The primary material requirements for in mold labeling are strict, and the technical content of in mold labeling is very high. The primary embodiment is the material. The first to enter the Chinese market is Yupo in mold label in Japan, which claims to be the most successful in mold label material in the world.

In mold label should have excellent printability, ensure ink firmly attached to the surface, and guarantee excellent processability in the post processing process, such as die cutting and cold stamping processability. Secondly, the material should be satisfied with the application characteristics and be integrated with the plastic bottle during blow molding.

In mold label materials are divided into two categories: paper and plastic film. The former will deform when encountering water or damp, reducing the use value, but its benefit is that there is no electrostatic interference, reducing the loss of the absorption label when blowing the bottle. Other materials are not homogeneous with plastic bottles, so it is not easy to recover and reuse. At present, plastic film type label materials are generally used at home and abroad.

The inner label material structure is composed of printing surface, middle layer and adhesive layer. The effect of printing surface is to receive ink and form color image and text; the middle layer supports the printing surface and gives the material enough stiffness and transparency. It does not deform on the printing machine and under the high temperature effect to ensure the accuracy of overprinting. The adhesive layer will melt under the effect of high temperature, so that the label material and plastic container become a whole, ensuring that the label and plastic bottle are firmly stuck together.

There are three kinds of printing materials: PE, BOPP and PE + PP. At present, most plastic containers are made of PE raw materials, so it is better to use PE in mold labels for recycling, because they are all made of homogeneous materials. In order to improve the ink affinity of printing materials, the surface coating or corona discharge are usually needed to improve the surface energy.

There are two kinds of structures on the surface of the adhesive layer: plane non reticulated structure and reticulated structure. The former is directly touched with the blank when using, natural exhaust, suitable for small area label. The latter has embossed the screen structure on the surface, when using, the gas exhausts through the exhaust channel of the screen, avoiding the production of bubbles. The adhesive layer also has anti-static property to avoid double printing; in addition, it also has the sliding property to ensure the smooth separation of labels and the smooth printing process.

Article source: Jiangmen film inner paste manufacturerhttp://www.amstitle.com