Talking about the Use of Label Adhesive

The label represents the brand, and off-label is a major defect in beer packaging. I was fortunate enough to capture a business opportunity. However, when I quoted this case from other customer factories, I encountered the challenge of the on-site technicians because they were more worried about the label washability when recycling bottles, and the packaging efficiency and cleaning costs were incorporated into the bottle placement program. Visible, labeling process is not simple, the label is only the surface, glue is its core.

Wet glue

The back of the label is attached to the surface of the container. This action is done on the labeler.

The stackable single label (cutstack) is wet glued, first glued to the surface of the rubber roller by a glue pump and transferred to the target, and the label is glued from the label box when the target is rolling. The label of the tape label continues to move forward, and the unfolding of the labeling label exposes the label by removing the label from the side edge of the label, and then turns to the container turntable to quickly and accurately press the container surface. After the labeling container rotates with the receiving table, it is fixed by the standard brush.

The substrate of the wet adhesive label is aluminum foil, paper and film, which are respectively printed by gravure printing, offset printing, flexo printing and mixed printing. For aesthetic or labeling purposes, embossing and pinhole processes are also common.

A lot of aluminum foil is used in beer and wine bottles. The processed thin foil has good laminating performance. Compared with paper, aluminum foil has no wire flow direction, but the dimensions, punching quality and embossing depth Closely related to the impact of labeling efficiency, such as the size of the deviation is too large to prevent high-speed labeling, labels either stuck in the standard box, or fall from the front of the box; punching quality is not good will make the label stack adhesion, resulting in difficult or failure.

Paper is an active material, and the paper label is particularly sensitive to the temperature and humidity of the labeling environment. With the label flatness, flying labels, waste labels, and glue spills can be reduced. When labeling, too high or too low backside water absorbability will result in insufficient sizing or excessive amount of glue resulting in label slippage, detachment, or glue waste. The technical indicators for measuring the running capacity of paper labels are: wet tensile strength, tear strength, curl degree, reactivity with water, backside water absorption, time for washing labels, and alkali resistance.

Thin film material wet adhesive labels have the absolute advantages of the above technical specifications and can be used with conventional paper labeling machines. The biggest obstacle in the past is that the standard glue can't volatilize under the strict plastics. After the labeling, bubbles and wrinkles form on the surface of the container. The surface of the new OPP film has paper surface properties. The water-based glue is used, and the glue consumption is paper label. 50%, but adhesiveness, adhesiveness and paper labels are no different.

Casein Glue is a water-based glue made from milk casein and other natural raw materials. It has a solid content of about 30-40%. It is non-toxic, odorless, odorless, biodegradable, has a high initial viscosity, and has a fast curing speed. Strong shear force, good water resistance and moisture resistance, especially suitable for high-speed labeling of beer, wine, and dairy products in a condensation environment. Casein gel and food share milk resources, and price fluctuations and high prices are its weaknesses.

Starch gum originated from potato, wheat and corn is another kind of natural adhesive. It has the characteristics of relatively low initial viscosity, temperature resistance, and environmental protection. It is especially suitable for hot filling containers such as tea, fruit juice, and mineral water. .

The synthetic rubber produced by the mixture of casein and resin has a solid content of about 50-60%. When used, it is slightly heated. It is suitable for plastic containers of pe, pet, pp and ps, and the surface of metal containers after polishing. The recycled pet bottles are synthesized. Glue, with good adhesion, removable advantages.

The components of hot-melt adhesives include thermoplastic raw materials, waxes, and resins, which melt at a processing temperature of 120-170°C, and have good initial tack and fast tackiness. Hot-melt adhesives are often used in irregular shaped containers such as drums and polygons. on.

Stickers (psl)

Drinks (alcoholic, soft drinks), foods, medicines and health products, and personal care products are the traditional markets for wet labels, but stickers are rapidly infiltrating the high-end market. For example, beer crystal labels bring consumers “unlabeled” vision.

The self-adhesive is said to be a pressure-sensitive roll label (psl), and the pre-applied glue is automatically adhered to the surface of the container under pressure. When the labeling machine sensing device issues a labeling instruction, the drive wheel drives the roll label to run. When the adhesive backing paper moves in close proximity to the peeling plate to change direction, the label is passively disengaged and ready for labeling due to its own stiffness. At this point, the container travels on a conveyor belt, and the labeling wheel causes the label to be quickly and synchronously affixed to the surface of the container. After labeling, the sensor issues a stop command, the drive wheel is stationary, and a labeling cycle is completed.

Self-adhesive labels are widely used in automotive, electronics, and chemical industries, as well as variable information and anti-counterfeiting functions. Polyethylene (pe) and polypropylene (PP) films account for 60%, and paper accounts for 40%. Self-adhesive labels have very flexible printing methods. Embossing, soft gravure, and screen printing are suitable for batch printing; thermal, thermal transfer, laser/inkjet, and even needle printing are used for small prints.

The technical indicators for measuring the running capability of adhesives are surface material, release force, backing paper, initial viscosity, final viscosity, and shear strength. Adhesives for adhesive labels are the media between the label material and the bonding substrate and act as a connection.

According to the characteristics can be divided into two kinds of permanent and removable, so there are many different kinds of adhesive formulations to adapt to different surface materials and the use of the environment. Adhesives are the core of self-adhesive labels. The main technical indicators are UV resistance, solvent resistance, cold flow capability, minimum labeling temperature, and application temperature range.