Review Of The Development Of Composite Material Processing Equipment At Home And Abroad: Filament Winding Process

 

Development Of The Layout of Filament Winding Machines 1

 

In 1946, the first patent for filament winding technology was registered in the United States, and the filament winding molding process began to develop. According to the main motion mode for forming the spiral line, the layout type of the winding machine used was basically completed in the 1960s [1-8], as shown in Figures 1 to 12.

 

 

In 1965, Beijing 251 Factory designed my country’s first horizontal fiber winding machine “525” (see Figure 3), which was “retired” in 2011. In 1966, the chain-type horizontal fiber winding machine with a toothed chain mechanical stepless adjustment of the winding law as shown in Figure 3 was designed. This machine does not need a hanging wheel, and can easily adjust the winding law and yarn density, and produces gas cylinders of various specifications.

 

Considering the structural layout, the chain winding machine used to produce gas cylinders of 15 L and below adopts a chain drive vertical plane arrangement (as shown in Figure 4 “525”); the chain winding machine used to produce gas cylinders of 20 L and above adopts a chain drive horizontal plane arrangement, and its sprockets are changed from two to four.

 

 

 

Beijing Factory 251 (Beijing FRP Research Institute, then called the Institute) and Harbin FRP Research Institute (then called the Institute) derived fiber winding laws with different expressions in 1965 and 1966 respectively, and developed mechanically controlled horizontal fiber winding machines.

 

In 1964, Harbin FRP Research Institute successfully developed the orbital winding machine, which was the first fiber winding machine in my country. Figure 8 shows the domestic orbital winding machine used by enterprises in recent years.

 

 

 

 

 

Fig. 14 Rotary filament winding machine

 

In 1974, Beijing 251 Factory successfully developed the X2 type planetary filament winding machine [9, 10], and the transmission system adopted the three-axis concentric planetary principle, see Fig. 15 and Fig. 16.

 

Fig.   15 Planetary Filament Winding Machine

 

Planetary Fiber Winding Machine Polyester Fabric Composition

 

In recent years, in Japan, aramid fibers are wound by dry winding and then coated with matrix resin. Aramid dry fiber winding machine is shown in Figure 17.

 

Entering the 21st century, there have been new developments in the layout of fiber winding machines to achieve main motion. Gifu University and Murata Machinery Co., Ltd. in Japan have developed the “MFG⁃Multi Supply Filament Winding” machine. Its main shaft simultaneously moves in an axial linear motion and rotates around its own axis, thereby achieving spiral winding. This machine can wrap gas bottles with geodesic and non-geodesic wires, and can also produce pipes. It uses 180 carbon fiber yarn bobbins for automated winding. The productivity has been improved, the torsional strength of the pipes produced has been greatly improved, and it is planned to produce automobile parts. See Figure 18 to Figure 21.

 

Fig. 18 Mandreal Biaxial Motion Filament Winding Machine

 

Fig. 19 The Principle Diagram of Multi-Supply Filament Winding Method in Japan

 

Fig.   20 Mandrel Biaxial Motion Filament Winding Machine (Japan)

 

Fig. 21 Local area of Japanese Mandrel Biaxial Motion Filament Winding Machine

 

Due to the need for multi-station winding, gantry winding machines came into being. This also avoids the contamination of the guide rails caused by the winding head (some with glue grooves) passing through the bed.

 

In recent years, due to the introduction of robots, the layout of fiber winding machines has changed a lot, and in response to the need to improve productivity, there is a trend of development based on production line layout.

 

For example, the auxiliary robot fiber winding automatic production line developed by MICROSAM in North Macedonia continuously carries out the lining conveying, loading and unloading of lining or wound workpieces, until solidification into finished products.

 

It can produce products such as CNG tanks, LPG tanks, and hydrogen cylinders for fuel cells, with an annual production capacity of more than 60,000 pieces per single production line. See Figures 22 and 23.

 

Fig. 22  Auxiliary Robot Filament Winding Machine(North Macedonia)

 

Fig. 23 Automatic Filament Winding Production Line (North Macedonia).

 

Fig 24 Automatic Production Line of Domestic Filament Wound Cylinder

 

Cygnet Texkimp of the UK has pioneered the world’s first high-speed 3D filament winding system (see Figure 25), which can produce composite parts with nonlinear center axes and diverse cross-sections.

 

 

Development of Filament Winding Machine Control

 

In terms of control, fiber winding machines have gone through four stages: mechanical (1950s to 1960s), CNC (1970s), microcomputer control (late 1970s to present), and robot (1990s to present).

 

In 1947, Kellog Company of the United States manufactured the world’s first mechanical winding machine.

 

Mechanical control is to adjust the control by the transmission system itself. For example, chain winding machines generally adjust the winding law and yarn density by adjusting the hanging wheel. The yarn density is calculated to the 8th decimal place. The commonly used reference book is the hanging wheel selection table.

 

Before the 1970s, it was calculated by hand, and then by calculator. Small angular displacement will affect the accuracy of the product and cause instability, so the transmission of the Martens mechanism is not suitable. It is worth mentioning that the “heterogeneous” winding machine developed by Changquan Machinery Factory in Jizhou City, Hebei Province in 2001. The movement of the wire guide head is controlled by a flat cam on the vertical plane. Without a tension system, the problem of winding at the ends of the ends when winding gas cylinder products can be solved. Its structure is not complicated, but its unique design is rare.

 

The CNC fiber winding machine was first introduced by Anderson Company (Mc Clean Arderson) in the United States in the mid-1960s. In 1974, Harbin Fiberglass Research Institute introduced the WE-250 digital program-controlled electro-hydraulic servo fiber winding machine from Joseph.Bayer Company in West Germany (see Figure 26).

 

The machine has 4 axes: spindle rotation, trolley reciprocating movement, winding head vertical to the vertical plane of the spindle axis, and winding head vertical to the vertical plane of the spindle axis. The yarn frame of this machine is placed on the car, and this car reciprocates synchronously with the trolley where the winding head and the dipping tank are located to reduce the tension fluctuation of the winding yarn. Aerospace 43 Institute also introduced the winding machine of this West German company.

 

Fig. 26 We-250 Digital Program Control Electro-hydraulic Servo Filament Winding Machine System Structure Diagram.

 

Fig, 27 CNC Filament Winding Machine (WE-250)

 

Since the 1980s, microcomputer controlled fiber winding machines (MCFW) have developed rapidly. Well-known manufacturers include American Anderson Company, Goldsworthy Engineering, Entec-Engineering Technology, German BSD Company, Walttritisch & Wachter Company, etc. . Now the winding machines on the international market have reached six axes, as shown in Figure 28.

 

Fig. 28 The action of 6-axis Filament Winding Machine Controlled by US Anderson Company Microcomputer.

 

 

Harbin FRP Research Institute once introduced a 5K-48-360 microcomputer-controlled fiber winding machine from an American engineering technology company. The machine uses two microcomputers, one for calculation and one for control. The 43rd Institute of the Fourth Academy of Aerospace Science and Technology once introduced a WEⅡ-220/1200-E-S/20 microcomputer-controlled fiber winding machine from Bayer, Germany.

 

The maximum yarn output speed of this machine is 1 m/s. In addition to the general winding program, it can also perform various nonlinear windings and zero-degree laying. It can wind variable-diameter rotating bodies such as cylinders, tubes, tanks, balls, cones, and some non-axisymmetric bodies [11]. The institute also introduced a Russian fiber winding machine. Figures 29 and 30 show the BSD5 fiber winding machine and the MIKROSAM new automated compressed natural gas cylinder production line, respectively.

 

Founded in 2004, the French company MFTech was the first to research and commercialize robotic winding. The robotic winding equipment provided by the company fully utilizes the flexibility of the robot and can be wound in two ways: grabbing the mold and driving the wire guide. See Figure 31 and Figure 32.

 

Fig. 29 Type SBD 5 Filament Winding Machine

 

Fig 30 New Automatic Compressed Natural Gas(CNG) Production Line of MIKROSAM.

 

Fig. 31 METech Robot Winding.

 

Fig. 32 MFTech Robot Multi-station Winding

 

Chengdu once considered introducing winding machines from Lincoln Company in the United States to produce gas cylinders. At that time, the company’s technology was at the highest level in the world and its equipment had a high level of automation. However, exports to my country were restricted, so it later purchased a German BSD winding machine.

 

Beijing has introduced winding machines from the French company Plastrecs to produce gas cylinders. European precision winding software is more expensive. Relevant units in our country introduced German winding machines and improved them, greatly improving their functions.

 

Since the 1990s, some domestic universities and enterprises have carried out research and development of MCFW and robot winding machines, such as Harbin FRP Research Institute,

 

Wuhan University of Technology (see Figure 33), Harbin Institute of Technology, CSSC 625 Institute, Wuhan Jiudi Composite Materials The company,

 

Harbin University of Science and Technology (see Figure 34),

Nanjing University of Aeronautics and Astronautics and its cooperative partners Shanghai Wange Company,

Suzhou Zhongke Times Electronic Technology Company, Hengshui Huacheng Company, Lianyungang Zhongtong Company,

Lianyungang Weide Company, Shijiazhuang Laide Company, Hunan Jiangnan Siling CNC Machinery Co., Ltd.,

Taiwan Industrial Research Institute, Taiwan Jincaixing Company, etc.

 

In 2000, the author visited the Industrial Research Institute in Hsinchu and learned that it had successfully developed a 7-axis winding machine.

 

A few years ago, our country’s customs issued an order to restrict the export of our country’s winding machines with four or more axes. Looking back on the past, the author is deeply proud of our country’s progress!

 

 

In order to improve the interface between the winding layer and the plastic lining, it is necessary to perform plasma treatment on the lining surface. The plastic lining plasma treatment machine is shown in Figure 35.

 

Fig. 35 Plastic liner plasma processor

 

The microcomputer-controlled yarn frame for fiber winding tension has been promoted at home and abroad. It was successfully developed by Suzhou Zhongke Times in the early 21st century (see Figure 36), and Beijing 251 Factory was the first to put it into use (2004). It has also been put into use by Wuhan University of Technology, Harbin Institute of Technology, Jiangnan Siling CNC and other units.

 

 

The key to thermoplastic composite winding is the heating method. Among the various heating methods, infrared, laser, and flame are accepted by the industry, among which laser heating is the fastest. The principle of laser heating winding is shown in Figure 37.

 

Fig 37 Principle Diagram of Laser Heating Winding.

 

In 1917, Einstein proposed the concept of stimulated emission of radiation. In 1960, the first laser was produced. It is unclear when lasers were used for composite materials. In 1998, when the author inspected the research institute of the University of Kaiserslautern in Germany, he saw the use of laser heating to wind nylon matrix composite gas cylinders. See Figure 38 and Figure 39.

 

 

 

Continuous Pipe Filament Winding

 

Filament Winding of Thermosetting Composite Continuous Pipes

As early as the 1950s, the United States, France, the United Kingdom, Sweden, the Soviet Union, and other countries had already developed various types of filament winding machines for both fixed-length and continuous pipes. The Kharkiv Mining Institute of the former Soviet Union developed a stepping-type continuous pipe winding machine with an 8-segment sliding mold [7] (see Figures 40 and 41). The United States once developed a vertical movable mandrel continuous pipe winding machine [7] (see Figure 42).

 

Fig. 40 Step Continuous Winding Machine of Former Soviet Union

 

 

 

 

In the 1960s, the Danish company Drostholm developed the world’s first cam steel belt continuous pipe winding machine. In the 1970s, the American OC Company and the Japanese company Sekisui successively introduced continuous winding technology from Denmark. The Norwegian VEROC and the United Arab Emirates jointly established three continuous pipe production lines in Dubai. Large FRP pipe companies in the world such as Amiantit, Future, and Flowtite all use steel belt continuous winding machines to manufacture FRP sand-filled pipes. See Figures 43 to 46.

 

Fig. 43 Steel Belt Continuous Tube Winding Machine Core Principle Diagram.

 

 

 

 

Fig. 48 Mandreal Schematic Diagram of Steel Belt Continuous Winding Pipe Production Line.

 

 

 

 

Fig. 52 Non-steel Belt Vector Continuous Pipe Winding Machine.

 

Fig. 53 Stepped Mandrel of FRP-LX300 Continuous Production Line of GFRP Pipe.

 

 

 

Fiberspar, an American company, began commercial production of continuous winding flexible pipes in 1999 and is said to be the global industry leader today. Its production process is: extrusion of high-density polyethylene or cross-linked polyethylene thermoplastic plastic lining layer (pressure leakage prevention layer) – multiple circumferential winding of glass fiber epoxy layer (structural layer) – external coating of thermoplastic plastic layer (wear-resistant layer).

 

The entire production line is fully automatically controlled (see Figure 55), consisting of 14 winding machines, traction machines, curing furnaces, winding devices and two extruders. After the fiber is wound on the plastic pipe, the outer plastic protective layer is extruded online to make the pipeline. The production speed depends on the pipe diameter, generally 2.7 m/min ~ 3.6 m/min. The continuous production length of a pipeline can reach 10,800 m, and theoretically it can reach unlimited length.

 

Fig. 55 Fiberspar continuous Pipe Production Line in USA.

This kind of production process. Its 12th Five-Year Plan 863 Science and Technology Project – Research on Key Technologies of Flexible Submarine Pipelines passed the expert acceptance organized by the Ministry of Science and Technology in 2016. Its continuous pipeline production line is shown in Figure 56.

 

Fig. 56 Continuous Pipe Production Line.

 

 

In 2012, the Australian Long Pipes Company (Long Pipes) launched a continuous pipeline production line for on-site production called “fluid highway” technology (see Figure 57). The product diameter is 300 mm ~ 1000 mm. Its production process is: 450 m of pipeline prefabricated fabric is folded on a rack and stored in a container with resin, etc. – during field production, the prefabricated fabric and resin and other materials are fed from the container to the pipe making machine – air support and resin infiltration, and the outer shell is wrapped to form the final pipe.

 

The “fluid highway” prefabricated fabric has three layers:

① Liner layer: designed to adapt to the transmission of fluids;

② Support layer: glass fiber, aromatic fiber, basalt fiber or carbon fiber and resin;

③ Outer shell layer: not installed until field construction.

 

 

In 2020, Chongqing Qingyang Holding (Group) Co., Ltd./Henan Qinyang Composite Materials Research Institute and Puyang County Furuipu Building Materials Company successfully developed a high-efficiency continuous winding FRP pipe production line with a diameter of 10 mm~250 mm. This line has no steel belt modeling.

 

On simple equipment, it can complete the continuous molding of FRP pipes at low cost and high efficiency, and its production speed can reach 2 m/min. The trick is that the traction crawler machine revolves and rotates synchronously. South Korea also has similar equipment. The small-diameter non-steel belt continuous winding FRP pipe production line and its traction components are shown in Figures 58 and 59.

 

 

 

 

Thermoplastic Composite Continuous Pipe Fiber Winding

 

In 2008, the Dutch company Airborne put into operation a continuous pipe production line (see Figure 60). It is said that the company is the world’s first full-size thermoplastic composite pipe manufacturer. It has developed a unique fully automated continuous winding process orbital winding machine, which uses thermoplastic prepreg tape to wind into a pipe and consolidate it on site to directly form the product. The inner diameter of the product is 25.4 mm ~ 190.5 mm, and it can mass-produce thermoplastic composite pipes with a single roll continuous length of 3000 m.

 

 

 

The “RTP Taping Line” of Ridgway Machines Ltd in the UK is a typical thermoplastic continuous pipe production line (see Figure 61). Changchun Gaoxiang Special Pipe Company has introduced this production line, and similar production lines have been put into operation in Anhui, Jiangsu and other places (see Figure 62).

 

Fig. 61 British Ridgway Continuous Pipe Production Line.

 

 

Pipelife Nederland B.V. of the Netherlands, Polyflow Global of the United States, Nanjing Aerospace Morning Light, Flexpipe Systems of Canada, Magma Global of the United Kingdom, TherCoil of the United States, etc. all produce composite continuous pipes.

 

The high-pressure RTP winding composite pipe production line produced by Shanghai Jinwei Machinery Manufacturing Co., Ltd. in China has three models, and the product diameter is 63 mm~315 mm. Guangzhou Lijin Pipe Technology Co., Ltd. has also launched a similar production line. See Figure 63 and Figure 64.

 

 

 

Fiber Winding of Fixed-Length Pipes and Storage Tanks

 

General machines for fiber winding container products can produce fixed-length pipes, so I will not elaborate on them. In the 1970s, Anderson Company of the United States developed a mandrel reciprocating winding machine [8] (see Figure 65).

 

In 2002, a winding machine model based on this principle was exhibited at the JEC exhibition in Paris.

 

Since 2013, the bamboo tube winding machine manufactured by Shijiazhuang Lai De Company for Zhejiang and other places also uses this principle, but its structure is very different. The mandrel of the bed head box of the bamboo tube winding machine moves back and forth along the guide rail, and the mandrel rotates; the bamboo frame, the glue dipping tank, and the bamboo belt guide are fixed in the middle position outside the bed. See Figures 66 and 67.

 

In 2014, Hengshui Huacheng FRP Company developed a tube winding machine that lays fibers axially at zero angle over the entire circumference, with the core shaft performing translational reciprocating and rotational motions, and with the yarn frame, rubber groove, and yarn guide head fixed but without a trolley.

 

 

 

 

 

Fixed-Length Winding Process Pipe Production Line

 

As early as 1974, the Ministry of Building Materials Industry of China issued a document requiring Beijing Factory 251 to collect foreign FRP pipe production technology, but due to historical reasons, it was suspended and not implemented until ten years later. After communicating with many companies in many countries, we believe that the technology of Italy’s Vetroresina S.P.A. is mature, advanced and practical.

 

During the inspection of the company, we have a deep understanding of each production link, even the specific formula and operation details, and also visited some places where the products are applied. The company was the largest FRP pipe manufacturer in Europe at that time, and the chairman was the chairman of the European Fiber Reinforcement Association.

 

On December 17, 1986, Ji County, Hengshui District, Hebei Province, signed a contract to introduce the company’s microcomputer-controlled FRP pipe tank production line, which was put into production the following year. There are FW2500, FW4000 winding machines, MT4, MT6 multi-axis core molds, cantilever large tank mold machines, head manufacturing machines and other equipment (see Figures 68 and 69).

 

The maximum diameter of the pipe is 4 m, the length is 6 m ~12 m; the storage tank capacity is 1 m³~150 m³. This marked the beginning of my country’s industrialized production of composite pipes and tanks. Years later, it was proved that this was another successful introduction of unsaturated polyester resin production line from Scott Bader in 1966, which was recognized by industry insiders. Because it was introduced from Italy and we wanted to satisfy customers, we suggested that the company introduced and built in Ji County be named “Zhongyi Fiberglass Company”.

 

 

Subsequently, Lianyungang, Nanjing Gaochun, Guangzhou, Sichuan Zigong, and Guangdong Maoming also successively introduced Italian production lines (the latter three were introduced from Sarplast, but they were still Widler Rosina’s technology).

 

Jilin Longjing introduced the pipe production line of Japan Fuji Chemical Co., Ltd., with a maximum pipe diameter of 900 mm. Shandong Qingzhou and Xinjiang Miquan introduced the pipe tank production line of the International Reinforced Plastics Company (I.R.P.) of the United States, with a maximum product diameter of 3.6 m and a storage tank volume of 2 m³ ~ 100 m³.

 

Shanghai Chemical Machinery Plant No. 2 and Jiangsu Wujiang introduced the fiber winding machine of the American composite material company FABRI, which uses hydraulic speed change and gear adjustment and is second-hand equipment. The maximum product diameter is 3.6 m and the length is 12 m. Tianjin once introduced three winding machines from ENTEC of the United States.

 

Fixed-Length Winding Sand-Filled Pipe Production Line

 

In 1992, Wuhan University of Technology assisted Hebei Zhongyi FRP Company to introduce the fixed-length winding sand-filled pipe production line from Italy’s Wedler Rossina Company. This production line consists of 6 equipment: 1 winding lining machine, 1 sand-filling winding machine, 4 curing stations, 1 finishing machine, and 1 demoulding machine. Hengshui Huacheng Company and Lianyungang Weide Company changed the sand-filling method from upper sand-filling to lower sand-filling, and from throwing to screw extrusion. See Figures 70 to 74.

 

 

 

 

 

In 1994, Siyang, Jiangsu also introduced an Italian production line. Yunyang County, Chongqing and Hangzhou introduced the French Plastrecs sand-filled pipe production line in 1995 and 1998 respectively.

 

After several years of competition in the technical strength of the pipeline market, the ones that have survived are basically derived from the technology of Vetroresina/Sarplast of Italy.

 

In the mid-1990s, although nearly 40 pipeline production lines had been introduced in China at that time, they were all large and medium diameter systems, and the production efficiency of domestic 50mm ~ 400mm diameter FRP pipes was low and the supply was insufficient. Sino-Italian FRP Company manufactured an FRP pipe production automatic line named CAMLINE in China according to the technical documents provided by Sarplast of Italy.

 

The maximum production time for producing pipes with a diameter of 75 mm and a length of 6.2 m is 7 minutes. It is worth noting that the method of the pipe lining is to spray resin on the mold wrapped with polyester film and wrap the surface felt at the same time to form a resin-rich layer (see Figure 75); then spray resin and chopped glass fiber at the same time.

 

The vertical pipe winding/pole and chimney production line

 

Vertical pipe tapered pole winding machine.

 

 

In 2013, Hengshui Huacheng Company successfully developed a large-scale winding machine for axial 0° laying, using 16 pneumatic yarn pressing devices to keep the fiber bundle laid at 0° always parallel to the axis (see Figure 78). The trolley can be used to go back and forth and the main shaft can be rotated for circumferential winding.

 

The main shaft can be rotated at a small angle and then paused for 0° laying; the entire bed with the headstock and the main shaft can also be moved along the guide rail for winding and laying. There are yarn hanging teeth on the circumference of both ends of the main shaft to avoid overtravel.

 

The motivation for developing this machine is to manufacture the fiberglass tower of wind turbines.

 

Using this machine can reduce the amount of materials used and greatly improve the mechanical properties of the parts. This machine has been acquired by Hebei Kenite Company. It was once very confidential and neither reported for awards nor transferred.

 

Fig 78  FW/Placement Productionline

 

Epoxy High-Pressure Pipe

 

In 1995, my country’s first fiber-wound high-pressure FRP pipe enterprise, Sino-US joint venture Harbin Smith FRP Products Co., Ltd., was established, and American high-pressure FRP pipe production equipment entered China. Jiangsu Jiangyan introduced the high-pressure FRP pipe production line of ENTEC Company of the United States (see Figure 79). The latter was resold to a company in Daqing.

 

The two American technologies have their own advantages and disadvantages. The former uses steam to heat the inner cavity of the steel mandrel without a curing furnace; it is simple and convenient to remove the cured pipe without a demoulding machine; the latter is characterized by a round yarn guide head, which can improve the yarn laying efficiency. The author personally believes that the comprehensive advantages of the former are better than the latter.

 

Nearly 100 existing production lines in China are almost all derived from the former, and their main features are: integrated design of winding, curing and demoulding, no hoisting and transportation of molds during the production process, no need for electric heating curing furnace and demoulding machine, and the production line occupies only one-third of the area of ​​traditional equipment; two or four-station design (see Figure 80) to meet the needs of continuous production; steam mold conduction heating curing, high thermal efficiency, good curing quality, and high production efficiency; cooling water without damage and rapid demoulding, its principle is to use the difference in thermal expansion coefficients between metal molds and polymer-based composite materials to separate the two when the metal mold is quickly cooled.

 

When Shandong Jinguang FRP Group Co., Ltd. manufactures epoxy FRP pipes with an inner diameter of 1 m, a FRP pipe is built into the steel core mold, and steam is passed between the annular cylinder formed between the outer wall of the FRP pipe and the inner wall of the steel core mold to achieve energy saving.

 

 

Four-station Fiber Winding Epoxy FRP High Pressure Pipe Production Line

 

Harbin University of Science and Technology developed the world’s first fully automatic FRP pipe production line (see Figure 81) that integrates winding, curing, demolding, grinding, cutting and transmission processes for Future Pipe Industries of the Netherlands (the world’s second largest composite pipe manufacturer with an annual output value of more than US$1 billion), and exported it to the United States, Russia and other countries.

 

 

 

Electric Pole Production Line

In order to ensure the insulation and weather resistance of electric poles, aromatic (structural layer) and aliphatic (surface layer) polyurethane resins are used in the production of FRP electric poles. The production line must use a polyurethane mixer with appropriate pressure and flow, and the applicable period of the resin must be considered. The size of the dipping tank should be appropriate. Polyurethane resin gels and solidifies quickly, and the amount of resin in the dipping tank should be appropriate. Figure 82 shows the polyurethane dipping device for manufacturing electric poles by winding method in Factory 251.

 

Fig 82  FW Polyurethane Impregnating Device for Manufacturing Electric Rod

 

The Polyurethane Fiberglass Pole Winding Machine (see Figure 83) developed by Wuhan Jiudi Composite Materials Company in recent years combines the advantages of two epoxy high-pressure pipe production lines, such as the yarn laying system composed of arc wire guide heads and needle rings, which can achieve precise laying of large fiber quantities and reduce fiber redundancy in the transition section; the unique impregnation method combined with the mold design can achieve repeated use of the mold head and tail needle rings and save resin glue; the automatic glue supply system can achieve precise control of the glue content of the product; the follow-up bracket design of the fiber movement path greatly reduces the labor intensity of workers and makes logistics smooth.

 

 

 

For steel core molds, electromagnetic induction heating can be used. During curing, the product and core mold are placed on one side of the curing plate, and the temperature probe is placed about 20 cm away from the core mold. Infrared temperature measurement is used to control the temperature of the core mold. See Figure 84.

 

 

In recent years, laser rapid curing of pipes has also been promoted, see Figure 85.

 

 

Inner Winding

 

When the author visited BSD Company in Germany in 2002, he saw the inner wall winding machine at work that the company specially designed and manufactured for the Ariane rocket engine combustion chamber of the French Space Center. The diameter of the combustion chamber is 3 m, the length is 1.10 m (the winding time is 1.11 m), the working temperature is Tmax=5000 ℃, and the inner wall is covered with silicone rubber.

 

The company’s chief engineer said that the thickness of the inner silicone rubber is 25 mm, and 6 mm is burned away during operation.

 

The silicone rubber tape is pre-impregnated with thermoplastic ablation-resistant resin. The combustion chamber is cylindrical, and its outer cylindrical surface is supported by two rollers, which are driven to rotate. The guide rail (i.e., cross beam) of the winding machine passes through the middle of the combustion chamber along the axial direction, and the “car” moves along the axial direction.

 

The prepreg tape is placed on the “car” and adhered to the inner wall of the shell through the pressure roller. The shell rotates and moves axially at a speed of 5 m/min. It is said that there is already one such machine at the French Space Center, and what we have seen is the second one.

 

At that time, there was no such machine in the United States, and the inner wall of the combustion chamber was currently bonded with silicone rubber by hand. The United States has proposed purchasing this winding machine.

 

Thermoplastic Fixed-Length Composite Pipes

 

The continuous glass fiber and polyethylene online composite winding thermoplastic fiberglass pipe production line developed by Chengdu Kangpu Youli Technology Co., Ltd. can produce large-diameter thermoplastic composite pipes. Compared with existing thermoplastic composite material production lines at home and abroad, it has a series of advantages:

 

Optimize the combination of extrusion, prepreg and winding processes to reduce the intermediate links in the circulation process, save energy, reduce consumption, have high efficiency and low cost;

 

The three process parameters can be flexibly adjusted online to meet the requirements of pipes with different specifications and performance;

 

The selection and adjustment of resin matrix and reinforcing fiber are convenient and diverse;

 

Compared with the existing production equipment at home and abroad that uses the winding method to manufacture thermoplastic composite pipes, it is easier to control the tension and improve the fiber strength development rate.

 

See Figure 86 and Figure 87. Its main equipment and its functions are shown in Table 1.

 

 

 

Automated Dynamics equipment can produce continuous or fixed-length thermoplastic composite pipes, with the same plastic inside and outside the pipe, and the inner lining and outer covering are extruded, which may or may not contain fibers, and the inner lining and outer covering can be optional.

 

The patents owned by the company are shown in Figure 88, and the pipe making machine it produces is shown in Figure 89.

 

Fig. 88 Patents owned by Americal Automation Powder Company.

 

 

On-Site Production of Storage Tanks

 

The on-site production horizontal storage tank production line signed by Sino-Italian Fiberglass Co., Ltd. and Italian Widler Rosina Company on September 11, 1988 and put into production the following year, the maximum diameter of the contracted product is 10 m and the maximum volume is 1000 m³; after improvements by Sino-Italian Company, the maximum diameter of the product is 15 m and the maximum volume is 2250 m³. The horizontal winding machine is shown in Figure 90.

 

 

Some private enterprises in Lianyungang, Shijiazhuang, Anqiu, Shandong and other places have also successively manufactured similar wrapping machines and made some improvements.

 

 

Fig. 93 Vertical Winding Mould of 6000M3 GFRP Tank

 

Generally, vertical tanks are not wound in spirals, which is due to the force analysis of vertical tanks. The winding machine for horizontal large tanks introduced from Italy in the late 1980s only has circumferential winding, not to mention the vertical winding machine introduced from the United States and made by Jiangsu later.

 

In 2013, Mr. Yang Xuezhi, a farmer entrepreneur of Anqiu Aerospace Fiberglass Company in Shandong Province, successfully developed a large vertical tank winding machine in which the mold does not rotate and the trolley rotates around the mold.

 

The schematic diagram is shown in Figure 94.

 

During winding, the trolley moves in a circle on the track with the center axis of the mold as the center, and the wire winding head moves up and down along the vertical guide rail on the trolley, thereby realizing circumferential winding.

 

 

The winding machine has been awarded a national invention patent. A vertical storage tank for storing 10,000 tons of hydrochloric acid was manufactured using this machine. The tank has an inner diameter of 32 m and a height of 12.6 m. It has been in safe operation for 7 years (see Figure 95). The use of large storage tanks greatly reduces the unit volume cost, saves land area, and thus reduces storage costs.

 

Thoughts On FW Pipe Tank Production

 

In 1987, the microcomputer-controlled FW pipe tank production line introduced from Italy was put into production. In 1989, the on-site winding tank production line was introduced from Italy. In 1993, the sand-filled pipe production line was introduced from Italy. Subsequently, although production lines were introduced from Japan, the United States, France, and Canada, due to the relatively mature and reliable technology, the best domestic products so far are still basically imported or imitated from Italian technology.

 

At present, my country has been at the forefront of the world in terms of FW theory and equipment, and there is no lack of independent innovation. Such as multi-degree-of-freedom winding machines, laying machines, wet sanding, and camless transmission systems of continuous winding machines.

 

In terms of practical software, the combination of theory and practice is concise, economical and practical, and has been well received and exported to the United States. Not only developing countries, but also Japan, South Korea, Europe and the United States purchase FW-related equipment from my country.

 

At present, the first problem that troubles the FRP pipe tank industry is not the technical level, but the use of inferior raw materials, low-price competition, shoddy workmanship, and barbaric construction, so that some places even ban the use of FRP pipes, and very promising products are cut off.

 

Double-Wall Tank Wrapping Machine

 

The original tank wrapping machine with molds at both ends of the original American CSI company can alternately operate to improve production efficiency. Lianyungang Weide Company and Shijiazhuang Lai De Company in China manufacture such machines for the production of FRP double-wall tanks (see Figure 96)

 

 

Appendix:

The inner liner of the SF double-wall tank is steel (S), which is formed by bending and pressing the steel plate and then welding it.

 

It is covered with polyester film or 3D fabric, and then sprayed with resin and chopped glass fiber and cured.

 

The required manufacturing equipment mainly includes the inner liner rotating device, the spraying machine and its axial moving device (see Figure 97).

 

 

In modern winding production lines, the use of multiple robots in linkage has become increasingly common. Figure 98 shows the automated winding gas cylinder production line of Sinoma Science & Technology Chengdu Co., Ltd.

 

 

Pultrusion winding is becoming increasingly popular both at home and abroad [5], and it started in my country in 2003. Its principle and equipment are shown in Figures 99 and 100.

 

 

Online braiding and pultrusion in my country [6] began in 2005. Its principle and equipment are shown in Figures 101 and 102.