Reactive hot melt adhesives are heated before processing and applied in molten state. When the adhesive cools down, it builds up its green strength through a physical hardening process. Water molecules (from the substrate or the air) then trigger a chemical reaction which transforms the adhesive into an elastomer. After complete crosslinking, reactive hot melt adhesives provide a stronger bond with a superior resistance against moisture, heat and chemicals.
The reactive groups in the adhesive will also form strong (covalent) chemical bonds with suitable reactive partners on the surface of the substrate, which significantly expands the range of adhesion.
Jowat provides reactive hot melt adhesive based on polyurethane and polyolefin in different supply forms, as well as a new unfilled high-performance PUR adhesive in granulate form – for highest demands regarding quality and appearance.
Reactive hot melt adhesives provide the following benefits:
- a 100 % solids content, solvent-free
- highest resistance to water and steam after chemical curing
- highest heat resistance after chemical curing
- high production speeds due to short setting times
- a wide range of adhesion to different materials
- due to low processing temperatures, they are ideal for bonding thermoplastic foils
- they can level out of irregularities in the surface
- elastic bondlines
PUR hot melt adhesives will start to crosslink when they come into contact with water molecules. Moisture-proof containers and special processing equipment are therefore necessary to prevent an unwanted crosslinking of the adhesive.
Product series, properties and application:
Jowatherm-Reaktant® PUR hot melt adhesive
Properties: One-component, moisture-curing hot melt adhesives. Reactive polyurethane hot melt adhesives have a 100 % solids content and are free of solvents and water.
Application: Edgebanding, assembly bonding, coating / laminating, End-of-Line packaging, straw application, bookbinding
Packaging: Granulate, cartridges, tin cans, hobbocks, drums
Jowatherm-Reaktant® POR hot melt adhesive
Basis: Polyolefin (e.g. ethene, propene, butene)
Properties: One-component, moisture-curing hot melt adhesives. POR hot melts are a special form of moisture-curing adhesives. While PUR hot melts contain isocyanates for the chemical crosslinking process, POR hot melts use silanes as the reactive component and are therefore not subject to hazardous substance labelling. Adhesives from this product group are characterised by a very high heat resistance compared to classic, thermoplastic PO hot melts.
Application: Assembly bonding, laminating
Packaging: Cartridges, tin cans, hobbocks, drums