What should I do if there is a broken waste in die cutting?

In recent years, competition in the self-adhesive label-printing industry has become increasingly fierce. Many companies are trying to improve production efficiency and reduce production costs. Printing equipment is becoming faster, and the die-cutting process is also changing from the original offline die-cutting to online die-cutting. In daily production, die cutting waste breakage is a problem for many operators. This failure not only affects the production efficiency, but also leads to an increase in the material loss rate. Especially in online die cutting, if the waste discharge edge is often broken, the equipment will not be as efficient as it should be, but it will even waste more man-hours and raw materials than offline die cutting. Therefore, what are the factors that cause the waste edge of the self-adhesive labels to break during die cutting?

Waste discharge edge is too narrow

Currently, the maximum running speed of mainstream self-adhesive label-printing equipment is 150~200m/min. In actual production, different product equipment operate at different speeds. The actual printing speed for many label companies is 80~120m/min. When the equipment is running at a high speed, varying degrees of vibration occur. This vibration has little impact on printing but has a greater impact on waste discharge. Owing to cost or raw material package width restrictions, many label companies have designed the waste discharge edge to be very narrow, only 1–3 mm. Owing to the narrow design of the waste edge, its tensile strength of the waste edge is reduced, especially for paper-based self adhesive label materials. There are several solutions for these problems.

Reduce device speed

The breakage of the waste discharge edge is related to the running speed of the equipment. The faster the equipment runs, the easier it is for the waste discharge edge to break down. Enterprises can use actual production testing to find a speed that can stabilize waste discharge, such as 60m/min, and then analyze the pros and cons of production at this speed. If they feel that this operating speed is acceptable for this product, the device is allowed to run at a low speed. The advantage of this approach is that it does not require any other investment and different product designs have different waste edge widths. This product runs slowly, which does not mean that the other products can only be produced at this speed.

Widen waste discharge edge

If the enterprise feels through analysis and calculation that reducing the production speed is not worth the loss, it can also widen the waste discharge edge so that the tensile strength of the waste discharge edge will increase and it can adapt to higher production speeds. There are also some self adhesive labels manufacturers that design the waste discharge edge to be very narrow because the materials used need to be purchased in the package width. In this situation, where the width cannot be changed owing to the limitation of the raw material format, the width of the waste discharge edge cannot be increased; however, the production efficiency cannot be too high. Low; otherwise, there will be no money to be made.

Improve equipment waste disposal methods

This situation can be solved by improving the equipment waste discharge method. Under normal circumstances, traditional die-cutting equipment uses traction-type waste discharge; that is, the waste discharge edge is pulled up and wrapped around the paper tube of the waste discharge roller through the waste removal and paper guide rollers. This waste discharge method has a long paper path and a high waste discharge tension, which can easily break the waste discharge edge. At this time, we can change the crushing waste discharge method. This waste discharge method involves pulling up the waste discharge edge, immediately crushing it, and discharging it through an exhaust pipe. This can effectively solve the problem of waste waste breakage; however, it requires a certain amount of time to modify the equipment. cost. In the past two years, mainstream printing equipment has been equipped with crushing waste discharge devices as a standard.

Material glue is too sticky

The glue used in many self-adhesive materials is too sticky and fluid, which can easily cause the waste edge to break during the die cutting process. This fracture is often unrelated to the width of the waste discharge edge. Many labels with a waste edge width of approximately 5 mm often experience waste edge breakage, especially paper-based hot-melt adhesive self-adhesive label materials that are particularly prone to such problems. The waste discharge edge can be manually pulled to determine whether there is any obvious drawing phenomenon in the glue. If the glue is stringy, this is most likely the reason why the waste discharge edge is broken.

When encountering this problem, we can use heating and solvent methods. The heating method is particularly suitable for hot-melt adhesive self-adhesive materials because the hot-melt adhesive softens after being heated, and the glue easily breaks when drawn, which is more conducive to waste disposal.The solvent method involves first wrapping a piece of cotton cloth on a pressing board (usually a flat iron plate) and then pouring a small amount of alcohol or some easily volatile solvent on the cotton cloth. Press the solvent side against the paper outlet of the die cutting station so that the solvent can quickly penetrate the die cutting material, making it easier to break. Thus, this method is suitable for industrial applications. Pharmaceutical and food labels have strict hygiene requirements and may worry about solvent residues. Therefore, they are not recommended.