Why don't paper disposable paper cups get wet as easily as ordinary paper?

Disposable paper cups are made of paper, but they are not as easy to get wet as ordinary paper. Even if it is soaked in the water in the cup for a long time, it still does not penetrate, which is why in the end?

If you look closely at the paper cup, you will find that the paper used in the paper cup is different from ordinary paper. There is a smooth coating similar to plastic film on the inside of the paper, which prevents water from penetrating into the paper. This paper is called "coated paper".

Disposable paper cups are more like half paper and half plastic cups, which are very widely used in our lives, and disposable paper cups are widely used in household, milk tea shops, and fast food restaurants. Although it is called "paper cup", it is not paper in the absolute sense, the basic composition of paper cup and ordinary paper are from the plant fiber of wood pulp, in order to make the paper cup can be more practical, the manufacturer will be coated with a layer of polyethylene waterproof film on the inner wall, polyethylene is the safest chemical substance in food processing, with moisture resistance, moisture permeability is small. In other words, the outside of the disposable paper cup is a layer of paper, and the inside of the cup is actually a layer of plastic film, so that the sealing of the paper cup is good, and it can also play a good barrier role, and then the inside of the paper cup is treated by the film, and the bottom of the cup is glued tightly, so the cup will not produce water leakage. Ordinary paper is made from a "pulp" mixed with various fibers, a certain adhesive and water, and the water in it is dried. Therefore, ordinary paper encounters water, and it is easy to return to "pulp" over a long period of time, and is no longer "paper". Only special treatment of paper will make ordinary paper "not afraid of water"

PE coating: that is, the base paper (white paper) is coated on the PE film with the coating machine, and the paper on one side of the coating is called single-sided PE coating paper; Coated on both sides is called double-sided PE coated paper.

First, the difference between single pe and double pe.

Single-sided PE coated paper cup: Paper cup made of single-sided PE coated paper. Its appearance is characterized by: the side of the paper cup containing water has a smooth PE coating.

Double-sided PE coated paper cup: Paper cup made of double-sided PE coated paper. Its appearance is characterized by PE coating on the inside and outside of the cup

Second, different uses.

Hot cup with a single PE coated paper cup, the cup has a layer of PE coated paper can be slightly heat insulation, the most important is to prevent water seepage, so that the hot drink will not leak out.

Cold cup with double-sided PE coated paper cup, cold cup outside that layer will have condensed water vapor, will make the cup deformation and soft, plus a layer of film, can play a role in increasing hardness and shaping.

Third, the quality is slightly different.

Single-sided PE coated paper cup is produced by single-sided PE coated paper cup, and double-sided PE coated paper cup is produced by double-sided PE coated paper cup. Compared with single-sided PE coated paper cup, double-sided PE coated paper cup has better quality, longer service life, higher cup height and higher relative cost.