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 Wysłany: Sob 21:12, 07 Maj 2011 Temat postu: oakley norge Permeability of packaging materials r |
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Permeability of packaging materials and discussion of Test Method
; And Coulometry reasons due to its sensor can only measure the oxygen permeability. 2. Thin, ■ both sides of the-q. Yu-pressure method with the tomb of the test, put some pressure on the side of the film's standard gas. The other side have been drawn into the vacuum, thin film on both sides there is a certain pressure difference, pressure difference of gas permeability will have a greater impact, at this time,[link widoczny dla zalogowanych], the gas molecules in the air pressure difference and concentration difference of the dual role through the film. This situation just like the actual vacuum packaging, and we often see is the packaging container internal and external pressures being equal, with the differential pressure method can not truly simulate the actual transport of these packaging and storage conditions encountered in; and Coulomb Calculated by equal pressure method is used in the film equal to the total pressure on both sides. They are able to better simulate the actual situation 3. Pressure test for gas mixing method, the high-pressure side of the gas must be a single standard and not a mixture of gas, because its sensor can only feel the change in the total gas pressure, gas mixture can not distinguish between a gas partial pressure is much . For example: We want to simulate the actual atmospheric conditions, the 21% oxygen and 79% nitrogen mixture filling high-pressure chamber, oxygen and nitrogen, respectively, penetrate into the low pressure chamber through the membrane, pressure sensors can only feel the general pressure of oxygen and ammonia, but can not measure how much oxygen through to the concrete, which can not be calculated through the amount of oxygen; Coulometry able to easily do this, which can simulate the real atmosphere for oxygen permeability testing. 4. Disheartened by the degree of humidity on the permeability properties of films have a greater impact Coulometry can control the standard gas and carrier gas relative humidity, humidity environment can be simulated to test a variety of oxygen by volume; the pressure law is no such function. 5. Package tiny Wei shame fitness-q. Xingluchaoshi 602 ∞ 0Vd20No. 4 marrow Ⅲ PACKAC4NG packaging container when the product performance requirements are very strict permeability,[link widoczny dla zalogowanych], light permeability test of packaging materials is not enough, the seal must also be taken into account the permeability performance, which requires a whole up to the packaging container permeability testing. Coulometry can be more easily test the permeability of packaging containers, packaging containers will be put the test A a closed loop, can measure the permeability of packaging containers; with the differential pressure method gas permeability test of packaging containers to connect not only more complex pipeline , and because the pressure differential pressure method is to calculate the permeability by measuring the volume of gas, so the permeability properties of the test containers must be accurately calculate the volume of the entire test chamber (including the volume of containers and the connecting pipe of the volume), It is generally difficult, especially for plastic packaging, there is pressure inside and outside the packaging, the volume also can not be accurately calculated, the differential pressure method test equipment is generally not designed to test the packaging container interface. 6. Tuo plot Lian cover in practice, the oxygen through the packaging container to remain in the packaging container, packaging container so the oxygen content increased, the oxygen concentration difference inside and outside the base gradually smaller. Also will be reduced by the amount of oxygen. In theory, differential pressure method can realistically simulate the process to measure food quality,[link widoczny dla zalogowanych], freshness, and Coulometry only change the standard gas mixture of oxygen and ammonia down to measure than the difference in concentration under different The oxygen transmission rate, but can not simulate the gradual accumulation of containers in the process of oxygen. Of course. Because the amount of packaging materials generally low permeability, the product shelf life, shelf life longer. To simulate the whole process, we must invest a lot of manpower, material and time, not an economic, there are ways to save. General packaging materials by measuring the permeability to calculate the amount of food shelf life, shelf, but using this method must be considered when calculating the cumulative oxygen problems. 7. Internal-q. Cicada by Coulometry test. Both sides of the film in the flow of gas. But in reality is a million containers of the general flow. When oxygen through the film came out after the film surface evaporation, the evaporation rate without air will have some impact, of course, because the air is very slow (typically flow 5os), so the effect is weak shake. V. Conclusion The Air Permeability of packaging materials in the above two methods for testing various aspects of research and comparison, can be found: Coulomb oxygen permeability test method, although in some small areas there are shortcomings, but overall, it is more better simulate the packaging container in the storage and transport of the actual situation,[link widoczny dla zalogowanych], and therefore the test results more scientific, more accurate and reliable; pressure test testing theory is simple, although some do not meet the actual situation, but if by actual experience or practice inspection, already know that ventilation reached a target of the packaging materials to meet the food quality, preservation requirements, now the quality control of packaging materials,[link widoczny dla zalogowanych], in which case the differential pressure method or economic and feasible. . .
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