Advantages and technical application of in mold la

2022-08-07
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Advantages of in mold labeling and its technical application

in foreign countries, the in mold labeling process has long been widely used, and has only been gradually derived to China in recent years. This new technology is not only recognized by industry insiders, but also quickly and widely used

there are two types of in mold labeling: blow molding and in mold labeling. The in mold labeling product of blow molding is a process in which printed composite labels are sent to the bottle blowing mold cavity with special structure through special mechanical equipment, and the labels and plastic bottles are dissolved into one by using the extruded plastic temperature and blown air pressure. It is mainly applicable to plastic packaging products made of PE and PP materials

advantages of in mold labeling

◆ it plays an anti-counterfeiting role

the high technical content of in mold labeling is an effective defense line against counterfeiting. It is mainly that the selection of high-quality materials, the production of in mold labeling, the design structure and production process of labeling production equipment and molds should be closely coordinated with each other, and cannot be produced unilaterally, which increases the difficulty of counterfeiting

◆ in mold labeling can improve the grade of products

in mold labeling products are more beautiful than silk screen printing and out of mold labeling products, with brighter label colors and smooth hand feel

(1) it is inevitable for social development to pursue the aesthetics and interest of commodities in design

(2) attract in the form of beauty, and reflect the sense of the times with concise, clear and generous practicality

◆ in mold labeling products have strong practicability and low loss. Compared with silk screen printing and out of mold labeling products, there will be no ink dropping, label warping, label dropping and damage. They have the functions of extrusion resistance, water resistance, oil resistance, mildew resistance, friction resistance, acid and alkali resistance, cooling and heat resistance, so that the labels are not easy to be damaged and stained under special circumstances

◆ the price of in mold labeling products is not much different from that of self-adhesive and silk screen printing products. The use of in mold labeling can improve the efficiency without manual labeling, eliminating the production process of re labeling

common problems of in mold labeling process

◆ product deformation problem

selecting the shrinkage ratio of the label material plays an important role in the production process:

(1) the product will be affected and deformed by different shrinkage ratios of the label material (the bottle body bulges and both sides are recessed)

the shrinkage of the materials used in the in mold label material market is the characteristic of most plastic thin molds, However, the shrinkage rate of different films is different. The plastic bottle body will also shrink when it is cooled. When the shrinkage rate is different from that of the bottle body, the bottle body will be deformed

(2) the shrinkage ratio of label paper material is close to that of PP material, and the product shape has little influence.

the same shrinkage ratio does not have the problem of mutual extrusion, and it will be tightened as much as it is squeezed during production. If the label paper is torn off, even if the label paper is pulled open, the grain printed on the bottle is also on the back of the label paper highway bridge plate rubber bearing specification series jt3132.1 (8), and the original grain will not change

◆ bubble generation

the mold design structure is unreasonable, which is easy to cause product shape change, deformation, bulging and poor exhaust during the production process, resulting in bubble round bottle bodies, stepped bottle bodies and other unreasonable bottle types. Some manufacturers who produce and process oil cylinders plan that uneven blowing air flow and uneven labels caused by hot stamping are the main reasons for bubbles. Hot stamping heating is not easy to generate bubbles. In mold labels can use two hot and cold stamping technologies. In order to avoid convex and concave deformation of in mold label materials and poor exhaust to generate bubbles, it is recommended to use the cold stamping technology on the premise that the customer accepts its visual effect. If the processing temperature is low and the hot-melt adhesive will soon solidify with the molten plastic parison, the volatile gas will not be smoothly eliminated and form bubbles

◆ in mold label printing, bronzing, too large label handle viscosity, and poor electrostatic treatment of labels will cause problems such as re labeling, label dropping, label missing, label slanting, and dust in the in mold label production

(1) the adhesive strength is not strong (picture). The label paper is hard and soft enough, which is easy to cause bubbles in the product, and the label will be torn off. The adhesive strength is not firm, mainly because the temperature of molding plastic, the pressure during bottle blowing and the cooling temperature must be strictly controlled during labeling. If the control is not good, the label paper will be separated from the bottle body. (it indicates that the label will be torn off and the adhesion is not firm)

(2) re labeling: two or more pieces of label paper are stuck to the bottle at the same time. This is very rare, but it can lead to skew and falling labels

because the general manipulator adsorbs labels in the way of vacuum adsorption, excessive vacuum suction or excessive friction coefficient between labels are the main reasons for multiple or double sheets. Adjusting the vacuum suction of the manipulator to effectively eliminate static electricity and selecting appropriate varnish is an effective way to solve the double sheet problem

label dropping: in the process of the manipulator transporting the label, it fell off when it broke away from the suction cup, and was not sent to the mold cavity at all or due to the vacuum adsorption force. I. random switching of multiple languages of the cardboard tensile testing machine: Simplified Chinese, traditional Chinese and English are not strong, and fell out of the mold cavity

lack of label: normal startup, no label on the front and back, mainly caused by air pressure and label dropping

(3) solution to double waste caused by inaccurate labeling in the mold

the first is the selection of the labeling manipulator. The accuracy of the precision labeling of the manipulator used for in mold labeling produced by different manufacturers is different. It should be compared in many ways to select the products with good quality. The second is the selection of the label. The quality of the in mold label produced by different in mold labels is also different. Generally speaking, the in mold label with good stiffness and less static electricity is conducive to the accuracy of label bonding, In addition, the influence of operation process and other factors can not be ignored. Finally, in terms of waste disposal, the general method cannot be adopted. Because the material of the label is the same as that of the bottle body, the label paper and the bottle body have been completely dissolved together after one-time forming in the production process. The ink printed on the label paper should be scraped first, not the whole label. Then it should be crushed and finally added to the inner layer of the bottle to achieve regeneration and environmental protection

at present, the selected raw materials include transparent materials, opaque materials, adhesive layer materials with easy exhaust lines, etc. there are great differences in the quality of labels produced by different in mold label manufacturers. Generally speaking, in mold labeling with good stiffness and less static electricity contributes to the accuracy of bonding

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