Conical/Pleated Paper Cups The first paper cups were conical, handmade, glued together, easy to separate, and had to be used as soon as possible. Later, folding paper cups added pleats to the sidewalls to increase the strength of the sidewalls and the durability of the paper cups, but it was more difficult to print patterns on these folded surfaces, and the effect was not ideal.
Waxed Paper Cups
In 1932, the first waxed two-piece paper cup was introduced. Its smooth surface can be printed with various exquisite patterns to improve the promotion effect. Waxing paper cups can avoid direct contact between beverages and paper materials, protect the adhesion of glue, and enhance the durability of paper cups. On the other hand, it also increases the thickness of the sidewalls, greatly improving the strength of paper cups, thereby reducing the amount of paper required to make stronger paper cups and reducing production costs.
As waxed paper cups became a container for cold drinks, people also hoped to use a convenient container to hold hot drinks. However, hot drinks will melt the wax layer on the inner surface of the paper cup, and the glue joint will separate, so ordinary waxed paper cups are not suitable for holding hot drinks.
Straight-walled double-layer cups
In order to expand the application range of paper cups, straight-walled double-layer paper cups were launched on the market in 1940. This kind of paper cup is not only easy to carry, but also can be used to hold hot drinks. Later, manufacturers coated these cups with latex to cover the "cardboard smell" of the paper material and enhance the leak-proofness of the paper cups. Single-layer waxed cups treated with latex coating are widely used in self-service vending machines to hold hot coffee.
Film-coated plastic paper cups
Some food companies began to coat polyethylene on cardboard to increase the barrier and sealing properties of paper packaging. Since the melting point of polyethylene is much higher than that of wax, the new beverage paper cups coated with this material can be ideally used to hold hot drinks, solving the problem of product quality affected by the melting of the coating material. At the same time, the polyethylene coating is smoother than the original wax coating, which improves the appearance of the paper cup. In addition, its processing technology is cheaper and faster than the latex coating method.