Acoustic application

1. Presented by:
S.Rajesh Kumar
PSG TECH

2.  Glass wool fibers are fine glass fibers forming a mass resembling wool, commonly used
for insulation or filtration.
 Glass wool is made from sand and recycled glass (up to 80% in New Zealand). This
blend is melted, spun into a fibrous mat and bound together by resin. The material‟s
texture is similar to wool, hence the name „glass wool‟.
 Glass wool consists of individual fibers, which have been basically defined since the late
1950s as being over 5μm long and having a length-to-width aspect ratio of at least 3:1.
 Glass wool fibers have the potential to cause genetic damage. Respirable fibers are those
that can penetrate into the humans lung upon inhalation, a fiber with an aerodynamic
diameter of less than 5μm is respirable .

3.  Insulation wool fibers typically have nominal diameters of 1 to 10μm, and special-
purpose fibers have nominal diameters of 0.1 to 3 μm
 The fiber diameter is controlled by the manufacturing process. All glass fibers are
manufactured to nominal diameters that vary based on the manufacturing process and
the fibers intended use.
 In glass wool insulation, most fibers are several centimeters long; however, fibers break
crosswise and lengths of less than 250 μm.

4.  Glass fibers can generally be classified into two categories based on usage:
(1) Low-cost, general-purpose fibers typically used for insulation applications
(2) Premium special-purpose fibers used in limited specialized applications.
 Glass wool is also used for industrial, equipment, and appliance insulation.
 The primary use of glass wool is for thermal and sound insulation. The largest use of
glass wool is for home and building insulation in the form of loose wool, blankets or
rolls, or in the form of rigid boards for acoustic insulation.

5.  The largest market for special-purpose glass fibers is for battery separator media,
i.e., the glass wool fibers physically separate the negative and positive plates in a
battery, while allowing the acid electrolyte to pass through.
 Another important use is in high-efficiency particulate air (HEPA) filters that are
used in settings where high-purity air is required.
 Aircraft, spacecraft, and acoustical insulation are also applications for special-
purpose glass fibers.

6. Differences between Glass Wool, Fibre Glass and Asbestos Insulation
 Although glass wool, fibre glass and asbestos are all forms of insulation, they have
some significant health and safety differences.
 Glass wool is thermal and acoustic insulation used around the world in homes,
commercial and industrial buildings, vehicles and white goods.
 Fibre glass is a composite plastic reinforced by extremely fine glass fibres, making it
very strong and flexible. It is often used to make yachts, canoes and light-weight
vehicles.
 These fibres are different to the type used in glass wool. Fibreglass fibres are not known
to be cancer-producing but they are also not broken down inside the human body,
unlike glass wool fibres.

7.  Asbestos was once widely used to make roofing shingles and to insulate walls and
floors around wood-burning stoves. Although it is a good insulator, asbestos is
now known to be carcinogenic and is no longer used.
 Glass wool fibres can be a source of temporary skin irritation. As a precaution, we
recommend you wear long-sleeves and trousers, gloves and a facemask when
installing insulation. You can also wash off any loose fibres on your skin with soap
and cold water.

8.  The major methods for fiber manufacture historically have been
1) Steam attenuation 2) The rotary or centrifugal process 3) Flame attenuation
 Rotary process : In this production process, raw materials are first weighed and
blended before being added to the fiber glass furnace, where the materials are melted
and homogenized at approximately 1,370 C (2,500 F).
 In the rotary process, fibers are produced as centrifugal force extrudes the molten
material through small holes in the side of the spinning device.
 The primary fibers pass through a circular burner flame, whose hot gases attenuate the
fibers to their final diameter and break the fibers into shorter lengths, ultimately
forming a veil of interlaced fibers that often are sprayed with a binder and lubricant
(IARC 2002). A gas-fired oven dries the product and cures the binder.

9.  A two-step flame-attenuation process is used to produce very small diameter fibers.
 In the first step, the melt is drawn through the bushings of the furnace to produce
strands of coarse fibers.
 The fibers are then remelted with a high-temperature gas flame that attenuates the
coarse fibers into finer fibers that are propelled through a forming tube.
 The combined value of imports of insulation products consist of the five product
categories:
(1) Mats as Nonwoven of glass fibers
(2) Thin sheets (voiles) as Nonwoven of glass fibers
(3) Batts as Nonwoven of glass fibers
(4) Pipe coverings of nonwoven glass fibers
(5) Other insulation products of nonwoven glass fibers

10.  Glasswool Sectional Pipe Insulation (SPI)
It is manufactured by spinning molten glass,
containing a up to 80% recycled content, into
fine wool like fibres. These are bonded
together using a thermosetting resin.
 Combining PVC cladding with glass wool creates a complete off the shelf, easy to
install, UV resistant vapour sealed insulation system.
 It provides excellent thermal insulation up to a working temperature of 200°C as
well as personnel protection and energy savings benefits.
 Glasswool SPI is available faced with Thermofoil to provide some minor
protection or un-faced to be covered by a suitable jacketing.
 Weather protective jacketing may be required to protect the pipe insulation and
piping from weather and mechanical damage.

11. videoGlass wool production
line.mp4

13.  Twiga commenced its operations in 1979 and is a technology licensee from Saint
Gobain, the leading manufacturer of insulation worldwide. Located in Northern and
Western India (offering a total capacity of 16,000 tons per year).
 Twiga Insul is a lightweight, compressible insulation material, consisting of fine,
long, inorganic glass fibers bonded together by a high temperature binder.
 The product is light gold in colour and its superior tensile strength, handleability and
resilience offer significant advantages during transport and installation.
 These unique characteristics of glass wool, combined with its fire safe properties, make
it especially suitable for a wide variety of thermal and acoustic insulation applications,
ranging from duct and metal roof insulation to applications in solar collectors and
generator acoustic enclosures.

18.  The product is recommended for use in both hot and cold applications ranging in
temperature from minus 195 to plus 450 C.
 Factory applied facings include reinforced aluminium foil, fiberglass tissue, black glass
tissue and a wide range of imported premium facings, which are widely used in metal
building applications.
videoNZ How to Install Earthwool Glasswool Wall Insulation.mp4

21.  In 2000, an estimated 3,388 million pounds (1.7 million tons) of fiber glass were used
in building insulation with almost 81% being used in residential construction and 19%
in commercial or industrial construction (Maxim et al. 2003).
 ATSDR (2004) reported Glass Manufacturing Industry Council (GMIC) data that
indicated 10 major manufacturers were operating approximately 40 plants within the
United States in 2002, and the production volume of all glass fiber types, including
glass wool, was estimated at about 3 million tons annually.
 The value of exports for the product category “insulation products of glass fibers”
increased steadily from $59 million in 2000 to $121 million in 2008 (note that the
product categories differ for imports and exports) (USITC 2009b).