Quality Outside and In

Margarine, liverwurst or ice cream, salads or paints: Many manufacturers package their products in ready-to-use pre-produced plastic containers. That reduces the effort required and cuts cost. Another benefit: Labels do not have to be put on them. What is more, this kind of packaging is environmentally friendly because it is easy to recycle.

Experts use the term in-mold labeling (IML) for the manufacture of this increasingly popular packaging method. Production is carried out in two steps. First, the label is made. The label foil is printed with color and then lacquered and punched out. In the second step, the label (with the printed side facing downward) is fed into a special mold. Then the hot molten plastic is injected into the mold, and label and plastic fuse into a single material. As soon as it has hardened, the container is finished, complete with the design.

Later, the containers are subjected to different loads: when goods are packaged, during transport, and at wholesalers and retailers. Initially, the consequences are apparent on the top coat. If there are scratches on it, the whole appearance is affected, and the product will probably not sell very well.

Optimized to Meet Myriad

Challenges Here the packaging artists at ACTEGA Terra come into play. Under the brand name TerraWet, they have developed a portfolio of waterbased coatings, for IML packaging, among others. The coatings are suitable for all common printing processes. They not only enable the printed image to glisten in splendor, but are also optimized to meet the various chal lenges the packaging materials face in the course of their lifecycles. This begins with the printing process and extends to the temperatures of refrigerated sections in stores.

Litmus Test for Coatings

What are the properties of IML coatings? R & D employee Marcel Altenburg lists them: “They have to be able to dry in a fraction of a second, as the entire printing process including drying with hot air and infrared light lasts less than a second. ”Then comes the next litmus test: The finished label films are stacked, punched, and transported to injection molding production, where they are separated again. “The coatings have to be scratch- and abrasion- resistant,” says Altenburg. It is essential that they are not deformed during injection molding. Experts call this property anti-curling.If required, the coatings should be able to withstand huge temperature fluctuations. For example, food is pasteurized at 80 °C (176 °F) but is subsequently cooled down to refrigerator temperature. Finally, the coatings have to be unobjectionable according to food law.

Innovation through Teamwork

The development of this successful coating family involved teamwork in the best sense. Researchers and developers worked together with product managers and market experts. As a result, the team managed to combine product and process innovations. In addition, the developers identified suitable new raw materials and employed new formulation strategies. Everything together was reason enough for an accolade: In 2013, the Lehrte-based team received the ALTANA Innovation Award.