Full definition
Molded neoprene, also known as polychloroprene (CR), is a type of synthetic rubber that is produced by placing an uncured neoprene compound into a heated mold. The vulcanization process occurs under specific temperature and pressure conditions, typically between 150-180°C and 50-200 bar, allowing the material to form three-dimensional shapes with precise dimensions and consistent physical properties. The molding methods utilized for producing molded neoprene include compression molding, transfer molding, and injection molding. Compression molding is the most commonly used method, where a pre-formed rubber compound is placed in an open mold and subsequently closed to allow for vulcanization. Transfer molding involves forcing the rubber into a closed mold using a piston, which is particularly useful for creating complex shapes or incorporating metal inserts. Injection molding is an automated process that provides the highest production rates, making it advantageous for high-volume applications.
The unique characteristics of neoprene rubber, such as its resistance to oil, ozone, and flame, coupled with its excellent dynamic performance, render it suitable for a variety of industrial applications. Molded neoprene parts are widely used in environments where exposure to harsh conditions is common, such as anti-vibration mounts for engines and machinery, suspension bushings, bellows, flexible boots, pump diaphragms, expansion joints, cable grommets, dust covers, and bridge bearing pads. Neoprene typically exhibits a hardness range of 40-80 Shore A, tensile strength between 12-25 MPa, and an elongation at break of 200-500%, varying based on the specific formulation and application requirements.
When selecting neoprene compounds for specific service conditions, factors such as operating temperature, chemical exposure, and dynamic loading should be considered. For applications requiring rubber-to-metal bonding, the metal inserts must be pre-treated with a primer and adhesive, such as Chemlok or Chemosil, to ensure a strong bond during the molding process. This attention to detail in the selection of materials and processes is crucial for achieving the desired performance and longevity of molded neoprene components in industrial settings.