Designing Fabric Imitating Stomata Of Plant Leaves And Study On Its Moisture Dissipation

With the increasing demand of people for leisure sports clothing,comfort has gradually become the first demand of consumers for clothing,especially thermal-wet comfort,and the current fabric can not meet the demand of thermal-wet comfort.Especially when the human body sweats a lot,it not only affects the heat balance,but also affects the skin tactile system,and seriously affects the thermal and wet comfort of clothing.This is because the current fabric has a better water conduction function,but it does not have the ability of rapid moisture dissipation.The thermal-wet comfort of fabrics is often affected by "moisture absorption,moisture conduction and moisture dissipation".However,the current research focuses on improving the moisture absorption and moisture conduction of fabrics to improve the thermal-wet comfort of fabrics from the stages of fiber,yarn,fabric and finishing.It also develops from bionics to imitate the tree branch structure to improve the moisture transport performance of fabrics,while for the moisture dissipation mechanism research has been in a state of scarcity,which was why fabrics cannot meet the needs of thermal-wet comfort.Based on the similarity of fabric moisture dissipation process and leaf stomatal transpiration process,in this paper,plant leaf stomatal structure was applied to fabric and its moisture dissipation was studied.First of all,the main reason of the high-speed transpiration rate of stomata is the special stomata and its lower cavity structure in the leaves.This structure was simplified to form a simplified model,and then the corresponding fabric model was formed.Its characteristics are that the surface layer of the fabric has a hole for diffusing moisture,the inner layer of the fabric has a cavity for transpiration moisture corresponding to the surface hole,and the outer and inner layers have a channel for dissipating moisture.According to the characteristics of the model,the suitable structure was found,and the fabric design of imitating the stomata of plant leaves was carried out.In order to study the moisture dissipation of bionic fabrics,several kinds of single-layer fabrics and bionic fabrics were prepared and tested.This test method is different from the traditional test method.It is to control the moisture content of fabrics by changing the height of the floating plate to give the fabrics different dynamic equilibrium states of absorption,conduction and dissipation,and then affect the moisture dissipation rate of fabrics.Then measure the evaporation per unit area and per unit time,this method simulates the skin multi-point and continuous sweating,more consistent with the actual situation.The experimental results show that when the moisture content of the fabric is low,the moisture dissipation of the bionic structure fabric is equivalent to that of the ordinary single-layer fabric,while when the moisture content of the fabric is high,the bionic structure shows better moisture dissipation.And the more the moisture content,the better the moisture dissipation of bionic structure,but the moisture content is too much,which has a blocking effect on the moisture dissipation.Secondly,due to the difference between bionic structure and ordinary fabric structure,the relationship between fabric structure parameters and bionic structure parameters was established firstly,and then the bionic structure parameters were changed by changing fabric structure parameters.Yarn material affects moisture content and moisture conduction gradient.Fabric density affects the size of the hole and the cavity.The connection mode,i.e.the number of joints affects the depth of the cavity.The size of the hole affects the hole area,and the size and depth of the cavity jointly affect the surface area of the cavity.Therefore,three factors and three levels of orthogonal experiment were used to analyze the influence degree of the three factors on the moisture dissipation property of the fabric,and the optimal scheme was found out.The experimental results show that the surface layer of polyester and inner layer of cotton has the best moisture dissipation.The increase of hole area is conducive to the diffusion of wet gas.The influence of cavity depth on the moisture dissipation performance has two aspects.On the one hand,the deeper the depth,the larger the actual exposed area.On the other hand,for deep and steep pit,it is difficult for the bottom wet air to convection,and the water vapor will become the boundary layer still at the pit bottom,which is not conducive to the continuous evaporation of liquid water and the reduction of the moisture dissipation performance.The larger the cavity size and the deeper the cavity depth,the larger the surface area of the cavity,the larger the liquid air contact area in the cavity,the larger the evaporation area is,and the better the moisture dissipation is.However,if the depth of the cavity is too deep,even if the surface area of the cavity is increased,the influence on the moisture dissipation will be a side effect.Based on the bionics,this paper designed and prepared the fabric imitating the stoma of plant leaves,which met the design requirements.Then studied the moisture dissipation of the bionic structure fabric,which was proved to be more suitable for a large amount of perspiration by the comparative test.And analyzed the influence of different bionic structure parameters on the moisture dissipation,it provided a certain experimental basis for other researchers to study the moisture dissipation of fabric and develop the fabric.