Source: Link Testing Instruments Co.,Ltd.
Sterile surgical membrane refers to a medical material made of polyurethane, polyethylene and other films as the base, and coated with medical pressure-sensitive adhesive on its surface. It is used to stick to the surgical site during surgery to prevent skin dandruff that may carry bacteria from diffusing to the surgical wound surface, and to prevent microorganisms in the deep skin around the surgical incision from migrating to the skin surface and spreading to the surgical incision, thereby preventing surgical incision infection. The viscosity of the sterile surgical membrane is an important factor affecting whether it can fully exert the above-mentioned effects. This is because if the viscosity is poor, the sterile surgical membrane cannot fully fit with the skin during the operation, or even separates, which will weaken the sterile surgical membrane's barrier effect on dandruff and microorganisms, or even lose this function, and it will also cause inconvenience to the surgical operation. Therefore, viscosity is an important property of the sterile surgical membrane.
Testing Standard and Test Instruments
The main indicators that characterize the stickiness of sterile surgical membranes are stickiness and peel strength. This article specifically tests the peel strength. This test process is based on the peel strength test in the YY 0852-2011 "Disposable Sterile Surgical Membrane" standard. The test uses the XLW-500N automatic tensile tester as the test equipment to test the samples. The equipment is independently developed and produced by Link Testing Instruments Co., Ltd.
Test principle: The peel strength test is the force required to peel the sterile surgical film from the stainless steel plate. The sterile surgical film sample is pasted on the stainless steel plate. During the test, the unfixed end of the sample and the stainless steel plate are clamped in the upper and lower clamps of the equipment respectively. The upper clamp can move upward, and the lower clamp is fixed. When the upper clamp moves upward at the set speed, it will drive the sample to peel off the surface of the stainless steel plate. The force generated in the process is monitored and recorded in real time by the force sensor configured in the upper clamp. After the test, the peel strength of the sample is calculated and displayed based on the monitored value.
Test samples and test process
Test samples: The test samples used in this test are sterile surgical membranes provided by a certain enterprise. Test process:
(1) After the sample is placed in an environment of 22℃ and 60%RH for 24 hours, 5 samples with a width of 25.0 mm and a length of 400 mm are cut from the surface of the sample.
(2) Take a sample, tear off the protective layer, and immediately stick the sample to the middle part of the stainless steel plate. The length of the pasted sample should be at least 200 mm, and the two sides of the sample should be parallel to the two long sides of the stainless steel plate. Roll the sample along the length direction of the sample 4 times with a roller and place it for 10 minutes.
(3) Clamp the free ends of the sample and the stainless steel plate in the upper and lower clamps of the equipment respectively, set the parameter information such as sample name, sample width, test speed, etc., click the test option, and the test starts. The equipment displays the real-time force value during the sample peeling process and reports the test results after the test.
(4) Test the remaining 4 samples according to the steps in (2) and (3).
Test results and analysis
The test results of the five samples tested this time were 5.314 N/25mm, 6.076N/25mm, 5.904 N/25mm, 5.731N/25mm, and 6.008 N/25mm, respectively. The peel strength of the sample was the average of the test results of the five samples, which was 5.807 N/25mm.
Viscosity has an important influence on the performance of sterile surgical membranes, and peel strength is one of the indicators that reflect the viscosity of sterile surgical membranes. This paper uses a automatic tensile tester to test the peel strength of the sample. The equipment is simple to operate, highly intelligent, and has high test accuracy. The test process data is clear. From the test results, the peel strength of the sample is 5.807 N/25mm, that is, the peeling width of the sample with a force value of 5.807N is required, and the average force required for peeling every 1cm of width is 2.323 N, which meets the standard requirement of not less than 1.0 N.
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