primary wound dressing should have proper water vapor and gas transmission properties, so as to form an environment of high humidity, slight acid and low oxygen, and promote speedy healing. Thus, water vapor transmission rate of primary wound dressings is a key index for manufacturers.

1. Water Vapor Transmission Rate (WVTR) Testing for Primary Wound Dressing
Abstract: primary wound dressing should have proper water vapor and gas transmission properties, so as to form an
environment of high humidity, slight acid and low oxygen, and promote speedy healing. Thus, water vapor transmission rate of
primary wound dressings is a key index for manufacturers.
Keywords: primary wound dressings, water vapor transmission rate, WVTR, water vapor transmission rate tester, Labthink
Exposed wound needs dressing as a protective means to form favorable environment for healing and revival. The healing of
the wound is an important premise for convalescence. With the remarkable development of modern science and technology
and the introduction of multifunctional products, primary wound dressing has been developed to replace the existing swab
dressing which only functions as the covering for wounds. The new primary wound dressing can meet modern clinical
demands, protecting wounds, promoting organic revival, accelerating healing. Primary wound dressing also acts as germicide.
Qualified primary wound dressing should have proper water vapor and gas transmission properties so as to form a favorable
environment for speedy healing: high humidity, slight acid and low oxygen. Thus, water vapor transmission rate (WVTR) is a
key index for manufacturers. Hereafter, the article will introduce water vapor transmission rate (WVTR) testing for primary
wound dressings with the help of Labthink W3/060 Water Vapor Permeability Tester.
1. Significance of Water Vapor Transmission Rate Testing (WVTR) for Primary Wound Dressing
Skin is the guard for internal stability and screening against external microorganism. Many infected cases are related to the
functional loss of skin. The earlier the primary wound dressing applies, the less the infection would be caused. With the help
of primary wound dressing, severe wounds can be better healed. If water vapor transmission rate of primary wound dressing
is too high, a humid environment could not be created. On the contrary, if the rate is too low, normal metabolism would be
influenced. Therefore, water vapor transmission rate should be regulated within a proper range.
2. Testing Method for Water Vapor Transmission Rate of Primary Wound Dressing
Testing method of water vapor transmission rate for primary wound dressing refers to YY/T0471.2, Test Methods for Primary
Wound Dressings—Part 2: Moisture Vapour Transmission Rate of Permeable Film Dressings. Humidity difference is formed
between the two sides of the sample at a certain temperature. Then, water vapor permeates through the sample and into the
dry side. Water vapor transmission rate can be determined by measuring the weight changes of the weighing cup. Labthink
water vapor transmission rate tester applies highly precise weighing sensor, so as to improve testing accuracy and shorten the
time for determination of permeation equilibrium as well as the thorough testing time. Meanwhile, the instrument integrates
temperature and humidity control technologies, weighing technologies and computer control technologies in one, so as to
realize testing without human interference and external influence. The precise testing results can completely satisfy testing

2. demands for water vapor transmission rate through high barrier materials, such as aluminum foil, etc. Besides, there are
several instrumental options, namely single cell, three-cell, six-cell or twelve-cell instruments to meet the needs of different
customers.
When water vapor transmission rate of primary wound dressing is qualified, other indexes, including gas transmission rate,
mechanical strength and histocompatibility of it should be evaluated, so as to guarantee quality and properness for usage.
More information, please visit: www.labthink.cn
Yarina Gao
Marketing Department
Email: trade5@labthink.cn
Tel: 86-531-85060139
www.labthink.cn/en