CONTINUOUS FILAMENT GLASS FIBRE

The continuous filament glass fibre industry is the cornerstone of the glass-based composite materials and technical textiles value-chains. The European production of continuous filament glass fibre is one of the smallest sectors of the glass industry in terms of tonnage. Glass Fibre Europe members produce approximately 1,000,000 tonnes of melted glass annually from 12 installations operating in 9 countries in Europe (Discover more). The industry directly employs over 4,500 workers in the European Union and it supports hundreds of thousands of indirect jobs down the industry value-chains.

The European glass fibre industry, including manufacturers, distributors, and related industries, is an essential industry sector. (Discover more) It is the cornerstone of the glass-based composite materials value-chain, which accounts for 95% of the European total production of reinforced composite, and the technical textiles value-chain.

Glass fibre’s unique properties enable the production of wind energy, electric and electronic devices, and the development of sustainable solutions in a wide range of applications, such as transport and construction. Glass fibre is a versatile material which will be vital to the achievement of the twin transitions to a green and digital economy.

THE MANUFACTURING PROCESS

Glass fibre manufacturing is a continuous industrial process, whereby the furnace runs without interruption for seven to ten years. The raw materials are melted in furnaces operating at high temperatures to form the glass. The molten glass is then extruded through a bushing into filaments, the filaments are cooled with water and a chemical sizing is applied before final fabrication. The continuous filament glass fibres products include glass fibre reinforcements (i.e. chopped strand, rovings and mat / veil) and yarns.

PRODUCTS

The continuous filament glass fibre industry produces 4 main products which are used in a wide array of applications.

Roving

Glass fibre roving consist of single filaments brought together into a bundle in order to result in a well-defined design. The properties are influenced by the number of strands, orientation of the fibres and the linear density.

Chopped strand

Glass fibre filaments are cut (chopped ) to a specific length. These filaments can also be milled which results in shorter fibres, while keeping the original diameter

Mat / Veil

The glass fibre (chopped or not) are laid-out flat and consolidated by means of a chemical or mechanical binder system. The properties of the glass mat can be tailored by altering a variety of parameters with a binder application.

Yarns

Glass fibre yarns consist of a defined number of filaments brought together to form a yarn. These are further processed and available in form of twisted, plied, volumized and texturized yarns.

PROPERTIES

Innovations in the glass fibre industry have made possible the development of a vast array of products offering significant advantages in use, such as lightweighting, design flexibility, resistance to fire / chemicals / corrosion or changes in temperatures, soundproofing and durability. These advantages arise from the intrinsic and newly developed properties of the glass fibre products presented below.

Mechanical
strength

Dimensional
stability

Electrical
insulation

Low thermal
conductivity

Fire
resistance

Compatibility with organic
matrices / materials

Durability

Dielectric
permeability

Resistance to
chemical agents

APPLICATIONS

Glass fibre’s versatility and unique properties makes it a material of choice for a wide range of applications. Demand for glass fibre has been growing over the last decade with the constant development of new products and applications by the industry, and the increase in demand generated by sustainability and climate objectives. Glass fibre is an essential, enabling material for the transition to a climate neutral economy. The growing demand for glass fibre is expected to further intensify in the coming years with the implementation of new policy measures in Europe.

Renewables:

Glass fibre made possible the advent of the wind energy industry, the largest contributor to renewable energy generation in the European Union, as an economically viable clean alternative to fossil fuel. Over the last decade, research and development enabled the development of increasingly larger lightweight wind turbine blades for improved energy generation efficiencies. Glass fibre is also present in other applications linked to the renewable industry. Glass fibre can be used as a reinforcement for plastics for the backing and framing of PV panels. It also contributes to the deployment of hydrogen as an alternative feedstock when used in reinforced stationary or vehicles tanks.

Transport:

Glass fibre’s reinforcement characteristics can help to reduce the weight of a range of plastic parts in passenger aircrafts, cars, trucks, ships, and trains, which helps increasing fuel efficiency and reducing CO2 emissions. Therefore, glass fibre is also instrumental for the production and deployment of light-weight electric vehicles. In this applications area glass fibre is also used for battery casing, to lower weight, while providing fire protection, underbody protection and optimum temperature conditions within the battery. Glass fibre is also present in thermoset plastic housings of electrical vehicle charging stations to make them robust.

Electric & Electronics:

The outstanding electrical properties of glass ¬fibre make it a vital material for the computer and electronics industries. Glass fi¬bre is a great electrical insulator even at low thickness. It is used to produce printed circuit boards (PCBs) which are present in any electronic equipment.

Building, Construction and Infrastructure:

Glass fibre products are broadly used in construction applications because they add strength, are naturally fire resistant, do not elongate or shrink and do not decay. Examples of applications include the reinforcement of light-weight concrete, light-weight and fire-protective plaster boards, façade or internal walls, bituminous roofing, PVC flooring, wall covering, noise absorbing acoustic panels, or reinforcement of roads for extended lifespan.

Sports/Leisure:

Glass fibre has been used in recreational and leisure markets for decades. Glass fibre can be found in boats, canoes, paddle boards, skis, snowboards, wakeboards, kayaks, and hockey sticks, to only name a few.

Others:

Glass ¬fibre is used in countless types of applications such as pipes and tanks, medical casts, ¬filtration products, insulation blankets and protective clothing, consumer goods,…

Key industry data

The manufacturing sites

01 Batch

Before entering the furnace, raw materials (primarily silica sand, limestone, kaolin and dolomite) are carefully weighted and mixed to form a uniform ‘batch’.

02 Melting The raw materials or ‘batch’ are heated in the furnace at a temperature of approximately 1500°C to form molten glass. The molten glass then flows into the refiner, where its temperature is reduced in the range of 1300°C.

03 Bushing | Fiberization

The last section of the furnace is the forehearth, beneath which are located multi-hole heat resistant trays called ‘bushings’ made from platinum/rhodium alloys. The molten glass flows through 500 or more precisely drilled openings in the bushing to form filaments of a diameter from 5 to 30 μm (one-tenth of the human hair diameter).

04 Sizing | Coating

The filaments are then cooled by water spray, coated with a ‘sizing’ via an applicator roll enhancing their properties and making the glass filaments suitable, through adequate processing properties and adhesion properties to the matrix, for a wide range of specific reinforcement uses. In most cases the filaments assembled into strands are sent to an oven to cure the coating.

05 Fabrication

The final fabrication includes twisting, chopping, weaving, and packaging the fibre. The continuous filament glass fibre industry produces 4 main products: roving, chopped strands, mats and yarns.