How to reduce the cost of compounding rubber

In the highly competitive world of the rubber industry, the cost of compounding is critical to the economic success of a product. It is possible to develop a compound formulation that meets the customer's needs in terms of both performance, but is rejected by the customer because it is too expensive.

In addition, rubber products are generally sold by volume rather than by weight (molded products are generally sized). Therefore, it makes sense to compare the "cost per volume" rather than the "cost per weight" of the rubber.

The following scenarios may reduce the economic cost of the compound. Note: These general experimental scenarios may not be applicable to each specific case. Any one variable that reduces cost will definitely affect other properties, for better or worse.

1. Carbon black/plasticizer

Choosing a high structural carbon black and using a high filler oil will keep the modulus of the compound constant while the cost goes down.

2. Carbon black filling amount

Consider choosing low structured and low specific surface area carbon black, because this carbon black is not only cheaper, but also has high filling amount, which can effectively reduce the cost of rubber.

Choose ultra-low structured semi-reinforced carbon black, because it can be filled in large quantity, which can effectively reduce the cost of rubber.

Choose low specific surface area and low structured carbon black to fill high cost rubber, and keep the viscosity of rubber not too high, so that the rubber can be injection molded or vulcanized by other methods, and the cost will be moderately reduced.

3. Silica

For low rolling resistance and good slip resistance, silica is often used as a filler and an organosilane coupling agent is used. Silane coupling agents are expensive, and if a very small amount of silane coupling agent can be used and the performance of the compound remains unchanged, the cost of the compound can be greatly reduced. A common practice is to use silica with a high surface hydroxyl content, as it has been studied to be more easily coupled. Thus, with more hydroxyl groups in the compound, less silane coupling agent is needed and the same mechanical properties are maintained while the cost is reduced.

4. Filler

In TIO2-filled white compounds, other low-cost white fillers (such as water-washed clay, calcium carbonate, whitening agent, etc.) can be considered to replace some of the TIO2, and the compound will still have a certain covering capacity and whiteness.

In silica filled tread compounds, replacing some of the silica with carbon black-silica biphasic fillers can also reduce the cost of the compound, because it can reduce the amount of silane coupling agent, and also reduce the heat treatment step in the mixing process.

Filling the rubber with calcium carbonate will significantly reduce the cost of the rubber. Likewise, clay will significantly reduce the cost of the adhesive.

Although the density of talc (2.7g/cm3) is greater than that of carbon black (1.8g/cm3), if 1.5 parts (by mass) of talc is used instead of 1 part (by mass) of carbon black, the cost of the compound can be reduced. In addition, the talc powder will increase the extrusion speed and improve the output, which will indirectly reduce the cost.

5. Density reduction

Rubber products are usually priced by volume rather than by weight. If you change the rubber formula to make the density lower, while keeping the price per unit volume unchanged, then you can indirectly reduce the cost. For example, by replacing CR with NBR, the cost per unit volume of rubber drops, provided that other changes in the rubber do not offset this cost advantage.

6. has replaced two-step compounding with additive compounding.

If possible, replacing two-step compounding with one-step compounding through energy control techniques and effective process energy testing can also reduce costs.

7. Processing aids

The use of processing aids can improve the extrusion or calendering speed of the compound, thus reducing costs.

8. FKM/ACM blending

Replacing pure FKM with peroxide-cured FKM/ACM blend (Dai-El AG-1530) can make the rubber have better heat and oil resistance.