Water Vapor Transmission Testing of Scar Plaster

1.Instrument
  W3/030 Water Vapor Transmission Rate Tester
2.Specimen

Fig.1 Scar Plaster

3.Introduction to Testing Operation
Scar plaster, also called silica gel plaster, is manufactured with new medical polymer materials. It can effectively reduce, soften and help eliminate the scars. The mechanism of scar plaster is as follows: Firstly, its high oxygen transmission rate guarantees the normal breath of our skin. Secondly, the water vapor transmission rate is lower than the human skin, so as to preserve moisture inside the cuticle. Once the skin absorbs the moisture, the reproduction of capillary vessels is restrained and the accumulation of collagen is reduced. Meanwhile, water soluble protein and its products are spread quickly, that can help reduce, soften and eliminate the scars, as well as restrain itching and hurting feelings. Therefore, it’s an important index to carry out water vapor transmission rate testing of scar plaster.
The thickness of the scar plaster to be tested is 3mm. The front side, (side towards skin), has two pieces of protection film with patterns (as shown in Fig. 2). The back side, (side opposites to the skin), is a layer of transparent protection film (as shown in Fig. 3). When testing, take off the protection film of the front side. Since scar plaster is quite thick, customized water vapor transmission cup is needed. 

4. Testing Process
4.1 Testing Environment
Place: Labthink Permeability Lab
Temperature: 38℃
Relative Humidity: 90%RH
4.2 Testing Procedure
First, prepare specimen as regulated (Fig. 5); and peel off the protection film on the front side; then, clamp the specimen into the water vapor transmission cup. Second, place the cup onto the frame inside instrument; set the testing parameters and start testing (Fig. 7). Third, test ends automatically, and the results are displayed in the software. 

4.3 Testing Results
Scar Plaster      Water Vapor Transmission Quantity       19.463 g/(m2·24h)