Raw Materials for Paper Cups

Inferior paper cups utilize recycled polyethylene; the reprocessing stage can trigger thermal degradation, resulting in the formation of numerous harmful compounds that are more likely to migrate into the liquid during use. Professor Zhang Qinfa, an expert in food packaging materials at the College of Food Science, South China Agricultural University, has noted that paper cups are coated with a polyethylene water-resistant film on the inner wall to prevent leakage. While polyethylene is considered one of the safest chemical substances in food processing, the use of substandard materials or inadequate manufacturing techniques can lead to oxidation-converting the polyethylene into carbonyl compounds during the hot-melt or coating process. Although these carbonyl compounds do not readily volatilize at room temperature, they can be released when hot water is poured into the cup, producing an unpleasant odor. From a theoretical standpoint, long-term ingestion of such organic compounds is undoubtedly harmful to human health.