Initial Tack of Adhesives and Sealants

Initial tack is one of the most important features of adhesives and sealants. A high tack adhesive means that larger weights will be held without slippage while the adhesive is drying.

It defines the ability of a wet adhesive to hold materials in place while the adhesive cures, without the material slipping or moving.

Initial Tack of Adhesives

These tests illustrate laboratory tests which are the only true method of testing adhesives consistently so adhesives can be compared.

There are 2 aspects to initial tack:

1. Horizontal – which relates to the weight required to pull materials off a horizontal surface eg. panels being fixed to a ceiling.

One square metre can be defined on a horizontal surface such as a ceiling, through drawing a square.

Once this is done, this one square metre area needs to be covered in adhesive.

This square metre area can now hold 1000 kg at the point of contact with the adhesive.

2. Vertical – which relates to the weight required to move materials on a vertical surface eg. a mirror being fixed to a wall.

One square metre can be defined on a vertical surface such as a wall, through drawing a square.

Once this is done, this one square metre area needs to be covered in adhesive.

This square metre area can now hold 250 kg at the point of contact with the adhesive, without the material slipping down the wall.

Initial Tack Comparisons

When comparing initial tack specifications some brands only mention 1 of the above: horizontal or vertical. It is important to know which specification is being discussed so the best solution is chosen.

A recent focus in the adhesives industry is an advantage for industry and DIY. Having a high tack adhesive means less labour is needed to hold materials while drying. This also means less fixings, such as screws, are required to hold materials in place.

The higher the initial tack is the greater ability of the adhesive to hold more weight while it cures

For instance Ritetack Instant Grab adhesive, has an extreme initial tack of 1000kg/per sqm horizontally. In a vertical situation, it is 1000kg/per sqm.

When comparing the initial tack of adhesives both the vertical and horizontal aspects need to be considered.