IML In-mold labeling process

The "mold" of "In Mold Label" (IML for short) refers to a mold for molding a plastic container. The label in the mold means "a label stuck in the mold" and is a bottle for blowing a plastic bottle. And pre-decorating processes for injection molding and thermoplastic containers. That is, the container is labeled before filling the product. Specifically, when the injection molding container is manufactured, the printed in-mold label is sucked by the robot (the printing surface of the label is inward and the adhesive surface is outward) is placed in the mold, and the hot melt adhesive on the back of the label is melted by the plastic melting temperature. Melted and integrated with plastic containers.

(a) Comparison with traditional labels

There are three main types of traditional labels: heat-shrinkable labels, direct screen-printed labels, and adhesive labels (mainly self-adhesive labels).

(1) The direct screen printing label is to print the pattern and text on the container packaging by screen printing. The overall effect is good, the pattern and text have texture, but the direct screen printing quality is not ideal, it is difficult to reflect the delicate pattern With small text, if the color is more, the price of using direct screen printing is more expensive.

(2) The use of heat-shrinkable films (mainly PVC films) as packaging labels, the relative cost of self-adhesive labels and direct screen-printed labels is low, but heat-shrinkable labels are easily damaged and the overall image is not good, which is not conducive to environmental protection.

(3) Adhesive labels (mainly self-adhesive labels) can perfectly represent the requirements of fine labels, but their cost is more expensive than that of heat shrink film labels.

( B) Considering the cost of labels

(1) In general, if the direct screen printing label color exceeds 4 colors, the cost is the most expensive of the 3 conventional label printing methods. From the point of view of the cost of the label material, the in-mold label does not require a backing paper, so the material cost has a certain space for decline.

(2) The label is embedded in a plastic bottle to increase the strength of the plastic container, reduce the amount of resin used in the container, and reduce the storage capacity of the plastic bottle.

(3) However, the use of in-mold labels requires special die-cutting equipment and labeling equipment during the printing process, and the printing process needs to pay attention to electrostatic treatment. Therefore, the cost of printing the in-mold labels may be higher than that of conventional labels.

(c) From an aesthetic point of view

(1) The use of in-mold labels is undoubtedly very novel and aesthetically pleasing. It is firmly embedded, waterproof, moisture-proof, non-foaming and smooth to the touch, especially for daily chemical products that use labels as their main packaging.

(2) The in-mold label is tightly integrated with the bottle body, and the label has good adhesion with the container. When the container is warped and squeezed, the label does not separate from it, and it can resist collision, scratching and pollution during production and transportation. To maintain the integrity and aesthetics of the tag over time.

(D) From the perspective of security

(1) Enhancing the product's anti-counterfeiting capability is a major starting point for many manufacturers to use in-mold labels, because the use of in-mold labels requires special processing molds (in-mold labeling robots) or modifications to the original molds. Million yuan, higher production costs.

(2) The printing process of in-mold labels is more difficult than conventional labels. Currently, only a handful of manufacturers can provide in-mold labeling, which increases the difficulty of anti-counterfeiting. This provides users of plastic packaging products seeking quality, quality, and branding. Very reliable protection.

(E) Considering environmental protection

There are many types of materials for in-mold labels. Common plastic containers are matched with the same in-mold label materials. At the same time, due to the label and the container together, the recycling rate of the bottle body is improved. This is in line with the current environmental protection theme. Consistent.

(6) Considering from the production process

(1) Container molding and labeling are completed at one time, no post-processing, immediate shipment, reduced inventory, shortened production cycle, and improved production efficiency.

(2) Using plastic (such as PP, PE, PVC, etc.) films as in-mold label substrates, with oil resistance, stain resistance, waterproof properties, and good chemical stability.

(3) With good printing performance, beautiful patterns can be printed in the same way as stickers.

(VII) Limitations of in-mold labels

(1) In practical applications, if adhesive labels are used, problems occur in the printing process. Even if they are reprinted, they will only waste some labels; even if they are already attached to plastic bottles, they will only change the bottles if they are not satisfied with the labeling style. Body, the label can also continue to use. However, using in-mold labels will result in double waste of bottles and labels if they are not satisfied with the printing or labeling process.

(2) The use of in-mold labels requires expensive molds, special containers for blow molding or injection molding equipment, increased counterfeit costs, anti-counterfeiting, and increased unit production costs.

(3) If the container made by the blow molding process uses the in-mold label, the shape of the container (curvature size) must be considered. If the curvature of the container is too large, such as a round bottle, in-mold labeling may cause difficulty in exhausting; in addition, if the volume of the blow-molded container is too large, the in-mold label should not be used.

In-mold labeling has been popular for years in several countries in Europe and America. The production and labeling process of in-mold labels is relatively mature. In-mold labels were developed during the era of long-run printing. At that time, there was a large amount of product consumption. For the domestic laundry industry, one product required millions of identical labels. The in-mold label gradually opened its market with its advantages in production efficiency, aesthetics, and environmental protection.

The in-mold label was first used in injection-molded containers, and later developed into blow-molded containers, making it more vital and competitive. The first-generation in-mold label consists of two layers of paper, one coated with a heat-seal adhesive and the other a printed layer. Most of the in-mold labels are now made of plastic film. The film does not have to be completely melted during the blow molding process, but is integrated with the plastic container, providing better heat, moisture, and chemical stability than paper.

In-mold labels are now widely used in a variety of plastic packaging, such as HDPE, PP, PET and PS. In Europe and the United States, the proportion of in-mold labels in container labels is about 12% to 15%. In North America, the blow molding products account for 95% of in-mold label production. Most of the in-mold label products in Europe are molded by injection molding. main application:

(1) Nursing products such as shampoo, hair conditioner, shower gel, etc.

(2) Detergents, such as detergent, laundry detergent, etc.

(3) Lubricants, refined oils, chemical raw materials, etc.

(4) Food products such as dairy products, ice cream, condiments, etc.