Introduction To Coating Of Disposable Paper Cups

Disposable paper cups are becoming increasingly popular these days. For the convenience of entertaining guests, people often choose to use disposable paper cups to pour tea. While this may seem hygienic, have you noticed that some paper cups emit a strange odor after being filled with hot water? This is because these unpleasant-smelling cups are coated with a polyethylene film to create a water-tight barrier during production. Polyethylene is the safest chemical in food processing, it's insoluble in water and is non-toxic and odorless. Let's discuss the coating of disposable paper cups!

I. Currently, disposable paper cups in China can be divided into three types according to their uses: cold drink cups, hot drink cups, and ice cream cups. And according to the coating of the paper cups, they can also be divided into three types: wax-coated cups, straight-walled double-layer cups, and polyethylene-coated cups.

1. The wax-coated cup is similar to the paper cup described in the rumor. The surface is coated with a layer of wax to prevent water. Regular manufacturers will use edible-grade paraffin wax, which will not cause harm to the human body if accidentally drunk.

2. If you want to put hot drinks in it, you need to add another layer of emulsion. The straight-walled double-layer cup uses this coating, and because the double-layer cup has good heat insulation, it is often used as a hot drink cup and ice cream cup.

3. Polyethylene-coated cups are made with a thin layer of polyethylene on the cup wall. This is a new process. Its advantages include being able to handle both cold and hot drinks and having a smoother surface. Polyethylene itself is non-toxic and odorless, but if exposed to heat for a long time, poorly made materials, or inadequate processing, it may oxidize into carbonyl compounds. Carbonyl compounds are not easily volatile at room temperature, but they can evaporate when hot water is poured into the paper cup, which is why people sometimes smell strange marks on paper cups. Generally speaking, long-term ingestion of these organic compounds is definitely harmful to the human body.

4. Currently, the most commonly used disposable paper cups on the market are made from polyethylene coated material, which is safer. The production process for polyethylene coated paper cups is: base paper - coating - printing - die-cutting - forming - packaging. These paper cups typically have a layer of coated paper on the inside and a layer of paper on the outside. Some manufacturers apply a further coating to the outside after printing. Currently, nearly all qualified disposable paper cups available are coated, wax-coated disposable cups are virtually non-existent.

II. The composition of paper cup paper:

1. Paper cup paper is made by extruding and compounding paper cup base paper and plastic resin particles. The plastic resin is generally PE resin. Customized paper cup base paper is coated with single-sided PE film or double-sided PE film to become single-sided PE paper cup paper or double-sided PE paper cup paper.

2. PE itself has the advantages of being non-toxic, odorless, tasteless, reliable in hygiene, chemically stable, well-balanced in physical and mechanical properties, good cold resistance, water and moisture resistance, a certain degree of oxygen barrier, good oil resistance, excellent moldability, and good heat sealing properties. PE film is produced in large quantities, is easily sourced, and is inexpensive, but it is not suitable for high-temperature cooking. If special performance requirements are required for disposable paper cups, a resin with corresponding properties should be selected for lamination.