Label testing is available on individual troubleshooting issues as well as on global quality control bases.
LES packaging experts provide label analysis and testing, using state-of-the-art-equipment.
The quality of labeling materials and the specifics of the labeling environment have a direct effect on machine efficiency and package quality. Variations in labels do occur; therefore, just as proper machine adjustments and cleanliness are important, materials within specifications and of sufficient quality are important as well.
Our label testing clients gain understanding of how their labels are manufactured, the paper physical and chemical properties, and how finished labels perform in the end-use labeling machines. The clear and concise testing reports highlight any issues with the materials being run on the equipment.
LES material and labeler experts help optimize labeler production and resolve troubleshooting problems.
Methodology
GRAPHIC DESCRIPTION - This information was extracted from the samples submitted for testing & data was transferred to the data result table accordingly.
MANUFACTURE DATE - This information was extracted from the samples submitted for testing & data was transferred to the data result table accordingly.
COEFFICIENT OF FRICTION (COF) - A sample label is clamped graphic side up on a steel plate. A second sample is tightly fastened to a carrier block with the backside of the label exposed. The carrier block & its label are placed on the 1st sample. The angle of the steel plate is slowly increased. The point at which the carrier block breaks free & slides down the ramp is recorded. The static coefficient of friction is the tangent of the angle at which the block broke free. (This test is repeated 10 times & the lowest & highest values are dropped with the final 8 values averaged.)
COBB (MOISTURE ABSORPTION RATE) - The label sample is cut down to a known dimension (normally 40X80mm) & is then weighed dry. It is submerged for 30 seconds under water bath, removed, & hung for 30 seconds. It is then shaken gently 5 times over vertical amplitude of 1 inch. It continues to hang for an additional 30 seconds & is shaken gently twice over a vertical amplitude of 1 inch. The sample is then weighed. The difference between the 1st & 2nd weights is recorded. (The test is repeated 5 times, averaged, & recorded in the 10th of a gram per sq. centimeter.)
LOT NUMBER - This information was extracted from the samples submitted for testing & data was transferred to the data result table accordingly.
CURL PROPENSITY - The sample is clamped in the direction of the grain between 2 stainless steel blocks with 20 mm of the sample left exposed. The clamping blocks & label are submerged for 10 seconds. The length of time for the label to curl 10mm is recorded in seconds. (The test is repeated 5 times and averaged.)
HEIGHT - Height is taken by measuring with caliper & recorded in millimeters (SAE). In the case of irregularly shaped labels the height is taken in two vertical axes, one at the point of the greatest dimension, & one at the point of the least dimension. Five samples are measured & averaged.
RESISTANCE TO TEARING - A single label is clamped over a horizontal span of 50mm. A round hammer (similar to a set collar) is swung through a vertical arc of 300mm, striking the top 5mm of the sample at bottom center of the arc. The test is repeated with increasingly greater arcs until the weight is able to tear the sample. The weight of the hammer is multiplied times the degrees of arc & recorded. The test is repeated 5 times & averaged.
WIDTH - Width is taken by measuring with caliper & recorded in millimeters (SAE). In the case of irregularly shaped labels the width is taken in two horizontal axes, one at the point of the greatest dimension, & one at the point of the least dimension. Five samples are measured & averaged.
VARNISH COATING - A sample is treated with an appropriate dye coat material & allowed to dry for 20 seconds. The dye coat is wiped off which reveals the non-varnish coated area of the label. The uncoated area is measured & recorded.
WEIGHT PER CM SQUARED - This is the direct measurement of a specific section of the sample label in a specific dimension. The dimensions used are 40x80 mm sq. or 80x100 mm sq. (This is the average of 10 samples.)
GRAIN DIRECTION - The sample is submerged in water for 30 seconds and directly observed. The direction of the curl indicates the direction of the grain. This is recorded as horizontal or vertical as the label would be viewed when applied directly to the product. (One sample is tested and recorded.)
CALIPER (THICKNESS) - This is the direct measurement of thickness of the submitted label samples. The thickness is taken using a paper caliper at the ends and the graphical center of the label and recorded in thousandths of an inch. The recording format is center/ends. (10 samples are measured as 1. This measurement is the average of 5 lots of 10 sample labels. This test is repeated 10 times & the lowest & highest values are dropped with the final 8 values averaged.)