A brief description of the process of PLA coated paper cups
Disposable paper cups are often used in people's daily life. Disposable paper cups currently on the market are mainly divided into three types: one is made of white cardboard, which is mainly used to store dry things and cannot hold water and oil; the other is waxy paper cups, because they have been waxed It has been soaked, so it is more waterproof and thicker, but as long as the temperature of the water in the cup exceeds 40°C, the wax will melt, and the wax contains carcinogenic polycyclic aromatic hydrocarbons; There is a layer of coated paper inside. The quality of the coated paper determines whether the paper cup will produce harmful substances during use.
1. Why choose PLA coated paper?
The most common type of coated paper is PE, but when it comes to true environmental protection, coated paper should be as degradable as paper cups, without causing pressure on the environment. Therefore, PLA coated paper made of new environmentally friendly material PLA came into being.
Traditional paper composite materials are based on paper and compounded with plastic coatings such as LDPE and PET. Due to the non-natural degradability of plastics such as PE and PET, such packaging materials cannot meet the full sense of environmental protection. Requirements, and the development of completely biodegradable material PLA and its coating paper technology has completely solved this worldwide problem. PLA coated paper itself is an environmentally friendly and healthy product that is completely decomposable and compostable. PLA coated paper is made of 99.99% corn plastic PLA material without any additives.
2. The process of PLA coating
Polylactic acid (PLA) has good thermal stability, the processing temperature is 170-230°C, and it has good solvent resistance. It can be processed in various ways, such as extrusion, spinning, biaxial stretching, injection blow molding. In addition to being biodegradable, products made of polylactic acid have good biocompatibility, gloss, transparency, feel and heat resistance, as well as certain bacteria resistance, flame retardancy and UV resistance.
1. Traditional PLA coating process
The hot-melt PLA corn plastic is plasticized by the screw and then extruded linearly from the die of the flat die head. After stretching, it is attached to the surface of flexible substrates such as paper, film, non-woven fabrics, and woven fabrics, and is smoothed by pressing rollers. Finally, it is cooled and shaped and pressed to form a composite material that has both the barrier properties and heat sealability of the plastic film layer, the strength and toughness of the base material, and functional properties.
However, in order to make the paper covered with PLA corn plastic, the length of the pressing roller needs to be greater than the width of the paper. This way makes the PLA corn plastic easy to drip from both sides of the paper to the equipment after being pressed.
2. A new type of coating system for PLA coated paper
From one end to the other end of the coating system frame for PLA coated paper, there are unwinding rollers, preheating rollers, scratching devices, laminating devices, squeezing rollers, cooling rollers, and winding rollers. The unwinding roller and the winding roller are rotatably connected on the frame, and the winding roller is driven to rotate by a motor installed on the frame.
