The waxed paper cup
In 1932, the first waxed two-piece paper cup was introduced, with a smooth surface that could be printed with elaborate designs to boost sales. Paper cup coated with wax, on the one hand can avoid drink and paper material direct contact, and can protect the adhesive adhesion, enhance the durability of paper cup. On the other hand, it also increases the thickness of the side wall, so that the strength of the paper cup is greatly improved, thus reducing the amount of paper necessary to make a stronger paper cup, and reducing the production cost.
As waxed paper cups became a convenient container for cold beverages, people wanted a convenient container for hot beverages. However, the hot drink will melt the wax layer on the inner surface of the paper cup, and the glue will be separated. Therefore, the general waxed paper cup is not suitable for holding hot drinks.
Straight wall double cup
In order to expand the application range of paper cups, in 1940, straight wall double paper cups were introduced to the market. This paper cup is not only easy to carry, but also can hold hot drinks. The cups were then coated with latex to mask the "cardboard smell" of the paper and to make the cups more leak-proof. Latex-coated single-layer waxed cups are widely used in self-service vending machines to hold hot coffee.
Plastic coated paper cups
Some food companies began to put polyethylene on cardboard to increase the barrier and sealing of paper packaging. Because the melting point of polyethylene is much higher than that of wax, the new type of beverage paper cup coated with polyethylene can be used to hold hot drinks, which solves the problem that the melting of the coating material affects the product quality. At the same time, the polyethylene coating is smoother than the original wax coating, improving the appearance of the paper cup. In addition, the processing process is cheaper and faster than latex coating method.