Abstract: Three specifications of stainless steel ultra fine wire (diameter: 0.03mm, 0.040mm and 0.05mm) and cotton yarn were twisted into composite yarns.The functional fabrics were woven by cotton yarn as warp,both cotton and the composite yarn as weft.The fabric performances wire tested after weaving and some treatments, especially the anti-static and ant-radiation properties.
Research on the properties of Fabrics Containing Stainless Steel Ultra Fine Wire
Abstract: Three specifications of stainless steel ultra fine wire (diameter: 0.03mm, 0.040mm and 0.05mm) and cotton yarn were twisted into composite yarns.The functional fabrics were woven by cotton yarn as warp,both cotton and the composite yarn as weft.The fabric performances wire tested after weaving and some treatments, especially the anti-static and ant-radiation properties. The results showed that these fabrics had a good anti-radiation ability. So there functional fabrics have good application prospects in protective clothing and technical textiles.
In the past 20 years, stainless steel metal fibers and their products have emerged as new industrial materials and high-tech products with high added value. They possess the flexibility of chemical fibers and synthetic fiber products, as well as the excellent thermal conductivity, corrosion resistance, and high temperature resistance of metals. They have been widely used in fields such as textiles. The stainless steel metal wire fabric, with its permanent anti-static and radiation protection properties, has become a highlight in functional fabrics.
Textile stainless steel metal wire is made from stainless steel such as 304, 304L, 316, 316L as the substrate, processed by special techniques into extremely fine metal wires. The finest diameter can reach 2 micrometers, and the flexibility of stainless steel ultra fine wire with a general diameter of 8 micrometers is equivalent to that of flax fibers with a diameter of 13 micrometers. The production of stainless steel metal wire involves many scientific fields such as physics, chemistry, and material processing. Due to considerations of economic interests, there are few reports on the production technology of stainless steel fibers, especially the research results on the influence of composition and processing technology on product performance.
This experiment utilized three specifications of stainless steel ultra fine wire, 0.035mm, 0.04mm, and 0.05mm, combined with 15.6tex cotton yarn at a twist of 53T/10cm to produce stainless steel composite yarn. Plain weave fabrics were woven with two or three cotton yarns alternately inserted in the warp direction. Additionally, fabric samples were woven with stainless steel composite yarns added in both the warp and weft directions. After a series of post-processing treatments such as singeing, mercerizing, bleaching, and setting, the antistatic and radiation-resistant properties of the stainless steel ultra fine wire fabric were investigated.
Preparation of Fabric Containing Stainless Steel Ultra Fine Wires
1.1 Introduction to Stainless Steel Ultra Fine Wires
Stainless steel ultra-fine wires refer to stainless steel metal wires that, after bundle drawing, do not require a drafting process and are directly used in single-wire form. These ultra-fine wires are combined with other yarns for weaving, or used as the core yarn to produce wrapped yarns. Based on functional requirements, different specifications of stainless steel ultra-fine wires are selected, and the amount of insertion in the warp and weft directions, as well as the tightness in both directions, are adjusted. Suitable post-processing steps are chosen to produce fabrics containing stainless steel ultra-fine wires. With fewer drawing operations and no drafting process, and without the problem of poor cohesion that arises from blending stainless steel fibers, it is easier to control the weaving process, and the performance is better than that of fabrics woven with blended stainless steel short fibers.
The specifications of the stainless steel ultra-fine wires used in the experiment are shown in Table 1.
|
Diameter mm |
Length Km/kg |
Tolerance mm |
Tensile strength N/mm² |
Min elongation % |
||
|
304 |
316L |
304 |
316L |
|||
|
0.035 |
130.25 |
±0.0015 |
610~720 |
680~770 |
11 |
23 |
|
0.040 |
99.72 |
±0.0020 |
755~884 |
700~765 |
16 |
25 |
|
0.050 |
63.82 |
±0.0020 |
755~884 |
700~765 |
16 |
25 |
1.2 Preparation of Stainless Steel Composite Yarn
The 0.035mm, 0.040mm, and 0.050mm specifications of stainless steel ultra-fine wires are combined with cotton yarn at processing speeds controlled between 10 to 15m/min and twist levels controlled below 55T/10cm. Stainless steel wire spools with larger angles are selected to facilitate unwinding. If necessary, the stainless steel wire spools can be pre-soaked in soapy water to increase lubrication and reduce damage to the stainless steel ultra-fine wires during compounding, especially for the 0.035mm ultra-fine wire with relatively low breaking strength. The method of wrapping or core-spinning is not employed here. Firstly, it is to facilitate the processing of stainless steel ultra-fine wires and cotton yarn, making the process relatively simple and easy to control, thus improving production efficiency. Secondly, it provides better overall performance. While wrapped yarn requires a significantly larger amount of stainless steel ultra-fine wires, and though core-spun yarn requires a similar amount, their conductivity and microwave protection effectiveness are inferior to that of composite yarn.
1.3Anti-static Performance of Fabrics Containing Stainless Steel Ultra-fine wire
Comparing the methods and standards suitable for testing the static electricity performance of fabrics containing conductive fibers in the current national and industry standards of the textile industry, this experiment employs the charge density method for measurement [351].
The experimental setup consists of an electric potential measurement device composed of a rubbing cloth, rubbing rod, padding, insulating plate, Faraday cylinder, capacitor, and voltmeter. Three samples each of warp and weft direction with dimensions of 25cmx35cm are tested.
Experimental results are presented in Table 4.
Table 4 The amount of charge in the fabric
|
Specimen number |
|
1 |
2 |
3 |
4 |
5 |
6 |
|
Qty of charge/(10-3μC/m²) |
longitude |
16.37 |
18.43 |
16.42 |
17.62 |
34.18 |
27.78 |
|
Weft |
16.37 |
36.87 |
16.42 |
17.62 |
34.18 |
37.04 |
|
|
Average |
16.37 |
27.65 |
16.42 |
17.62 |
34.18 |
32.41 |
From Table 4, it can be observed that due to the presence of stainless steel ultra-fine wire, the charges in the fabric are rapidly discharged, resulting in a significantly lower charge quantity compared to the 570.6uC/m² charge quantity measured in the experiment with pure polyester. This indicates a significant anti-static effect.
Theoretically, stainless steel ultra-fine wire act as continuous conductors within the yarn, with a resistance of only 10^-3 to 10^-Ω·cm for 0.035mm stainless steel ultra-fine wire. Under normal external forces, the resistance does not change, and it decreases gradually with increasing diameter. However, experimental results show that there is no decreasing trend in fabric charge quantity with decreasing resistance of stainless steel wires. Instead, the charge quantity increases with the increase in the percentage of stainless steel ultra-fine wire, which is related to the blending of yarns in the fabric and the twist level of the stainless steel composite yarn.
During the testing process, the presence of many interlacing points in the plain weave structure, varying yarn lengths, and frequent yarn bending, as well as instances where the stainless steel ultra-fine wire are positioned on the reverse side of the fabric, can all lead to inadequate contact between the rubbing rod and the stainless steel ultra-fine wire. These factors have a certain impact on the test results.
3. Radiation Protection Performance of Fabrics Containing Stainless Steel Ultra-fine wire
The radiation frequencies of typical household appliances are above 30MHz, with the frequency of color TVs ranging from 68 to 300MHz, and the radiation frequency of computers and mobile phones around 1000MHz, with the screen being the area of highest radiation intensity [6]. For the convenience and authenticity of this experiment, a computer is selected as the radiation source. The sample size is 50cmx50cm. The monitor is adjusted to its brightest state and positioned vertically to the plane. After setting up the test equipment, the person stands 30cm away from the test equipment to avoid interfering with the test results, and the readings are taken once the test instrument stabilizes. The instrument used is the JJD-1 electromagnetic radiation tester [78], with a testing frequency range of 50Hz to 3000MHz (sensitivity: <1uW/cm², accuracy: ≤|2dB|, testing range: 0 to 1999μW/cm²).
Initially, the electromagnetic radiation intensity near the computer screen is measured to be >2000μW/cm², while it measures 1382.W/cm² at a distance of 5cm from the screen. After placing the sample, the microwave radiation intensity of the fabric is measured at a distance of 5cm from the computer screen. The results are shown in Table 5.
Table 5
|
Specimen |
|
1 |
2 |
3 |
4 |
5 |
6 |
|
Electromagnetic radiation intensity |
Longitude |
2 |
2 |
2 |
5 |
3 |
4 |
|
Weft |
1 |
2 |
1 |
2 |
2 |
2 |
From Table 5, it is evident that without the addition of stainless steel ultra-fine wire, the electromagnetic radiation intensity is high. However, after adding stainless steel ultra-fine wire, the fabric shows a significant radiation protection effect. When stainless steel ultra-fine wire are added in both the warp and weft directions, the electromagnetic radiation from the computer is completely shielded, yielding a measurement of 0. Additionally, through testing, it was found that a single layer of coverage can completely shield mobile phone signals, demonstrating excellent radiation protection. However, due to the high tension in the warp during weaving, stainless steel ultra-fine wire are prone to breakage, affecting functionality and wearability, and causing many difficulties in manufacturing, making it unsuitable for large-scale production.
Under the condition of only adding stainless steel ultra-fine wire in the warp direction, a certain shielding effect can still be achieved, with the shielding effect in the warp direction significantly better than in the weft direction. Furthermore, under the same method of addition, the strength of shielding computer radiation is similar, indicating that the diameter of the three types of stainless steel ultra-fine wire has little effect on electromagnetic radiation shielding.
Microwaves with frequencies ranging from 300MHz to 300GHz correspond to wavelengths of 1m to 1mm. According to relevant research reports, the wavelength of electromagnetic waves from computer radiation is typically 2mm to 10mm or more, and shorter wavelengths exhibit stronger reflective properties. In the fabric, the diameter of the cotton yarn between the stainless steel composite yarns is 0.397mm, and the spacing between two stainless steel composite yarns is only 0.794mm, while the spacing between three is 1.191mm. Thus, the spacing between stainless steel ultra-fine wire is less than 2mm, making them prone to reflecting electromagnetic waves. Therefore, the addition of composite yarns in the warp direction alone has a significant effect.
Conclusion
From the experimental results, it is evident that the presence of stainless steel ultra-fine wire rapidly discharges charges in the fabric, providing significant anti-static effects. Moreover, the spacing between the stainless steel ultra-fine wire in the composite yarns is smaller than the wavelength of electromagnetic waves emitted by computers, making them easily reflect these waves. Even when stainless steel ultra-fine wire are added only in the warp direction, a certain shielding effect can be achieved. Taking into account the comprehensive anti-static and radiation protection effects, wearability of the fabric, and material cost, the use of 0.040mm stainless steel ultra-fine wire is more suitable for production.