Detection means of residual odor and solvent purit

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Detection methods for residual odor and purity of solvents

recently, with the exposure of CCTV on the "Gansu food bag poison bag" incident, People from all walks of life pay full attention to the hidden danger of endangering human safety - the problem of "excessive solvent residue" of films for food and pharmaceutical composite packaging... (Note: the National Bureau of quality and technical supervision GB/T200 expressly stipulates that the residue of solvent in packaged food should be ≤ 10mg/M2, including benzene solvent residue ≤ 3mg/m2). Its meaning is: if the residual solvent in all kinds of packaging bags we use exceeds this standard, the toluene, xylene, butanone, isopropanol, ethyl acetate and other substances in the residual solvent will be like an invisible killer and pose a great threat to human safety

therefore, the social responsibility of "strictly controlling the residue of organic solvents" has undoubtedly pushed our flexible packaging enterprises to the forefront. So, what is the reason for the excessive solvent residue? How to control the production process? How does the special "gc-9800 gas chromatograph" detect solvent residues? What problems should be paid attention to in the detection experiment? What will be done to the composite film that has exceeded the standard

there are many factors that cause the solvent residue to exceed the standard (with peculiar smell), such as improper selection of substrate, non-standard production process, too simple and aging equipment, failure to carry out necessary detection and control in all links of production, etc., which have a direct or indirect impact on the exceeding the standard (peculiar smell). Take the raw material and substrate as an example: the quality of the ink, the release of the ink, the thickness of the ink, the quality of the adhesive, the coating amount, etc., the purity and proportion of the organic solvent and the consistency with the substrate will all affect the residue of the solvent. In addition, the soft packaging production equipment is too simple and aging, resulting in inappropriate heating temperature, insufficient drying air volume, or no clear operation instructions, non-standard operation of employees, substandard startup printing speed, insufficient additives, uneven coating, casual packaging materials for finished products, etc., are the main factors that cause it to exceed the standard

it is particularly worth mentioning that a large number of flexible packaging enterprises have completely omitted the important control link of "quality inspection" in the whole production process, and have not configured special detection equipment for detecting the residual odor and purity of solvents at all. As for the elbow detection of "packaging bag odor", it is said that simply judging by experience depends on people's smell. This unscientific way greatly increases the probability of excessive solvents, which will cause great harm to the using enterprises and society. At the beginning of September, an enterprise took the mask bag with serious odor that had been produced to our company and tested it with gc9800 gas chromatograph. The results showed that the benzene content had reached 7Mg/m2, which seriously exceeded the standard, causing odor, causing direct economic losses of millions of yuan to the enterprise (not counting the reprocessing cost of these exceeded standard composite membranes)! Imagine: if the enterprise pays attention to strengthening the quality control of important processes in advance and is equipped with a special gas chromatograph, can this result be avoided

based on the above analysis, it can be concluded that it is completely possible to produce qualified and safe composite packaging with reasonable composite layer structure, reasonable purchase and use of raw materials, correct production process, necessary professional detection equipment - gc9800 gas chromatograph, strict standard detection methods

application of gc9800 gas chromatograph, a professional testing equipment in the field of flexible packaging. The working principle of chromatography is: chromatography with gas as mobile phase and solid as stationary phase. The components to be separated are distributed in the mobile phase and the stationary phase. The chromatographic process is that the sample components are repeatedly adsorbed and desorbed, or dissolved and resolved when passing through the chromatographic column. Due to the different adsorption energy or distribution coefficient of each component, the moving speed along the carrier gas direction is different, and the time of successive washing out from the column is different, so that the components are separated. The components flowing out of the column enter the detector, convert the chemical signals into electrical signals and are recorded to obtain the qualitative and quantitative information of each component

gc9800 gas chromatograph is a high-precision intelligent detection system specially used for accurate and rapid detection of solvent residual content and solvent purity of printed packaging products. It has a series of characteristics such as fast qualitative and quantitative analysis, intuitive comparison performance, accurate and reliable data:

1. It can not only directly display the names of residual solvents of packaging films, such as isopropanol, ethyl acetate, butanone, benzene (toluene, xylene), etc, And without accounting and measurement, it can directly display the residual solvent content of mg/m2 per square meter of the packaging film. The result is intuitive, convenient, and the data is accurate and reliable

2. In addition to detecting the residual solvent content of the packaging film, it can also detect the purity of the solvent used and identify the component characteristics of odorless solvents, such as isopropyl alcohol, ethyl acetate, butanone, benzene (toluene, xylene loading device should also be regularly detected) and other solvents. After chromatographic detection, the content and impurities and other unknown substances can be directly and quickly measured, which can effectively prevent the adulteration of solvents and prevent the use of unqualified products. The detection of gc9800 gas chromatograph can provide an accurate direction for packaging enterprises to effectively adjust the production process and control the solvent exceeding the standard. For example, if benzene exceeds the standard, the process parameters that need to be adjusted in the printing process can be immediately determined to improve the volatilization efficiency of the solvent; If the ethyl ester exceeds the standard, the problems existing in the drying process can be judged and adjusted in time in the process of the experiment; Testing the printing semi-finished products can effectively determine that the solvent volume index in the printing process needs to be replaced after the equipment has operated for a period of time, providing guidance for production quality control. Testing in the compounding process can effectively identify the index of the solvent in the compounding process

through the above detection of gc9800 gas chromatograph, we can judge whether the solvent residue of the composite film for packaging exceeds the standard, whether the production process needs to be re developed, and provide theoretical and technical support for the appropriateness of the substrate used, Fundamentally and comprehensively control the generation of excessive residues (Note: this instrument is supplied by Guangzhou standard international packaging equipment Co., Ltd. - the only one in the domestic supply chain of flexible packaging testing instruments). It is worth mentioning that the representativeness of sampling, the first inspection before compounding and the inspection after ripening are the key factors to be considered when using gc9800 gas chromatograph

gc9800 gas chromatograph is economical and practical, with superior performance and reasonable price. Connected to the chromatographic workstation, the eighth order programmed temperature rise can detect the tested substances more quickly and accurately. There are five detectors for customers to choose to meet different detection fields: FID ionic hydrogen flame detector is used to detect the content of organic compounds; TCD thermal conductivity detector is used to detect and analyze permanent gas, water and low-carbon compounds; FPD flame photometric detector is applicable to the analysis of pesticide residues and sulfur and phosphorus; ECD electron capture detector is applicable to the analysis of chlorine containing solvents in pesticides; NPD nitrogen and phosphorus monitor is suitable for trace nitrogen and phosphorus detection. Guangzhou Biaoji and China Plastics Association jointly promote the rapid development of flexible packaging testing technology. Recently, at the invitation of the professional committee of composite film products of China Plastics Association, Guangzhou Biaoji company attended the annual meeting of the association on behalf of the flexible packaging testing industry, and made a technical discussion entitled "control and detection of residual odor of solvents" in response to the recent focus event of "Gansu food bags and poison bags" that has attracted full attention from all sectors of society. As the only one among many suppliers of testing instruments, it can provide professional testing equipment - GC 9800 gas chromatograph (a high-precision intelligent testing system for professional testing of solvent residue content and solvent purity of printed packaging). The meeting adopted the exchange method of "case combination and mutual consultation". On the social problems caused by excessive solvent residues in the field of flexible packaging, combined with the cases, people deeply analyzed the causes of odor, discussed the selection of printing raw materials, the process control of odor, the treatment technology of odor/and so on, and asked questions from the delegates at the meeting, This paper mainly introduces the detection technology of Guangzhou standard gc9800 gas chromatograph, a professional detection equipment in the flexible packaging industry. After on-site test and demonstration, industry users fully affirmed the performance of this series of gas chromatographs and expressed strong interest in purchasing. In addition, the participants also paid full attention to other products that Guangzhou standard international brought to the exhibition, which can fully meet the relevant testing needs of the flexible packaging industry: back pressure cooking pots, electronic tensile testing machines, friction coefficient testers, solvent moisture testers, water and oxygen permeability testers, heat sealing testers and other testers

(Luo Xiaoyu)

source of information: China Flexible Packaging News

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