IML (In Mold Labeling)

IML (In Mold Labeling; IML, also known as In Mold Film; IMF), generally can be called in-mold lamination (In Mold Lamination; IML), this technique was developed by P & G for more than 40 years.

In other countries, in-mold labeling (IML) technology has been widely used. In recent years was gradually deployed to Taiwan, this new technology was not only be recognized by the industry, but also widely used quickly.
This technology is when filling, at the same time adding to the plastic surface for printing and decoration.

The operation adds to the value of plastic products and improve production efficiency. IML injection molding is the process of laying printed, hot-pressed film into a mold first, then during the filling stage, the melt into the mold cavity combines with the film.

Its advantages and disadvantages are as follows:

1. When text, or graphics or color is changed, no secondary processing or changing 
    of the plastics is required. It can improve production efficiency.
2. If the multilayer labels are attached to the entire outer surface of the container,
    the IML helps to improve the barrier properties and extend the shelf ife of the 
    content in the pails.
3, Capable of carrying static electricity, it will not pollute the product
4. color varieties, printable four or more different colors, as well as highly chromatic
    contrast, and the product can be translucent
1. If the label material was not selected properly, it tend to have deformation 
2. If the static electricity was not treated properly, it prones to have overlay labels,
    missing label, and misplaced label.
IML Production Technology
The IML production system has a lot of features in the application, but the most important considerations is how to position the labels in the mold correctly. In most of the applications, it has two approaches, vacuum labeling and static labeling.

(A) Vacuum Labeling
Through a specially designed vacuum point, stickers can be accommodated in the mold at the desired position. The steps are as follows: The robot picks up the label and delivers to the special designed vacuum point of the mold. Once the vacuum turned on, the IML begins.
Its advantages and disadvantages are as follows:
When the shape of the product requires   complicated and prefabricated label, or when the label and plastic part require textured surface, the vacuum approach is especially advantageous to use. 
1. The mold needs special design and machining to accommodate the vacuum. This 
    would considerably increase the cost of the mold.
2. If label is not strong enough, the vacuum suction will distort the label in the
    finished products
3. Due to the vacuum channels existing in the mold, they can cause uneven mold
    temperature and affect mold life.
4. When the shape of the product to be complicated prefabricated label, or when the  
    label needs to be plastic parts and textured surface, the vacuum is especially
    advantageous use of it.
(B) Static Labeling
In the static labeling approach, vacuum mold is no longer needed. It has the advantage of lower cost and higher reliability. The steps are as follows: After the robot picking up the label and moving close to the mold surface, the electrostatic charges were applied to the label. The label will be electrostatically attracted to the grounded metal mold surface.
Its advantages and disadvantages are as follows:
1. Because the mold does not require a vacuum, lower mold cost and higher
    reliability were achieved.
2. Because of each product shall have a dedicated mold core and the periphery to be
    matched with adjustment. For the sake of economy, it is more suitable for mass-
    production products.
3. Due to the thickness, curvature, and surface texture affecting the adhesion to the mold, the
    label requires suitable materials and structures. The surface shall be a good insulator to
    accept and hold electrostatic charge.
Overall, the static label is placed at appropriate positions in the mold. It is a reliable, economical and efficient way and can replace vacuum method. This method can provide molding industry, their customers, and end users significant benefits. To reliably applying electrostatic charge to stick the label into the mold, label’s physical and electrical properties are extremely important.  In general, it is advised to choose the label material with contraction ratio close to that of the product. .
IML outlook
IML technology has been very mature and will continue to apply to larger application areas. Comparing with conventional decoration, IML achieved cost savings and the enhanced processing technology has greatly improved the economic attractiveness. Its application range can be extended from the technical products to food packaging products. Their application characteristics are as follows:
(A) Packaging Products
1. Can meet the high standards of packaging design. (for example: regulations, high insulation
     properties, etc).
2. Through external packaging to exhibit more information and messages (for example: the 
    ability to attract attention and convey brand features, etc.).
(B) Special Applications
1. Anti-counterfeit Function (for example: through the selection of materials and labels, it can 
    provide anti-counterfeit evidence).
2. Foil stamping, grinding sand ,velvet, and suede, external appearance applications
In the coming years, through many materials and technology development, IML will continue to advance in all aspects of the application and develop its own market place.