heat generated by the chemical reactions of the additives.
3. Extrusion
   • The well - mixed rubber compound is then extruded through the die to form the initial shape of the rubber strip. The extrusion speed is adjusted according to the desired production rate and the characteristics of the rubber compound. The extruded strip is continuously monitored for its shape and surface quality. Any irregularities in the extrusion process, such as die blockages or uneven flow, can lead to defective strips.
4. Vulcanization
   • The extruded strip enters the vulcanization stage. The vulcanization parameters, such as temperature (usually between 140 - 180°C), time (which can vary from a few minutes to half an hour depending on the strip thickness and other factors), and pressure (if applicable), are carefully controlled. The vulcanization process transforms the plastic - like rubber compound into a more elastic and durable material with improved mechanical and chemical properties.
5. Cutting and Winding
   • After vulcanization, the rubber strip is cut to the desired length and wound onto reels. The cutting precision is crucial to meet the customer's length requirements. The wound reels are then labeled and packaged for shipment to customers.

1. Physical Property Testing
   • Throughout the production process, samples of the rubber strip are taken for physical property testing. Tests such as tensile strength, elongation at break, hardness (using Shore A hardness tester), and density measurements are carried out. These tests ensure that the rubber strips meet the required standards. For example, the tensile strength of a good - quality EPDM rubber strip used for sealing applications should typically be in the range of 5 - 10 MPa.
2. Visual Inspection
   • Visual inspection is also an important part of quality control. The surface of the rubber strip is checked for any defects such as bubbles, cracks, or surface roughness. The shape and dimensions of the strip are also verified to ensure they match the specified requirements. Any non - conforming products are separated and either reworked or discarded.
3. Chemical Resistance Testing
   • Given the importance of EPDM rubber strips' chemical resistance, samples are tested against various chemicals such as acids, alkalis, and solvents. This testing helps to ensure that the strips can withstand the chemical environments they are likely to encounter in their intended applications. For example, in the automotive industry, the rubber strips used for sealing engine compartments need to be resistant to engine oils and other automotive fluids.