Hygienic requirements for gravure ink for cigarette packaging (1)

With the rapid development of packaging industry, people have made more and more explicit requirements for packaging materials, especially in the field of food packaging. Although cigarettes do not belong to food, they are closely linked with people's daily lives. Therefore, cigarette manufacturers also put forward various requirements for cigarette packaging materials. Although ink is not a direct packaging material, it is an important part of the packaging material, so it is only natural that it requires hygiene. The current hygienic requirements for packaging related to ink can be roughly divided into the following three categories. The first category is the detection and control of heavy metal content, ie, the content of harmful heavy metals or toxic and hazardous elements and compounds; the second category is the content of organic volatiles (VOC), that is, the VOC content of inks and prints, and the key organic solvents in packaging materials. The residual content is detected and controlled; the third category is odor, that is, dried printed matter must not contain irritating or even harmful odor. The first type of heavy metal content can be directly measured, and the point of control lies in the rational choice of controlled elemental compounds. The second type of VOC content needs to be clearly defined in the determination conditions and test methods. The third type of odor cannot be determined quantitatively at present. It can only use scientific statistical methods to express people's average feelings. Although this method does not have clear data, it can also reflect people's subjective feelings to a certain extent.

1 The detection standard of heavy metal content

At present, the standards for the detection of heavy metal content mainly include the arsenic and lead content specified in the hygiene standard for food packaging paper GBll680-89, and the eight elements content specified in the safety standard EN71-3 of the European Community Toys. See Table 1 for details. The testing organization is National Tobacco Quality Supervision and Inspection Center (CNTQSTC), China Import and Export Commodity Inspection Corporation Zhejiang Branch.

1.1 Sample preparation for heavy metal content

Taking EN71-3 as an example, the detection principle of this method is to imitate human stomach acid to dissolve the elements in the test sample, and then quantitatively detect the amount of soluble elements that can be taken. First, let the tested ink naturally dry at room temperature, and then crush and filter with a metal mesh with a pore size of 0.5 mm to obtain at least 100 mg of a solid powder; then use 50 times the mass of hydrochloric acid solution (C=0.07 mol/L, 37 ±2°C) Mix the powder in the container, shake it for 1min, measure the acidity value and control the pH value at 1, 0-1.5; keep the mixed solution under light and 37±2°C for 1h. After standing for another 1h, the solids are separated from the solution and filtered out as soon as possible. If necessary, a centrifuge can be used, but the centrifugation time cannot exceed 10 minutes. Finally, the obtained solution sample was detected by inductively coupled plasma mass spectrometry. After the measurement data was converted, the data of each heavy metal content was obtained and the result was expressed in mg/kg.

The paper and paperboard (such as smoke) detection process is basically the same as the above process. First, the paper to be tested was sampled at least 100 mg, soaked in 25 times mass of deionized water at 37±2°C to soften and homogenize; then quantitatively transferred to a container and 25 times the mass of hydrochloric acid solution was added ( 0.14mol/1,37±2 degrees Celsius). After shaking for 1 minute, test its acidity value and control the PH value at 1. O-1-5. The following process is the same as the ink process described above.

1.2 Test Results of Heavy Metal Content

This paper tests the paper gravure printing ink and the corresponding printed cigarette markings of New Oriental Weinore Group Co., Ltd. The test data are shown in Table 2. The results show that the contents of heavy metals in the gravure printing ink and smoke labels are much lower than EN71-3. Provisions.

(to be continued)