Improving the appearance of all textile products from clothing to home textile using laser technology

Denim trousers, commonly known as “blue jeans”, have maintained their popularity for many years. For the purpose of supporting customers’ purchasing behaviour and to address their aesthetic taste, companies have been trying in recent years to develop various techniques to improve the visual aspects of denim fabrics. These techniques mainly include printing on fabrics, embroidery and washing the final product. Especially, fraying certain areas of the fabric by sanding and stone washing to create designs is a popular technique. However, due to certain inconveniences caused by these procedures and in response to growing demands, research is underway to obtain a similar appearance by creating better quality and more advantageous manufacturing conditions.

As is known, the laser is a source of energy which can be directed on desired objects and whose power and intensity can be easily controlled. Use of the laser enables us to cut a great variety of material from metal to fabric. Starting off from this point, we thought it would be possible to transfer certain designs onto the surface of textile material by changing the dye molecules in the fabric and creating alterations in its colour quality values by directing the laser to the material at reduced intensity.

This study mainly deals with a machine specially designed for making use of laser beams to transfer pictures, figures as well as graphics of desired variety, size and intensity on all kinds of surfaces in textile manufacturing such as knitted—woven fabrics, leather, etc. at desired precision and without damaging the texture of the material.

In the designed system, computer-controlled laser beams are used to change the colour of the dye material on the textile surface by directing the laser beams at a desired wavelength and intensity onto various textile surfaces selected for application. For this purpose, a laser beam source that can reach the initial level of power and that can be controlled by means of a computer interface; reflecting mirrors that can direct this beam at two axes; a galvanometer which comprised of an optical aperture; and a computer program that can transfer images obtained in standard formats to the galvanometer control card were used.

Developing new designs by using the computer and transferring the designs that are obtained on textile surfaces will not only increase and facilitate the production in a more practical manner, but also help you to create identical designs. This means serial manufacturing of the products at a standard quality and increasing their added values. Moreover, creating textile designs using laser will also contribute to the value of the product as far as the consumer is concerned because it will not cause any wearing off and deformation in the texture of the fabric unlike the sanding and stoning processes.

Another advantage of this system is that it gives a richer look to the product by causing the textile surfaces to get wrinkled and become three-dimensional by deformation as well as enabling you to create pictures and patterns on leather and synthetic fabrics by means of heat.

As for the results of the study, the first step was to prepare 40 pairs of denim trousers, half of which were prepared manually and the other half by using laser beam. Time studies were made at every step of the production. So as to determine the abrasion degrees of the trousers in design applications, tensile strength as well as tensile extension tests were conducted for all the trousers.     

A comparison between characteristics of various laser-based denim fading processes

Our experiments show that the laser fading process has similar, even better results, in some cases, than the conventional technologies of indigo-dyed denim. Using the beams from Nd:YAG laser (1064 nm and its second harmonic 532 nm), CTH:YAG laser (2.09 μm), CO₂ laser (10.6 μm) and various laser beam parameters we found the optimum fluence and power density in order to obtain a similar fading appearance like the one obtained by conventional processes. The purpose of this work was to determine the effectiveness of laser-based technologies and to measure the wear characteristics of the processed textile like colorfastness, strength resistance, tearing strength, and dimensional changes.     

Design of aspheric collimation system for semiconductor laser beam

In this paper, semiconductor laser beam collimation lenses system has been optimum simulated and designed. The new design methods for aspheric cylinder lenses collimation system have been discussed in detail and the system parameters are calculated and optimized by using a geometrical ray optics approximation. The optical system has been further simulated by software MATLAB, and the simulation results showed that the emergence angle can be collimated effectively, and the output beam can be expanded to a circular spot in centimeter level beam radius.     

Plasma enhanced CVD of SiOxCyHz thin film on different textile fabrics: Influence of exposure time on the abrasion resistance and mechanical properties

In order to improve textile fabric abrasion resistance, in this work a SiO_xC_yH_z thin film was realized by low pressure plasma chemical vapour deposition (PCVD) at room temperature, using hexamethyldisiloxane (HMDSO) as precursor compound. To test changes in the performance properties of the surface finished samples as a function of the type of the substrate, the deposition was carried out on different textile fabrics. The polymerization processes were followed by weight measurements of textile fabrics. It was found that, after PCVD, a significantly lower fabric weight loss was observed on treated samples after rubbing than on the untreated samples. The morphology, elemental composition and type of chemical bonding present in the film applied on textile fabrics were also investigated using electron scanning microscopy (SEM), energy dispersive X-ray (EDX) and infrared spectroscopy techniques (FT-IR (ATR)). The results showed a substantial enhancement of wear resistance for the surfaces modified with the presented process, while tensile and tearing strength were adversely affected.     

基于哈特曼-夏克波前测量原理的焦距测量

本文从哈特曼-夏克波前测量原理出发,提出了基于波前测量的透镜焦距测量方法|得到了使用这一方法测量焦距的计算公式.使用633 nm和780 nm两种波长的半导体准直激光器作为光源,测量了三片双合透镜的焦距,结果表明,633 nm光源下测量得到的波长与透镜的设计焦距值相吻合,能够正确测量透镜焦距|而780 nm光源的测量结果显示出较大的相对测量偏差,但可用于评估透镜的剩余球差、色差以及制造公差.     

Ultrafast fiber lasers for strong‐field physics experiments

The recent demonstration of rare‐earth‐doped fiber lasers with a continuous‐wave output power approaching the 10‐kW level with diffraction‐limited beam quality proves that fiber lasers constitute a scalable solid‐state laser concept in terms of average power. In order to generate high peak power pulses from a fiber several fundamental limitations have to be overcome. This can be achieved by novel experimental strategies and fiber designs that offer an enormous potential towards ultrafast laser systems combining high average powers (> kW) and high peak power (> GW). In this paper the challenges, achievements and perspectives of ultrashort pulse generation and amplification in fibers are reviewed. This kind of laser system will have a tremendous impact on strong‐field physics experiments, such as the generation of coherent light by high‐harmonic generation. So far, applications in the interesting EUV spectral range suffer from the very low photon count leading to nonrelevant integration times with highly sophisticated detection schemes. High repetition rate high average power fiber lasers can potentially solve this issue. First demonstrations of high repetition‐rate strong‐field physics experiments using novel fiber laser systems will be discussed.     

子午面大视场、孤矢面大孔径的耦合系统设计

本文提出了一套由４块柱面透镜组成的激光二极管阵列泵浦固体激光器的耦合系统，它可以将尺寸为４０ｍｍ×３．６ｍｍ的半导体激光二极管阵列的发光面所发出的子午面发散角±１０°，弧矢面发散角为±３０°的泵浦光耦合到接收面的系统可用于半导体激光二极管阵列泵浦固体激光器的研究。     

Atom lithography with a cold, metastable neon beam

We study different aspects of atom lithography with metastable neon atoms. Proximity printing of stencil masks is used to test suitable resists that are sensitive to the internal energy of the atoms, including dodecanethiols on gold and octadecyltrichlorosilanes grown on a SiO₂ surface. As an example of patterning the atomic beam with laser light, we create parallel line structures on the surface with a periodicity of half the laser wavelength by locally de-exciting the atoms in a standing quenching wave. Received: 29 June 1999 / Revised version: 30 August 1999 / Published online: 10 November 1999     

Removal of the indigo color by laser beam–denim interaction

Our experiments show that the laser fading process removes efficiently indigo-dye from denim support. We use the beams from Nd : YAG laser (1064 nm and its second harmonic 532 nm) and CO₂ (10.6 μm) lasers. Different laser pulse parameters were used in order to obtain laser power density and fluency to start the ablation process. The purpose of this work is to determine the change of denim diffuse reflectivity spectra after laser irradiation with different wavelength and different power density. The change of diffuse reflectivity coefficient was up to 17% at 450 nm wavelength (from 8% reflectivity for unirradiated denim).     

Evaluating the use of laser radiation in cleaning of copper embroidery threads on archaeological Egyptian textiles

Cleaning of copper embroidery threads on archaeological textiles is still a complicated conservation process, as most textile conservators believe that the advantages of using traditional cleaning techniques are less than their disadvantages. In this study, the uses of laser cleaning method and two modified recipes of wet cleaning methods were evaluated for cleaning of the corroded archaeological Egyptian copper embroidery threads on an archaeological Egyptian textile fabric. Some corroded copper thread samples were cleaned using modified recipes of wet cleaning method; other corroded copper thread samples were cleaned with Q-switched Nd:YAG laser radiation of wavelength 532 nm. All tested metal thread samples before and after cleaning were investigated using a light microscope and a scanning electron microscope with an energy dispersive X-ray analysis unit. Also the laser-induced breakdown spectroscopy (LIBS) technique was used for the elemental analysis of laser-cleaned samples to follow up the laser cleaning procedure. The results show that laser cleaning is the most effective method among all tested methods in the cleaning of corroded copper threads. It can be used safely in removing the corrosion products without any damage to both metal strips and fibrous core. The tested laser cleaning technique has solved the problems caused by other traditional cleaning techniques that are commonly used in the cleaning of metal threads on museum textiles.     

Optimization of laser beam welding process parameters to attain maximum tensile strength in AZ31B magnesium alloy

An empirical relationship is developed to predict tensile strength of the laser beam welded AZ31B magnesium alloy by incorporating process parameters such as laser power, welding speed and focal position. The experiments were conducted based on a three factor, three level, central composite face centered design matrix with full replications technique. The empirical relationship can be used to predict the tensile strength of laser beam welded AZ31B magnesium alloy joints at 95% confidence level. The results indicate that the welding speed has the greatest influence on tensile strength, followed by laser power and focal position.     

An Efficient Retrieval System Framework for Fabrics Based on Fine-Grained Similarity

In the context of “double carbon”, as a traditional high energy consumption industry, the textile industry is facing the severe challenges of energy saving and emission reduction. To improve production efficiency in the textile industry, we propose the use of content-based image retrieval technology to shorten the fabric production cycle. However, fabric retrieval has high requirements for results, which makes it difficult for common retrieval methods to be directly applied to fabric retrieval. This paper presents a novel method for fabric image retrieval. Firstly, we define a fine-grained similarity to measure the similarity between two fabric images. Then, a convolutional neural network with a compact structure and cross-domain connections is designed to narrow the gap between fabric images and similarities. To overcome the problems of probabilistic missing and difficult training in classical hashing, we introduce a variational network module and structural module into the hashing model, which is called DVSH. We employ list-wise learning to perform similarity embedding. The experimental results demonstrate the superiority and efficiency of the proposed hashing model, DVSH.     

High speed drilling by YAG laser

A high-quality laser beam has been obtained using a telescope inserted into a laser cavity. Based on this cavity structure, a high speed laser drilling machine, which produces ruby bearings using a single pulse, has been built. The drilling speed is 16 pieces s^-1 and the yield is 98.8% with a drilling diameter of 0.04–0.05 ± 0.005 mm, and bearing depth of 0.26–0.40 mm.     

A novel prism beam-shaping laser diode bar end-pumped TEM<Subscript>00</Subscript> mode Nd:YVO<Subscript>4</Subscript> laser

A beam-shaping diode end-pumped TEM₀₀ mode CW Nd:YVO₄ laser is presented. A special beam-shaping element made up of isosceles right-angled prism pieces is adopted to realize beam symmetric. Two cylinder lenses are used to couple the shaped beam into a 3 × 3 × 9 mm Nd:YVO₄ crystal with 0.3 at % neodymium doping. By using this laser system, we have achieved 6.1 W CW laser operated in single transverse mode at 1064 nm with 95.2% reshaping efficiency and 25.6% optical-optical conversion efficiency.     

环内选模对撞锁模激光器能量输出特性研究

环内选模Nd:YAG激光器的输出能量比环外选模的输出能量提高了近一倍,而且激光器的其它性能也有了很大的改善．本文从理论和实验上对环内选模激光器的能量输出特性进行了分析和研究,该研究对激光器模式选择方式及方法具有指导意义．     

Coherent probe-pump-based Brillouin sensor for centimeter-crack detection

We provide a theoretical explanation for a coherent probe-pump-based Brillouin sensor system that achieves centimeter spatial resolution with high-frequency resolution. It was recently discovered that, when a combination of cw and pulsed light (the probe beam) interacts with a cw laser (the pump beam), centimeter spatial resolution with high-frequency resolution can be achieved even though the probe-pulse duration is 1.5 ns [Opt. Lett. 29, 1485 (2004)]. Our study reveals that the coherent portion inside the pulse length of these two interactions caused by the same phase is responsible for this behavior. It allows us to detect 1.5-cm outer-layer cracks on an optical ground-wire cable.     

Development of beam-pointing stabilizer on a 10-TW Ti:Al2O3 laser system JLITE-X for laser-excited ion accelerator research

We developed a beam-pointing stabilizer for a 10-TW Ti:sapphire laser system to study laser-induced ion acceleration. We confirmed the improvement in the laser beam pointing stability by using a 10-TW laser system (we call it JLITE-X) at JAERI-APRC. The original long-term pointing stability on a 10-TW laser system is ～70 μrad without beam stabilizing. By using a beam-pointing stabilizer, the laser beam stability was improved within 10 μrad. If f/1 focusing optics and a target which is tilted 45° to the target normal is used, the fluctuation of the laser intensity at the focus will be improved from 80% without stabilizing to <0.4% with it.     

一种新颖的实现纳米条纹沉积方法研究

利用近共振激光驻波场操纵中性原子实现纳米量级条纹沉积技术是一种新型的研制纳米结构长度传递标准的方法,采用了一种新颖的方法,通过预准直孔的设定,将原子束在空间分成三部分,利用中间部分的原子束和近共振激光驻波场相互作用,在激光驻波场辐射压力作用下使原子按照特定周期沉积在基板上,从而实现纳米条纹的制作.利用两侧部分的原子束与探测激光束相互作用,通过其感生荧光来监测中间部分原子束沉积过程中的准直效果,从而为原子的沉积过程提供实时的原子束特性监测.最后对纳米沉积条纹在经由三狭缝预准直结构作用前后的效果进行了三维仿真,结果表明,未采用该三狭缝预准直结构时,纳米沉积条纹的半高宽为32nm,对比度为8∶1,而采用该三狭缝预准直结构之后,纳米沉积条纹的半高宽为6.2nm,对比度为28∶1,大大提高了纳米沉积条纹的质量.     

腔内波片产生的Nd∶YAG激光纵模分裂规律研究

简要介绍了激光纵模分裂的基本原理，研究了腔内含有1个和2个1/4波片时产生Nd∶YAG激光纵模分裂的规律。实验结果表明：在1064nm Nd∶YAG激光的腔内放置一个1/4波片时，每一激光纵模分裂为2个正交的线偏振模，在波片表面垂直于激光光线的条件下，纵模分裂量（即频率差或波长差）恰好等于激光纵模间隔的一半；当在Nd∶YAG激光腔内沿垂直光线方向平行放置2个1/4波片时，也能产生纵模分裂现象，其纵模分裂量取决于2波片快（慢）轴之间的夹角。在0°～ 90°范围内调节角度，可使纵模分裂量在一个激光纵模间隔内线性调谐。实验结果与理论分析相吻合。     

Optimization of laser printing of nanoparticle suspensions for microelectronic applications

Digital printing of interconnects for electronic devices requires processes capable of delivering controlled amounts of conductive inks in a fast and accurate way. Laser-induced forward transfer (LIFT) is an emerging technology that enables controlled printing of voxels of a wide range of inks with micrometer resolution. Its use with high solids content nanoparticle suspensions results in the deposition of voxels shaped as the impinging laser beam. This allows higher processing speeds, increasing the throughput of the technique. However, the optimum conditions for printing spot-like voxels have not been determined, yet. In this work, we perform a systematic study of the main experimental parameters, including laser pulse energy, laser beam dimensions, and gap distance, in order to understand the role that these parameters play in laser printing. Based on these results, we find that there is a narrow fluence range at distances close to the receiving substrate where spot-like voxels are deposited. We also provide a detailed discussion of the possible mechanisms that may lead to the observed features.