Dennison Wax Pick

This test is performed to determine the pick resistance of a paper, solid board or folding board which cannot be tested using ISO 3783.

Leave the samples exposed for 24 h to 23°C and 50% R.H., according to ISO 187.

Heat the end of the selected wax stick in a low flame or by electrical heat element, rotating the stick slowly between the thumb and finger until several drops of melted wax have fallen, the molten wax should not “bubble” which indicates wax is too hot. The entire surface should be molten wax.

Quickly place the melted end of the wax stick on the surface of the test piece with firm, but not undue, pressure so that the end spreads out to about 20 mm diameter, allow the wax stick to stand vertically on the paper.

Allow the wax to cool for at least 15 minutes and not more than 30 minutes. Place the wooden block with the hole over the stick of wax so that the stick protrudes through the hole; press the block down firmly with one hand to prevent the paper from wrinkling or tearing, then pull the stick from the sheet with a quick jerk at right angles to the paper surface.

Examine both the tip of the wax and the specimen under normal reading illumination with no magnification. There must be a definite indication of fibres or coating disturbed to be called a pick or surface rupture.

If the surface is not ruptured, repeat the test, using the same specimen with waxes of ascending numerical order until the surface of the paper specimen blisters, breaks, picks, or lifts. Test a minimum of five specimens. Test only the top marked side (side with the sticker on the packing).

Report 3 measures in Stick number, their mean and standard deviation calculated to 3 significant figures.