Liquid-curing

Any method of vulcanising rubber products which proceeds without interruption from start to finish as compared to the method of vulcanising separate batches of products or sections of a product. Continuous vulcanisation processes include the cold curing of proofed cloth, the vulcanisation of belting and flooring, of cables and certain extruded products by either the Liquid Curing Medium, Fluid Bed, Microwave, or Hot Air techniques. 

Extrusion with the aid of a vacuum applied to the screw. The process is applied particularly in the preparation of extrudates to be vulcanised by either the liquid curing medium or fluid bed techniques. It assists in removing the volatiles from the compound and thus improves the quality of the extrudate. 

Steel belts are used to transport rubber profiles through the liquid salt medium in the LCM (liquid cure medium) baths. These belts, either used singly or in multiples are often used in conjunction with chain driven roller systems. Steel belts, in the high temperatures of a LCM medium expand considerably, and the multiple belt system helps to overcome this problem to some degree, by allowing easy adjustment for overall length. The belts used in these systems are customised to the particular equipment and normally can only be sourced from the original equipment manufacturer. 

This system involves the use of some form of heating by air or steam in a chamber in a manner such that the vulcanization occurs immediately after the rubber is formed in an extruder or calender. This is a suitable process for extruded profiles and calendered sheets and conveyor belts. Liquid curing method (LCM) is also a continuous process which involves the use of suitable hot liquid baths in which extruded profiles can be passed through and vulcanized continuously. Items can be cured rapidly at temperatures from 200°C to 300°C however the compounds must be suitably designed to prevent porosity as this is a common problem with any extrudate. Suitable materials for curing medium includes bismuth-tin alloys, an eutectic mixture of potassium nitrate and... 

Chemical cure - A tank lining system which can cure at low temperatures by topically applying a liquid curing agent. 

Polyisocyanates differ as regards their chemical structure, reactivity, functionality, and isocyanate content. They are the principal curing constituent of two-pack polyurethane paints. Curing agent solutions have an isocyanate content of 5-16 wt%. Solvent-free, liquid curing agents may contain up to 30 wt% isocyanate. 

Py-GC at 420 °C and 470 °C of liquid cured [LP2(I)] and ammonium dichromate cured [LP2(II)] polysulfide polymers gave pyrograms in which the predominant components were ... 

Anaerobic adhesives take extreme advantage of the air inhibition of acrylic polymerization. They are catalyzed in such a manner that they depend upon the presence of oxygen to remain an unpolymerized liquid. Cure is affected only in the absence of oxygen (1). 

Mi, F. L., Shyu, S. S., Lee, S. T., and Wong, T. B. (1999a). Kinetic study of chitosan-tripolyphos-phate complex reaction and acid-resistive properties of the chitosan-tripolyphosphate gel beads prepared by in-liquid curing method. J. Polym. Set B Polym. Phys. 37(14), 1551-1564. 

Cure When a liquid cures to form a solid material, it sets as a result of a chemical reaction. ... 

These materials have the advantage of being relatively easy to apply. However, melt adhesives are typically not reactive in nature and, therefore, do not develop sufficient strength and sufficient heat and chemical resistance for certain applications [37]. Advantages of hot melt curable adhesives over traditional liquid curing adhesives are ... 

Liquid Cure Medium (LCM) uses a eutectic mixture of salts to heat the extrudate. The molten salt bath usually has a metal conveyor to keep the rubber eompound submersed. This method has good heat transfer to the rubber. However, cleaning salt off the extrudate can be difficult and satisfactory disposal of dilute salt rinse is beeoming increasingly difficult. This method is advantageous for articles with the low compression set obtained by using peroxides. Sulfur can be used as a coagent to minimize surface tack. Deformation problems versus other atmospheric methods are sometimes minimized. 

Liquid curing medium (LCM) is a practical method provided that a rapid cure rate system and a high viscosity CSM are selected. A peroxide system may leave a tacky surface unless complete submersion or rain of the LCM on the part is provided. 

---