When nitrile rubber or nitrile reclaimed rubber is used as the main raw material to prepare rubber products, it can be compounded with metal materials to produce products with higher strength and better durability. Nitrile rubber and nitrile reclaimed rubber can choose to use vulcanization bonding method or rubber surface chemical treatment method to bond with the metal skeleton. In actual production, the rubber hardness, surface roughness, bonding method, etc. will affect the adhesion between the nitrile rubber compound and the metal material.
3. Basic properties of nitrile rubber
Nitrile rubber has good bonding performance. When nitrile rubber or nitrile reclaimed rubber is used to prepare rubber products with metal skeletons, the adhesion strength of nitrile rubber will first increase and then decrease with the increase of rubber hardness. Generally, the hardness of nitrile rubber/reclaimed rubber 2YLYY39 reaches about 75 degrees (Shore hardness), and the bonding strength is greater. In actual production, the surface treatment of nitrile rubber or nitrile reclaimed rubber is carried out in advance, and sandpaper is recommended to further improve the adhesion between nitrile rubber and metal materials.
4. Application of coupling agent
One group contained in the coupling agent can be combined with the metal material (adhesive material), and the other group can be combined with the nitrile rubber/reclaimed rubber (rubber material), forming a higher chemical bond at the bonding interface , The more this kind of chemical bond, the better the adhesion between the rubber and the metal material. As a low-viscosity compounding agent, the increase in the amount of coupling agent will reduce the overall viscosity of the rubber compound, so that the wettability between the adhesive and the metal material will increase, and the bonding strength will be better. It can be seen that increasing the amount of coupling agent can increase the adhesion between the two.
It should be noted that the excessive amount of coupling agent will lead to a decrease in the strength of the adhesive body, and ultimately reduce the overall bonding strength, so the amount of coupling agent should be appropriately controlled. When silane coupling agent is used in nitrile rubber products or nitrile reclaimed rubber products, the amount of coupling agent is controlled at about 15 parts, and the adhesion between rubber and metal materials is better. The use of silane coupling agent will also increase the water resistance and heat resistance of nitrile rubber products.
5. Other points to note
To improve the bonding strength between the nitrile rubber compound and the metal skeleton, rubber product manufacturers can also appropriately increase the curing time at room temperature. When applying adhesive, if the primer is too thick, the shear strength will decrease, which requires special attention. When bonding between rubber and frame material, vulcanized bonding needs to pay attention to the vulcanized rubber not to shift; the glue application process needs to avoid problems such as leakage, missing coating, or air bubbles that cause the shear force to drop.
Do you have any other good ways to improve the adhesion between the nitrile compound and the metal frame material? I look forward to discussing with you.
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