Contact angle measurement of medical surgical masks
一、Background
Medical surgical masks are made of one or more layers of non-woven fabrics. The main production processes include meltblown, spunbond, hot air or acupuncture. Compared with ordinary disposable masks, it has strong resistance to liquids, filtering particles and bacteria.
The face of the mask is divided into inner, middle and outer layers. The inner layer is a skin-friendly material (ordinary sanitary gauze or non-woven fabric), the middle layer is an isolation filter layer (superfine polypropylene fiber meltblown material layer), and the outer layer is a special material. Bacteriostatic layer (non-woven or ultra-thin polypropylene meltblown material layer). Medical surgical masks have a medium protection level and have certain respiratory protection performance.
The reuse of masks is imminent. Is the traditional method of alcohol disinfection and water washing feasible?
By using a contact angle measuring instrument to compare the contact angle of the mask, and tell everyone through scientific experimental data, is the reused mask reliable?
二、Experimental method
Divide the untreated disposable medical nursing mask into four pieces and test 2-3 points per piece:
The first piece: untreated disposable medical nursing mask
Second piece: Disposable medical nursing mask soaked in 75% alcohol for 1 hour to dry
The third piece: Disposable medical nursing mask after soaking in 84 disinfectant for 1 hour and drying
Fourth piece: Disposable medical nursing mask after soaking in ordinary pure water for 1 hour and drying
三、Experimental results
By measuring the contact angle of four pieces of samples, each piece of material was measured 5 times in parallel to obtain data for analysis.
The sealing performance of the mask depends on the hydrophilic and hydrophobic properties of the material. The simple verification method is to take a new mask and add water to it to see if it leaks. The mask with super-hydrophobicity (contact angle of more than 120 degrees) will not leak at all, thus effectively blocking the introduction of droplets (viruses) and achieving better results. protective performance.
Test results: After soaking in alcohol, soaking in 84 disinfectant, and drying the mask material treated with pure water, the middle layer is melt-blown non-woven fabric, and the contact angle between the middle layer or the outer layer material and water has not changed much. , still has good hydrophobicity. From this, it can be inferred that with the increase of the use time of the mask, the exhaled air will have a certain influence on the hydrophobicity of the mask, and the contact angle with water will decrease, but it still has a good hydrophobic effect.
