For self-adhesive products on the market today such as labels, barcodes, signs and other products. Whether using companies or manufacturers, they have many doubts about their testing methods. Most of them know that they need to test the viscosity of self-adhesive. In fact, the viscosity of self-adhesive mainly consists of three indicators: initial tack, sustained tack, and bonding strength. Here we sit down and discuss its detection methods.

(1) Situation: When labeling self-adhesive labels on automatic labeling machines, many manufacturers have found that corners often appear.

Reason: Initial stickiness problem, instant stickiness The combined force is not strong

Test method: According to GB4852 pressure-sensitive adhesive tape initial tack test method (inclined rolling ball method), by using the inclined plane rolling ball method, through the steel ball and self-adhesive label sample When the sticky surfaces are in brief contact with slight pressure, the initial viscosity of the sample is tested by the adhesion of the label to the steel ball.

Result: There are 33 standard steel balls in a set, and the initial tack is represented by the model of the largest steel ball whose label can stick to it

Instrument used: initial tack Tester

(2) Situation: Many people find that after a short time, the label falls off by itself and loses its stickiness

Reason: The problem of maintaining stickiness is Poor retention force

Test method: According to the GB4851 pressure-sensitive adhesive tape retention test method, use a 2kg standard pressure roller to press the label on two test boards, and put the adhesive sample on it One test plate is hung vertically on the test frame, and a 1kg weight is suspended from the lower end of the other test plate.

Result: Use the displacement of the sample to detach after a certain period of time, or the time for the sample to completely detach to characterize the ability of the adhesive to resist pull-off.

Instrument used: Adhesion tester

(3) Situation: The attached label is easily peeled off and the adhesive strength can be felt to be low

Reason: The peel strength is too small

Test method: According to the GB2792 pressure-sensitive adhesive tape 180? peel strength test method, use a 2 kg standard pressure roller to bond the label to the cleaned test plate, and then The free end of the sample is folded 180°, and the adhesive surface is peeled off from the test panel.

Results: The peel strength (kN/m) was recorded and calculated by the peel testing machine.

Instrument used: electronic peel tester