Introduction to Butyl Rubber

Butyl rubber is a synthetic rubber, also known as polyisobutylene, which is produced by polymerizing isobutylene, a type of olefin. It has a very low gas permeability, making it an excellent material for manufacturing products that need to maintain airtight seals.

Butyl rubber is also resistant to moisture, chemicals, and ultraviolet light, which makes it useful in various applications. It is used in the manufacturing of medical products, such as syringe plungers and stoppers for vials, due to its inertness and low extractable levels.

Overall, butyl rubber parts are versatile and have excellent properties that make them suitable for a wide range of applications across many industries.

Molding Butyl Rubber Parts

Butyl rubber parts can be molded using various molding techniques, including compression molding, injection molding, and transfer molding. The choice of molding method depends on the specific application and the shape and size of the part to be produced.

Here is a brief overview of each molding technique for butyl rubber:

1. Compression molding: In compression molding, a pre-measured amount of butyl rubber is placed into a mold cavity, which is then compressed under heat and pressure until the rubber fills the cavity and takes the desired shape. The mold is then cooled, and the part is removed.
2. Injection molding: Injection molding is a process where butyl rubber pellets are melted and injected into a mold under high pressure. The rubber fills the mold cavity and takes the shape of the part. Once the rubber cools and solidifies, the part is removed from the mold.
3. Transfer molding: Transfer molding is a variation of compression molding that involves preheating the butyl rubber in a chamber and then transferring it into the mold cavity using a plunger. The rubber is compressed under heat and pressure until it fills the cavity and takes the shape of the part. The mold is then cooled, and the part is removed.

Each molding technique has its advantages and disadvantages, and the choice of method depends on the specific requirements of the application. Complexity of the part, the production volume, and the desired quality of the final product help determine what molding process to use.

Applications of Butyl Rubber

Due to Butyl rubber’s versatility it finds its use in various applications, some of which are:

1. Seals and Gaskets: Butyl rubber’s airtight and water-resistant properties make it ideal for manufacturing seals and gaskets. It is commonly used in the construction industry for sealing windows, doors, and roofs.
2. Medical Products: This form of rubber is used in the medical industry for manufacturing various products, such as stoppers for vials and syringe plungers. It is ideal for use in medical applications because of its inertness and low extractable levels.
3. Sporting Goods: It is used for manufacturing various sporting goods such as soccer balls, basketballs, and volleyballs. Its excellent air retention properties make it ideal for inflatable products.
4. Electrical Equipment: This material is used for manufacturing electrical equipment, such as cable insulation, due to its excellent electrical insulation properties.

Cryogenic Deflashing Butyl Rubber

Molded butyl parts can be cryogenically deflashed. Cryogenic deflashing is a process that involves inserting the molded parts in a cryogenic deflashing system. The parts are then cooled using gaseous nitrogen to a low temperature, based on the glass transition point of the material. The butyl parts are then blasted with polycarbonate cryogenic-grade media and tumbled against one another. This process effectively removes any flash left over from the molding process, leaving a clean and smooth surface finish.

Butyl rubber is a suitable material for cryogenic deflashing because it can withstand the low temperatures without becoming brittle or cracking. The rubber deflashing process is particularly useful for removing flash from intricate parts with complex geometries, where traditional deflashing methods such as hand trimming may be challenging or near impossible.

Cryogenic deflashing can be a cost-effective and efficient way to produce high-quality molded butyl parts that meet drawing requirements. However, the process requires specialized equipment and expertise, so it is important to consult with a qualified rubber deflashing service provider such as Nitrofreeze before using this method for your specific application.

Want to send your molded Butyl parts for a no-cost deflashing evaluation? Learn more by calling us at (508) 459-7447 or email us at info@nitrofreeze.com.