(I) In-mold label materials are divided into four types according to material characteristics:

1. BOPP: Biaxially stretched, with special coating on the surface, good printability. The disadvantage is that it is easy to deform on a large area of ​​the container. If the material of the barrel is PE and the label material in the mold is PP, because the shrinkage ratio of the two is different, the orange peel phenomenon will appear on the surface of the barrel after the application of the label.

2. PE: Without stretching, corona treatment is required on the surface of the material, poor printing adaptability, and large deformation after hot stamping. Since it is a PE material, no deformation occurs after being applied to a PE bottle body.

3. PP+PE: Uniaxial tensile deformation, corona treatment on the surface of the material, good printability, and stable tension. Since the material contains a PE component, a low-temperature hot stamping foil is required in the label hot stamping process. The biggest advantage is that the label has a smooth surface, no distortion, and good visual effect after application.

4. Paper: Applied to low-grade packaging products, suitable for non-deformation or small deformation of the barrel. The commonly used materials are high-grade coated papers, and the printability of paper materials is better.

(B) In-mold label materials have two appearances depending on the application range

1. Smooth surface material: Suitable for curved bottle shape, because the curved bottle body can naturally exhaust when contacting with the label during the blowing process, without bubbles or wrinkles.

2. Rough surface material: It is a regular pattern that is manually printed or rolled out and is suitable for a flat bottle body. When the flat bottle body is in contact with the label during the blowing process, the air can be naturally exhausted through the small pattern that passes through, and bubbles and wrinkles do not occur.

(3) Japan YUPO Synthetic Paper

(1) Characteristics of YUPO Synthetic Paper In-mold Labels

A. Polypropylene PP is a raw material, and is made of biaxially-stretched inorganic fillers. It has the characteristics of paper and plastic films. Compared with ordinary paper, it is more resistant to acids, alkalis, water, oil, mold, and friction.

B. It can be fully affixed to the container, even if the edge of the special shape paper can be free of protrusions and falling off easily.

C. No coating process, no problem of coating stripping, easy exhaust stripe on the back layer, short molding time and high efficiency.

D. Excellent weather resistance (light), it will not discolor or crack under the harsh outdoor environment such as ultraviolet radiation, and it can be used or stored for a long time.

E. The smoothness of the surface height, excellent flatness and stable thickness, and excellent compatibility with the adhesive.

F. The surface is smooth and the whiteness is high, which faithfully reflects the printing effect. The printing effect is exquisite, suitable for rotary offset printing and flexo printing.

G. Has different grades of self-adhesive products that can be applied to permanent adhesives, removability adhesives.

H. Can be used for offset printing, small and medium batch of label products, if it is a large number of prints recommend the use of gravure; if the demand for ink is recommended to use UV printing.

(2) Use of YUPO Synthetic Paper In-mold Labels

A. Use of life products

● Food use: frozen food label (ice-cream box)

● Medical use for life: shampoo, hair conditioner label, medicine label

● Use of clothing: Advertising labels, size labels

B. Industrial use

● Car use: battery label, wire label, tire label

● Use of electronic home appliances: description labels, warning labels

● Container labels: iron drum labels, chemical container labels, oil barrel labels

(3) Printing of YUPO "IML"

A. The YUPO "IML" in-mold label has a variety of printing methods, generally using offset printing, flexo printing, and gravure printing. Japan mostly uses UV offset printing, UV rotary printing and gravure printing; China mainly uses ordinary offset printing, flexo printing and gravure printing, and coating after printing.

B. Although YUPO is less prone to static electricity than other plastic films, it may also generate static electricity in a low-humidity environment. It is recommended to keep the humidity between 50% and 60%, or use a static eliminator to remove static electricity.

C. When YUPO in-mold labels are printed, the last coat of oil is required. The surface polish can improve the smoothness so that the labels do not stick to each other.

(d) Avery Dennison Film Labels

Avery Dennison's patented film products Primax, FasClear, which are transparent and white polyolefin multi-layer composite mold label film, functionally divided into print layer, core layer and adhesive layer. The printing layer surface can provide excellent printability, the core layer determines the stiffness and transparency of the label, and the adhesive layer ensures excellent composite properties between the label and the bottle body.

(1) Characteristics of Avery Film Labels

A. The label and bottle body are on the same surface, and the color pattern is printed directly on the surface of the bottle body.

B. Film materials, especially materials such as Primax and FasClear, which can be used for stretching and shrinkage, can be deformed as the bottle body is deformed, and the wrinkling of the label will not occur on the surface of the bottle body.

C. The surface of the film material does not absorb ink, and the printed label has a bright color and a strong three-dimensional effect, and the color effect is better than the paper material.

D. The in-mold label of the film has good environmental protection, and the label and bottle body can be melted at the same time and suitable for recycling.

E. Primax and FasClear are smooth and matte films, respectively. The printability after corona treatment is good, and it is suitable for various printing processing methods. It is especially suitable for labels used on cosmetics and cosmetic products.


(2) Manufacturing Process of Primax and FasClear of Avery Film Materials

Primax and FasClear are a mixture of BOPP and PE. The process flow is:

A. The plastic pellets of BOPP and PE were placed in an extruder and melted and squeezed separately into a casting device.

B. The solution was mixed in a casting device and the mixed solution was passed through the gap of the casting device by compressed air.

C. Cool and thin the film with a chill roll.

D. After the machine direction of the film is elongated by the orientation drawing device, the film is formed into a longitudinally deformable film.

E. Increase the surface tension of the film by the corona device.

F. Rolled into a printable or coated film material.

(3) Printing of Avery Film Primax, FasClear

A. Paper Feeding and Tension Control

The 6-inch (152mm) paper core tube is used as the label material, and a large-diameter paper core ensures that the material near the paper core has little bending deformation.
Deformation of the label after processing.

B. Corona treatment

When the surface tension of the material is greater than 40 dyne, the ink can be wetted and corona-free, and direct printing can be performed. Primax and FasClear are themselves corona-treated film materials.

C. Printing

● Primax and FasClear are suitable for various inks. UV inks are recommended to achieve the best print quality.

● Primax and FasClear can use galvanized aluminum bronzing foils made of thin film materials for bronzing.

D. Polishing

Primax and FasClear must be glazing after printing to protect the surface of the ink and label. It is required to use high-quality, scratch-resistant special coating oil that does not cause shrinkage deformation, and reduce the bending deformation of the label after it is polished.

E. Die-cutting

According to the customer's specific situation, it can be die-cut on-line or after die-cutting. However, special hardened steel die-cutting tools must be used. On-line die-cut die-cutting sticks are specially manufactured by the supplier.

F. Electrostatic problems

Static electricity is the biggest hidden danger affecting the quality of in-mold labels. Static electricity is related to temperature and humidity. It is recommended that the temperature control of the printing factory should be 22°C±2°C and the relative humidity should be 50%. The static eliminator is installed on the processes of printing, die cutting, waste disposal, die cutting, and stacking to ensure that the finished product label has less static electricity.

(five) sanding, pearlescent, plain synthetic paper

The main products distributed by Beijing Honghe Weiye Technology Development Co., Ltd. are frosted, pearlescent, and plain light three series of in-mold label synthetic paper. The transparent, transparent matte, and porcelain white high-gloss in-mold label synthetic papers that were developed have also been successfully tested and have recently formed a production scale. This technology has completely changed the situation in which the surface properties of polymer materials are poorly printed. The ink can achieve better adhesion and drying speed.

(1) Features of matte, pearlescent, plain synthetic paper

A. The matte label surface has a matt effect, and the matte texture has a non-slip effect, which effectively prevents the bottle body from slipping; the plain label is an ordinary paper effect; the pearlescent label surface has a natural pearl color and has a strong anti-counterfeiting function.

B. Use universal offset printing, gravure printing, flexo printing, etc. for surface printing. Only need to be coated with glazing oil after printing to achieve a certain degree of solidity, eliminating the need for the coating process after the printing of traditional polymer substrates and reducing The label production cost.

C. The advantage lies in the superior surface performance, which is more suitable for offset printing. It has a wide range of products, a variety of products, and is made in China with high cost performance.
D. Inadequacies are poor stiffness, which is limited by the application of high-end products.

(2) Main applications of products
A. Washing, cosmetics. Such as: shampoo, hair conditioner, bath liquid, washing liquid, kitchen cleaning agent and so on.

B. Trademarks and instructions for large-capacity blow barrels and injection containers for chemical raw materials, pesticides, paints, and lubricants.

C. Labels and instructions for plastic barrels, bottles and boxes of salad oil, ice cream, condiments, soy sauce, vinegar, etc. (HC)