Introduction

Urethane is a synthetic material that belongs to the class of polymers known as polyurethanes. It is a versatile material that can be formulated to have a wide range of properties, including flexibility, toughness, hardness, and resilience.

Urethane is known for its durability, resistance to abrasion and chemicals, and its ability to withstand extreme temperatures. It can be molded into complex shapes, making it ideal for use in a range of products.

Overall, urethane is a highly useful material with a broad range of applications due to its versatility, durability, and performance properties. They are also used in the manufacture of automotive parts, sports equipment, medical devices, and industrial components.

Molding Urethane Parts

Urethane is typically molded into parts using a process called reaction injection molding (RIM). RIM is a manufacturing process that involves the mixing of two liquid components, polyol and isocyanate, under high pressure and injecting the mixture into a mold. The mixture then reacts and cures inside the mold, forming a solid part with the desired shape and properties.

The RIM process typically involves the following steps:

1. Mold preparation: The mold is first prepared by cleaning and coating it with a mold release agent to prevent the urethane from sticking to the mold walls.
2. Mixing: The two liquid components (polyol and isocyanate) are blended in a mixing chamber under high pressure.
3. Injection: The mixed liquid is then injected into the mold at high pressure and fills the entire mold cavity.
4. Reaction and curing: The urethane mixture reacts and then cures inside the mold, forming a solid part.
5. Demolding: Once the part has cured, it is removed from the mold.
6. Finishing: The part may then undergo additional finishing processes, such as deflashing or coating, to achieve the desired final appearance and properties.

The RIM process allows for the production of high-quality, complex parts with a wide range of physical and mechanical properties.

Molded Urethane Applications

Some common examples of parts that are molded out of urethane include:

1. Seals and gaskets: Urethane is often used to produce seals and gaskets due to its excellent chemical resistance, durability, and flexibility.
2. Wheels and rollers: The material’s high strength, abrasion resistance, and impact resistance make it ideal for manufacturing wheels and rollers used in conveyor systems, industrial machinery, and material handling equipment.
3. Bumpers and shock absorbers: It’s ability to absorb impact and vibration makes it an ideal material for manufacturing bumpers and shock absorbers used in automotive and industrial applications.
4. Electrical components: This material’s electrical insulation properties make it suitable for use in electrical components such as switchgear, transformers, and motors.
5. Medical devices: Urethane is used to manufacture medical devices such as catheters, tubing, and diagnostic equipment due to its biocompatibility, chemical resistance, and flexibility.

Cryogenic Deflashing Urethane Parts

Urethane parts can be cryogenically deflashed. Cryogenic deflashing is a process that uses liquid nitrogen to freeze and then remove excess flash or mold flash from molded parts. Mold flash is the excess material that protrudes from a molded part after it has been removed from the mold.

The cryogenic deflashing process involves placing the molded parts in a chamber and exposing them to gaseous nitrogen at near the glass transition point of the material. The rapid cooling causes the flash to become brittle. The parts are then tumbled and blasted to remove the mold flash.

Urethane is a material that can withstand cryogenic temperatures, so it is suitable for cryogenic deflashing. Cryogenic deflashing can be particularly effective for urethane parts with complex geometries or delicate features, as it can remove flash without changing the dimensions or surface finish of the part.

Want to send us your Urethane part samples for a no-cost deflashing proof of concept? Contact us at info@nitrofreeze.com or call us at (508) 459-7447X105 to learn more.