glass fiber cloth glass fabric
glass fiber fabric, glass fiber ribbon, glass cloth
glass fiber cloth or fabric and tape the diameter of glass fiber used to produce glass roving is from 12 to 23 μ m. The number of untwisted roving ranges from 15 to 96 (tex). Untwisted roving can be directly used in some composite molding methods, such as winding and pultrusion. Because of its uniform tension, it can also be woven into untwisted roving fabric, and in some applications, the untwisted roving is further chopped.
the quality requirements of the square grid cloth are as follows: ① the fabric is uniform, the edge of the cloth is straight, the cloth surface is flat and mat-like, and there are no stains, fuzz, creases and wrinkles; ② The warp and weft density, area weight, cloth width and roll length all meet the standards; (3) winding on a solid paper core, winding neatly; ④ Rapid and good resin permeability; ⑤ The dry and wet mechanical strength of laminated materials made of fabrics should meet the requirements.
The composite material paved with grid cloth is characterized by low interlaminar shear strength and poor compressive strength and fatigue strength. (1) chopped strand mat glass strands (sometimes with roving) are cut into 5mm long, which are spread on the mesh belt randomly but evenly, and then the chopped strand mat is bonded by applying emulsion binder or spreading powder binder after heating and curing. Chopped felt is mainly used in hand pasting, continuous board making, die pressing and SMC process. The quality requirements for chopped strand mats are as follows: ① the area quality along the width direction is uniform; (2) the chopped strands are evenly distributed in the felt surface, without large holes, and the binder is evenly distributed; ③ Moderate dry felt strength; ④ Excellent resin infiltration and permeability.
(2) The continuous precursor felt is formed by laying glass precursor formed in the drawing process or continuous precursor unwound from the precursor cylinder on a continuously moving mesh belt in a figure of eight and bonding it with a powder binder. The fibers in the continuous glass fiber precursor felt are continuous, so the reinforcement effect of the continuous glass fiber precursor felt on the composite material is shorter than that of the chopped felt. Mainly used in pultrusion process, RTM process, pressure bag process and glass felt reinforced thermoplastic (GMT) process.
(3) FRP products with surface felt usually need to form a resin-rich layer, which is generally achieved by using medium alkali glass surface felt. This kind of felt is made of medium-alkali glass (C), which endows FRP with chemical resistance, especially acid resistance. At the same time, because the felt is thin and the diameter of glass fiber is small, it can absorb more resin to form a resin-rich layer, which covers the lines of glass fiber reinforced materials (such as checkered cloth) and plays a role in surface modification.
(4) needled felt needled felt can be divided into chopped fiber needled felt and continuous precursor needled felt. Chopped fiber needled felt is made by cutting glass fiber roving into 5mm pieces, randomly laying it on the substrate placed on the conveyor belt in advance, and then needling with barbed needles. The needles stab chopped fibers into the substrate, and the crochet needles lift some fibers up to form a three-dimensional structure. The substrate used can be a thin fabric of glass fiber or other fibers, and this needled felt has a fluffy feeling. Its main uses include heat insulation and sound insulation materials, lining materials and filtering materials, and it can also be used in the production of glass fiber reinforced plastic, but the strength of the glass fiber reinforced plastic is low and its application range is limited. Another kind of continuous precursor needled felt is that continuous glass precursor is randomly thrown on a continuous mesh belt by a wire throwing device and needled by a needle board to form a three-dimensional structure in which fibers are interconnected. This kind of felt is mainly used in the production of glass fiber reinforced thermoplastic stamping sheets.
(5) Stitching felt chopped glass fibers from 5mm to 6cm in length can be stitched into chopped fiber or long fiber felt by stitching machine. The former can replace the traditional binder-bonded chopped fiber felt in several applications, while the latter can replace the continuous precursor felt to some extent. Their advantages are that they contain no binder, which avoids pollution in the production process, and at the same time, they have good permeability and low price. The following are all kinds of glass fiber cloth and glass fiber fabric woven with glass fiber yarns.
(1) Glass cloth The glass cloth produced in China can be divided into two categories: alkali-free and medium-alkali, and most of them are E-GLASS alkali-free glass cloth abroad. Glass cloth is mainly used to produce various electrical insulation laminates, printed circuit boards, various vehicle bodies, storage tanks, boats, molds and so on. Medium-alkali glass cloth is mainly used to produce plastic-coated packaging cloth and for corrosion-resistant occasions. The characteristics of fabric are determined by fiber properties, warp and weft density, yarn structure and weave. The warp and weft density is determined by the yarn structure and weave. The warp and weft density and yarn structure determine the physical properties of the fabric, such as weight, thickness and breaking strength. There are five basic weave patterns: plain plan (similar to plaid cloth), twill twill (generally +-45 degrees), satin static (similar to one-way cloth), rib leno (main weave method of glass fiber mesh cloth) and mat matts (similar to Oxford cloth).
(2) Glass fiber ribbon can be divided into woven edge ribbon (smooth edge ribbon) and non-woven edge ribbon (raw edge ribbon). The main weave method is plain weave. Alkali-free glass fiber ribbon is often used to manufacture electrical equipment parts with high strength and good dielectric properties.
(3) glass fiber unidirectional fabric, in which the unidirectional fabric is a four-warp broken satin or long-axis satin fabric woven by coarse warp and fine weft, which is characterized by high strength at degrees in the main direction of warp. There are also glass fiber single weft fabrics, including warp knitting and weaving, which are characterized in that coarse weft yarns, fine warp yarns and glass fiber yarns are fed in the weft direction and have high strength in the 9-degree weft direction.
(4) Compared with the plane fabric, the three-dimensional fabric of glass fiber has developed from one-dimensional and two-dimensional to three-dimensional, which makes the composite material with this reinforcement have good integrity and conformability, and greatly improves the interlaminar shear strength and damage tolerance of the composite material. It developed with the special needs of aerospace, aviation, weapons, ships and other departments, and its application has been extended to automobiles, sports equipment, medical equipment and other departments. There are five main categories: woven three-dimensional fabrics, knitted three-dimensional fabrics, orthogonal and non-orthogonal non-woven three-dimensional fabrics, three-dimensional woven fabrics and other forms of three-dimensional fabrics. The shapes of three-dimensional fabrics are block, column, tube, hollow truncated cone and variable thickness special-shaped section.
(5) Glass fiber special-shaped fabric The shape of special-shaped fabric is very similar to the shape of the product to be reinforced, and it must be woven on a special loom. Symmetrical shaped special-shaped fabrics include round covers, cones, hats, dumbbell-shaped fabrics, etc., and can also be made into asymmetric shapes such as boxes and ship hulls.
(6) Glass fiber channel core fabric Channel core fabric is a fabric composed of two parallel layers of fabric connected by vertical bars, and its cross-sectional shape can be triangular, rectangular or honeycomb structure.
(7) Glass fiber stitched fabric, also known as knitted felt or woven felt, is different from ordinary fabric and felt in general sense. The most typical stitchbonded fabric is that a layer of warp yarns and a layer of weft yarns are overlapped together, and the warp yarns and weft yarns are woven together through stitchbonding to form a fabric. The advantages of stitchbonded fabric are as follows: ① it can increase the ultimate tensile strength, delamination strength under tension and bending strength of FRP laminated products; (2) reducing the weight of FRP products; ③ Smooth surface makes the surface of FRP smooth; ④ Simplify hand-pasting operation and improve labor productivity. This kind of reinforcing material can replace continuous strand felt in pultrusion FRP and RTM, and can also replace grid cloth in centrifugal FRP pipe production. A reinforcing material which combines glass fiber cloth, chopped strand mat, continuous strand mat, roving fabric and roving in a certain order, Generally, there are the following types:
(1) chopped strand mat+roving fabric
(2) chopped strand mat+roving+chopped strand mat
(3) chopped strand mat+continuous strand mat+chopped strand mat
(4) chopped strand mat+random roving
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