Ways to faster cure

  Faster adhesives
  Accelerated cure by heated rooms
  Limitations of conventional UV curing adhesives 
Accelerated cure by Curex masterbatches
 


























  Faster adhesives
     
    Disadvantages:
    Shorter pot life of adhesive.
    Compromise between different adhesive properties.
    May reduce slitting time but still 8-10 days needed for full cure.
     
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  Accelerated cure by heated rooms
     
    Disadvantages:
    Heating a reel from outside may take up to 2 days before the reel is in heat- balance.
    Higher risk of piping, curling and higher waste.
    Heating of laminates with solvent free adhesives invites to telescoping.
    Excess heat during curing may change final properties of adhesive.
    Future CO2 legislation may forbid use of energy for this type of purpose.
     
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  Accelerated cure by Curex masterbatches
     
    Advantages:
    Very fast curing. Converting after a few hours.
    In combination with some adhesives faster than UV curing adhesives.
    Shipping in 24-48 hours possible.
    Pot life of adhesives unchanged.
    May offer higher final bond values for some adhesives.
    More flexibility in adhesive formulations.
    Faster reach of migration limits of uncured adhesives.
    Use of aliphatic solvent free adhesives now realistic.
    Cost reduction.
    No change of equipment.
     
    Disadvantages:
    None known after 12 month in full production
    Difficult to accept that adding the cost of Curex is in fact reducing the costs of converting.
     
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Film Considerations When UV Laminating          

   

One of the substrates must be at least 20% transparent to UV light

Polypropylene blocks 5-10% of UV light transmission  
Polyethylene blocks 10-18% of UV light transmission  
Polyester blocks 30-50% of UV light transmission  
Correct Surface energy is critical for proper wetting out of substrate  

Preferred dyne level of film for laminating is 42-46

Dyne levels of 38 and below usually result in poor adhesion and  inconsistent performance

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