Analysis For glass fiber market of Year 2018

The composite material industry in the United States showed strong performance in 2017 despite some disruptions to supplies of raw materials, shortage of shipping containers, extended shipping times and the closure of factories along the Gulf Coast and southeastern coast due to the effects of Haval and Weema. In the fourth quarter of 2017, the impact of hurricanes has stabilized and all sectors have shown positive results.

In the composite industry, fiber glass is the main reinforcing material. The glass fiber of US market increased by 4% in 2017, reaching a sale of about 1.134 million tons and a value of 2.1 billion U.S. dollars. It is estimated that by 2023, the market scale will be enlarged and reach 1.4 million tons with a compound annual growth rate of 3.4%.

Transportation, construction, pipelines&storage tanks are the three major areas of fiberglass applications, accounting for 69% of the total. With housing starts in the United States, the positive growth in the automotive and oil and gas sectors, and the growth in water and grey water infrastructure, it is expected that the glass fiber market will be boosted in and after 2023.

In terms of supply and demand, the global glass fiber production capacity in 2017 will exceed 5.08 million tons, with a current utilization rate of 93%. With the increase in capacity of fiberglass suppliers, capacity utilization of glass fiber production lines will drop to about 91% by 2018.

Fiberglass market is constantly evolving, various terminal markets are emerging more and more applications. Purchasing decisions in most markets are continuously to be highly influenced by the price of GFRP components. In order to promote the growth of glass fiber market and competitive advantage, the industry needs to focus on the following points:

Price cuts: because of the competition with steel, aluminum and concrete, the glass fiber industry needs to find ways to reduce the cost of composite parts. There are many innovative opportunities to reduce raw material costs, labor costs, and energy costs for composite parts. For example, to compete with the $ 200 billion market for concrete rebar, glass rebar manufacturers must implement an innovative technology that uses glass fibers and sand to make rebar, reducing the cost of glass rebar by nearly 40 percent.

Innovative Manufacturing Technology: The industry needs to develop transformative manufacturing technologies that reduce cycle times and costs. There are many innovative opportunities for composite materials because of their flexibility in design, material selection, manufacturing and compounding.

Robust Supply Chain: With the increasing globalization in many industries such as automotive, wind energy, aerospace and electronics, the glass fiber industry needs to develop a global supply chain for raw materials, design, molds and manufacturing for composite investment. For example, Ford’s global production of vehicles and the desire to have the same parts supplier for their global production needs are critical to achieving a global footprint in the supply chain.

Better simulation and forecasting techniques: the market needs to invest in better composite parts manufacturing simulation software. In the steel industry, simulation software programs predict component tolerances, warpage, quality and reliability.

Maintenance and Recycling Technology Investments: the industry needs to address the challenges of OEM in repairing and recycling by developing cost-effective technologies and infrastructure.

In short, there will be significant innovation opportunities in every nodes of the composite material industry value chain, shenzhen core-tex will take this chance to provide the industry with more quality products.

The world’s first e-glass fiber glass “composite” passenger lift was born

The world’s first e-glass fiber cloth “composite” passenger elevator, the elevator weight loss of 90% than traditional passenger elevator.

On January 10th, the opening ceremony of the world’s first e-glass fiber cloth composite passenger elevator was held at the hotel ,Singapore Lift Company(SLC). The elevator, known as “8”, has successfully built by a Singapore-based joint venture between the Far East agency, Woh Hup and the holding company Pronus (HK). Singapore Lift Company (SLC) .its weight is about 90% lighter than the traditional steel elevator, but carrying capacity is about doubled.The elevator is made of e-glass fiber cloth, carbon fiber and aluminum alloy honeycomb panel made of light weight, high strength, strong corrosion resistance, so as long as the appropriate maintenance, life can be up to sixty or seventy years.

SLC Managing Director Alister JA Bennett said,The use of e-glass fiber composite materials is not new, like the Boeing 787 Dreamliner and some BMW series of cars, all in the production process using such materials, but the use of e-glass fiber composite materials manufacturing elevator is a pioneering work.

“The advantages of e-glass fiber composite materials, including lightweight high strength, relative to steel, e-glass fiber composite materials is more corrosion-resistant, so as long as appropriate maintenance, e-glass fiber composite material’s life can be as long as sixty or seventy years.”

The weight of the e-glass fiber composite elevator “8” is about 150 kg, Compare with a traditional elevator the ratio is about 1500 kg, equivalent to only 10% weight of e-glass fiber composite elevator. General elevator can only carry about six people, but “8” ‘s carrying capacity can be 11 people, its carrying capacity can up to 825 kg.

Alister JA Bennett said,The traditional elevator T-type rails need to set a support point every 1.5-2 meters, otherwise the rail will bend, so the elevator shaft need a concrete wall or steel frame, so that the elevator rail bracket has a fixed place.

After we redesigned, ‘8’ do not need to use this complex elevator shaft and support frame, and lighter, so we do not have to install the balance hammer. In this way, the space saved allows us to expand the area of the elevator’s car. ”

In addition, the “8” elevator car will have a turning diameter of at least 1.4 meters, leaving enough turn space for the wheelchair. “8” is currently aimed at low-rise buildings, but the future can be extended to 20-storey buildings.

Alister JA Bennett also mentioned that the traditional elevator takes 5-7 days to complete a layer of installation, but the “8” installation process will be shortened to install at least one floor every day elevator, during which no need to use heavy equipment or welding.This will improve staff productivity and help reduce overall building spending.”

It is expected to begin selling in the third quarter of this year

“8” elevator design concept has been approved by the European elevator and escalator safety certification body Liftinstituut. Alister JA Bennett revealed that they had begun negotiations with the Construction Bureau for “8” certification, followed by an authorized elevator inspector to conduct a relevant review. “We plan to complete the certification in March and start selling the lift in the third quarter of this year.”

Alister JA Bennett said that they intend to produce “8” elevator cars in Singapore and hope to work with local universities to further improve the design and engineering of elevator components and promote the development of the overall composite industry.
A spokesman for the Far Eastern Agency and the Hopewell Construction Company said that “8” has the potential to meet the challenges of high cost and limited manpower faced by the local construction and construction industries. They will also assess the feasibility of adopting “8” in development projects in the future.

More products information, please contact us , we have a specialized technical engineers service for you, at the same time we can offer you free samples.

Analysis on the Problem of the Relaxation of the Warp in the edge of Glass Fiber cloth

With the continue development on the popularize and promote of the smart phone and tablet PC fiber cloth, as one of the main upstream raw materials in PCB field , is also increasingly development to the thin, ultra-thin type, And the requirements on the quality of the fiberglass cloth are getting higher and higher,In the air-jet loom weaving process of the fiberglass cloth , the relaxation of the warp yarns on both sides((Hereinafter referred to as loose edge) is a long-standing and troublesome problem in production. This article will address this issue on Analysis of Relevant Causes and Countermeasures.

Loose Edge Phenomenon
The loose edge phenomenon of glass fiber cloth refers to the fiberglass cloth weaving process, on the front of the machine, there has 5 or 8 counts warp yarn of the cloth edge is loose, the length direction is relaxation, the warp yarn is relaxation on the edge of the machine ,the most serious is the side of cloth ,So the yarn tension on both sides of the weaving yarn becomes smaller and the falling of the menstrual-stopping sheet causes the phenomenon of stopping.Usually, workers will be cut off the warp and butt the yarn in the processing of production,This will not only increase the fabric defects, but also increase the labor intensity .At the same time, due to the tension of the warp yarns becomes small, due to the insufficient tension of the warp yarn ,shrinkage defects can be easily produced in the weaving process.

Analysis for the Causes of Loose
The reasons for the shaft itself
In the whole pulp and by the process,The warp tension at the edge of the weave is less than the tension in the middle warp,Leading to loosening of the weaving yarn .
The bad tune in the production process,So that the diameter of the weaving shaft edge is slightly larger,when weaving, the length of the yarn to be sent increased, resulting in the relaxation of the side yarn .
In the first round of the shaft when the shaft bottom of the pad is too thick.
The weaving disc is deformed to change the shape of the side of the weaving shaft,In the weaving to form a lotus leaf edge, the tension of the edge warp while littler while larger, resulting in the relaxation of side yarn .

Glass fiber properties
Fiberglass yarns are made of hundreds of continuous glass monofilaments bundled together with very small twist and trace amounts of sizing agent (see Figure 1),as the characteristics of the glass monofilament itself are extremely smooth surface, and basically no flexibility, no elongation. In addition, Electronic cloth is mainly plain weave structure , Warp density is relatively thin (currently the most densely distributed in the industry by the density of 27. 5 / cm), and the warp, weft, twisted yarn are all glass fiber yarn so that Warp and weft between the friction resistance is small, it is difficult to fully twist does not produce relative slip (see Figure 2)

Weaving reasons
In the weaving process (see Figure 3), after the beating finished, the weaving of the cloth is from the weaving mouth to the time of the movement of the breastplate of the loom, and Weaving is continuing. As the heald frame of the continuous up and down movement, The warp yarns continue to be subjected to the ever-changing warp tension. In the weaving mouth office, Woven weft is constantly under the influence of the warp movement up and down so that the weft yarn further contraction bending, Because the weft yarn is basically inelastic, can not be elongated, and both sides of the twisted yarn can not be fully grasp the weft, The degree of bending of the weft yarn near the cloth edge becomes large, and the weft yarns closing the middle of the cloth face received more and more resistant from warp and the degree of the ability to continue to bend becomes smaller and smaller. Meanwhile, As the weft of the cloth edge of the degree of warp is greater than the middle of the weft, the edge of the weft on the warp yarn force is less than the middle of the weft on the force of warp so that the warp yarns on both side edges of the electronic cloth are less curved in the cloth surface than the intermediate warp yarns, and the edge of the heald frame at the back of the continuous “extension”, eventually leading to side yarn relaxation.

Particularly for the glass fiber electronic tissue (2116, 2113, 3313, 1080, etc.) and the ultra-thin fabric (1067, 106, 103, etc.), as the warp and weft yarn is finer, the warp and weft yarns on the fabric point are less curved, friction between each other is also smaller, so that the warp of both side edges is more likely to be relaxed. This is also seen in the air-jet loom on the menopausal halo on both sides of the lower mid-high slightly arc-shaped reasons. The author believes that this is also one of reason that Electronic cloth industry is always the middle of the fabric permeability is greater than both sides.

In addition, the wear of the rubber roller (or piera) at the breast beam of the loom is also one of the causes of loosening of the side yarn during the weaving process.

Strengthen the preparation process of production management, to ensure the quality of weaving axis
Using a twisted edge way of which has greater grip force on the weft,At present main twist ways in the fiberglass cloth industry are the leno twist and planetary twist,Such as the Tsudakoma loom is used in three yarn leno twist way, the Toyota loom using the planet twist way, In contrast, to the weft grip ,the three yarn leno twist is stronger than the planetary twist, and seen from the actual data of the factory, the edge of the loose side of the yarn may appear Sex smaller.

Change the edge of the law, increase the density of edge warp cloth , such as change (2.2.1) wear method (4.2.1) , as shown in Figure 4, However, this method should be based on different types of cloth, different strains of the test.To prevent the Alice edge caused by the excessive tension ,Due to the cloth with too thick or too tight side when cloth walking in the later procedure.

According to the thickness of different types of cloth, warp and weft yarn thickness and density, to adjust the twist yarn thickness, twist and twist tension,To increase the grip force on the weft. Also be careful not to make cloth edge too thick

Increase the number of waste side of the warp yarn and tension, in order to increase the waste side of the warp yarn on the grip force.

Adjust the time of the twist edge, in the case without affecting the weaving ,So that it can weft the weft earlier before weft insertion (i.e., before weft cutting).

Adjust action time of the the clamping mechanism and the electric shear,So that the position of the presser as close to the reed, adjust the action time of electric shear,So that the weft yarn is pressed by the blank holder before cutting the weft yarn,So as to reduce the degree of bending of the weft yarns side before being cut.

In the pre-preparation process to further increase the weaving side tension of the warp,we take a different approach for different tensioner , but try not to increase the mechanical friction of the yarn.

In the front preparation, the side warp yarns will use finer yarns to reduce the amount of side yarns to be weaved and to reduce the side yarn slack.

From the factory’s actual situation, through the integrated use of the above methods, the relaxation problems of glass fiber edge warp can be better improved,But for some special cloth,Such as the weft yarn is much finer than the warp yarn,Or 106 series even more thinner cloth,There will be individual loom relaxation or the edge relaxation phenomenon of the warp, which is our direction for the fiberglass cloth counterparts need to work together .

Electronic weaving technology and post – processing

High-performance electronic fabrics need high-quality electronic yarn. Some important characteristics of electronic cloth is almost entirely dependent on warp and weft yarn, and the quality of warp and weft yarn is closely related to the twisting process.

The warp and weft yarn twisting process is completed in the high-speed first twist machine. In the process of drawing a single pool of raw silk for the warp and weft yarn, has been in line with the weaving of electronic cloth requirements, no further shares. The reason why through the twisting process, but to the original fiber in the twister on the hot air through the further drying, a small amount of twisting after winding into a suitable for warping, weaving production needs of the bottle-shaped tube. Twisting speed has been reduced from the original 40 twist / m, to the current 28 twist / m, is also to 20 twist / m development, Yarn volume also increased from the original 2Kg to the current 4-8Kg. This series of process improvement of electronic yarn is to ensure the further improvement of the quality of electronic cloth. The electronic cloth production process is as follows.
Raw fiberglass》Initial twist》Batch warping》shaft sizing》drawing》Air – jet looms》Inspection cloth 》Continuous heat treatment 》Batch heat treatment 》Surface chemical treatment》test.

Electronic fabric structure
The arrangement of warp and weft yarns in the fabric and the state of joining with each other are called fabric structures. Fabric structure depends on the warp and weft yarn diameter, number of shares, twist, linear density, warp and weft density, fabric and fabric parameters and many other factors. Variations in these factors, as well as different combinations of each other, can constitute a number of structural properties of different glass fiber fabric to meet the needs of different uses.

The filament diameter of the electronic warp and weft yarns is 9 m or less, and there are four grades of 5 m, 6 m, 7 m and 9 m. In general, finer monofilaments can be made into finer yarns ,while finer yarns can be woven into thinner fabrics. And the same thickness of the cloth, such as the use of smaller diameter single warp and weft, the cloth’s softness, mechanical properties and durability are better. In addition, the original drawing coated fiberglass sizing, not only played at the time of drawing lubrication and cluster effect, but also improve the flexibility of the strand to a certain extent, abrasion resistance and resistance to bending performance. In particular, the current drawing infiltration agent, most manufacturers have adopted a modified starch infiltration agent, so that the original fiberglass textile performance has been significantly improved.

The fabric weave represents the weaving rule of warp and weft yarn. Industrial electronic fabrics are mainly plain, twill, satin and leno four organizations. Plain weave is the simplest and most commonly used fabric. Compared with twill and satin weave, weft and weft yarns in plain weave have the highest number of weave points and buckling numbers, and are close to each other. The fabric is relatively tight and flat and suitable for most electrical insulation and reinforcement materials. In general, plain weave are used in CCL with a variety of electronic fabrics .

Technical Characteristics of Air – jet Looms
At present, the electronic cloth air-jet loom production. The current air-jet loom speed has reached 600 ~ 750r / min, which can produce a uniform tension, smooth cloth, no hair loss and high-quality electronic embryo and maintain a high weaving efficiency. The roll length of the electronic fabric is usually 2000 m / roll, up to 4000 m / roll. Specific technical characteristics are as follows.

Using electronic let-off, electronic coiling, to achieve positive sent by the coiling and stabilize warp tension

Using photoelectric double-weft can detect the lack of weft, weft release, but also  beyond the detector weft So that reduce the zonal defects (for very little weft broken glass fiber fabric only need a weft)

Using electronic control weft storage device to stabilize the weft tension. The weft yarn discharged from the main nozzle is wefted by the auxiliary jetting force, and then is finally attracted by the terminal drawing nozzleso that reduce the weft and the weft untwisting defect

Using positioning parking, locating the effective control of driving and braking angle, and a shuttle, reversing and other functions, which effectively prevent the switch car’s dense road defects.

Using automatic pair shedding device and device for preventing the driving mark, So that the fabric weft defects greatly reduced

Electronic cloth post – processing
In order to further improve the physical and chemical properties of electronic cloth and its products processing performance, which need to post-processing electronic fabric. Including the heating, removal of raw silk in the drawing process of drawing the coating of infiltrating agent, as well as the yarn in the sizing process of coating the slurry, a surface layer of the fabric impregnated with coupling agent. This process is called thermal-chemical processing (“post-processing”). Electronic post-processing process, including continuous heat treatment, batch heat treatment and surface chemical treatment of three parts.

Continuous heat treatment
Continuous heat treatment, also known as pre-desizing. The continuous heat treatment of the gray fabric was performed on a continuous heat treatment unit (hereinafter referred to as KH unit). The core of the unit is a high temperature desizing furnace. To keep the continuous operation, the unit consists of several units, mainly for the cloth feeder, feeding and sending device, winding device. For the cloth machine with a roll for the cloth with a hot device, In order to change the volume in the continuous operation of cloth, feeding the fabric section and the feed section is configured with cloth storage device, The fabric is fixed on the cloth feeding machine, the cloth for feeding cloth is fed into the storage rack by the feeding roller, and the cloth drawn from the storage section of the feeding section enters the high-temperature desizing furnace through guide rollers. The fabric of organic matter in the high-temperature furnace decomposite and carbonize, volatiles discharged with the flue gas. As the glass cloth in the high-temperature furnace through the shorter time, there are still some incomplete carbonization of organic matter is still left on the cloth. Therefore, the high-temperature furnace pre-desizing cloth (also known as “KH cloth”) was dark brown. KH cloth guide roller into the feed section of storage rack, and then sent by the feeding roller into the winding device, winding to the heat treatment with the hole on the steel pipe.

After the warp sizing of the fabric woven into the general organic content of 1.7% to 5.0%, the variety of cloth is very different due to the size and sizing rate. The purpose of continuous thermal desliming is to remove most of the organic matter on the cloth, so that the amount of residual organic matter (referred to as the amount of residual fat) reduced to 0.5%. Continuous heat treatment process is the key to master the treatment of temperature and time, for KH unit, the key is to correctly set and control the temperature and desizing furnace temperature and operating speed. As the heating method, the heating principle and the furnace structure is different, different KH unit set temperature requirements will be different. The same unit with different operating speeds, the furnace temperature setting also need to change. When the speed increases, in order to ensure the desizing effect, the need to properly improve the furnace temperature, but the furnace temperature should not be too high, because the higher the temperature the greater the loss of electronic cloth. In general, the processing temperature of electronic cloth is not higher than 450 ℃ is appropriate, furnace temperature and operating speed setting and adjustment of the target is to achieve the technical requirements of organic residues indicators, while minimizing the loss of strength. The exact amount of residual fat should be sampled and sent to the laboratory for testing. Experienced by KH cloth color of the observation can also be roughly determine the treatment effect.

Continuous heat treatment furnace heating temperature is high, usually used for electric energy, this furnace commonly known as electric furnace. As long as the appropriate resistance elements connect into the power grid, you can convert electrical energy into heat, thereby performing heating. And the electric furnace structure is simple, easy maintenance, temperature control is simple and reliable, and its thermal efficiency is also high, up to 50% to 80% of the electrical parameters of the circuit can be adjusted to control the temperature of the power, therefore, the electric heating is the ideal glass fiber fabric for continuous heat treatment furnace heat source for most of the glass fiber plant used.

Gas, liquefied petroleum gas can also be used as heat treatment furnace heat source, mainly because of its high calorific value, more economical, but their combustion temperature is not easy to control, complex institutions, generally continuous heat treatment furnace does not use gas

Batch heat treatment
Batch heat treatment, also known as thermal desizing, referred to as “BH”, the task is to completely remove the remaining organic material on the cloth, , Electronic cloth residual fat content reached 0.05%, while minimizing the loss of fabric strength.

Batch heat treatment process is that after Pre-desizing the fabric, the wound in the stainless steel tube on the hole, on a dedicated steel shelf and put Into the BH furnace for stew burning.

The residual organic matter on the fabric is decomposed and carbonized in the furnace, and its volatiles are discharged out of the furnace through the recycle gas. The processing time of the fabric in the furnace can be determined according to the variety and specification of the gray fabric and the amount of the organic matter residue after the treatment in the KH furnace. After the set time, BH furnace will automatically stop running. Meantime, you can open the door heat, until the cloth surface temperature dropped to the handle is not hot, you can remove from the  shelf, transported to the surface of the chemical treatment furnace to be processed. As the residual organic matter on the fabric was completely decomposed and carbonized in the BH furnace, the surface of the fabric treated by the BH furnace showed a pure white color. The technological requirement of the process is that the temperature curve is set correctly and the treatment time is strictly controlled so that the residual amount of the organic matter in the gray cloth is controlled to be 0.05% or less, and the fabric is ensured to achieve the specified tensile strength.

Batch heat treatment process is the key to master the processing temperature and processing time. For the high-temperature oven, the key is to set the furnace temperature, heating time and holding time, these parameters should be based on the electronic cloth of different specifications, fabric content and KH process conditions, and the structure and heat oven work principle. rule of thumb often set the initial parameters, and then determine the optimum parameters by trial and adjustment. Furnace temperature generally not more than 400 ℃ is appropriate, processing time required 40 ~ 60h. The temperature is too high, the loss of electronic fabric strength is too large, the processing time is too short, the cloth roll may also be internal. Practice that setting the furnace temperature is slightly lower and longer processing time, to ensure the quality of electronic cloth is more favorable, you can achieve low residual fat and retain the effect of high strength.

Batch heat treatment furnace is a closed high-temperature baking furnace, You can not only use liquefied petroleum gas or gas, natural gas as a heat source, also fuel as a heat source. Different heat sources need to be equipped with different combustion devices. However, for the batch heat treatment furnace, because the processing time is longer, heat treatment furnace is fully enclosed, the use of hot air circulation heating type. If the use of electric, power consumption is very powerful and high cost. Wrapped in the steel pipe with a hole on the KH cloth placed in a dedicated steel rack to put BH furnace, filled with a furnace closed the door, the ignition temperature to reach the set temperature and then heat a few 10h.

KH cloth on the residual organic matter in the BH furnace is oxidized, its products free out, in the hot air under the guidance of the discharge from the furnace. When the set time automatically shut down, this time can open the door, to be slightly cool after the take-out cloth frame to complete the batch of thermal desizing process.

Surface chemical treatment
Electronic fabric surface chemical treatment is in the surface treatment unit (FN unit) on the completion of the surface chemical treatment of electronic fabric referred to as FN cloth. Surface chemical treatment unit is composed of multi-unit device composed of continuous processing unit, which is the core part of the processing of liquid immersion device and drying device.

The processing solution impregnation means is movable up and down while the immersion roller is fixed, When the speed of cloth is determined, by adjusting the dipping tank of the upper and lower position and height of the tank to adjust the liquid immersion time. The electronic cloth impregnated with the treating liquid leaves the treating liquid and is then squeezed by a pair of rubber pressing rollers to increase the permeation of the treating liquid, to drive out the bubbles in the cloth, and to remove the excessive treating liquid. Squeeze roller material hardness, higher pressure are also important parameter to determine the content of the treatment agent and impregnation quality electronic cloth. For the General electronic cloth, the content of the treatment liquid on the squeeze roller back cloth is controlled within the range of 20% to 30%.

About 99% of the treatment solution is water, so the squeeze roller leads to the electronic cloth also contains large amounts of water, need to be removed by oven. Oven heating principle and the furnace structure is different from the drying effect is also different, generally the temperature does not exceed 170 ℃ to the principle of the baking cloth after the moisture content of not more than 0.1% for the target adjustment and control. Because the temperature is too high affecting the effect of coupling agent, moisture content is too high will affect the application performance of cloth. Surface chemical treatment of the key quality indicators are organic content. As a result of batch heat treatment of BH cloth still has 0.05% of the following organic residue. Therefore, the FN cloth measured by the general test contains the content of the post-treatment agent and the residual amount of the original organic substance. The FN cloth that has undergone surface chemical treatment should be within the range of 0.05% to 0.25% according to the IPC standard.

Now the world’s electronics industry is developing rapidly, the electronic fabric has also been put forward higher requirements. To meet the new requirements of the electronics industry, electronics manufacturers not only research and development of new coupling agents and additives, and other chemical treatment of new technologies, but also research and development of a number of chemical processing combined with the new treatment methods, Such as high-pressure water jet method. Japan successfully developed this new electronic cloth known as the SP cloth. SP cloth processing principle is the use of high-pressure water jet, so that warp and weft exposed to the cloth part of the fiber evenly spread into flat, also known as the “open fiber” cloth. There is also a physical processing method, the purpose of the processing and the same as the open cloth, the difference is that it uses mechanical scrape method to achieve the effect of open fiber. It is said that this method can achieve the effect similar to the SP cloth, does not require high-pressure water injection system and extrusion drying device can be combined in the surface chemical treatment unit can also be combined in the inspection machine, the processing cost is lower. Further, there is a thermal burn-over method in which the glass cloth is subjected to an over-burning treatment at a temperature higher than the ordinary process or for a longer time in the thermal cleaning process to appropriately reduce the tensile strength of cloth, the cloth brittle, so as to improve the drilling of the cloth processing and improve the quality of the hole wall. After the burning of the glass cloth called cloth or brittle cloth.

Electronic grade fiberglass is an indispensable new engineering material and high-quality structural material for the further development of the electronics industry and scientific and technological progress, so the market prospects will be getting better and better. As an electronic grade fiberglass manufacturer not only to improve the number of electronic-grade glass fiber products, but also to continuously improve product quality, increase product specifications, expand product variety, in order to meet the market’s operational development.

Brief discussion on Some Technical Problems in the Production of E- Glass Fiber Cloth

Electronic grade fiberglass cloth (hereinafter referred to as “electronic yarn and electronic cloth”) is not only a rising star in the series of electrical insulation glass fiber products, but also a essential base material for CCL and printed circuit board .

Electronic grade glass fiber nurture grow in the “mother” of the tank furnace, and with the gradual development of the tank furnace and continuous improvement and growth, drawing from the crucible into the tank furnace drawing process. Since the 20th century, 60 years, the glass fiber products enter the electronics industry as the representative of the emerging industrial applications and become one of the main raw materials. Because of its high-speed and high efficiency gradually replace the traditional crucible method of production technology and promote the development of tank furnace fiber drawing technology so that most of the spinning yarn turn into the tank furnace production. At the same time, the rapid rise of emerging electronics industry plays a role in fueling on the replacement of electronic grade glass fiber products.

In this paper, I work on numbers of technical issues on the practice of electronic yarn, electronic cloth.

Electronic yarn production quality control
The electronic yarn adopts the multi-drawing process of multi-hole and large-leakage board of the tank furnace, which made by forced cooling, modified starch-type infiltration agent, roller-type monofilament oil impregnated, , and finally the use of big package frequency conversion velocity modulation drawing and the leakage board temperature compensation technology. At present, commonly used electronic yarn brands include G-75, E-225, D-450, now add DE-300, D-900, D-1800, BC-1800, BC-3000 and C-1200 , Monofilament diameter from the original 5μm, 7μm, 9μm, expanded to 4μm, 4.5μm. Generally speaking, the control electronic yarn quality mainly includes several aspects.

Physical properties. Properties affecting the quality of electronic yarns include tensile strength, electrical properties, tex control level and control accuracy, Sizing agent content and consistency. The forming and appearance quality of the precursor yarn also have a significant effect on the quality of the electronic yarn. Therefore, before the twisting , the original fiberglass need to be in accordance with the requirements of the original test one by one, If the glass composition in the alkali metal oxide content exceeds the standard, tex number exceeded, sizing agent content exceeding, uneven oil, forming bad, stains, bumps of raw fiberglass are not in line with the quality requirements of electronic yarn.

No joints are allowed during twisting and the original package is too small should be removed. For example, the nominal mass of 4 kg of the original fiberglass, according to the fixed length of the actual requirements of about 3.5kg, 1.5kg below the original fiberglass is not used. The nominal weight of 8kg of the original fiberglass, the actual weight of about 7.2kg, the minimum access to the weight of 2.5kg. Non-full tube of the original wire in the twister is not connected, Weaving as weft.

Single yarn for weaving electronic cloth to be used to change the program several times forming the principle of winding into a bottle-shaped tube yarn. Multi-forming is a multi-cycle after the cycle of winding into a full pipe. This winding principle can only be increased by increasing the number of loop cycles of the winding, the pitch and the pitch of each layer of yarn can be selected to be larger, and the forming cone angle can also be much larger than that of one forming step, ,and the tube structure is stable, rarely appear, the phenomenon of collapse, high-speed withdrawal is not easy when the ring off, forming a more ideal.

Electronic yarn purification requirements are high, does not allow stains, water stains, perspiration and flying wire, dust and other pollution, large package of single yarn cheese is not allowed to have joints, a full tube yarn twisting a long time, 4kg of 68tex yarn in the twister for processing nearly 7h, 8kg of yarn is nearly 14h, once the contamination of the entire tube should be scrapped, therefore, it is important to keep the electronic yarn clean as much as possible.

The water content of the electronic yarn should be controlled within a certain range. In the weaving process, the electronic yarn moisture content is too high and the yarn is sticky, back resistance is too large, resulting in warping and weaving difficult. In general, the requirements of electronic yarn moisture content control in 0.2%, In practice if they can reach 0.1% or less is better.

The stiffness of the electronic yarn is controlled in a suitable range. The stiffness of the single yarn is closely related to the sizing agent formulation, the sizing agent content, and the coating condition of the sizing agent. It is also related to the twist condition and the moisture content of the single yarn. Starch-based infiltrating agent to improve the oil content, yarn stiffness decreased, adjust the stiffness of yarn, it is necessary to master this law.

Electronic yarn adapt in batches and modified by modified corn starch sizing

Electronic cloth for warp tension uniformity demanding, therefore, the precision control warping tension and to maintain uniformity of warp tension are the key to the whole process. The warp tension of the warping in batches is divided into several parts, such as single yarn tension, warping tension and winding pressure, which can be fully adjusted and controlled to meet this requirement. The main purpose of using modified corn starch sizing is to improve the weaving performance of the warp. Electronic yarn is a collection of single-fiber, if one of the separation is likely to cause single-fiber breakage, and the adjacent yarn winding, which is the reasons for fluff and broken. Therefore, it is desired to increase the bundling property between single fibers by sizing. In addition, the low-twist single yarn sizing also has a stable twist effect, thereby ,so that enhance the weaving performance.

The modified corn starch has high water dispersibility and high water solubility, slurry viscosity stability, Gel phenomenon is significantly reduced, the slurry is not easy to freeze when cooled. The fluidity of the slurry is also improved, and the adhesion with the glass fiber is also improved. Serosa more transparent, tough and flexible, serous surface is more smooth and detailed, with good weaving performance. Electronic yarn sizing is to improve the weaving performance, while the sizing rate directly affects the weaving sizing performance. In general, the sizing rate is slightly higher, weaving performance is better, but when the sizing rate exceeds a certain limit, the weaving performance of the warp decreased. The best sizing rate of electronic yarn sizing, generally within the range of 2% to 6%. And the difference between the varieties is not, the overall trend is thin spun yarn sizing rate is slightly higher; high quality requirements, especially for hairiness requirements of varieties of sizing rate should be slightly higher. Slightly worse quality of the warp or weaving conditions are poor, the sizing rate is also set a little higher. In addition, the required slurry to be easy desizing , thermal residue after washing less, not to cause the surface chemical treatment, CCL and circuit board processing and application of obstacles. Special attention should be paid to the burning of the slurry, the residual ash requirements shall not exceed 0.3%; and shall not contain trace metal salts.

Discussion on influencing factors of utilization ratio of glass fiber infiltrating agent

In recent years, fiber glass strand and its products falling prices, and raw material prices rising, prices had a great influence on the rising cost of energy. How in the presence of these unfavorable factors to reduce costs, improve efficiency becomes the key to glass fiber enterprise survival and development.

Soakage agent cost holds a large proportion in glass fiber production, how to reduce soakage agent consumption in production, improve the utilization efficiency of soakage agent, become the urgent matter. Reduced consumption, the first should be thoroughly analyzes the influential elements of the soakage agent consumption, to adopt technology reform, actively adopt new technology, new technology of saving energy and reducing consumption, radically reduce the consumption of raw materials, in achieve the goal of product quality at the same time, ensure the realization of the cost control target.

The utilization of soakage agent
The concept of utilization
Soakage agent utilization is ratio that soakage agent content coated by glass fiber strand and consume total of soakage agent by producing these strands. Form (1) said:

In the form
C0 —the utilization of soakage agent,%;
C1 —the strand combustible content,%;
C2 —the solid content of water soakage agent,%;
M1 —the strand weight,kg;
M2 —weight for water soakage agent consumption,kg。

The influencing factors of utilization

In production, there are many factors that can affect water soakage agent consumption, among various factors are inextricably linked. Below factors influence the utilization ratio of soakage agent in production of a detailed analysis.

Production factors
Different and the same variety in different yield and other factors unchanged, under the condition of soakage agent utilization statistics are shown in table 1, the relationship between yield and utilization ratio is shown in figure 1.
Table 1 utilization statistics of soakage agent

Figure 1 relationship between output and utilization

You can see through the table 1 and figure 1, at the time of production is not particularly small, utilization rate basically stable, but the yield is too small, soakage agent utilization rate is relatively low, this is because the first production, soakage agent in circulating water system loss relative to the total soakage agent consumption is too large, lead to formula in M2 artificially high, cause soakage agent utilization is too low.

Strand combustible content and factor of soakage water solid content
Both strand combustible content and the solid content of water soakage agent has a very close relationship with Soakage agent utilization, a separate analysis could not realize, so the unified consideration of both.

When a certain solid content, in order to ensure sufficient combustible content in the coating rate, under the condition of the same homework (test is to use oil speed to achieve improved), coated strand on the number of soakage agent content after reaching a certain value, the strand combustible content will have a limit value, at this time no matter what the strand wire coating soakage agent content increase, combustible content is close to the limit, as shown in figure 2.

Figure 2 oil change curve
Visible, the demand of the strand combustible content is higher, but solid content is low, so, in order to ensure that the strand combustible content in the qualified range, only improve the oil linear velocity, and thus brings more problems, the soakage agent utilization reduce, under the condition of limit utilization rate is almost zero.

Strand can touch of the soakage agent + water quantity is certain, when stained with overburden amount reach saturation, more stained by strand agent will be replaced by water, resulting in the loss of soakage agents, reducing the efficiency of soakage agent.

When solids have been able to meet the requirements of the strand combustible content, while the strand combustible content in certain, the relationship between how much of solid content and the utilization of discretion is shown in figure 3.

Figure 3 the relationship between solid content and utilization

You can see from figure 3, solid content is low, utilization rate is higher. Therefore, strand combustible content and solid content must be in appropriate range, soakage agent utilization can reach ideal level.

Weight for water infiltration agent consumption
This is the result of joint action of many factors, in production, combustible content, solid content under the condition of relatively stable, glass fiber production field control level and the waste water soakage agent determines the soakage water consumption of the weight of high or low, relatively stable production and the sustainability of the single variety, to reduce the waste of water soakage agent weight has obvious effect.

Greased speed range of manufacturing has a large span (the same variety, same flow, oil frequency can differ 9), but oil frequency reach a certain extent, oil will not significantly change, frequency of oil gap among different cameras. Spray quantity is big, the position of the strand bunches drip down, in the drawing line the agent thrown around a lot, you can see through the table 2 and figure 4 wire drawing parameters right or not affect soakage agent consumption.
Table 2 Drawing on soakage agent consumption statistics

Figure 4 loss ratio

To improve these problems, the consumption of water soakage agent will reduce a lot, to improve the utilization rate of soakage agent has very great help.

To sum up, the utilization ratio of soakage agent is the result of the interaction of various factors, the stability of the production is the basis of the various discussions, and production control level also plays a very important role in it. Strand combustible content and solid content of high or low must be in the proper range, within the scope of the soakage agent utilization can reach ideal level.

Use of e-glass fiber cloth Flattening Techniques

Electronic Fiberglass Cloth (hereinafter referred to as e-glass fiber cloth ) usually made up of warp and weft yarns composed of a plurality of filaments.To meet the rapid development of the electronics industry, CCL enterprises require e-glass fiber cloth warp and weft single fiber can be spread evenly, forming flat, known as the “open fiber.”through the opening treatment e-glass fiber cloth can improve the resin impregnation, thereby improving the peel strength of copper clad laminate and circuit board drilling processability. The general opening of e-glass fiber cloth usually using three ways for fiber open ,such as high-pressure spunlaced fiber, roller open and high-pressure water spray,As the former huge investment, usually e-glass fiber cloth production plant using the latter two open fiber way. Roller opening technology and High Pressure Water Spraying Technology.

Contrast of Two Kinds of Opening

Roll open and high-pressure water spray fiber effect comparison in Table 4.
Table 4 is the pass rate comparison of 7628 e-glass fiber cloth in the two open-fiber way.

seen from Table 4, under the same air permeability standards, the high-pressure water-jetting of the e-glass fiber cloth,the greater the pass rate than the open-roll, so under the correct choice of the nozzle type, jet height and the injection pressure, the high pressure Water sprayed fiber way has a better opening fiber effect than the open-roll fiber.

The flattening(open fiber) of e-glass fiber cloth has become a must be in production process . In this paper, through the comparison of the principle and application about the two methods of open fiber analysis and analysis of the fiber technology to improve, I believe that high-pressure water spray open fiber way has a better effect than the open-fiber roller, which provides a more comprehensive guide on improve the e-glass fiber cloth opening technology.

High Pressure Water Spraying Technology

Working Principle

High-pressure water jet fiber technology works shown in Figure 2. e-glass fiber cloth through a number of guide rollers composed of the opening machine, through the high-pressure pump and nozzle, the high-pressure water (soft water) sprayed on the front and back of e-glass fiber cloth, there is a adjustable plate in the bottom , so that e-glass fiber cloth weft and warp yarn fibers can uniformly dispersed.

Figure 2 high-pressure water jet fiber works
Through the circulating pump, two filtration system, storage tank (plus pay), water tank to form a soft water circulation system. To ensure that the circulating soft water to achieve a dynamic balance, circulating water pump driven by the inverter motor. Work should always observe the two filter system pressure, once the filter bag, to clean up in time to prevent soft water overflow.

The selection of technical parameters
The open fiber effects of the e-glass fiber cloth depends on the high-pressure pump outlet pressure, nozzle type and nozzle-to-cloth distance. Different types of fiberglass fabrics, the choice of the parameters are also different. Usually the thinner the e-glass fiber cloth, the lower the pump pressure, the smaller the nozzle flow, the nozzle to the cloth spacing to be large, it is necessary to ensure adequate open fiber, but also can not produce water stains in the fabric.

Nozzle selection and distribution
Nozzle angle
Nozzle angle and the jet height and the relationship between the spray shown in Figure 3 and Table 2.

Figure 3 The relationship between the nozzle angle or the jet height and the spray
Table 2 Spray data records at different spray heights at different spray angles

From Figure 3 and Table 2 we can see the relationship between the spray angle, jet height and the spray. Taking into account the need to open a larger jet force, the general choice of spray angle is 65 ° ~ 80 °, the spray height is range from 70 ~ 100 mm, spray overlap is range from 1/4 spray from the above data can be roughly determined between the nozzle distance.

Nozzle pressure
The relationship between the ejection force , nozzle pressure and ejection height is shown in Fig.4
As is clear from Fig. 4, the ejection force is inversely proportional to the ejection height and proportional to the nozzle pressure. After the test contrast, the nozzle pressure with 7628 cloth is 3 ~ 5 MPa , the nozzle pressure with the thinner fiberglass cloth is 1 ~ 3 MPa.

Nozzle flow
Nozzle manufacturers generally will provide nozzle flow and pressure table, if the selection of data beyond the scope of the table can be calculated using the following formula.

Figure 4, the relationship between injection pressure, jet force and jet height

Among them

Qx ——the selection of the nozzle flow,l/min;
px ——the pressure of the nozzle flow,MPa;
Q———the nozzle flow rates on the table,l/min;
p——the nozzle pressure on the table,MPa。

Usually a single nozzle flow rate is 200 ~ 300l / min of the e-glass fiber cloth with width 1270mm,In the high-pressure, the soft water in the nozzle with a high-speed flow, especially after the soft water recycling, which inevitably mixed with glass fiber impurities, so that the nozzle mouth wear increased, so the opening nozzle materials are creamic, its service life is 20 to 30 times than stainless steel .

Water spray open fiber results
The air permeability data of the 7628 e-glass fiber cloth measured by the water spray open showed in Table 3
The air permeability data of the e-glass fiber cloth measured by the high-pressure water sprayed open showed in table 3

Roller opening technology

Working principle
The e-glass fiber cloth is wrapped on the perforated roller by the front and rear tension rollers, and the plum roller concentric with the perforated roller is driven by the variable frequency motor. The device is placed in a water filled water tank. when equipment operation, Plum roller vibration generated by the water roller through the porous roller to the fiberglass cloth, so that the e-glass fiber cloth warp and weft fibers to disperse, to achieve the purpose of opening.

Figure 1 roller open fiber works
Theoretical analysis
According to the forced vibration system with damping formula

In the formula:
y———Vibration displacement,mm;
ω———Angular velocity,rad /s;
t———Phase angle, mm /s
u———Vibration velocity,mm /s

According to the vibration mechanical wave principle

In the formula:
I———The average energy density is the wave vibration intensity,w /m2;
ρ———Medium density,g /cm3
Substituting (1) into (2) yields

From (3), the vibration intensity of the wave is proportional to the cube of the rotational speed and amplitude. Because the effect of opening the fiber is proportional to the vibration intensity of the wave, that is to say, increasing the rotational speed, increasing the petal number of the plum roller or increasing the petal will increase the vibration intensity of the wave. But the speed and the number of petals and the size of the increase to consider the e-glass fiber cloth fiber strength, that is, open fiber can not cause hairiness and weft oblique, hairiness and latitude to ensure control in the allowable range, select the appropriate speed and plum roller.

Open process
Open the process of fiber should pay attention to the following questions:
The speed of the perforated roller driven by the servo motor (see Fig. 1) should be synchronized with the master. To ensure fabric tension, the servo motor speed can be set on the touch screen by the manual adjustment.
In order to prevent the water wave oscillation so that the cloth from the porous roller, you can add a roller in the roller (see Figure 1), the gap between the porous roller and the pressure roller can be adjustable.
In consideration of the e-glass fiber cloth opening process with hairiness and weft obliquity, we adopt thirty-two petals roller, and then according to the variety of cloth and yarn source, select the plum roller speed, usually thin cloth is 200 ~ 400 r / m, thick cloth is 400 ~ 500 r / m.

Open fiber effect
The air permeability of the e-glass fiber cloth directly reflects the effect of the fiber opening. The air permeability of the unopened 7628 e-glass fiber cloth is generally 6-8 cm / s, and the air permeability of the 7628 e-glass fiber cloth after the roller is opened is less than 3 cm / s . Respectively, take the width of e-glass fiber cloth on the left, middle and right part of the three samples measured permeability, measured in Table 1.
Table 1 the air permeability after the opening of the fiberglass roller cloth