Vulcanization & Rubber molding

Forming the future with ZHENGXI

System solutions for Rubber

Rubber Industries

Production of raw NR might be classified as an agricultural industry because latex, the starting ingredient, is grown on plantations in tropical climates. By contrast, synthetic rubbers are produced by the petrochemical industry .Finally, processing into tires and other products occurs at processor (fabricator) plants, commonly known as the rubber industry .

Rubber Processing and Shaping

Production of rubber goods consists of two basic steps:

• 1.Production of the rubber itself
• 2.Natural rubber is an agricultural crop
• 3.Synthetic rubbers are made from petroleum
• 4.Processing into finished goods, consisting of:
•  5.Compounding
• 6. Mixing
• 7. Shaping
• 8. Vulcanizing

When it comes to producing rubber products, multiple manufacturing processes exist. Each manufacturing process has particular benefits that make it the ideal choice for manufacturing certain types of products. Knowing the manufacturing processes can help you understand cost implications and tradeoffs. Some of the most common rubber manufacturing processes are extrusion, latex dipping, molding, and calendering.

The additives must be thoroughly mixed with the base rubber to achieve uniform dispersion of ingredients

1.Uncured rubbers have high viscosity so mechanical working of the rubber can increase its temperature up to 150°C (300°F)

2.If vulcanizing agents were present from the start of mixing, premature vulcanization would result - the "rubber processor's nightmare"

The most common manufacturing process is called calendaring, which works by forcing softened material into the center of counter-rotating rollers. Rollers compact the material and the overall thickness of the product is determined by the gap distance between cylinders, which can be adjusted for varying product thicknesses. Once the material passes through cooling rollers, it must be vulcanized. This process works best to produce sheets or films of rubber. Some benefits of calendering include control over product thickness and the ability to produce parts thinner and wider than with the extrusion. However, calendering has high operating costs compared to other processes.

Vulcanization &  molding

Vulcanization or vulcanisation is a chemical process for converting natural rubber or related polymers into more durable materials by heating them with sulfur or other equivalent curatives or accelerators. These additives modify the polymer by forming cross-links (bridges) between individual polymer chains.Vulcanized materials are less sticky and have superior mechanical properties. The term vulcanized fiber refers to cellulose that has been treated in a zinc chloride solution to cross-link the cellulose fibers.

Although curing of rubber has been carried out since prehistoric times, the modern process of vulcanization was not developed until the 19th century, mainly by Charles Goodyear. Today, a vast array of products are made with vulcanized rubber, including tires, shoe soles, hoses, and conveyor belts.

The term "vulcanization" is named after Vulcan, the Roman god of fire. Hard vulcanized rubber is sometimes sold under the brand name Ebonite or the genericized former brand term "vulcanite", and is used in making articles such as clarinet and saxophone mouth pieces, bowling balls, and ice hockey pucks.

Each manufacturing process is ideal for producing certain types of rubber products. Understanding the processes available can make planning for manufacturing a lot easier because each process has its own cost and time limitations.

ZHENGXI has developed and implemented hundreds of hydraulic presses for rubber, plastics & composites applications all over the world. Apart from multi-platen press solutions, we serve the rubber industry with compression molding press dedicated to tire production.

Application

1. Aerospace

Re-useable silicone vacuum bags, pressure bladders, caul sheets, extrusions, compaction bags, molded parts, silicone sheet fluoroelastomer, tool sealant, infusion products.

2.Gasket Supplies

Silicone sheet, fluoroelastomer sheet, molded pads, sponge sheet, fabric reinforced sheet.

3. Automotive

Gasket material, extrusions, fluoroelastomer sponge sheet.

4. Composite Manufacturing

Re-useable vacuum bagging material, seals, caul sheets, tool sealant, vacuum infusion products.

5. Cabinet Manufacturing