Aseptic medical devices can be produced through final sterilization or sterile processing technology. That is to say, medical device manufacturers provide end users with medical devices that can be used directly without sterilization. The sterility of medical devices is related to the production process, the sterilization process, and the circulation process as well. During the whole circulation process, the packaging bag is an effective barrier to isolate medical devices from the external environment, so maintaining the integrity of the packaging bag is an important measure to prevent secondary pollution of medical devices.
In the process of medical devices circulation, kneading and extruding by external force is inevitable, so the packaging materials should have good flex durability, under the external force the packaging structure maintains intact and no leakage occurs, In this paper, the flex durability of aseptic medical devices packaging bags was tested.
Figure 1 Aseptic medical device Packaging bags examples
In this paper, a plastic composite film used for packaging aseptic medical devices was tested as a sample.
This experiment was conducted conforming to ASTM F392 “Standard practice for conditioning flexible barrier materials for flex durability”.
FDT-02 Flex Durability tester is used as test equipment, which is independently developed and manufactured by Labthink Instruments Co., Ltd.
图2 FDT-02揉搓试验仪
Figure 2 FDT-02 Flex Durability Tester
The testing instrument simulates the flexing effect that medical devices packaging materials may be subjected to in the actual circulation process, flexes the samples horizontally and vertically, and controlling the flex strength of the samples by choosing different flexing modes (different flexing times and different movement schedules). There are two main methods to evaluate the flex durability of samples. One is the method to compare the barrier properties of samples before and after flex, if there is no significant change of the barrier properties, the sample has good flex durability, otherwise the sample has poor flex durability is there is significantly difference in barrier properties before after flex; the other method is to use turpentine oil to analyze the flexed samples. If there are pinholes on the sample, turpentine will leave spots on the white paper. By comparing the number and size of the spots before and after flex, the flex durability of the samples can be obtained. In this paper, the flex durability of the samples was tested by turpentine method.
(1) Cut three 200 mm x 280 mm specimens from the sample material.
(2) Fix three pieces of specimens with pressure-sensitive tape on three workstations of the equipment and fix with clamps; closed the protective cover, selected the test mode and started the test; the equipment begins to flex, and stopped automatically after the set number of times of flex; open the protective cover, remove the clamp, and take off the specimens.
(3) Mark a test area of 150 mm x 200 mm in the middle of the each samples after flex.
(4) Take a piece of white paper and lay it on the test board. Place one specimen on the white paper. Apply the turpentine oil repeatedly on the test area of the specimen. Remove the specimen after 1 minute and observe the size and quantity of red spots on the white paper.
(5) Repeat (4) operation and test the remaining two samples.
In this experiment, C mode was used to knead the samples. One pinhole appeared in each of two specimens, three pinholes appeared in one specimen.
Good integrity and sealing properties of packaging bags is a guarantee to protect the aseptic medical devices from secondary contamination. The integrity of packaging is closely related to the flex durability of packaging materials. In this paper, the flex durability of plastic composite film for packaging aseptic medical devices was tested by measuring the number of pinholes on the surface of the sample after flex. The test process was simple, the equipment was easy to operate and the test results were accurate. Labthink Instruments Co., Ltd, is dedicated to providing customers with packaging testing solutions and helping the manufacturers to reach their goals of quality and safety assurance through improvement of packaging testing techniques and development of high-end packaging testing instruments. For more information please visit www.labthink.com