Cigarette, small food children nutrition breakfast, such as the paper or cardboard packaging made with environmental protection materials, after various printing methods, ink attached to the paper, will not be transferred to the harmful substances to food, how to test the safety of ink prints?

 

As we all know, printed packaging materials have different degrees of smell, depending on the composition and printing methods of the ink used. First of all, it should be explained that the emphasis is not on what the smell is, but how the packaging formed after printing has a substantial impact on its content.

 

Taste and smell are chemical senses, and their stimulation is the result of biomolecular reaction. Scientific research shows that the different positions of the tongue produce sour, sweet, bitter and salty taste effects, and the sense of smell is more sensitive and can quickly smell the subtle differences, but the same nose is also easily "tired" and does not continue to work, so it is usually recommended that perfume makers do not continue to identify more than 3 flavors. What is the testing standard for the smell of packaging printed matter? There are several testing methods used in German printing industry.

 

1, gas chromatography analysis

 

Gas chromatograph is widely used in the production of gravure printing packaging materials. The residual solvents and other odors in printed packages can be determined objectively by gas chromatography. In the process of gas chromatography, the gas passes through a separation column and is measured by the detector. Even a small amount of gas can be detected. The flame ionization detector (FID) is the main detection tool, which connects the detector to the PC to record the time and the amount of gas from the separation column. The free monomers can be identified by comparing with known liquid chromatography. At the same time, by measuring the peak area and comparing with the known volume, the free monomer content can be obtained. When investigating the unknown monomer of folding carton, gas chromatography and mass spectrometry (MS) are usually used together to identify unknown monomers by mass spectrometry. In gas chromatography analysis, the method of top space analysis is usually used to analyze the folding carton, which is heated by the measured sample in a sample bottle to make the analyzed monomer vaporized and enter the top space, and the subsequent process is the same as the test process described earlier.

 

2, Robimson detection method

 

In German standard DINlog55, the influence of packaging materials on the taste of test products was determined by the Robinson test method. For printing, what people are concerned about is the effect of solvent residue after printing ink, so the printing plant usually uses an improved Robinson test method (MHM) to achieve the purpose of testing.

 

In the testing process, the printed material is printed on the surface of 1.5%m2, and then the printed product and the finished product, such as the chocolate, are rotated for a certain time (about one day) to judge the taste of the package. The results are usually divided into 5, 0, and other flavors without any change; 1 is difficult to identify the change of taste. ; 2, there is slight change in taste and so on; 3, there is a certain change in taste and so on; 4, there is a distinct change in taste. Sometimes, it is also detected in the actual environment, for example, the carton is checked under the high temperature 75%RH, and the result is usually different from the method specified in the DINlog55.

 

The above two methods have made a quantitative test on whether the effect of printing ink on the smell and taste of the packaging after printing is safe, so as to provide a clear method for evaluating the environmental protection and safety of carton packaging printing. The printing plant and the relevant departments in China can refer to the advanced foreign testing methods and international standards, and formulate the testing methods and standards that are in line with the international and meet the production conditions of our country, thus promoting the development of the printing industry.