The evolution of the paper cup has unfolded in four stages:

Conical/Pleated Paper Cups: The earliest paper cups were conical in shape and handmade; they were held together by adhesive, prone to coming apart, and required immediate use. Later, pleated paper cups were introduced; adding pleats to the sidewalls increased structural strength and durability. However, printing patterns on these pleated surfaces proved difficult and yielded suboptimal results.

Wax-Coated Paper Cups: In 1932, the first two-piece wax-coated paper cup was introduced. Its smooth surface allowed for the printing of exquisite patterns, thereby enhancing promotional appeal. Wax coating served multiple purposes: it prevented direct contact between the beverage and the paper, protected the adhesive bond to improve durability, and increased sidewall thickness-significantly boosting cup strength. This allowed for reduced paper usage in manufacturing sturdy cups, thereby lowering production costs. While wax-coated cups became the standard for cold beverages, there was also a demand for a convenient vessel for hot drinks. However, hot beverages caused the internal wax layer to melt and the adhesive seams to separate, making standard wax-coated cups unsuitable for hot liquids.

Straight-Walled Double-Layer Cups:To expand the range of applications, straight-walled double-layer paper cups were launched in 1940. These cups were not only portable but also suitable for hot beverages. Manufacturers subsequently applied a latex coating to mask the "cardboard taste" of the paper and further improve leak resistance. Single-layer wax-coated cups treated with latex were widely adopted for hot coffee in self-service vending machines.

Polyethylene-Coated Paper Cups: Food companies began coating paperboard with polyethylene to enhance the barrier and sealing properties of paper packaging. Because polyethylene has a much higher melting point than wax, this new type of beverage cup was ideal for hot drinks, effectively solving the quality issues caused by the melting of coating materials. At the same time, polyethylene coatings are smoother than the original wax coatings, improving the appearance of the paper cups. Furthermore, the processing method is cheaper and faster than latex coating.