Crosslinking technology

Control of crosslinking is critical for processing thermoset plastics, both the reaction prior to the gel point and that subsequent to the gel point. The period after the gel point is usually referred to as the curing period. Too slow or too rapid crosslinking can be detrimental to the properties of a desired product. Thus, in the production of a thermoset foamed product, the foam structure may collapse if gelation occurs too slowly. On the other hand, for reinforced and laminated products the bond strength of the components may be low if crosslinking occurs too quickly. 

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Zotefoams has introduced a new 100% PP foam called Propozote, produced using unique crosslinking technology using an autoclave at a higher temperature... 

Lin, T.S., Whaley, P.D., Cogen, J.M., and Wasserman, S.H., Advances in crosslinking technologies for high temperature under-the-hood automotive cable apphcations, Proceedings of 52nd International Wire and Cable Symposium/Focus, Philadelphia, PA, 2003, pp. 92-97. 

In automotive applications, e.g., automotive seats, molded HR foam is the major process used. HR foam is produced by using four kinds of technologies (a) crosslinker technology, b) graft-polyol technology, (c) PHD polyol technology, and (d) specialty isocyanate technology. 

Figure 2.3 Functional printed electronic cards for CROSSLINK technology (source printed systems).

Vinyl functional silanes have been used for over 35 years to crosslink polyethylene. The most common commercial products using this crosslinking technology are crosslinked PE insulations for the global wire and cable market [11] and crosslinked HDPE pipes for potable water and natural gas. Some work recently has been done to combine this crosslinking technology with wood-filled polyethylene. 

Companies that practice the graft technology include Quantum Chemicals. Cable processors that practice both graft and crosslink technology include BICC, Alcan, and Okonite. 

Silicon-acrylic resin systems using the crosslinking technology overcome at least some of the defects of conventional waterbourne coatings [85]. 

For TP systems such as PE, chemical or irradiation techniques have been used as the crosslinking technology this is the recognized standard for manufacturing industrial materials such as cable coverings, cellular materials (foams), rotationally molded articles, and piping. 

The traditional crosslinking technologies utilized in the coatings market range from hydroxyl functional binders—acrylics or poly(esters)—crosslinked with melamines (IK) or isocyanates (2K) to drying oils that cure through oxidation of the unsaturated bonds, to epoxy resins crosslinked with amino resins (amido amines, amines, etc.). 

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