The self-adhesive sticker printing belongs to special printing. Generally, its printing and post-printing processing are completed at one time on a label machine, i.e. multiple processing procedures are completed at several stations of a machine. Due to on-line processing, the control of self-adhesive sticker printing quality is a comprehensive printing and processing problem, which should be comprehensively considered and implemented from the aspects of material selection, equipment configuration and control to the formulation of process route, etc., and the application of label products in customers should be tracked so as to further improve the quality of label products.
When selecting raw materials, we must choose high-quality adhesive materials with qualified physical and chemical indexes, instead of products with expired or unstable physical and chemical indexes. Because although the latter price is low, due to the unstable quality of this kind of materials, the consumption in each process is large, which even leads to the equipment unable to process normally, wasting a lot of manpower and material resources while wasting raw materials. As a result, the processing cost of finished product labels is not necessarily low, and more serious is the possibility of customers returning goods or even losing customers.
1. Surface gloss, color consistency and density uniformity of surface materials
Reaching some indexes determines the ink absorption uniformity of adhesive materials and also determines the color difference of the same batch of label printing products. The coating strength of the surface material determines whether a large amount of paper powder will be produced during printing, and is also an important index for determining the printing quality.
2. Uniformity and Strength Indication of Thickness of Base Paper and Face Material
These indexes are not only related to printing performance but also important indexes to determine die-cutting uniformity, waste discharge speed and paper edge fracture. If these indicators are too low, there will be no quick production in labeling machine.
3. The evenness of material or the uniformity of rewinding tension
Whether it is sheet-fed printing or roll printing, the flatness of the material determines whether the paper can be fed, run, registered and received correctly during printing. For reel materials, rewinding tension will play an important role in the flatness of the end face of the reel materials, whether there is glue leakage and whether there is correct registration.
4. Uniformity of adhesive and silicone oil coating and correct coating amount
These indexes directly affect the peeling force (release force) between the label and the backing paper, and the size of the peeling force directly affects the die-cutting, waste discharge and the speed of the machine. The peeling force also determines the labeling status of the label, that is, the application situation. In addition, the size of the glue amount will also affect the glue penetration on the end face of the material. Therefore, when purchasing self-adhesive materials, it is necessary to carefully inspect and select those materials with appropriate coating amount and silicon coating amount.