A Man Who Makes Clothes For Rockets

"We work together to assemble the equipment as soon as possible and test the performance."

In May 21st, a reporter at Xi'an Polytechnic University saw an associate professor of textile science and engineering and an intelligent functional textile composite innovation team leader, Fan Wei Shi. He was instructing the team of graduate students in the laboratory to assemble a high-precision CNC engraving machine just arrived.

"We are not the weavers and tailors we all remember. Our job is not to weave cloth, but to study the structure and properties of three-dimensional textile composites.

The new engraving machine is used to cut three-dimensional textile composites, and can make "structural materials" for rocket engines, aircraft and other equipment.

Fan Wei told reporters.

In addition to the study of three-dimensional textile composites, Fan Wei and his young team, after 80, also engaged in research on nanocomposite, smart fiber and intelligent wearable equipment, recycling of waste textiles and other aspects. In recent years, they have hosted 10 national, provincial and ministerial level projects, and applied for 13 national patents.

Show your skills in aerospace

When it comes to "textile", people will think of such materials as pure cotton, polyester and chemical fiber, because most of the clothes we wear are made from them.

But Fan Wei and his team studied the three-dimensional textile composite material is not so simple, because they are to rocket engine, aircraft and other aerospace equipment to make "clothes".

Fan Wei told reporters that the structural composite materials used in the aerospace field require very high mechanical properties, and the tensile strength must pass through. At the same time, the performance requirements of the interlayer are very high, so that the overall strength of the material can go up.

In order to overcome the problem of low interlaminar strength and delamination or cracking of traditional laminated composite materials, three dimensional integral fabric with fiber or yarn interlayer should be used as reinforcement.

To this end, Fan Wei and his team developed the production of three-dimensional overall fabric equipment and special-shaped parts manufacturing process, to achieve the aerospace field equipment "tailored".

Many equipment and accessories in the aerospace field are special-shaped parts instead of standard parts. After using specialized production equipment, they can make "net size production" according to the specific use occasions or parts.

Fan Wei said, "we first conduct computer simulation and calculation, once the whole production is formed, ensuring the safety performance of the product."

Shaanxi is a big province of science and technology, and the deep foundation of aviation and aerospace industry provides a useful place for Fan Wei's research.

At present, the team has cooperated with some aerospace research institutes, and the three-dimensional textile composites developed by ourselves have played a supporting role in scientific experiments in related fields.

"Next, we will continue to expand the research and development of 3D braiding, weaving, sewing, knitting, weaving and other automated production technologies and rapid composite curing technology for textile composites, reduce the cost of three-dimensional textile composites, and vigorously promote the application of advanced textile composites in aerospace, automotive and other fields."

Fan Wei said.

"Smart clothing" is coming.

Apart from the composite material used in aerospace and other fields, Fan Wei and his team also have the results of "grounding gas" in terms of intelligent wearable fabrics, recycling of waste textiles and so on.

"With the improvement of people's living standards, people now pay more and more attention to health problems. Intelligent wearable textiles with real-time monitoring functions such as heart rate, pulse and human motion status are popular."

Fan Wei said, "in order to achieve real-time monitoring of human activities in different conditions, clothing must have a certain sensing function.

Traditional materials such as cotton, linen, silk and wool do not have such properties. Therefore, the development of flexible sensing fibers has become the primary problem in the production of smart clothing.

After a lot of research, Fan Wei found that after adding a special functional nanoparticle, a polymer material can be processed into piezoelectric fibers after polarization treatment, which can respond to external loads, and has wide frequency response, high sensitivity and good corrosion resistance. At the same time, the piezoelectric fiber is easy to combine with ordinary fibers to make smart fabrics. It is an ideal intelligent textile material.

"We have made some smart wearable textiles with piezoelectric fibers, which are both capable of monitoring and having good processability and water resistance."

Fan Wei said, "in addition to the physical function monitoring of ordinary people, our smart clothing can also be used for athletes' training and competition. Through monitoring and analyzing the athletes' force points and movement gestures, we can provide feedback to athletes to help athletes improve their training level and reduce joint injuries."

At present, Fan Wei and his team have developed a piezoelectric sensor that can be woven into clothing, and applied for two national patents.

"Based on this, we can realize local intelligent monitoring in the wrist, heart and other parts.

Next, on the basis of modular application, we will develop real "integrated" smart clothing, all using piezoelectric fiber manufacturing, and introduce more intelligent wearable products.

Fan Wei said.

Young without limit

Since coming to Xi'an Polytechnic University in 2015, with the support of the school, Fan Wei and his young team have strengthened their research and development work, and have built an innovative team of intelligent functional textile composites. They have made great achievements in 3D textile composites, intelligent fibers and intelligent wearable devices, nano functional composite materials, and recycling of waste textiles.

"Our team is made up of 9 teachers and 17 postgraduates, and we are all very active in innovation."

Fan Wei said, "when building a team, I also focus on talent selection, material processing, image processing, chemistry and other related professionals, so as to facilitate cross innovation."

Take the recycling of waste textiles as an example, the members of different professional teams cooperate with each other and show "magical powers".

"In daily life, the high frequency of textile clothing replacement, whether incineration or burying, will cause serious environmental pollution.

At present, the recycling rate of textiles and clothing in developed countries in Europe and the United States can reach 25%, compared with 1% in China.

We are thinking about whether we can make use of technological innovation to improve the recycling efficiency of textile clothing, and at the same time, it is also good for the protection of the ecological environment.

Fan Wei said.

In the process of research and development, Dr. Yu Lingjie from Donghua University is responsible for image processing to find the optimal fiber distribution status of new materials.

Liu Tao, a Ph.D. from Donghua University, also carried out finite element calculation on the model built by Yu Ling Jie, and optimized the mechanical properties of the composite material.

Miao Yaping and Marry Ma are Ph. D. graduates from Xi'an Jiaotong University. One is in charge of fiber / matrix interface performance calculation, and one is for resin mobility analysis.

In this way, members of the team display their strengths, saving time and cost.

After repeated experiments, the team finally determined that the waste denim garment with the main component of cotton fiber was used as reinforcement material, and the waste polypropylene fiber was used as the base material. Then a three-dimensional waste fiber reinforced composite material was produced by using non-woven production, needling and hot pressing technology step by step.

"This material can be used to make office furniture, instead of wooden floor.

After testing, its functions such as mechanics, moisture absorption and peeling are completely up to standard, and it is "zero formaldehyde", which realizes the green utilization of waste textiles.

Fan Wei said.

Owing to the large amount of recycled jeans and the single fiber composition, Fan Wei's team has developed and mastered the recycling technology of waste textiles which are mainly composed of cotton fibers. Next, other types of waste textiles will be used.

"We will face the technological frontiers of textile materials in the world today, make innovations in science and technology and pform technological achievements, and make new contributions to enhancing the innovation and competitiveness of Shaanxi and even the whole country in the fields of aerospace, intelligent manufacturing, ecological environment protection and so on."

Fan Weiru said.