With the improvement of people's living standards in China, environmental protection, safety and hygiene are increasingly becoming the goal of everyone. In terms of clothing, food, housing and transportation, food safety is particularly important. As a part of food, the safety of outer packaging has become the focus of attention.
At present, the solvent residue in food packaging bags is an urgent problem for many packaging material printing factories to solve, especially some non fried foods and some foods with weak taste, such as milk powder, biscuits, oatmeal and chocolate, are very sensitive to the residual solvent.
Several factors affecting solvent residue are as follows
Standard for determining whether the residual amount of solvent is qualified or not
Solvent residue from printing process
Solvent residue from compound process
Keep the residual solvents during transportation
1. Standards for determining whether the residual amount of solvent is qualified or not
1 national standard
There are two standards about solvent residue in China. One is GB / t10004-1998 "cooking resistant composite film bag", which stipulates that the residual solvent is less than or equal to 10mg / m2, but it does not specify which kind of solvent is. The other is the standard GB / t10005-1998 biaxially oriented polypropylene (BOPP) / low density polyethylene (LDPE) composite film, bag, which stipulates that the residual solvent is less than or equal to 10 mg / m2, in which benzene is less than or equal to 3.0 mg / m2. These two standards are recommended standards, not national mandatory standards.
2. Internal standards
Instant noodle manufacturers generally require that the residual solvents in packaging bags should be less than or equal to 10 mg / m2, including benzene less than or equal to 3.0 mg / m2; a milk powder factory requires that the residual solvents in packaging bags should be less than or equal to 10 mg / m2, including benzene less than or equal to 2.0 mg / m2; chocolate manufacturers generally require that the residual solvents should be less than or equal to 5 mg / m2, without benzene solvents.
Why control the residual solvent?
According to the medical experiment, it has been proved that:
Organic solvents can cause cumulative poisoning (chronic poisoning)
According to the toxicity of solvents, it can be divided into
A. Non toxic: water
B. Weak toxicity: ethyl ester, isopropanol, ethyl acetate, butyl acetate
C. Toxic: benzene, xylene, methanol, butanone
D. Strong toxicity: dichloroethane, tetrachloroethane
Damage of several common solvents to human body
Toluene: to the central nervous system stimulation bigger, easy to cause the human body chronic poisoning, causes the appetite to drop, the emaciation, the leucocyte reduces, the anemia, has certain damage to the liver and kidney.
Xylene: it can stimulate the skin and inhibit the central nervous system.
Butanone: toxic, anesthetic effect, can cause central nervous function decline, stimulate eyes and trachea.
Isopropanol: on the human upper respiratory tract mucous membrane stimulation and anesthesia.
Ethyl acetate: has anesthetic effect, irritates eyes and mucous membrane.
Control of solvent residue in the second printing process
1. The influence of printing materials
Due to the different types of printing substrates, solvent residues have great differences
According to the toluene adsorption capacity from large to small: cellophane, K coating, BOPP, BOPP, PA, pet.
According to the adsorption capacity of ethyl acetate from large to small: cellophane, K coating, BOPP, BOPP, pet, PA.
According to the adsorption capacity of butanone from large to small: cellophane, K coating, BOPP, BOPP, pet, PA.
We should fully consider the above factors when designing the product structure
2. Printing screen design
The amount of residual solvent is related to the printing color sequence, ink layer thickness, field area and full plate white ink.
Dongguan Beite packaging materials Co., Ltd. - located in Dongguan City, the world's manufacturing city, is a subsidiary of Beite packaging (China) Co., Ltd., with a plant area of 6000 square meters. It is a flexible packaging enterprise integrating R & D, production and sales. It has a complete set of domestic advanced production equipment, a scientific and humanized management system and a group of experienced technical personnel For backing, to provide customers with quality products and first-class service.
The company produces composite bags, roll film, fruit bags, aluminum foil bags, suction mouth bags, self-supporting bags, zipper bags, anti-static bags, special-shaped bags, etc., which are suitable for the internal and external packaging of food, daily chemicals, electronics, toys, medicine, cosmetics, industrial products and other industries.
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