a person who makes "clothes" for the Rockets

“We work together to assemble the equipment and test the performance as soon as possible.” On May 21, the reporter saw the Associate Professor of the School of Textile Science and Engineering and the leader of the intelligent functional textile composite innovation team at the Xi’an Engineering University, Fan Wei, he was in the laboratory. The graduate student of the guiding team assembled a high-precision CNC engraving machine that had just been delivered.

“We are not the 'textiles' and 'tailors' that everyone thinks. Our work is not about weaving clothes, but mainly the structure and performance of three-dimensional textile composites. This new engraving machine is used to cut three-dimensional Textile composite materials can be 'tailor-made' structural materials for rocket engines, aircraft and other equipment." Fan Wei told reporters.

In addition to the research of three-dimensional textile composite materials, Fan Wei and his young team of “80s” are also engaged in research on nano-functional composite materials, intelligent fibers and smart wearable devices, recycling of waste textiles, etc. 10 provincial and ministerial level projects, and applied for 13 national patents.

Aerospace field

When it comes to "textile", people think of pure cotton, polyester , and chemical fiber, because most of the clothes we wear are made with them. But the three-dimensional textile composites that Fan Wei and his team studied were not as simple as they were "clothing" for equipment in the aerospace industry such as rocket engines and aircraft.

Fan Wei told reporters that the structural composite materials used in the aerospace industry require high mechanical properties, tensile strength to pass, and high performance requirements for the interlayer, so that the overall strength of the material can be upgraded. In order to overcome the problems of low interlayer strength, interlayer peeling or cracking of conventional laminate composite materials, it is necessary to use a three-dimensional integral fabric in which fibers or yarns are also present between the layers as a reinforcing material. To this end, Fan Wei and his team developed equipment for the production of three-dimensional monolithic fabrics and the manufacturing process of shaped parts, and realized the tailoring of equipment for the aerospace industry.

"A large number of equipment and accessories in the aerospace industry are shaped parts rather than standard parts. After using specially developed production equipment, we can carry out 'net size production' according to specific use occasions or parts." Fan Wei said, "We will proceed first." The computer simulation calculates that the whole shape is formed at the time of production, which ensures the safety performance of the product."

Shaanxi is a large province of science and technology, and the aerospace industry has a profound foundation, which provides a place for Fan Wei's research. At present, the team has cooperated with some aerospace research institutes, and the self-developed three-dimensional textile composite materials have played a supporting role in scientific experiments in related fields.

"Next step, we will continue to increase the development of three-dimensional weaving, weaving, sewing, knitting, non-woven and other automated production technologies and rapid composite curing technology of textile composite materials, reduce the cost of three-dimensional textile composite materials, and vigorously promote advanced textile composite materials. In the fields of aerospace, automotive and other fields." Fan Wei said.

"Smart clothing" is coming

In addition to the composite materials used in the aerospace and other fields, Fan Wei and his team also have the result of “grounding” in the aspects of smart wearable fabrics and recycling of used textiles.

"With the improvement of people's living standards, people are now paying more and more attention to health issues. Smart wearable textiles with real-time monitoring functions such as heart rate, pulse and human motion state have been welcomed." Fan Wei said, "To be in the human body Real-time monitoring of activity parameters in different states, clothing must have a certain sensing function. Traditional cotton, hemp, silk, wool and other materials do not have such performance, therefore, the development of flexible sensing fiber has become the primary production of smart clothing problem."

After extensive research, Fan Wei discovered that a polymer material can be processed into a piezoelectric fiber after being added with special functional nanoparticles, which can respond to external loads with an electrical signal, and has a wide frequency response and sensitivity. High in corrosion resistance, and the piezoelectric fiber is easy to be combined with ordinary fibers to form a smart fabric. It is an ideal intelligent textile material.

“We have made some smart wearable textiles with piezoelectric fibers, which can not only monitor, but also have the advantages of good processability and washability.” Fan Wei said, “In addition to the physical function monitoring of ordinary people, we also developed smart clothing. It can be used for athletes' training and competition. By monitoring and analyzing the athlete's power point and movement posture, it can provide feedback to the athletes to help the athletes improve their training level and reduce joint damage."

At present, Fan Wei and his team have also developed a piezoelectric sensing element that can be woven into clothing, and applied for two national patents. "Based on this, we can achieve local intelligent monitoring in the wrist, heart and other parts. Next, based on the modular application, we will develop a true 'integrated' smart clothing, all made using piezoelectric fiber, launched More smart wearable products." Fan Wei said.

Young without limits

Since coming to Xi'an Engineering University in 2015, with the support of the school, Fan Wei and his young team have strengthened research and development work and built an intelligent functional textile composites innovation team in 3D textile composites, smart fibers and smart wearable devices. The achievements in nano-functional composite materials and recycling of waste textiles have been fruitful.

“Our team consists of 9 teachers and 17 graduate students. Everyone has a strong innovation and vitality.” Fan Wei said, “When I formed the team, I also focused on selecting talents in materials calculation, image processing, chemistry and other related fields to facilitate cross-innovation.”

Taking the recycling of waste textiles as an example, members of different teams of the team cooperate with each other and each shows “magic”. “In daily life, the frequency of textile clothing replacement is high. Whether it is burning or burying, it will cause serious environmental pollution. At present, the recycling rate of textile clothing in developed countries in Europe and America can reach 25%, while only 1% in China. I think that we can use technological innovation to improve the recycling efficiency of textile clothing, and it is also good for ecological environment protection." Fan Wei said.

In the process of research and development, Dr. Yu Lingyu from Donghua University is responsible for image processing to find the optimal fiber distribution state of new materials . Liu Tao, also from Donghua University, performed finite element calculation on the model established by Yu Lingyi to optimize the mechanical properties of the composite. Miao Yaping and Ma Yanli are Ph.D. graduates from Xi'an Jiaotong University, one is responsible for fiber/matrix interface performance calculation, and one is responsible for resin fluidity analysis. In this way, the team members have their own strengths, saving time and economic costs.

After trial and error, the team finally determined that the waste denim garment with the main component is cotton fiber as the reinforcing material, the waste polypropylene fiber as the base material, and the non-woven production, needle punching, hot press forming and other processes were produced step by step. A three-dimensional waste fiber reinforced composite material. "This material can be used to make office furniture, substitute wood flooring, etc. After testing, its mechanics, moisture absorption, peeling and other functions are fully up to standard, and it is 'zero formaldehyde', realizing the green utilization of waste textiles." Fan Wei Say.

Due to the large amount of recycling of denim garments and the single fiber structure, Fanwei's team has prioritized research and development and has mastered the recycling technology of such textile fabrics with cotton fiber as the main component. The next step will be to use other types of waste textiles. the study. "We will face the technological frontier of today's world textile materials, do a good job in technological innovation and technological achievements, and make new contributions to the improvement of innovation capabilities and competitiveness in the fields of aerospace, intelligent manufacturing , and environmental protection in Shaanxi and even the whole country." Fan Wei If so.