How is the abrasion resistance of self-adhesive labels tested?

The core of abrasion resistance testing for self-adhesive labels is to simulate friction scenarios in actual use and evaluate the abrasion resistance of the label surface (printing layer, lamination layer) and adhesive layer.  Common testing methods are divided into two categories: laboratory standard tests and simplified on-site tests, as follows:

These tests follow national standards or industry specifications, and the results are accurate and comparable. There are three common methods:

Friction Fastness Test (Abrasion Testing Machine Method)

Test Principle: A standard friction head (dry/wet cotton cloth, brush, sandpaper) is used to rub the label surface with a fixed pressure and number of cycles, and the degree of wear on the printed pattern and text is observed.

Test Steps:

① Cut a 50mm×100mm label sample and fix it on the testing machine platform.

② Select the corresponding friction medium: dry cotton cloth (simulating daily friction), wet cotton cloth (simulating friction in a humid environment), 600-grit sandpaper (simulating friction on a rough surface).

③ Set parameters: pressure 4N (conventional), friction speed 60 cycles/minute, number of cycles 50-200 (adjusted according to the application scenario).

④ After the test, compare with a gray scale card or perform visual grading to determine the wear level (level 1 is the worst, level 5 is the best).

Applicable Scenarios: Abrasion resistance testing of the printing layer of food and daily chemical labels, reference standard GB/T 7706-2008 Gravure Printing Products.

Abrasion Resistance Test (Taber Abrasion Testing Machine Method)

Test Principle: A grinding wheel rotates under a constant load to rub the label surface. The abrasion resistance is evaluated by weighing the mass difference before and after wear or observing the surface condition.

Test Steps:

① Adhere the label to a rigid substrate (such as an aluminum plate) and cut it into a 100mm diameter sample.

② Install the grinding wheel (CS-10 grinding wheel for conventional testing, CS-17 grinding wheel for heavy wear testing), and set the load to 500g or 1000g.

③ Set the number of rotations (e.g., 500 rotations, 1000 rotations), and start the testing machine. ④ After testing, observe whether the label shows the underlying layer, whether the adhesive layer peels off, or calculate the mass loss rate.

Applicable scenarios: Abrasion resistance testing of the lamination layer/substrate of industrial equipment labels and outdoor labels.

Scratch Resistance Test (Pencil Hardness Test Method)

Test principle: Use pencils of different hardness to scratch the label surface at a fixed angle and pressure to evaluate the scratch resistance of the surface coating, indirectly reflecting wear resistance.

Test steps:

① Select pencils (from 6B to 6H, increasing in hardness), sharpen them to a 45° conical shape, and flatten the lead.

② Fix the label, hold the pencil at a 45° angle to the sample, apply 1kg of pressure, and draw across the surface at a constant speed.

③ Erase the pencil marks with an eraser and observe whether there are scratches. The highest pencil hardness without scratches is the surface hardness level of the label.

Applicable scenarios: High-end product labels with lamination and UV coatings. Reference standard: GB/T 6739-2006 Paints and varnishes - Determination of film hardness by pencil method.