Hot melt adhesives are very populair in gluing techniques, because they are very well modificable, so they will glue almost every substrate.
However hot melts demand special application equipment, with thermal adjustment possibility for heads, guns and hoses.
 

Hot melt units for the application of hot melt	Pressure sensitive hot melt in silicone package

Advantages

• Very fast tack, that means hardly any drying time
• Waterproof
• Gluing possible of non poreuze materials
• Optimal adjustable glue application
• Very compact machinery, because only very short pressure sections are needed.
• High machine speeds because of short pressure sections.
• Reduction of the adhesives consumption.
• Unlimited stock life (for most types of hot melt).
   

Hot melt in granulate shape	Hot melt application head

Common terms

• Hot tack

• This is the tack of the hot melt in molten/fluid condition.
   

• Open time

• This is the effective time in which the hot melt should be used to bond materials together.
  Short open time: high machine speeds.
  Medium open time: average machine speeds, applications by hand.
  Long open time: slow machine speeds, applications by hand.
   

• Machine open time

• This is the time between application of the hot melt and putting the to be bonded materials by the machine together.
  Regarding the open time; Characteristics of hot melt is always based on to a constant machine speed.
   

Production of hot melt on a Sandvik machine (Photo Sandvik)	Production of white hot melt on a Sandvik machine(Photo Sandvik)