Article catalogue:
- 1 、What are the matters needing attention in fiberglass construction?
- 2 、Where are the FRP winding machines used? What is the scope of application?
- 3 、What exactly do fiberglass operators do?
- 4 、If you want to know the manufacturing process and process of fiberglass, the more detailed the better. Thank you.
- 5 、What is the operation flow of fiberglass chopping machine?
- 6 、How is the FRP winding machine wound? Is there a pattern?
What are the matters needing attention in fiberglass construction?
Matters needing attention in construction of glass wool
The main production process of glass wool is to melt the mixture of various raw materials in a certain proportion into liquid glass in the melting cellar, which forms a stable liquid flow through the platinum leakage plate of the front furnace, and then flows through the spinning machine to the high-speed rotating centrifuge with small holes in the side wall. Under the action of centrifugal force, the liquid glass is thrown into a fiber. After that, under the action of the mixed gas ejected at a high speed, the fiber is pulled into glass fiber, and the glass fiber is sprayed with binder while landing the cotton-collecting mesh belt, and then compacted, solidified, crosscut and longitudinally cut to form a certain specification of the product. After zui, the bundles are compressed, packed and packed into storage.
Construction and installation method
The common installation method of zui for steel structure is to lay glass wool on the purlin perpendicular to the direction of the purlin from the end wall.
Application field
1. Roof with thermal insulation, sound absorption material (50kg/m3).
two。 Thermal insulation materials for buildings.
3. Venue (cinema, KTV …) And equipment, (computers, air compressors.) Sound absorption treatment.
4. Insulation of air conditioning ducts, refrigerated and refrigerated warehouses.
Because of its large number of tiny air gaps, glass cotton felt plays the role of thermal insulation, sound absorption, noise reduction and safety protection, so it is a building thermal insulation, sound absorption and irritability reduction material.
1. Unique technology, the rebound rate after compression packaging is 99.2%.
two。 Soft and slender glass fiber zui greatly reduces the production of flying catkins during construction.
Matters needing attention in construction of glass wool
3. Sound absorption and noise reduction can effectively prevent sound transmission.
4.A1 grade non-combustible material, simple construction, random cutting.
5. Balanced colony anti-mildew, anti-aging, anti-corrosion to ensure a healthy environment, low moisture absorption, stable physical properties.
During the construction of glass cotton felt, there are many projects that need to be discussed and customized. This paper mainly talks about some construction methods of glass cotton felt, what kind of materials are needed in the construction process and what key points need to be remembered and learned during the construction process. Let’s take a look.
1. Construction method
Process: the base of the wall-water vapor barrier layer-elastic wire grading-setting vertical tail wing-fin lateral performance-filled sound absorption board-sealed fiberglass dust-installation of aluminum mesh-delamination, closed-angle aluminum-quality control.
In the case of a concrete wall, you can immediately apply a layer of polyurethane waterproof paint 1.5mm thick. In the case of the wall, the unit should promptly clean the 20-thick cement mortar on the surface at 1:3 and apply a layer of waterproof paint.
According to the * height of each room’s construction, set it up to the light steel keel (see waterproof and floor tiles and walls should be set with reserved or closed base), the keel top corresponds to the creation of paradise and earth’s (if not breaking the ground ridge can be directly fixed by floor and ceiling light steel keel or wooden nails), and then press the spacing for the 600mm grading support or wooden nails to install the keel. After the keel is installed and then installed in the vertical horizontal keel fin gap, the horizontal and vertical tail is filled with sound-absorbing cottonseed elements that are a flat horizontal surface of the keel. The light is glued to the metal frame to join the keel steel frame glass and then sealed with the VERSAMAT aluminum meshing rack mounted on the metal frame with pressure fixing aluminum mesh aluminum rivets. The distance between the glass wool felt is 600 “1200 mm and the aluminum alloy doors and windows are closed to yin and yang.
Glass wool
Glass cotton is made of centrifugal glass cotton felt with Owens Corning (referred to as OC) unique patented centrifugal technology, which processes the molten glass fibrosis and the environment-friendly formula binder based on thermosetting resin. it is a kind of elastic felt made of glass fiber with a diameter of only a few microns, and different moistureproof veneers can be selected according to the requirements of use. It has a large number of tiny air pores, which make it play the role of thermal insulation, sound absorption and noise reduction and safety protection. it is the best material for thermal insulation, sound absorption and noise reduction of steel structure buildings. Glass wool belongs to a category of glass fiber, which is a kind of artificial inorganic fiber. Using quartz sand, limestone, dolomite and other natural ores as the main raw materials, combined with some soda ash, borax and other chemical raw materials to melt glass. In the melting state, with the help of external force blowing into flocculent fine fibers, the fibers and fibers are intersected and intertwined with each other, showing a lot of small gaps. This kind of gap can be regarded as a pore. Therefore, glass wool can be regarded as a porous material with good thermal insulation and sound absorption properties.
Where are the FRP winding machines used? What is the scope of application?
The application range of FRP winding machine:
The FRP winding machine is mainly used for winding the outer protective layer of the thermal insulation pipe and the anti-corrosion of the outer wall of the steel pipe is the equipment for producing FRP storage tanks and pipes. The main working principle is to protect and prevent the outer layer of fiberglass pipes or tanks by rotating winding according to certain technological requirements.
The FRP winding machine can be used for the manufacture of FRP cable pipes, FRP chimneys, sewage pipes, desulfurization towers and other pipes with a diameter of less than 50-1500mm. It can also be used in other industries to manufacture linear winding products. It is mainly composed of man-machine interface, programmable controller, spindle frequency conversion system or magnetic transmission system, trolley track, transmission head, control cabinet and so on.
Advantages of FRP winding machine:
The FRP winding machine has the advantages and characteristics of fast response speed, flexibility and flexibility, strong anti-interference ability, easy to use, convenient adjustment, flexible assembly, multi-use of one machine, and so on. its advantages make the FRP winding machine favored by colleagues in the domestic FRP industry and sold abroad.
What exactly do fiberglass operators do?
Untwisted roving is made of parallel filaments or parallel monofilaments. According to the glass composition, the untwisted roving can be divided into non-alkali glass roving and medium alkali glass roving. The diameter of glass fiber used in the production of glass roving ranges from 12 to 23 μ m. The number of untwisted roving ranges from 150 to 9600 (tex). Untwisted roving can be directly used in some composite process molding methods, such as winding, pultrusion process, because of its uniform tension, it can also be woven into untwisted roving fabric, and the untwisted roving can be further shorted in some applications.
The main results are as follows: (1) the non-twist roving suitable for spray forming of fiberglass should have the following properties: ① has good cutability and less static electricity during continuous high-speed cutting; ② roving has high efficiency of dispersion into precursor after cutting, that is, high beam splitting rate, which usually requires more than 90%; the filament cut by ③ has excellent mold covering property and can be covered in every corner of the mold. ④ resin is soaked quickly, easy to be rolled by rollers and easy to drive away air bubbles; ⑤ precursor drum has good decomposing performance and uniform roving linear density, so it is suitable for all kinds of spray gun and fiber conveying system. The untwisted roving for spraying is made of multiple strands of filaments, each of which contains 200 glass fiber monofilaments.
(2) untwisted roving SMC for SMC, namely sheet molding plastic, which is mainly used to press automobile parts, bathtubs, water tank plates, purification tanks and various seats.
Fiberglass checkered cloth
Wait. When manufacturing SMC sheet, SMC roving should be cut into lin (25mm) length and dispersed in resin paste, so the requirements for SMC roving are good short cutting, less wool, excellent antistatic property, and short cutting will not adhere to the knife roller when cutting. For colored SMC, the untwisted roving is soaked by resin in a resin paste with high pigment content. Usually, SMC roving is usually 2400tex, and 4800tex is also used in a few cases.
(3) the untwisted roving winding method is used to manufacture various caliber glass steel pipes, storage tanks and so on. The number of untwisted roving for winding is from 1200 to 9600, winding large pipes and tanks tend to be direct untwisted roving, such as 4800tex direct untwisted roving. The requirements for winding untwisted roving are as follows: ① has good ribbon, flat ribbon; ② roving has good disintegration, and does not detach from the cylinder and does not form a “bird’s nest”-shaped disorderly filament; ③ tension is uniform, no drape phenomenon; ④ linear density is uniform, generally less than ±7%; ⑤ roving has good permeability and is easy to be wetted and soaked by resin when passing through the resin groove.
(4) pultrusion with untwisted roving is used to manufacture all kinds of profiles with consistent cross section, which is characterized by high glass fiber content and high unidirectional strength. The untwisted roving for pultrusion can be a combination of multiple strands or a direct untwisted roving with a linear density ranging from 1100 to 4400. All kinds of performance requirements are roughly the same as the winding untwisted roving.
(5) one of the important uses of untwisted roving for weaving is to weave checkered cloth or unidirectional untwisted roving fabrics of various thicknesses, which are mostly used in hand paste FRP molding process. There are the following requirements for strong non-twist roving: good wear resistance of ①; good ribbon property of ②; forced drying of ③ weaving roving before weaving; uniform tension and drape of ④ roving; good disintegration of ⑤ roving; and good impregnation of ⑥ roving.
(6) No-twist roving for preform in the preform process, the non-twist roving is cut short and sprayed on the net of the predetermined shape, and a small amount of resin is sprayed to fix the fiber mesh, then the formed fiber mesh is moved into the metal mold and hot-pressed with resin to form the product. The performance requirements for non-twist roving in this process are basically the same as those for jet roving.
Untwisted roving fabric (plaid)
Checkered cloth is a plain fabric of untwisted roving, which is an important base material of hand-pasted FRP. The strength of the plaid cloth is mainly in the warp and weft direction of the fabric. for the situation where high warp or weft strength is required, it can also be woven into a unidirectional checkered cloth, which can arrange more untwisted roving in the warp or weft direction.
The quality requirements for checkered cloth are as follows: ① fabric is uniform, the cloth edge is straight, the cloth surface is flat and sheet-like, free of stains, fuzz, creases, wrinkles, etc.; ② warp and weft density, area and weight, cloth width and winding length are in line with the standard; ③ winding on a solid paper core, winding neatly; ④ fast, good resin permeability; ⑤ fabric made of laminated materials dry, wet mechanical strength should meet the requirements.
The composite laid with checkered cloth is characterized by low interlaminar shear strength and poor compressive and fatigue strength.
If you want to know the manufacturing process and process of fiberglass, the more detailed the better. Thank you.
Molding Technology of Fiber reinforced Epoxy Resin Composites
I. Preface
Compared with traditional materials, composite materials have a series of irreplaceable properties, which have developed rapidly since the second occupation. Although the output is small (according to French Vetrotex company statistics, the global composite materials reached 7 million tons in 2003), but the level of composite materials has been one of the indicators to measure the scientific and technological and economic level of a country or region. The United States, Japan and Western Europe have a higher level. North America and Europe account for 33% and 32% of global output, respectively, while Asia, dominated by China (including Taiwan Province) and Japan, accounts for 30%. Chinese mainland in 2003 Boban fiber reinforced plastic (glass fiber and resin composite materials, commonly known as “fiberglass”) more than 900000 tons, has ranked second in the world (1.69 million tons in the United States in 2003, less than 700000 tons in Japan).
The composite material is mainly composed of reinforced material and matrix material.
Reinforced materials: the main mechanical properties of composites that do not constitute a continuous phase, such as glass fiber in FRP and carbon cellulose in CFRP (carbon fiber reinforced plastics) are reinforced materials.
Matrix: the single material that makes up the continuous phase of the composite, such as the resin in GRP (epoxy resin mentioned in this article) is the matrix. Y
According to the different matrix materials, the composites can be divided into three categories:
Resin composite material
Metal matrix composites
Inorganic non-metallic matrix composites, such as ceramic matrix composites.
In this paper, epoxy resin matrix composites are discussed.
1. Why use epoxy resin as matrix?
The curing shrinkage is low, only 1%, 3%, while the unsaturated polyester resin is as high as 7%, 8%.
Strong bonding force
There is stage B, which is beneficial to the production process.
Can be cured at low pressure with very low volatile content
After curing, the mechanical properties, chemical resistance and electrical insulation are good.
It is worth pointing out that epoxy resin has better organic solvent resistance and alkali resistance than phenolic and unsaturated polyester weight grease, but poor acid resistance, brittleness and toughness after curing.
2. Properties of epoxy FRP (according to ASTM)
Taking the glass fiber reinforced epoxy resin made by FW (filament winding) method as an example, the glass fiber reinforced epoxy resin was compared with steel.
Table 1 comparison of properties between GF/EPR and steel
Glass content GF/EPR (glass fiber content 80wt%) AISI1008 cold rolled steel
Relative density 2.08 7.86 V
Tensile strength 551.6Mpa 331.0MPa
Tensile modulus 27.58GPa 206.7GPa
Elongation 1.6% 37.0%
Bending strength 689.5MPa
Bending modulus 34.48GPa
Compression strength 310.3MPa 331.0MPa
Cantilever impact strength 2385J/m
Flammability (UL-94) Vmuro
Specific heat capacity 535J/ kg ·k 233J/ kg ·k
Expansion coefficient 4.0 × 10-6k-1 6.7 × 10-6k-1
Hot deformation temperature 204C (1.82MPa)
Thermal conductivity 1.85W/ m ·k 33.7W/ m ·k
Dielectric strength 11.8 × 106V/m
Water absorption 0.5% (24 h)
Table 2 specific strength and specific modulus of several commonly used materials and composites
Density g/cm3 tensile strength × 104MPa modulus of elasticity × 106MPa specific strength × 106cm specific modulus × 109cm
Steel 7.8 10.10 20.59 0.13 0.27
Aluminum 2.8 4.61 7.35 0.17 0.26
Titanium 4.5 9.41 11.18 0.21 0.25
FRP 2.0 10.40 3.92 0.53 0.21
Carbon fiber / epoxy resin 1.45 14.71 13.73
Carbon fiber / epoxy resin 1.61049 23.54
Aramid fiber / epoxy resin 1.4 13.73 7.85
Boron fiber / epoxy resin 2.1 13.53 20.59
Boron fiber / aluminum 2.65 9.81 19.61 0.75 c2
2. Brief introduction of molding process of fiber reinforced epoxy resin composites.
1. Hand paste molding (hand lay up)
(1) the summary is applied on the surface of the mold in turn.
Mold release agent
Glue coat
A layer of moderately active liquid thermosetting resin with a viscosity of 0.3-0.4PaS (after the gel coat has solidified)
A layer of fiber reinforced materials (glass fiber, aramid, carbon fiber.), fiber reinforced materials include surface felt, untwisted roving (checkered cloth) and so on. The resin is impregnated with the fiber reinforced material with a hand-held roller or brush, and the air bubbles are removed to compact the base. The laying operation is repeated many times until the design thickness of the product is reached.
The resin is cured at room temperature due to polymerization. Can be heated to accelerate curing.
(2) Raw material F gb NG ^
Resin unsaturated polyester resin, hexenyl ester resin, epoxy resin, phenolic resin and so on.
Fiber glass fiber, carbon fiber, aramid and so on. Although thick aramid fabric is difficult to soak the resin by hand, it can also be used.
The core material is arbitrary.
(3) advantages
1) suitable for small production
2) it can be molded at room temperature, the investment of equipment is low, and the depreciation cost of mould is low.
3) can manufacture large-scale products and complex products
4) Resin and reinforced materials can be combined freely, so it is easy to design materials.
5) Local reinforcement of ribs can be used and metal parts can be embedded.
6) A free color and glossy surface can be obtained by using a glue coat (such as open molding, one side is not smooth)
7) the content of glass fiber is higher than that of spray molding.
About 50% of untwisted roving
Fabric 35% Muay 45%
Short cut strand felt 30% 40%
(4) shortcomings
The main results are as follows: 1) it belongs to labor-intensive production, and the product quality is determined by the training degree of workers;
2) the content of glass fiber can not be too high; the resin needs low viscosity to be easy to operate manually, the content of solvent / styrene is high, and the mechanical and thermal properties are limited.
3) the molecular weight of resin for hand paste is low; it may be harmful to human health and safety than the resin with high molecular weight.
(5) typical products
Warship, wind turbine blade, amusement equipment, cooling tower shell, building model.
2. Resin transfer molding (RTM)
(1) Summary
RTM is a method of closed mold and low pressure forming.
Place the fiber reinforced material between the upper and lower mold; close the mold and clamp the mold; inject the resin under pressure; open the mold after the resin is cured and remove the product.
Before the resin gelation process begins, the resin must be filled with the mold cavity, and the pressure urges the resin to be quickly transferred to the mold and impregnated with the fiber material.
RTM is a low pressure system, resin injection pressure range of 0.4-0.5MPa, when manufacturing products with high fiber content (volume ratio more than 50%), such as aerospace parts, the pressure can even reach 0.7MPa.
Fiber reinforcements can sometimes be pre-molded in one mold (with binder) and then injected into the second mold. In order to improve the ability of resin to soak into the fiber, vacuum assisted injection (VARI-vacuum saaistedrsin injection) can be selected.
Note that once the resin is soaked into the fiber material, the resin injection port should be closed so that the resin can be cured. Injection and curing can be carried out at room temperature or heating. Moulds can be made of composite materials and steel materials. If the heating process is adopted. Steel moulds should be used.
(2) Raw materials
Resin: general multi-purpose epoxy, unsaturated polyester, vinyl grease and phenolic; when heating, high-temperature resin double maleimide resin can also be used.
The thermoplastic resin RTM was developed by Vetrotex Company of France.
Fiber: arbitrary. Commonly used glass fiber continuous felt, stitch knitting materials (the gap between the fibers is obtained from resin transfer), untwisted roving, glass fiber and thermoplastic composite yarn and its fabric and sheet (French Vetrotex trade name TWINTEX).
Core material: no honeycomb, because the honeycomb space is filled with resin, the pressure will lead to its damage. Solvent-resistant foaming materials PU, PP, CL, VC and so on can be used.
(3) advantages
1) the fiber content of the product can be high, and the part that is not soaked by resin is very few.
2) closed mold forming, good production environment
3) low labor intensity and lower requirements for workers’ technical proficiency than hand paste and spray molding.
4) the product has light on both sides, it can be used as a product with surface glue coat, and its precision is relatively high.
5) the forming cycle is short
6) the product can be large-scale.
7) the strength can be directional according to the design requirements.
8) it can be integrated with core village and insert.
9) the cost is lower than that of injection equipment and mold.
(4) shortcomings
1) it is not easy to make smaller products
2) because of the pressure, the mold is heavier and more complex than the mold used in hand paste and spray process, and the price is higher.
3) there can be unimpregnated materials, resulting in waste of leftovers.
(5) typical products
Small aircraft and auto parts, bus seats, instrument housings
3. Filament winding (FW)
(1) Summary
Direct untwisted roving is usually used as reinforcing material. The roving is arranged on the frame. The roving is unwound from the frame, and through the tension system, resin groove and wire winding nozzle, the trolley drives it to and fro and wound on the rotating mandrel (mold). The filament winding angle and fiber arrangement density are designed according to strength and accurately controlled by the ratio of mandrel (mold) speed to the reciprocating speed of the trolley. The wound composite products will be demoulded after curing.
There is no need to release the mold for some products which are sealed at both ends, and the mandrel is wrapped in the composite product as an inner lining.
(2) Raw materials
Resin: any. Epoxy, unsaturated polyester, vinyl grease and phenolic resin.
Fiber: arbitrary. Untwisted roving, sewn knitted and non-woven fabrics. In the production of pipe cans, surface felt and short-cut strands are commonly used as lining materials.
Core material: available. Although composite products are usually single shells, they are generally not used.
(3) advantages
1) because the fiber is laid in a reasonable linear shape and bears the load, the structural properties of the composite products can be very high.
2) because of the combination of the same inner lining, the products with corrosion resistance, pressure resistance and heat resistance can be obtained.
3) products with closed ends can be manufactured.
4) the material laying is fast, economical, non-twist roving is used, and the material cost is low.
5) it can be measured by resin, but the resin content of the impregnated fiber can be controlled by extrusion or die.
6) Dali production and automation
7) Mechanical molding, the material and direction of the composite are uniform, and the quality is stable.
(4) shortcomings
1) the shape of the product is limited to cylindrical or other rotational bodies
2) the fibers are not easy to be arranged accurately along the length of the product.
3) for large products, the cost of core mold is high.
4) the appearance of the finished product is not “molded” and is not satisfactory.
5) for products under pressure, if the resin is not suitable or there is no lining, leakage is easy to occur.
(5) typical products’
Pipes, storage tanks, gas cylinders (fire breathing cylinders, compressed natural gas cylinders, etc.), solid rocket motor shell.
4. RIM (Reaction Injection Molding-reactive injection molding)
(1) Summary
Two or more components are mixed at low pressure (0.5MPa) in the mixing zone, and then injected into the closed mold at low pressure (0.5-1.5MPa). This is the technological process. If one component is polyol and the other is isocyanate, polyurethane is formed by the reaction. In order to increase the strength, ground glass fiber precursors and / or fillers can be added directly to one component. It can be reinforced with long fiber (such as preforms of continuous fiber felt, fabric, composite felt, short-cut strand, etc.), and the long fiber reinforced material is pre-placed in the mold before injection. Products with high mechanical properties can be obtained by this method. This process is called SRIM (Structural Reaction Injection Molding- structure reaction injection molding).
(2) Raw materials
Resin: commonly used polyurethane system or polyurethane / urea mixed system; can also use epoxy, nylon, polyester and other basic
Fiber: ground glass fiber with a length of 0.2-0.4mm
Core material: no.
(3) advantages
1) the manufacturing cost is lower than that of thermoplastic injection process.
2) it can produce products with large size and complex beginning.
3) it solidifies quickly and is suitable for rapid production.
(4) shortcomings
The cost of milled glass fiber reinforced materials is high, so mineral composites are recommended to replace them.
(5) main products
Car dashboards, bumpers, construction doors, windows, tables, sofas, electrical insulators.
5. Pultrusion (Pultrusion)
(1) Summary
It mainly uses glass fiber untwisted roving (pre-placed on the frame before use), which provides longitudinal (along the production line direction) reinforcement.
Other types of reinforcement are continuous filament felt, fabric, etc., which complement lateral reinforcement, while surface felt is used to improve the surface quality of the finished product. Fillers can be added to the resin to improve the properties of materials (such as flame retardant) and reduce the cost.
The procedure of pultruding is
1) impregnate the glass fiber reinforced material with resin
2) after preforming, the glass fiber is put into the heating mold for further impregnation (extrusion), curing of basic resin and setting of composite materials.
3) cut the profile according to the required length. Now there is the forming technology of pultruded products with variable cross-section and arc in the direction of length. Pultrusion molding will strengthen the material and impregnate the resin in two ways:
Glue trough impregnation method: this method is usually used, that is, the reinforcing material is dipped through the resin tank and then entered into the mold. The equipment of this method is cheap and workable and is suitable for unsaturated polyester resin and vinyl ester resin.
Injection impregnation method (figure 6): after entering the mold, the glass fiber reinforced material is impregnated by the resin injected into the mold. This method is suitable for producing resin matrix with short gel time and high viscosity, such as phenolic resin, epoxy resin and bismaleimide resin.
(2) Raw materials
Resin: commonly used unsaturated polyester resin, epoxy resin, vinyl ester resin, phenolic resin
Fiber: glass fiber roving for pultrusion, continuous felt, stitch-knitted felt, stitch-knitted composite felt, fabric, glass fiber surface felt, polyester fiber surface felt, etc.
Core material: generally not, the existing PU foaming material as the core material, the outside is a continuous pultruded frame profile, as a thermal insulation wallboard.
(3) advantages
1) typical pultrusion speed 0.5-2m/min, with high efficiency, suitable for mass production and long size products.
2) the resin content can be accurately controlled.
3) because the fiber is longitudinal and the aspect ratio can be high (40% / 80%), the axial structural characteristics of the profile can be very good.
4) it is mainly reinforced by untwisted roving, the cost of raw materials is low, and a variety of reinforcing materials are combined to adjust the mechanical properties of the products.
5) the product quality is stable and the appearance is smooth.
(4) shortcomings
1) the mold cost is high.
2) generally limited to the production of products with constant cross section.
(5) typical products
Building roof beams, rafters, door and window frame profiles, wall panels, oil extraction sucker rods, tent rods, ladders, bridges, tool handles, mobile phone microwave station casings, automobile leaf springs, transmission shafts, cable pipes, optical fiber cable cores, fishing rods, grids, automobile air conditioner cover, rail expansion cover. 0} 1x p* V
6. Vacuum bag molding (Vacuum bag process)
(1) Summary:
This method is an extension of hand paste and spray. The hand paste or sprayed layer is placed with the mold in the A stage of the resin, the layer is covered with a rubber bag, the periphery is sealed, and then vacuum is pumped by a vacuum pump, so that the layer is compacted and shaped under a pressure of not more than 1 air pressure.
(2) Raw materials
Resin: mainly use epoxy resin, phenolic resin. Unsaturated polyester resin and vinyl ester resin are generally not used because styrene (cross-linking agent) is excessively extracted from the resin by vacuum pump, which may cause problems.
Fiber: same hand paste method
Core material: arbitrary.
(3) advantages
The main results are as follows: 1) products with high fiber content can usually be obtained by ordinary wet laying technology.
2) large size products can be manufactured.
3) the light on both sides of the product
4) the porosity of wet coating is lower than that of wet coating.
5) due to the pressure, the resin flows through the structural fiber, and the fiber can impregnate the resin better.
6) it is beneficial to the health and safety of operators; vacuum bags reduce the volatile substances that escape during curing.
(4) shortcomings
1) additional processes increase labor and bag costs
2) operators are required to have a high level of technical proficiency.
3) Resin mixing and content control still basically depend on the skill of the operator.
4) the production efficiency is not high.
(5) typical products
Boat, racing car, core material bonding, aircraft nose cone radome, wing, rudder.
7. Resin film immersion molding (RFI-Resin Film Infusion)
(1) Summary
The dry strength and the resin sheet (the resin sheet is provided on a layer of release paper) are laid alternately in the mold. The layer is covered by a vacuum bag and vacuum is pumped by a vacuum pump to extract the air from the dry fabric. The resin is then heated, melted and leached into the fabric, which has been extracted from the air, and then cured after a de facto period of time.
(2) Raw materials
Resin: generally use only epoxy resin;
Fibers: arbitrary
Core material: many kinds of core material can be used. Due to the high temperature in the process, PVC foam needs special treatment to avoid foam damage.
(3) advantages
1) low voidage and high fiber content can be accurately obtained.
2) Clean bedding, which is good for health and safety (like pre-soaking)
3) the cost is lower than that of the prepreg method, which is the main advantage.
4) because the resin can only be transferred through the thickness of the fabric, the resin that is not immersed in the white spot area can be less than that of SCRIMP (Seaman Composite Company resin incorporation molding method-Seeman Composite Resin Infusion Molding Process).
(4) shortcomings
1) at present, it is only used in the aerospace industry and has not been promoted yet.
2) although the production of autoclave system for aerospace industry is not always necessary, heating chamber and vacuum bag system are always indispensable for composite curing.
3) the mold is required to withstand the process temperature of the resin diaphragm (60-100 °C for low temperature curing)
4) the core material used is required to withstand process temperature and pressure.
(5) typical products
Aircraft radome, warship sonar fairing.
8. Prepreg (autoclave) forming
(1) Summary
The fabric and / or fiber are pre-impregnated with a pre-catalytic resin under the condition of heating, pressurizing or using a solvent. Most of the curing agents can keep the prepreg materials stored for weeks or months at ambient temperature and can still be used in good quality. When the retention period is to be extended, the material must be stored in frozen conditions. The resin is usually a critical solid state at ambient temperature. Therefore, there is a slight sense of adhesion when touching the prepreg material, like duct tape. The fiber for making unidirectional pre-impregnated material is directly from the yarn frame and combined with the resin. The pre-impregnated material is laid on the mold surface by hand or mechanically, vacuumed through a vacuum bag and usually heated to 120-180 °C. Make the resin flow again and eventually solidify. The blooming additional pressure is usually provided by an autoclave (actually a pressure heating tank), which can exert pressure of up to 5 atmospheric pressure on the layer.
(2) Raw materials
Resin: commonly used epoxy resin, unsaturated polyester resin, phenolic resin and high temperature resin, such as polyimide, cyanate ester, bismaleimide resin, etc.
Fiber: arbitrary. Although in the process, the high temperature has some influence on the core material, it is necessary to use some special foam core material.
(3) advantages
1) the prepreg material manufacturer can accurately adjust the resin / curing agent level and the resin content in the fiber, and the high fiber content can be obtained reliably.
2) the material is very safe for the operator, no harm to health, and the operation is clean.
3) the cost of unidirectional ribbon fiber is the lowest because there is no need to convert the fiber into the secondary processing of the fabric in advance.
4) due to the use of permeable high viscosity resin in the manufacturing process, the chemical, energetic and thermal properties of the resin can be the most suitable.
5) the effective time of the material is long (the quality can be guaranteed for several months at room temperature), which means that the structure can be optimized and the composite is easy to lay.
6) it is possible to achieve automation and save labor.
(4) shortcomings
1) for pre-impregnated fabric, the material cost is high.
2) it is usually necessary to solidify composite products in high pressure kettle, which is expensive, slow and limited in size.
3) the mold should be able to withstand the working temperature.
4) the core material needs to bear the operating temperature and pressure.
(5) typical products
Aircraft structural composite materials (such as wings and tail wings), satellite and launch vehicle structures (solar cell substrate, sandwich structure board, satellite interface bracket, rocket fairing, etc.), racing cars, sports equipment (such as tennis rackets, skis, etc.).
9. Forming of low temperature solidified prepreg
(1) Summary
The low temperature curing prepreg is prepared completely according to the usual prepreg method, but the chemical properties of the resin enable it to be cured at a temperature of 60 °C to 100 °C. At 60 °C, the material operable retention period can be as small as 1 week, but can also be extended to several months. The flow section of the resin system is suitable for vacuum bag pressure to avoid the use of autoclave.
(2) Materials |
Resin: generally only epoxy resin is used.
Fiber: arbitrary, same as usual prepreg
Core material: arbitrary, although general PVC foam requires special attention.
(3) advantages
1) it has the advantages of (1)-(6) of the traditional prepreg method.
2) the mold material is cheaper, such as wood, because its curing temperature is lower.
3) large structures can be easily manufactured. Because only the vacuum bag pressure is needed and the curing temperature is low, a simple hot air circulation heating chamber can be used (heating chambers larger than products are often built on site).
4) ordinary PVC foam core material can be used with a little treatment.
5) low energy consumption.
(4) shortcomings
1) the material cost is still higher than that of pre-impregnated fabric.
2) heating chamber and vacuum bag system are required to solidify the product
3) the mold should be able to withstand a temperature higher than the ambient temperature (usually 60-100 °C)
4) there is still energy consumption, because the curing temperature is higher than the ambient temperature.
(5) typical products
High-performance wind turbine blades, rowing boats, lifeboats, train parts.
10 、 SCRIMP,RIFT,VARTM
Fig. 11 schematic diagram of SCRIMP,RIFT,VARTM
(1) Summary
The principles of SCRIMP (Seeman Composite Infusion Molding Process- Seaman Composite Company resin infiltration molding), RIFT (Resin Infusion umder Flexibe Tooling- flexible mold resin infiltration) and VARTM (Vscuum Assisted Transfer Molding- vacuum assisted resin transfer molding) are similar.
The fabric is put into the mold as a dry-laying material, just like RTM. It is then covered with stripped protective layer and stitched non-structural fabric. The whole layer is covered with a vacuum bag. When there is no leakage in the bag, let the resin flow to the accumulation layer. The resin can easily flow through the non-structural fabric and distribute throughout the layer. The SCRIMP method can place a pressure module between the vacuum bag and the layer, which is beneficial to improve the appearance and structural compactness of the fabrication.
(2) Materials
Resins: Changhe epoxy resin, unsaturated polyester and vinyl ester resin
Fiber: any kind of ordinary fabric. These processes sewing and knitting materials are easy to use because of their gaps that make the resin flow quickly.
Core materials: all kinds of core materials can be used except honeycomb.
(3) advantages
1) same as RTM, but the product has only one side light, unlike RTM two sides light.
2) because half of the mold is a vacuum bag, the main mold only needs low strength, so the mold cost is very low.
3) large size products can be manufactured.
4) the usual wet laying tools can be improved to be used in these forming methods
5) the core material structure can be produced in one operation.
(4) shortcomings
1) to complete the relatively complex operation process.
2) the viscosity of the resin must be very low, which limits the mechanical properties of the products.
3) the waste caused by the layer not soaked in resin is very large.
4) some technological elements of SCRIMP have been limited by patents.
(5) typical products
Semi-finished boats, train and truck body panels.
What is the operation flow of fiberglass chopping machine?
Background technology:
Glass fiber chopped strand felt is a reinforced glass fiber product made of glass fiber short cut into a certain length and bonded with powder or emulsion adhesive. It is mainly used for FRP molding processes such as hand paste molding, winding molding, molding, mechanical molding, etc. The current processing methods of glass fiber include silking, shorting, sizing, winding and packaging, etc., which have some shortcomings, such as uneven spraying of emulsion or powder, high moisture content of glass fiber chopped filament felt, emulsion adhesion and so on.
Elements of technology implementation:
In order to overcome the shortcomings of the processing method of glass fiber, the invention provides an improved processing method of glass fiber.
In order to achieve the above purpose, the technical proposal adopted by the invention is that the processing method of glass fiber is composed of silk, short cutting, sizing, heating, dehumidification, drying, winding, packaging and the like. The glass fiber precursor enters the short-cutting device from the top filament device, and after the short-cutting process, the short-cut glass fiber precursor is changed into a 40-50mm length short glass fiber precursor. The short-cut glass fiber precursor evenly settles on the mesh conveyor and becomes the short-cut glass fiber felt embryo. The mesh conveyor belt moves forward through the sizing device, and the emulsion or powder of the sizing device is evenly sprinkled on the short-cut glass fiber felt embryo from above. The chopped fiberglass strand felt embryo continues to move forward to the heating device through the mesh conveyor belt. At the melting temperature of 100,230 ℃, the chopped fiberglass filament felt and emulsion or powder are bonded to form a glass fiber chopped strand felt. The glass fiber chopped strand felt continues to move forward from the mesh conveyor belt to the dehumidification device. After dehumidification, the glass fiber chopped strand felt moves forward from the belt conveyor to the drying device, and after drying Glass fiber chopped strand felt enters the winding and packaging process.
How is the FRP winding machine wound? Is there a pattern?
There are two main winding methods of FRP winding, which have certain rules:
1. Circumferential winding: that is, winding along the circumference of the mandrel. When winding, the mandrel rotates at a uniform speed around its own axis, and the guide head moves in the cylinder body parallel to the axis. Every time the core mold rotates, the guide head moves a width of the yarn, and press this cycle until the yarn is covered with the body surface of the core mold. The characteristic of circumferential winding is that the winding can only be carried out in the barrel section, not the head. The adjacent yarns are connected but not intersected, and the winding angle is between 5 °and 15 °.
2. Cross winding: the mandrel rotates uniformly around its own axis, and the guide head reciprocates along the axis according to a certain speed ratio. As a result, cross-winding is realized on the cylinder body and head of the mandrel. The winding angle is generally 45 °~ 85 °. The characteristic of cross winding is that each fiber corresponds to a tangent point on the circumference of the polar hole, and the adjacent yarns meet but not intersect in the same direction, while the fibers in different directions intersect. In this way, a double layer is actually formed when the fiber is uniformly wrapped around the surface of the mandrel.
Speed ratio requirements: according to the winding law, there is a strict speed ratio relationship between the rotation of the mandrel and the round trip times of the guide head. In the winding process, whether it is the winding of the cylinder body, or the stop and start at both ends of the head, the above speed ratio relationship should be strictly unchanged, so that the FRP products produced are qualified.
This is the end of the introduction of the safe operation procedures of the glass fiber winding machine and the glass cloth winding machine. I wonder if you have found the information you need? If you want to know more about this, remember to collect and follow this site.