Adhesives
A wide variety of adhesives can be used for bonding Formica® laminates; however, some have limitations with regard to the end application.

The characteristics of the various adhesives that may be used with Formica laminates are shown in the following tables.

Table 1 gives details for Urea / Melamine Urea, Resorcinol and Epoxy adhesives.

Table 2 gives details for PVAc, Contact and Hot Melt adhesives.

The tables include reference to the EN 204 durability classes; the codes have the following meanings.

D1 Interior areas, where the temperature only occasionally exceeds 50°C for a short time and the moisture content of the wood is 15% maximum.
D2 Interior areas, with occasional short term exposure to running or condensed water and/or to occasional high humidity, provided the moisture content of the wood does not exceed 18%.
D3 Interior areas, with frequent short-term exposure to running or condensed water and/or heavy exposure to high humidity. Exterior areas not exposed to weather.
D4 Interior areas with frequent long-term exposure to running or condensed water. Exterior areas exposed to weather.

Table 1
Urea / Melamine Urea Resorcinol Epoxy
Description
• Rigid thermosetting adhesives.
• Curing by polymerisation with correct amount of catalyst added to resin.
• Rate of cure rapidly increased by applying heat.
Application
Use:
Flat lamination.
Hot or cold press.
Bonds laminates to:
1. most wood-based substrates;
2. moisture-resistant substrates. 		Use:
Flat lamination.
Hot or cold press.
Bonds laminates to:
1. moisture-resistant wood-based substrates;
2. some flame-retardant substrates;
3. non-combustible substrates. 		Use:
Flat lamination.
Hot or cold press.
Bonds laminates to:
1. primed metal substrates;
2. aluminium honeycomb cores.
Gap-filling:
Poor.
Often extended by fillers which also reduce telegraphing of imperfections. 		Gap-filling:
Good. 		Gap-filling:
Excellent.
Minimal telegraphing due to high solids content (lack of shrinkage).
Pressure:
Good bonds at relatively low pressures. 		Pressure:
Satisfactory bonds at low pressure. 		Pressure:
Bonding requires only low pressure.
Cure time:
Typically 1-3 hours at room temperature depending on hardener system. 		Cure time:
Typically 5-8 hours at room temperature. 		Cure time:
Wide range of times at room temperature depending on hardener system.
Other factors:
Not suitable for Metallic Laminate. 		   
Typical temperature resistance
-20˚C to +120˚C -20˚C to +150˚C -20˚C to +100˚C
Typical EN 204 Durability class
D3 - D4 D4 D3 - D4

Table 2
Polyvinyl Acetate (PVAc) Contact Adhesives Hot Melt Adhesives
Description
• Aqueous emulsion adhesives.
• Cure by dispersion of solvent.
• Available in single and two-part (catalysed) varieties.
• Catalysed variety has better heat and moisture resistance. 		• Polychloroprene-based.
• Available in solvent or water-based types.
• Available with and without hardener. 		• Normally supplied in pellet or cartridge form.
Application
Use:
Flat lamination.
Hot or, more usually, cold pressed for bonding laminates
to most wood-based substrates.
Also for producing postformed components. 		Use:
1. Flat bonding.
2. Postforming. 		Use:
Bonding edging materials.
Gap-filling:
Poor. 		   
Pressure:
Requires only low pressure. 		Pressure:
Requires only momentary but high uniform pressure. 		Pressure:
Best applied to edge before applying surface laminate.
Cure time:
Fast at room temperature giving quick press turn round (20-40 minutes), with long pot life to glue mixes.
Glue-line cures to a semi-rigid condition. 		Cure time:
Use only in warm, dry conditions. Bond occurs when both coated surfaces are brought into contact under high pressure.
Observing correct application and drying time is very important. 		 
Substrate:
Must have good surface uniformity and strength. 		Substrate:
Bonds laminates to wide variety of substrates. 		 
Telegraphing:
Control glue spread carefully to avoid telegraphing due to water base causing raised grain, fibre and chip swell. 		Telegraphing:
Minimal, providing adhesive spread is uniform and glue-line is kept free from debris. 		 
Other factors:
Easy wash down of equipment and removal of glue spillage. 		Other factors:
Can be applied by spray (hot or cold) or by hand application with serrated spreader.
Useful for on-site work where it is not possible to apply sustained pressure.
Not recommended for use with Veneer Laminate or Formica ColorCore® Laminate. 		Other factors:
Will begin to soften under moderately elevated temperatures. Should not be used to edge materials for use near hot surfaces.
Typical temperature resistance
Standard
-20˚C to +80˚C
Catalysed
-20˚C to +120˚C 		Standard
-20˚C to +60˚C
With hardener
-20˚C to +100˚C 		-10˚C to +50˚C
Typical EN 204 Durability class
D2 - D3 D1 - D2 D1
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