Reactive hot melt adhesive
Reactive hot melt adhesives are based on polyurethanes (PUR), epoxides or silicones with a thermoplastic character. When used , these polymers react with air humidity (PUR and silicone) or when heated to temperatures well above the processing temperature (epoxides) to form a cross-linked polymer.
The reactive hot melt adhesives , which solidify through cooling, allow fast production processes as well as short joining and pressing times without the adhesive having to dry beforehand . They combine the advantages of thermoplastic hot melt adhesives with the strength and durability of cured two-component adhesives . Reactive hot melt adhesives can serve as a more environmentally friendly substitute for solvent-based adhesives in many areas.
With PUR, the reaction with humidity takes place via isocyanates (mostly MDI ), which can be released especially when the hot processing equipment is filled. An estimated 5% -10% of workers who have been exposed to isocyanates for a long time are allergic to isocyanates, which can range from shortness of breath to severe asthma-like attacks. For this reason, extraction and protective clothing / respiratory protection is mandatory when processing isocyanate-containing PUR hot-melt adhesives.
Individual evidence
- ↑ http://www.alles-zur-allergologie.de/Allergologie/Artikel/3887/Allergen,Allergie/Isocyanate/ Retrieved on December 7, 2017.
- ↑ Collection of regulations of the Baden-Württemberg trade supervisory authority, technical rules for hazardous substances; Isocyanates - Risk assessment and protective measures; TRGS 430 . Retrieved December 1, 2017.