Contribution to advancement of knowledge / Technological progress

The knowledge of the formulation and the control of the mixing process and the understanding of the volatiles released during vulcanization, are the basis for the optimization of the manufacturing process, especially in the vulcanization stage, lowering costs and rejection rate.

The following innovations within each stage of the manufacturing process will contribute to develop a complete solution for the improved manufacture of the rubber hose.

Design of new rubber compounds

The correct selection of the ingredients to minimize the gases produced during vulcanization will reduce the chance of rejection by blister formation on the surface.

The design of a new formulation with good processing (good extrusion characteristics) and performance (good abrasion and rubber-textile adhesion as the most important physical properties) will improve the properties of the rubber compound allowing for some reduction in thickness of the rubber layers while keeping the properties above the level required by the standards, reducing costs and producing lighter hoses.

Development of new processing methods for the un-vulcanized compound

Processing of the un-vulcanized compound is another source of variables to be controlled. During the mixing stage of the compound, a careful control of the parameters handled by the compounder such as addition order or mixing temperature, including filtering of the compound, will minimize the rejects due to impurities, pre-vulcanization and insufficient homogeneity on the compound.

The knowledge of the effect of degassing or venting, and of extruder filters, on the volatiles released and state of vulcanization of the compound will reduce the reject rate on the manufactured hoses.

Development of a new continuous vulcanization method

To improve productivity to the maximum and increase the length of the manufactured hoses, a continuous vulcanization system is to be developed. The first objective to face is to keep the shape of the rubber hose without the application of internal pressure. The surface vulcanization of the rubber hose at extruder exit will allow the rubber to maintain the round profile when entering the rest of the continuous vulcanization line. In addition, the surface pre-vulcanization of the hose at extruder exit will increase the strength of the cover at the vulcanization step, reducing its plasticity when heated at vulcanization temperature, and reducing the chance for the appearance of blisters on the surface, the main defect encountered on the current manufacturing process.