Plastic packaging bags have brought great convenience to people's lives, and have become one of the indispensable items in daily necessities. We often see a variety of graphics printed on some plastic packaging bags, and some are some businesses Publicity information, are these pictures harmful to humans?
The ink used for printing plastic packaging bags is mainly composed of pigments, linking agents, solvents and auxiliary agents. Among them, organic solvents and heavy metal elements cause serious damage to the human body.
There are two kinds of pigments in the ink: inorganic and organic. Both are insoluble in water and other media, and have a bright color and stability. Some inorganic pigments contain heavy metal elements such as lead, chromium, copper, mercury, etc., which are toxic and cannot be used for printing food packaging and children's toys; some organic pigments contain biphenyl glue, which has carcinogenic ingredients and should be strictly prohibited. Organic solvents can dissolve many natural resins and synthetic resins, and are an important component of various inks, but some of them will damage the human body and subcutaneous fat. Long-term contact will make the skin dry and rough. If it penetrates into the skin or blood vessels, it will endanger people with blood. Blood cells and hematopoietic function; it is sucked into the airway, bronchus, lungs or passed to other organs through blood vessels and lymphatic vessels, and may even cause chronic poisoning of the body. Some inks have toxicity problems of heavy metal ions. Pigments and dyes contain carcinogenic ingredients, which are very harmful to human health.
In the printing of composite packaging materials, a large amount of inks, organic solvents and adhesives are used. Although these auxiliary materials have no direct contact with food, some toxic substances will migrate into the food during food packaging and storage and endanger people's health.
Organic solvents such as ethanol, isopropanol, butanol, propanol, methyl ethyl ketone, ethyl acetate, butyl acetate, toluene and xylene are often used in printing inks. Although most of these solvents can be removed by drying, the residual solvents will migrate into the food and harm the human body. The solvents used in gravure inks are generally butanone, xylene, toluene, butanol, etc. Especially butanone, the residual smell is very strong. The pigment particles in the ink are very small and have strong adsorption force. Although they have been heated and dried during printing, they are often not dried thoroughly due to the short time and fast speed, especially for the printed products with large ink area and thick ink layer. There are many residual solvents. These residual solvents are brought into the compounding process, which is more difficult to run away after compounding, and will slowly migrate and penetrate, so the solvent residues must be controlled to a minimum.