Common materials used for disposable plastic cups include polypropylene (PP), polycarbonate (PC), polyethylene terephthalate (PET), polystyrene (PS), and polylactic acid (PLA), among others.
According to plastic recycling codes, the heat resistance of different materials varies significantly; for instance, PP (Code 5) can withstand high temperatures up to 120°C, PET (Code 1) is heat-resistant up to 65°C, while PS (Code 6) is resistant to both heat and cold but should not be heated in a microwave oven. The compressive strength of disposable plastic cups varies depending on the material; traditional plastic cups (such as those made from PP, PS, or PET) exhibit compressive strengths ranging from 26 N to 975 N, whereas PLA plastic cups range from 26 N to 151 N. In terms of thermal insulation, disposable paper cups generally outperform disposable plastic cups; specifically, paper cups featuring corrugated or double-walled hollow structures offer the best insulation, with their surface temperatures potentially differing from those of ordinary PE plastic cups by more than 20°C.
Some disposable cups marketed as "degradable" fail to fully degrade under simulated industrial composting conditions-exhibiting a disintegration rate of 0%-due to the inclusion of non-degradable PP plastic. Tests indicate that plastic cup samples made from materials such as PS, PET, and PLA showed no detectable migration of microplastics after being immersed in boiling water for two hours. However, some substandard products pose a risk of exceeding permissible limits for harmful substances; for example, certain products have been found to contain excessive residues of 3-chloro-1,2-propanediol-a substance classified as a Group 2B "possibly carcinogenic to humans" agent by the International Agency for Research on Cancer (IARC) of the World Health Organization.
Plastic cups must comply with national standards such as the *National Food Safety Standard: Plastic Materials and Articles in Contact with Food* (GB 4806.7) and *Plastic Drinking Cups* (QB/T 4049); common areas of non-compliance include sealing performance and impact resistance.
