The advantages of in-mold labeling and its technical application

In foreign countries, the in-mold labeling process has already been widely used. In recent years, it has gradually been derived to China. This new technology has not only been recognized by people in the industry, but also quickly used widely.

In-mold labeling and blow molding are two kinds of in-mold labeling. Blow-mold labeling products are used to send printed composite labels to a special structure blow mold cavity by using special mechanical equipment. The plastic temperature and the air pressure that is blown in, the process of dissolving the label and the plastic bottle into one, is mainly applicable to plastic packaging products of PE and PP materials.

The advantages of in-mold labeling

â—† play a role in security

The high in-mold labeling technology is an effective line of defense against fraud, mainly from the selection of high-quality materials, the production of in-mold labels, and the design structure and production process of the labeling production equipment and molds. Produced, this increases the difficulty of fraud.

â—† In-mold labeling can improve the grade of the product

The in-mold labeling products are more beautiful than silk screens and die-labeled products, and the labels are more vivid in color and feel smoother.

(1) It is inevitable for the development of society to design more aesthetic and interesting products.
(2) To attract people in the form of the United States, and to reflect the sense of the times in a simple, clear and generous manner.

â—† In-mold labeling products have strong practicability and low loss. Compared with screen printing and mold external standard products, there will be no ink drop, labels will not be tilted, label drop, breakage, and they are resistant to extrusion, waterproof, and oil. Anti-mildew, anti-friction, acid and alkali resistance, cooling and heat resistance, make the label not easily damaged and stained under special circumstances.

â—† The price of in-mold labeling products is similar to that of self-adhesive and screen printing products. The use of in-mold labeling can improve the benefits without manual labeling, eliminating the need for re-labeling.

In-mold labeling process frequently asked questions

â—† product deformation problem

Selecting the shrinkage ratio of the marking material plays an important role in the production process:

(1) Different shrinkage ratios of PE material for the label material, the product will be deformed due to the impact (bottle bulging on both sides)
At present, the materials used in the in-mold label material market shrink after being heated is the characteristic of most plastic thin molds, but the shrinkage rate of different films is different, and the plastic bottle body also shrinks when cooled, when the shrinkage rate is different from the bottle body. When shrinking, the bottle will be deformed.
(2) The shrinkage ratio of the label material is close to that of the PP material, and the shape of the product is not greatly affected. The shrinkage ratio does not have problems of squeezing each other. When squeezing more tightly in production, it will be tighter. If you tear the label, it will be a Forming, even if you pull the label paper, the lines printed on the bottle is also the back of the label, the texture will not change the original.

â—† produce bubbles

The stencil design structure is irrational. In the production process, the shape of the product may be easily changed, and the shape of the product may be deformed. The bulging and poor exhausting result in the appearance of bubble-shaped round bottle during the labeling process, and the unsuitable bottle design of the stepped bottle body. The main reason for the appearance of air bubbles is the non-uniformity of the blowing air flow and the unevenness of the label caused by hot stamping. Hot foil stamping is not easy to generate air bubbles. In-mold labels can be hot or cold and hot. In order to avoid convex and concave deformation of the label material in the mold, the exhaust air does not generate air bubbles. Under the premise that customers accept their visual effects, cold stamping technology is recommended. If the temperature during processing is low, the hot melt adhesive quickly solidifies with the molten plastic parison, and the volatilized gas cannot be smoothly removed to form bubbles.

â—† In-mold label printing, hot stamping, and labeling have too great a sticky feel. When the labels are not properly handled by electrostatics, problems such as re-labeling, dropping, missing, sticking, and dusting will occur during in-mold labeling.
(1) Adhesiveness is not strong (image). The label paper is hard and soft, which can easily generate bubbles in the product. The label will also be peeled off and the adhesiveness will not be firm, mainly because of the temperature of the mold plastic when labeling. , Blowing pressure, cooling temperature and other aspects must be strictly controlled, if the control is not good will appear the phenomenon of separation of the paper and the bottle. (Indicating that the label will be torn off and the adhesiveness will be weak)
(2) Re-labeling: Two or several sheets of sticking paper are stuck on the bottle at the same time. This is rarely seen, but it can lead to the appearance of defects and dropping marks.
Because the general manipulator absorbs tags by means of vacuum adsorption, excessive vacuum suction force or excessive coefficient of friction between the tags is the main cause of multiple sheets or double sheets. Adjust the vacuum suction of the manipulator to effectively eliminate static electricity and select the appropriate varnish. It is an effective way to solve the double sheet problem.
Dropping the label: During the process of transporting the label by the robot, it drops out of the suction cup in the middle, and is not sent to the mold cavity at all, or is dropped out of the mold cavity due to the weak vacuum adsorption force.
Out of standard: normal boot, no label on the front and back, mainly due to air pressure and drop mark problems.
(3) Inaccurate in-mold labeling leads to a double waste solution.
The first is the choice of labeling robots. The precision of precision labeling for robots produced by different manufacturers for in-mold labeling is different. It should be compared in multiple ways, selecting good quality products, followed by the selection of labels, and different in-mold labels. The quality of in-mold label produced is also different. In general, the in-mold label with good stiffness and low static electricity contributes to the accuracy of the label adhesion. In addition, factors such as the operation process cannot be ignored. Finally, in terms of waste disposal, the general method cannot be used. Because the label and the bottle are made of the same material, the label and the bottle have been completely melted together during the production process, and they must first be scraped and printed on the label sheet. The ink is not scraped off the entire label, then crushed, and finally added to the inner layer of the bottle to achieve regeneration and environmental protection.

Currently selected raw materials include transparent materials, non-transparent materials, glue layer materials are equipped with easy-to-exhaust materials, and so on. The labels produced by different in-mold label factories have large differences in quality, and generally have good stiffness. The less static in-mold labeling aids the accuracy of bonding.