Abrasion resistance is a required and necessary property of printed packaging materials. When our printed packaging components have abrasion damage, it can occur during freight, warehouse, loading and unloading handling, and end-use. The outcome is a significant decline in product appearance and legibility of product information.
The part of abrasion damage to a printed packaging component substrate is conditional on shipping type, perhaps temperature and humidity, time, and numerous other variables. The practice approximates the abrasion resistance of printed packaging materials under laboratory circumstances.
Why is Abrasion resistance required in printed packaging components?
There are several factors that affect the abrasion resistance of printed substrate material. These include the type and thickness of the material, the design and finish of the printing, the packing methodology (i.e., crush or weight), and environmental conditions such as temperature and humidity.
What type of printed packaging components can be considered?
This practice applies to labels, folding cartons, corrugated boxes, inserts, circulars, and other packaging materials having applied graphics on a flat substrate.
How to Perform Sutherland Rub Test?
o Sample preparation
- For this test, five samples from each press are needed, and five identical samples of the same substrate are also required, unprinted.
- Samples (unprinted) must be cut to 7.6cm x 15.2cm.
- Do not get fingerprints on samples.
- Set up samples so that the rub is across the machine direction.
- Samples must be conditioned at the testing room’s temperature for 24 hours before testing.
Preparation of Sutherland Rub Tester
- A room must be between (22 and 24 degrees Celsius or 71.4 and 75.4 degrees Fahrenheit).
- A room must be between 48 and 52% humidity.
- Decide how many strokes to set the Rub Tester at and record. The testing instrument in IPL is set to 40 rubs, which will use in this research.
- Mount 7.6cm x 15.2cm rubber pads to the top and bottom bases of the machine (mount to receptor blocks).
- Attach sample to the rubber pad on the base with the printed surface exposed (option of choosing a slight or considerable weight, determinant upon how severe shipping and handling simulations you want to create).
- Attach the receptor to the receptor block.
- Brush sample and receptor with an anti-static brush removing any particles from the surface of each.
- Place receptor block in the holder.
- Set the dial on the Sutherland Rub Tester to decide upon several strokes (40) and record.
- Turn the machine on, and it will automatically perform the test and shut off when it is finished. Repeat the process for each sample to be tested.
- Record the testing conditions (i.e., temperature, humidity, etc.).
- Record changes in receptor (i.e., rub-off, ink transfer, discoloration, etc.)
- Record any changes in samples as compared to the original.
- Record L*a*b* values and compare them to the original measurements.
- Measure reflectance densities, compare them to original sample densities and record the differences (“varying the test accordingly to the countries standards).
What are the Benefits of the Sutherland Rub Test?
This method also can be utilized to assess the relative abrasion resistance of printed packaging inks, coatings, laminates, and substrates. It can modify the process to calculate the effects of the product (detergent powder, food, beverages, etc.) on abrasion resistance, as may occur in spillage or leakage in transit.
How to evaluate the Sutherland Rub Testing?
Examine every specimen for the degree of degradation and the amount of material transferred from the print for each receptor. Report test conditions and results for abrasion using predetermined criteria established by the user.
Rub proof testers are the measurements (density and L*a*b* of the ink) taken before and after the testing. It is required for the visual assessment, and also, we can take the reference of the spectrometer. We can have the limitation of delta value acceptance after the test is taken.
The test is a good simulation for print packaged in bulk to be shipped; these results could benefit printers, print buyers, and vendors.