In 1932, the first wax-coated two-piece paper cup came out. Its smooth surface can be printed with various exquisite patterns to improve the promotional effect. Waxing paper cups, on the one hand, can avoid direct contact between the beverage and the paper, and can protect the adhesiveness of the glue and enhance the durability of the paper cup; on the other hand, it also increases the thickness of the side wall, which greatly improves the strength of the paper cup, thereby reducing The amount of paper necessary for making stronger paper cups reduces production costs.
As waxed paper cups become containers for cold beverages, people also hope to use a convenient container to hold hot beverages. However, hot beverages will melt the wax layer on the inner surface of the paper cups, and the glue joints will be separated. Therefore, the general waxed paper cups are not suitable for holding hot beverages.
Straight wall double cup
In order to expand the application range of paper cups, in 1940, straight-walled double-layer paper cups were introduced to the market. This paper cup is not only easy to carry, but also can be used to hold hot beverages. Later, the manufacturer applied latex to these cups to cover the "paperboard flavor" of the paper and to strengthen the leak-proofness of the paper cups. Single-layer wax-coated cups treated with latex coating are widely used in self-service vending machines to hold hot coffee.
Some food companies began to coat polyethylene on cardboard to increase the barrier and tightness of paper packaging. Since the melting point of polyethylene is much higher than wax, the new beverage paper cup coated with this material can be ideally used to hold hot beverages, and solve the problem of product quality that is affected by the melting of the coating material. At the same time, the polyethylene paint is smoother than the original wax paint, which improves the appearance of the paper cup. In addition, its processing technology is cheaper and faster than the latex coating method.
