Research On Ice Repellency Of Fabrics

In this paper,the anti-icing properties of fabrics were defined,the anti-icing mechanism of fabrics was discussed,and four anti-icing theories(hydrophobic anti-icing theory,smoothing anti-icing theory,melt promotion anti-icing theory and hydrophobic-melt promotion anti-icing theory)were adopted to explain the concept of anti-icing properties of fabrics.An anti-icing performance of fabrics testing system was designed,which was composed of a device for testing the de-icing time and a device for testing the freezing adhesive strength between the ice and the fabrics.This testing system solved the problem that there was no test method for testing the anti-icing performance of flexible materials.By analyzing the data obtained from the test,the anti-icing performance of the fabric samples can be evaluated comprehensively.A numerical simulation method for evaluating the anti-icing properties of materials was presented.The effect of the thermal conductivity and the permittivity of fabrics on the ease of ice removal performance of materials was studied,and a device for testing the melting rate of ice on the surface of fabrics was developed independently.Two equations describing the relationship between the thermal conductivity and the permittivity of woven or knitted fabrics and the melting rate of ice on their surface were derived by experimental test and mathematical method.A simulation analysis method for evaluating the anti-icing properties of materials was presented.The hydrophobic-melting promoting anti-icing theory was put forward and verified by experiment and test.Based on the melting promoting anti-icing theory,an experimental simulation model for simulating the melting process of ice on the surface of woven fabrics was established,and the credibility of the model was systematically tested by the comprehensive method of theoretical analysis,experimental observation and error analysis.Based on the research above,a fabric anti-icing finishing technology was developed,which was applied in the preparation of anti-icing firefighter clothing fabrics,and a kind of anti-icing coated fabric was developed.The properties of the samples were analyzed by using various experimental instruments such as a fabric freezing adhesive strength tester,a fabric de-icing time tester,a melting rate tester,a scanning electron microscope(SEM),a thermal constant analyzer,a thermal protective performance tester(TPP),a dielectric constant instrument,a video optical contact angle measuring instrument,an universal material testing machine,a horizontal burning test box,a chemical permeation tester,etc.Results show that,the fabric anti-icing performance evaluation system can evaluate the anti-icing properties of fabrics accurately,directly and systematically.When x values in[0.17,240]W/m·K,the relationship between x and the melting rate(MR)of the ice on the surface of the fabric samples is MR(x)=0.907×x^0.3108+4.641.When y values in[0,155.67]U[446.02,588.27],the relationship between y and MR is MR(y)=20.25×sin(0.004161×y-0.4794)+13.27×sin(0.006534×y+1.797)+1.554×sin(0.02484×y+1.97),When y values in[86.68,446.02],the relationship between y and MR is MR(x)=-3.694e5×x^-2.754+7.329.For materials with a higher thermal conductivity than water,hydrophobic treatment can effectively promote the melting of ice on their surface,improving their anti-icing performance.The experimental simulation model for simulating the melting process of ice on the surface of woven fabrics can obtain the phase transition and temperature variation of the ice,which is helpful for studying the anti-icing performance of the samples.Compared to the untreated fabric samples,the freezing adhesive strength between the anti-icing coated fabric and the ice on its surface was reduced by 60%/94%(tangential/normal),and the melting time was reduced by65%/92%(tangential/normal).