The main components, characteristics and common different forms of glass fiber

 

  一、The main components of glass fiber

  Its main components are silica, alumina, calcium oxide, boron oxide, magnesium oxide, sodium oxide, etc. According to the alkali content in the glass, it can be divided into alkali-free reinforced fiberglass (sodium oxide 0%~2%, belongs to aluminum Borosilicate glass), medium alkali glass fiber (sodium oxide 8%~12%, belongs to boron-containing or boron-free soda lime silicate glass) and high alkali glass fiber (sodium oxide more than 13%, belongs to soda lime silicate glass).

  Main features: melting point glass is a kind of amorphous, it has no fixed melting point, it is generally considered that its softening point is 500~750 ℃, boiling point 1000 ℃, density 2.4~2.76g/cm3, fibreglast is used as a reinforcing material for reinforced plastics When it is large, it is characterized by high tensile strength. The tensile strength is 6.3~6.9 g/d in the standard state and 5.4~5.8 g/d in the wet state. Density 2.54g/cm3. Good heat resistance, no effect on strength when the temperature reaches 300 ℃. It has excellent electrical insulation, is an advanced electrical insulation material, and is also used for thermal insulation materials and fire shielding materials. Generally only corroded by concentrated alkali, hydrofluoric acid and concentrated phosphoric acid.

  Raw materials and their application: Compared with organic fibers, glass fiber has higher temperature resistance, non-combustibility, corrosion resistance, good heat insulation and sound insulation, high tensile strength and good electrical insulation. But it is brittle and has poor wear resistance. Used to make reinforced plastics or reinforced rubber, as reinforcing material glass fibers have the following characteristics, these characteristics make the use of glass fibers price more extensive than other types of fibers, and the development speed is also ahead of its characteristics are listed as follows:

  (1) High tensile strength and small elongation (3%).
  (2) High elastic coefficient and good rigidity.
  (3) The amount of elongation within the elastic limit is large and the tensile strength is high, so the absorption of impact energy is large.
  (4) It is an inorganic fiber, which is non-flammable and has good chemical resistance.
  (5) Low water absorption.
  (6) Scale stability and heat resistance are good.
  (7) It has good processability and can be made into different forms of products such as strands, bundles, felts, and woven fabrics.
  (8) Transparent through light.
  (9) Good adhesion to resin.
  (10) It is not easy to burn, and can be melted into glass beads at high temperature.

 

 

 二、What are the common glass fiber forms, do you know?

  In the previous articles, we also introduced some basic knowledge of FRP, you can review it if you are interested. FRP is currently widely used. In fact, FRP is simply the abbreviation of glass fiber and resin composite. The often-mentioned glass fibre roll will adopt different forms according to different products, processes and performance requirements of use, so as to achieve different Requirements. Today we will talk about the different forms of common glass fibers.

  1. Twistless Roving

  Unidirectional roving is further divided into direct roving and ply roving. Direct yarn is a continuous fiber drawn directly from glass melt, also known as single-strand untwisted roving. The plied yarn is the coarse sand made of multiple parallel strands, which is simply the synthesis of multiple strands of direct yarn.

  Teach you a little trick, how to quickly distinguish between direct yarn and plied yarn? One strand of yarn is drawn out and shakes quickly. The one that remains is straight yarn, and the one that is dispersed into multiple strands is plied yarn.

  2. Bulk yarn

  Bulked yarn is made by impacting and disturbing glass fibers with compressed air, so that the fibers in the yarn are separated and the volume is increased, so that it has both the high strength of continuous fibers and the fluffy properties of short fibers.

  3. Plaid
  Plaid is a roving fiber fabric, the warp and weft are interlaced at 90° up and down, also known as woven fabric. The strength of the gingham is mainly in the warp and weft directions.

 

 

  5. Glass fiber mat
  Continuous strand mat fiberglass, collectively referred to as "felt", is a sheet-like product made of continuous strands or chopped strands that are non-directionally bound together by chemical binders or mechanical action. Felt is further divided into choped strand mat, stitched mat, composite mat, continuous mat, surface mat, etc. Main applications: pultrusion, winding, molding, RTM, vacuum introduction, GMT, etc.

  6.Glass fiber strands

  The fiberglass yarn is chopped into strands of a certain length. Main applications: wet chopped (reinforced gypsum, wet thin felt), BMC, etc.
 

  7. Grinding fibers
  It is made by grinding chopped fibers by hammer mill or ball mill. It can be used as a filler to improve resin surface phenomenon and reduce resin shrinkage.