How to glue Melt Processible Rubber (MPR), known as Smelteformbar Gummi in Danish.

Melt Processible Rubber is a single-phase polymer alloy. It is a mixture of ethylene interpolymers, chlorinated polyolefins with partial crosslinking of the ethylene components, plasticizers, and fillers. Hydrogen bonding between the ethylene interpolymers and the chlorinated polyolefins is achieved by incorporating the correct functional groups on the ethylene interpolymer.

MPR (Melt Processible Rubber) is a very soft rubber with flexibility and feel similar to vulcanized rubber. The main advantages of MPR are oil resistance, good heat aging resistance, and weather resistance. MPR has good resistance to hydrocarbon-based oils as well as lithium- and silicone-based greases. MPR retains its properties well when exposed to water and aqueous solutions of inorganic acids. This is typical for many non-vulcanized elastomers. Although MPR retains its properties well within this range, its low crystallinity and absence of vulcanizate phase make it prone to unacceptable compression set at elevated temperatures. MPR has shown good property retention both under long-term outdoor exposure and in simulated aging environments.

MPR (Melt Processible Rubber) is used across a wide range of industries. In construction, it is used for weatherstrips that help protect buildings from the elements. In the electrical sector, MPR is used for jackets for electrical wires and cables as well as electrical boots. Industrially, MPR is ideal for seals, gaskets, hoses, pipes, conveyor belts, and coated fabrics due to its durability and flexibility. Additionally, MPR is used for various applications such as suction cups and sports field markers, where its softness and flexibility are advantageous.

Typically, the surface tension for thermoplastic elastomers such as MPR ranges from 20 to 40 dyn/cm.

One of the best-known trade names for MPR is Alcryn, developed by DuPont. Alcryn is a specific blend of ethylene interpolymers, chlorinated polyolefins with partial crosslinking of the ethylene components, plasticizers, and fillers, enabling the creation of a melt-processable rubber with special properties such as good oil resistance, heat resistance, and weather resistance.

Bonding

Bonding Melt Processible Rubber (MPR) can be challenging due to its special composition and surface properties.

Clean and prepare the MPR surface thoroughly before bonding. It is important to remove any oil, dirt, or contamination that could affect the adhesive bond. Use an appropriate cleaning method, such as a non-etching cleaning fluid. For optimal adhesion, it is often recommended to treat the surface with a primer or undergo corona or plasma treatment before bonding, particularly depending on the strength requirements for the bonded joint.

Choose an adhesive compatible with MPR and the specific application.

• -Cyanoacrylate adhesive is known for its rapid curing and strong adhesion properties, meaning it forms a solid and reliable bond with the MPR surface. In summary, MPR is suitable to bond with cyanoacrylate adhesive due to the fast cure, strong adhesion to rubber and elastomers, and its simple and reliable use.
• -Methyl acrylate adhesive is a type of adhesive that cures via polymerization and is known for its strong mechanical properties and durability. In many cases, methyl acrylate adhesive can be an effective solution for bonding MPR, especially if the correct adhesive type is chosen and applied correctly according to the manufacturer’s instructions.
• -Silicone adhesive is highly flexible and can adapt to materials with varying elasticity. Silicone adhesives generally also provide good adhesion to rubber and elastomers, including MPR.
• -UV adhesive cures rapidly when exposed to ultraviolet light of suitable wavelength. UV adhesive can be an effective solution for bonding MPR, especially in applications where fast curing and precise control of adhesive placement are important. However, it is important to select the correct type of adhesive and perform proper surface preparation and application to achieve optimal results.

Follow the adhesive manufacturer’s instructions regarding application and curing time.

Test the strength and durability of the MPR adhesive on the specific MPR material and in the current application.

Manufacturers

DuPont is a leading manufacturer and pioneer in Melt Processible Rubber (MPR). They developed Alcryn, one of the first commercially available forms of MPR.

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