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Food flexible packaging material mainly include polyethylene, polypropylene, polyester, polyamide and other polymers. These packaging materials by the molecular structure and molding process and adding different additives showed a larger difference. For food manufacturers, therefore, choose a suitable for their products packaging materials is particularly important, can appear otherwise problem such as food safety.
In order to keep the food fresh in the process of circulation and provide consumers with safety and health ", must be conducted for food packaging safety inspection. We are food packaging performance requirements are:
(1) solvent residual
Packaging molding generally need blow molding, printing, composite, such as process, to improve the optimum printing to speed up the printing speed, usually add some solvent, solvent residue after "lanzhou event" has increasingly become the focus of packaging safety. Solvent residue of national standard to less than 10 mg/m2, enterprise standards are generally higher than the national standard is less than 7 mg/m2, total for the solvent residues can use gas chromatograph for testing control.
(2) the blocking performance
Barrier property including to cut off gas and water blocking, bad food has a great part of the reason is because of the selected material blocking performance is not appropriate. The choice of material according to different folded, shelf-life, storage condition etc. Choose the appropriate block material. GB19741 that was introduced at the end of 2005-2005 (liquid food packaging plastic composite film, packaging standards for packaging film barrier property is put forward by GB/T1038 (plastic membrane permeability test method) and GB/T1037 (plastic film and sheet of water vapour permeability test method) for testing. Because the material barrier property testing technology is difficult, independent development ability of the nation's only jinan lincom mechanical and electrical technology co., LTD.
(3) the tensile properties
Mechanical strain in the process of packaging film, also will be affected by external force such as extrusion, in the process of transportation which requires the film must have enough tensile strength. For composite membrane should guarantee the membrane interlayer stratification, which requires the composite membrane has high peel strength, so as to avoid material stratification. Can choose electronic tensile machine to control the tensile properties and stripping performance.
(4) the film smooth
Membrane surface should be good smooth, to ensure that its high-speed packaging, should be based on GB10006 (plastic film and sheet friction coefficient determination method), general requirements of film on the surface of the friction coefficient between 0.2 to 0.4. Here should pay special attention to is that with the increase of temperature, the surface of the material performance will have great changes, can use FPT - F1 / stripping tester to determine the friction coefficient is very temperature (room temperature is 99.9 ��) under the activity coefficient of friction materials.
(5) heat sealing performance
Modern filling machine filling speed more and more high, the sealing process is easier to seal, virtual seal leakage, stick head, wire drawing, sealing burst, this request before for automatic packing of heat sealing temperature of the heat sealing machine, heat sealing time, heat sealing pressure necessary test validation, improve efficiency, avoid waste. It is important to note that most of the filling line from seal to filling the process time is shorter, at this time of the sealing temperature down to room temperature, low intensity, easy to leak. So the strength of hot glue sealing strength (high temperature) to predict for the filling process is particularly important, can choose HTTP - T1 heat sealing tensile testing machine to solve the above problems.
(6) ink performance
Food packaging film in addition to the general to the requirement of printing ink and substrate adhesion strength, abrasion resistance, but also be able to deal with the request, sterilization and water resistance, frost resistance and heat resistance in order to make sure not happen in the process of transportation, storage, printing ink, the phenomenon such as condensation. According to GB7707 used printing fastness testing machine for testing.
For food safety, general administration of quality supervision, inspection and quarantine in 2005 on food packaging mandatory product certification management system (i.e., 3 c certification), products must be after inspection qualified can be put on the market. Therefore, the author suggested that the packaging products and food manufacturers, food packaging materials testing must be carried out, and have an independent development ability of choosing a specializing in the production of packaging testing instrument of well-known enterprises.