Glass Fibre - Textile Scholar

Glass fiber is a generic name like carbon fiber or steel or aluminum. Just as different compositions of steel or aluminum alloys are available, there are many of different chemical compositions of glass fibers that are commercially available. Common glass fibers are silica based (~50 - 60 % SiO₂) and contain a host of other oxides of calcium, boron, sodium, aluminum, and iron.

 

Fibre Types and Grades:

Silica is the basis for all commercial glasses. They are obtained by fusing a mixture of materials (various oxides) at tempreatures ranging from 1300 ⁰C to 1600 ⁰C. There are different types of glass fibres commercially available all of which have different compositions and very often specific technical significance. The following is an outline of some popular varieties of glass:

 

Type:

• A –  Soda-lime  glass
• E – Electrical type (Borosilicate)
• C – Chemical Resistant type
• AR – Alkali Resistant type 
• S – High performance application

Grades:

• General purpose glass fibre
• Quartz Fibre
• Protective Fibre
• Hollow Fibre
• Conducting/ Semi-conducting

Ingredients used in Glass Fibre:

The ingredients normally used in making glass fibre are

• Silicon Dioxide
• Calcium Oxide
• Aluminum Oxide
• Boron Oxide Plus a few other metal oxides..

 

Chemical Composition Of Glass Fibre (wt %):

Physical Properties of Glass Fibre:

Chemical Properties of Glass Fibre:

1. Acids: Hydrochloric acid and Hot Phosphoric acid cause harm to glass fibre

2. Basic: It has enough protection ability to alkali

3. Effect of Bleaching: Bleaching agent does not cause harm to glass fibre

4. Organic Solvent: It does not change on Organic solvents

5. Protection ability against Mildew: It does not affected by mildew

6. Protection ability against insects: Insect does not affect on glass

7. Dyes: It is not possible to dye glass fibre after production. But it could be colour before production by adding dye in the solution bath

 

Manufacturing Of Glass Fibre:

1. Mixing silica sand, limestone, boric acid and other minor ingredients.  

2. The mixture is heated until it melts at about 1260OC/2300OF. 

3. Letting the molten glass flow through fine holes. (In a platinum plate). 

4. The glass strands are cooled, gathered and wound. (Protective coating may be added.)

5. The fibers are drawn to increase the directional strength.  The fibers are woven into various forms for use in composites.

 

Applications Of Glass Fibre:

1. Commercial E-glass variants, distinguishing E-glasses by end use.

2. Compositions containing 5 to 10 wt% by weight of boron oxide are certified for printed circuit board and aerospace applications.

3. Compositions containing 0 to 5 wt% by weight of boron oxide are certified for general applications. Boron-free E-glasses have a slightly higher dielectric constant (7.0) than boroncontaining E-glasses (5.9 to 6.6). As a result, boron-containing, E-glass fibers are needed for electronic circuit boards and aerospace applications.

4. On the other hand, boron-free and boron-containing E-glass fibers are used in structural composites where the dielectric constant is of no concern.

5. Uses for Regular glass fibre include mats and fabrics for Thermal Insulation, Electrical Insulation, Sound Insulation, High-strength fabrics or Heat & Corrosion Resistant fabrics.

6. It is also used to reinforce various materials, such as tent poles, vault poles, bows & crossbows, translucent roofing panels, Automobile bodies, hockey sticks, boat hulls & paper honeycomb.

7. Glass fibre is extensively used for making FRP tanks and Vessels.