Characteristics of nonreactive synthetic glues
Ethylene vinyl acetate (EVA) |
PolyVinyl Acetate (PVA) (white) |
PolyVinyl
Acetate (PVA) (yellow) |
Contact |
Hot-melt |
|
Applications |
ideal for bonding melamine-faced cabinet parts and for gluing cross-grain solid-wood assemblies where
wood movement is likely;
can be coloured with dyes etc. |
low grade (craft or hobby glue);
edge- and face-gluing, bonding structural joints;
bonding plastic laminates etc;
can be coloured with dyes etc. |
high grade (professional/ industrial glue);
edge- and face-gluing, bonding structural joints;
bonding plastic laminates etc;
can be coloured with dyes etc. |
bonding plastic laminates;
decorative overlays;
other rigid sheet materials;
some modern water-based cements are fast drying and give high performance;
applying significant pressure to the work greatly increases the strength of the bond. |
hot-melt glues and guns are available with high, low or dual melt-point glue;
high-melt systems widely available/used;
low-melt systems are safer and less likely to harm the materials being glued;
hot melt is useful for edge-banding sheet material and for the rapid assembly of temporary fixtures. |
Availability/ using |
ready to use |
ready to use;
water can be added up to 5% to increase working time. |
ready to use;
water can be added up to 5% to increase working time. |
ready to use |
supplied in solid sticks;
must be applied hot;
low-melt glue shouldn't be applied with a high-melt gun. |
Typical working time
# |
10 to 15 min | 5 to 30 min | 5 to 30 min | dry prior to assembly;
open drying times: 10 to 20 min (water based), 2 to 15 min (solvent based), |
5 to 30 sec,
longer if parts preheated |
Clamp time # |
1/2 to 2 hrs | 20 to 90 min | 20 to 90 min | 1 to 5 min will increase bond strength | No clamping needed; firmly press parts together as quickly as possible |
Cured working properties |
soft and pliable;
can be worked with hand tools; machines well; sands moderately well;
reversible with water and/or heat;
compatible with some stains and finishes. |
fairly soft and workable;
can be cut with hand tools, machines well but loads paper when sanded;
reversible with water for 2 to 6 weeks after curing;
resist stains and finishes.
|
cures hard;
can be cut with hand tools, machines well but loads paper when sanded;
can be softened or reactivated with heat up to several days after application;
not reversible with water after curing;
resist stains and finishes. |
soft and elastic;
can be machined and sanded but will gum up cutting edges and sandpaper;
may be softened by solvents (may be affected by solvents in stains and finishes. |
soft and elastic;
can be cut with hand tools when hardened;
machines and sands adequately but can gum up cutting edges and sandpaper;
reversible with heat;
may be softened or dissolved by some stains and finishes. |
Cured properties |
acceptable strength but with little rigidity or creep resistance. |
adequate strength;
low rigidity and creep resistance; |
greater strength, rigidity, creep resistance and durability than white PVA. |
initially very weak;
develops increased strength when pressed into thin layer;
no rigidity;
little or no creep resistance. |
very low strength, unsuitable for permanent structural bonds;
increased strength if pressed into thin layer before it cools;
limited rigidity and creep resistance;
some gap-filling ability. |
Longterm properties |
low resistance to heat and moisture;
fair resistance to acids and solvents;
fair shock resistance;
will gradually degrade if exposed to intense UV light. |
low to moderate resistance to heat, moisture, acids and solvents and good shock resistance;
will gradually degrade if exposed to UV light. |
greater resistance to heat, moisture, acids and solvents and very good shock resistance;
will gradually degrade if exposed to UV light. |
good to excellent heat resistance if pressed into thin layer;
poor to fair moisture resistance if subjected to prolonged exposure;
poor solvent resistance. |
good moisture resistance;
no heat resistance;
poor solvent resistance;
poor to fair shock resistance;
will gradually degrade if exposed to UV light. |
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