【Abstract】 The paper introduces the importance of packaging aging test, classification, basis and methods, the actual operation of the concerns and results evaluation.
Packaging aging test
1. The importance of aging tests
Aging test is also an important project to consider in the MDSP die-cutting stamping indentation, because for medical devices such products with high security requirements, the aging test is related to the guarantee of product validity, and therefore can not be ignored, and aging The concluding report of the trial can also be submitted to the relevant agencies for review, such as the European Union's CE certification or FDA 510K application materials, is the product validity statement of a supporting document.
In the ANSI / AAMI / ISO 11607 standard before and after several versions, there has been such a very clear statement: "The manufacturer should be responsible for the proof, the final product packaging in the long-term circulation and storage process, as long as the packaging is not Damaged or unopened, and in the storage conditions specified by the manufacturer of the paper, the product marked the validity of its packaging should remain intact, "This is the product of aging test the most authoritative standards based on the. However, this standard is, after all, a general standard, but referred to the aging test should be to ensure the validity of the product validity, but did not mention how the details of the aging test.
In fact, a very scientific point of view to analyze over-aging packaging test, is not difficult to find this test is actually a systematic, complex and long-term sample environment adjustment process, which with the provisions of ASTM D4332 test sample adjustment process in those Is essentially the same, that is, the sample in a specific environment, after a certain period of time to adjust, and then to these specific environmental regulation of the sample the necessary physical, chemical, biological and mechanical properties of the test, to prove that the sample Whether the environmental regulation before and after the existence of various types of performance differences. If a simple words to summarize the aging test, then excessive packaging, should be: aging test is a long, systematic and does not involve the product performance test of the environmental regulation process. rubber products
2. Classification of aging test
Aging test according to the nature of different, can be divided into real aging test (Real Time Aging Testing) and accelerated aging test (Accelerated Aging Testing). As the name suggests, the former is in the normal temperature environment, or in the product is expected to flow under the storage environment, until the design expiration date packaging and decorating, packaging and then complete the product out to do the relevant performance tests, and to this performance The results of the test with the aging test samples before the performance test results were compared in order to determine whether the validity of the product design is reasonable. The accelerated aging test is designed to design a specific aging test environment, which greatly shorten the usually very long duration of the aging test, this specific environment and the shortening of the time there is a correlation between the ratio.
It can be seen wine packaging, real aging test is very simple, but the time required is very long, may not be suitable for fierce competition in the market requirements of the timeliness, it is often used to accelerate the aging test. But the real aging test is essential, because it is the result of the most accurate and authoritative Han Guanhua, and accelerated aging test results is only a transition, when the real aging test results come out, the final reference to the real aging test results. The focus of this paper is a relatively complex accelerated aging test.
3. Accelerated aging test basis and method
Before the MDSP Accelerated Aging Test, I would like to make the following statement: This is a fuzzy science digital printing post-processing, because the test itself involves chemical reactions are too complex, and its theoretical basis so far can not get scientific authority Confirmed. Process
The MDSP Accelerated Aging Test is based on ASTM F1980, the ASTM F1980, a working group under ASTM F02.60 (F02 is a working group on ASTM standards for flexible packaging and 60 is a member of the F02 Working Group A sub-working group on MDSP), a standard developed specifically for the MDSP Accelerated Aging Test, which currently has two versions of activity, the original May 1999 edition and the January 2002 edition, updated three years later . ASTM F1980 is also the first officially published guidance on how to carry out MDSP accelerated aging test of the standard, which accelerated the development of accelerated aging test should be regarded as a big step forward. Of course, this is not to say that there is no standard or plan for accelerating the aging test until the standard is introduced, although some methods are not systematic or common.
ASTM F1980 includes guidance on how to prepare packaging accelerated aging test program, as well as a number of related information such as statements and statements packaging trade, but does not involve real aging test program and some specific test methods to determine the performance of the product packaging.
ASTM F1980 explicitly refers to the theoretical basis for the accelerated aging test described in Section 6.3 of Section 6 of the Accelerated Aging Test, which is based on the Arrhenius reaction rate law assuming that the chemical reactions of the material deteriorate. This law stipulates that a single process to increase or decrease the temperature 10 ℃, the chemical reaction to accelerate the proportion of factor Q10 corresponding to an increase or decrease of about doubled. Of course, there are some information behind this theory need to understand the contents of folding, such as packaging materials will always be affected by external environmental factors; such as to accurately determine the Arrhenius theory to accelerate the scaling factor Q10 is a very complex process, the need for material reaction dynamics Learning model, so in the MDSP in the general use of more conservative Q10 values, such as 2.0. MAN Roland
Here, the author will not elaborate on this complex Arrhenius theory of the vendor information, only gives a simple calculation method of the case for the reader to learn.
As the Arrhenius theory says, "a temperature change of 10 ° C will result in a doubling of the chemical reaction rate", so the Accelerated Aging Rate (AAR) is calculated as:
AAR = Q10 (Te - Ta) / 10
Where Te is the test controlled ambient temperature and Ta is the ambient temperature.
Thus, the Accelerated Aging Time Duration (AATD) should be:
AATD = Desired Real Time / AAR
Here, AATD is the accelerated aging test duration for the corresponding validity period. For example, packaging logistics, if the product design is valid for 3 years, the normal ambient temperature is 22 ℃, and the predetermined accelerated aging test environment temperature is 55 ℃, accelerated aging factor Q10 take 2.0, the AAR is calculated as follows:
AAR = 2.0 (55-22) / 10 = 9.85
The test time for the aging test is 1 year
AATD = 365 days / 9.85 = 37.06 days
AATD is 38 days / year (Note: When calculating the case of a decimal point plus 1 rounding)
So the variable data printing, simulation 3 years of aging test test time is 38 × 3 = 114 days.
In the actual accelerated aging test should pay attention to the following issues related to accelerated aging theory:
(1) When the aging test environment temperature exceeds 50 ℃ three-dimensional printing, the reaction rate and the temperature may no longer be a linear relationship, which is why the aging temperature can not be too high. Of course, if the aging temperature is set too low, and the actual aging test is almost, so the general case of the ticket printing, in order to balance the duration of the aging test and the relationship between chemical reaction stability, accelerated aging test temperature is usually set at 55 ℃, which is the author access to many foreign literature to the conclusion, ASTM F1980 recommended not to exceed 60 ℃.
(2) As mentioned earlier, the accelerated aging test is a fuzzy scientific publishing dynamics, and contains a variety of chemical composition of the packaging materials in the accelerated aging process of the reaction rate may also be diversified, but the actual operation is one-size-fits-all , Only assume that Q10 is 2.0.
(3) Excessive test temperature will cause packaging materials appear at room temperature can not be the problem, resulting in aging test is unconventional and is difficult to predict the failure, which is accelerated aging test temperature can not exceed 60 ℃ reasons one.
(4) There is no published authoritative scientific literature to prove that aging test theory is effective for packaging materials. Of course, digital presses, since the ASTM can publish the relevant standards, but also fully demonstrated that although the MDSP accelerated aging test theory can not be scientifically fully proved, but in actual industrial production operations, MDSP accelerated aging test results are reliable, or at least Is a reference value. High-fidelity printing
Accelerated aging test method is not the only three-dimensional printing, the author access to information in the process also found that some of the existing products for the specific test environment is also different, if the temperature 40 ℃, 60% humidity two weeks , A temperature of 70 ℃, humidity 15% and 85% alternating environment for two weeks, a temperature of 60 ℃, 80% humidity environment, a week of metal packaging, but these methods can not find a theoretical basis, may be more And the product and its expected circulation process is highly targeted, which is of little reference value to the accelerated aging test of MDSP.
4. Accelerated aging test in the practical operation of the concerns
MDSP Accelerated Aging Test is also very practical in practice, which means that not read a complete ASTM F1980 will be able to understand how to correctly carry out the specific operation of the accelerated aging test cutting, the following are worthwhile in practice Focus on the operation:
(1) Prior to the accelerated aging test, a written test plan signed by the responsible person must be provided detailing how the test is to be carried out.
(2) test equipment and equipment used in the calibration parameters to be recorded and recorded.
(3) It is useful to understand the trend of this aging effect when depicting the aging properties of materials and packaging, as this will allow the test designer to detect the point in time when the problem is occurring and take action to remedy the organization / Rather than wasting a lot of manpower and material costs but only get a conclusive report of the failure of the trial. Therefore, although the minimum number of time points required for the accelerated aging test can be set as long as one (except for the zero time point test), that is, the expected expiration date of the product. But in practice, often set up three test time points, in order to grasp the aging trend. For example, the product design is valid for 3 years ink balance, you can consider setting 6,12,24 and 36 months of these four accelerated aging test simulation test point. Lithographic printing
(4) The initial, sterilized and accelerated aging packaging samples can be replaced without products or simulated products. It is of course best to use the final complete product. Although the cost is high, the test results can best simulate the actual situation. And therefore the most authoritative, credible; of course, ink, in some cases may have to use the final complete product for testing.
(5) Process-proven samples should be selected for aging tests, since such samples are most reliable and are continuous and stable. And if you can not ensure continuous quality and stability of the sample to do the aging test, the time required to test the cost may not be affordable for each business.
(6) Sample sterilization should be performed using a validated sterilization procedure, since the sterilization process may affect the stability of the packaging material or system. Inkjet printing should therefore be used in the most severe sterilization conditions, including the worst sterilization parameters And the number of sterilization increased in two cases.
(7) Although the Arrhenius theory itself does not mention the role of humidity in accelerating chemical reactions, it should be considered in conjunction with packaging materials and product characteristics. Accelerated aging tests should take into account the effect of humidity, that is, Inside.
(8) Accelerated aging test samples can not be immediately completed the performance test Prepress process, should refer to ASTM D4332 sample adjustment, generally in the conventional environment, namely, temperature (23 ± 2) ℃, humidity 50% ± 5 % Of the environment, 24 hours; combined with the actual situation, some of the samples also need to carry the transport test, transport test program should refer to ISTA (International Safety Transit Association lithography, International Transport Safety Association) series of test programs suitable for, and for The transport test sample must be a complete sample. color
(9) The packaging performance of the samples after the accelerated aging test should be evaluated against the performance requirements of the original packaging and a conclusion as to whether the samples are acceptable after the accelerated aging test.
5. Accelerated aging test results evaluation
Finally, the remaining question may be how to conduct the accelerated aging test results of the assessment, the results of the assessment of the existence of the following two situations:
(1) If the accelerated aging test results meet the acceptance criteria, the validity of the product will depend on the results of the actual aging test CTP, which is in line with the expected conventional situation.
(2) If the accelerated aging test results do not meet the acceptance criteria, then the following two options: The first is to investigate the production process of packaging products, redesign the product or packaging, try to verify a shorter product validity; Test results, if the real aging test results through the color sequence, then in this case, we can only prove that the design of accelerated aging test more stringent than the actual situation and conservative.
The true aging test results also have the same pattern of assessment problems: if the actual aging test results meet the acceptance criteria, then the packaging is validated; if the true aging test results do not meet the acceptance criteria, the shelf life must be reduced to the real aging test has been The longest time, which is mentioned earlier in the aging test to set a few more time points to grasp the importance of the trend of aging test. If the product has been placed on the market in accordance with the accelerated aging test data at risk (ie where the accelerated aging test has not passed the prepress process and the real aging test has not been carried out), a careful review and evidence collection must be carried out and appropriate Remedial measures to circumvent the relevant market risk.