The unique features of water-based film products

The film has three kinds of oiliness, water-based and hot-press precoating (dry), and the production process of oily and hot-press precoating (dry) film is polluted. It is a production process that has gradually been eliminated, and the water-based film is economical. Affordability is a popular mode of production in China.

The process of water-based film coating is: paper feeding at the paper feeding section - paper feeding at the paper feeding table - film coating adhesive - printing film coating - winding - hanging and drying - slitting - lay flat. The plastic film used for water-based film coating is basically the same as the traditional oil film, and is mainly a polypropylene film, and also a polyvinyl chloride film, a polyethylene film, a polyester film, and the like. The corona treatment of the film is less demanding. After the film is stored for a long time, the oil-based, hot-press precoating (dry) film requires a higher corona treatment of the film. Adhesives are also known as water-based adhesives. The ratio of the main raw materials is: vinyl acetate ethylene polymerization emulsion (VAE) 75%-85%, rosin 3%-5%, emulsifier 3%-5%, water 5%-10%, other additives 1%-2 %. The water-based film does not need to be heated and dried, and it is directly wound up. The speed reaches 70-80 meters per minute, which is 2 to 3 times that of other film-covering methods.

The water-based film coating process uses water-based green glue, does not require heating and drying devices, high-speed energy-saving and high gloss, because of its characteristics also have some deficiencies, in some products should be used with caution. Film-based water-based film adhesives that are not suitable for large-scale graphic products contain a certain amount of moisture. When used in large-area (especially large-scale film-covered) graphic products, they have a large area of ​​snowflake on the surface of the graphic. Spots, affect the appearance of the product quality, increase the amount of sizing also changed little, can only use oily or hot-press pre-film process instead of construction.

Due to customer requirements, some products require double-sided lamination. If the water-based lamination process is used, the moisture content of the glue in the lamination film is too high, resulting in short-term volatilization of the printed product due to moisture, making the printed product soft and unable to meet customer requirements. , there is a quality accident problem. Within 3 to 5 days after filming, it is not easy to carry out embossing. Since the water-based film of water-based film contains water, it is difficult to completely dry within 3-5 days after the film is coated. If the product is pressed and embossed, it will be stuck on the contact surface. Insufficient, blistering and other issues are most prominent on coated paper. For example, in some handbags, the indentation line after water-based coating is not very straight, and sometimes it is whitened and blisters, which affects the appearance of the product. Subsequent processing waits, the preparation time is too long The product of the water-based film is laid flat after 24 to 48 hours after being separated by a large sheet, and sometimes it is baked at 35 to 40°C before it can flow into the next process for the purpose of bonding its glue. Moisture volatilization, stable paste strength and stiffness of film products can be used for subsequent processing, and sometimes some special measures must be taken to meet the requirements.

Discoloration of printed graphics mainly occurs on large-area spot-color prints. For example, gold and silver ink products will change color after water-based coating, due to some chemical substances in the glue, water and gold ink (including copper (More powder) or silver ink (containing more aluminum powder) occurs due to chemical reactions. Only oil-based or hot-press precoating processes can be used.

Waterborne film products have their own unique features:

1 For the saddle-stitched cover, especially the thin cover, the water-based cover film does not suffer from dampness;
2 Production suitability requirements are not high, suitable for mass production line production;
3 The cost of input is not high and the overall cost is low;
4 is not easy to pollute the environment, is environmentally friendly products, but also represents the development direction of the film.

Reproduced from: newmaker