Surface Material
Label stiffness is crucial for label application, requiring a certain level of strength and hardness in the surface material. Label stiffness is related to material thickness and label area; therefore, when using soft film materials, the thickness should be appropriately increased, generally controlled to be above 100μm. Thin paper materials, such as 60-70g/m² labeling paper, are generally unsuitable for large labels but suitable for small labels, such as price tags used on price guns. Poor label stiffness can lead to label failure or rewinding of the label along with the backing paper, causing automatic labeling to malfunction.
Release Force
Also known as peel force, this is the force required for the label to detach from the backing paper. Release force is related to the type and thickness of the adhesive, the silicone coating on the backing paper surface, and the ambient temperature during labeling. Insufficient release force makes it easy for the label to fall off during transport (detach from the backing paper); excessive release force makes it difficult for the label to detach from the backing paper, preventing label application. All technical indicators should be comprehensively controlled to keep the release force within a reasonable range.
The backing paper is also a crucial indicator for controlling automatic labeling. It requires uniform silicone coating and consistent release force; uniform thickness and good tensile strength to ensure it doesn't break during labeling; and uniform thickness and good light transmittance to ensure the sensor correctly identifies the label's position.
Processing Quality
The backing paper must be flat on both sides after slitting, without any tears, to prevent breakage under tension changes. During die-cutting, avoid cutting through the backing paper or damaging the silicone coating. Damage to the backing paper and silicone coating can easily lead to tearing or adhesive seepage into the backing paper, resulting in label failure or tearing. Furthermore, static electricity must be eliminated from the roll labels before labeling, as static electricity can cause labels to fail to apply or result in inaccurate labeling.
Solutions to Label Lifting Issues
To achieve perfect visual results during labeling, one key aspect is preventing label lifting. Labels are applied before the tubes are filled, and then the tubes are filled and sealed. The heating during the sealing process puts a particularly severe strain on the labels, and the closer the label is to the bottom, the greater the chance of it peeling off.