3. DEFINITION
BLD62003_MAK_GLASS
FLOAT GLASS
STEP –BY- STEP PILKINGTON PROCESS
FLOAT GLASS
• Float glass is a sheet of glass made by
floating molten glass on a bed of molten
metal, typically tin, although lead and
various low melting point alloys were used
in the past. This method gives the sheet
uniform thickness and very flat surfaces.
• is also known as the Pilkington process
FLOAT GLASS PROCESS
STAGE 1: Melting and refining
STAGE 2: float bath
STAGE 3: coating
STAGE 4: annealing
STAGE 5 : inspection
STAGE 6 : Cutting to order
3
8. THE PROCESS
• The embossed glass was originally used to
produce structural translucent glass and has
been manufactured by sand blasting process
and acid etching process.
• This process which was developed by Ford,
U.S.A in 1920, is called horizontal sequence
roll process.
• By letting melted glass pass between two
patterning rollers, the pattern in the upper
and lower rollers are imprinted on plate glass
and patterned plate glass is produced.
BLD62003_MAK_GLASS
(Source: Philkington)
8
9. THE PROCESS (CONT’D)
• This process was used to manufacture
ordinary plate glass before float process was
introduced.
• At that time, in order to improve the
smoothness of surface, the surface grinding
took place after molding.
• The plate glass produced by this process has
about 2mm ~ 10 mm thickness and 2m
width.
• Unlike plate glass, the embossed glass is
translucent and the degree of translucency
gets classified into 1~5 classes depending on
the shape and depth of embossing.
BLD62003_MAK_GLASS
Roller Wave Distortion in Roll-Out Process
(Source: Glaston)
9
12. DEFINITION
COLORS
BLD62003_MAK_GLASS
STAINED
GLASS
STAINED GLASS AS MATERIAL
• The term stained glass can
refer to coloured glass as a
material or to works
created from it
• stained glass is glass that
has been coloured by
adding metallic
salts during its
manufacture. The
coloured glass is crafted
into stained glass
windows in which small
pieces of glass are
arranged to form patterns
or pictures, held together
(traditionally) by strips of
lead and supported by a
rigid frame.
• The term stained glass is
also applied to windows
in which the colours have
been painted onto the
glass and then fused to
the glass in a kiln
Ordinary soda-lime glass appears
colourless to the naked eye when it is thin
deeper greens can be achieved by the
addition of Iron(II) oxide which results
in a bluish-green glass.
Green glass
adding cobalt, which at a concentration
of 0.025 to 0.1% in soda-lime glass
blue glass
Metallic gold, in very small
concentrations (around 0.001%),
produces a rich ruby-coloured glass
("ruby gold"); in lower concentrations it
produces a less intense red
red glass
Silver compounds (notably silver
nitrate) are used as stain applied to
the surface of glass and fired on.
They can produce a range of
colours from orange-red to yellow.
yellow glass
the addition of Manganese gives
an amethyst color
purple glass
Tin oxide with antimony and arsenic oxides
produce an opaque white glass
white glass
12
13. STAINED GLASS MAKING PROCESS
BLD62003_MAK_GLASS
STAINED
GLASS
• Glass is made by fusing together some form of silica such as sand, an alkali
such as potash or soda, and lime or lead oxide. The color is produced by
adding a metallic oxide to the raw materials.
• Copper oxide, under different conditions, produces ruby, blue, or green
colors in glass. Cobalt is usually used to produce most shades of blues.
• Green shades can also be obtained from the addition of chromium and iron
oxide. Golden glass is sometimes colored with uranium, cadmium sulfide,
or titanium, and there are fine selenium yellows as well as vermilions. Ruby
colored glass is made by adding gold.13
14. THE MANUFACTURING PROCESS
BLD62003_MAK_GLASS
STAINED
GLASS
• Large manufacturers of stained glass mix the batch of
raw materials, including alkaline fluxes and stabilizing
agents, in huge mixers.
• The mix is then melted in a modern furnace at 2500°F
(1371°C).
• Each ingredient must be carefully measured and
weighed according to a calculated formula, in order to
produce the appropriate color.
• For cathedral glass, the molten glass is ladled into a
machine that rolls the glass into 1/8-inch mm thick
sheets.
• The sheets are then cooled in a special furnace called an
annealing. The glass is then inspected, trimmed to
standard size, and packed into cases.
STEP 1 :processing the stained glass
14
15. THE MANUFACTURING PROCESS
BLD62003_MAK_GLASS
STAINED
GLASS
STEP 2 :creating the window pattern
The first step of the process involves the artist creating a
small scale version of the final design. After the design
has been approved, the craftsperson takes
measurements or templates of the actual window
openings to create a pattern. This pattern is usually
drawn on paper or cardboard and is the actual size of the
spaces to be filled with glass.Next a full-sized drawing
called the cartoon is prepared in black and white. From
the cartoon, the cutline and pattern drawings are
made. The modern cutline drawing is a careful, exact
tracing of the leadlines of the cartoon on heavy paper.
The leadlines are the outlines of the shapes for patterns
to which the glass is to be cut. This drawing serves as the
guide for the subsequent placing and binding with lead
of the many pieces of glass. 15
17. THE MANUFACTURING PROCESS
BLD62003_MAK_GLASS
STAINED
GLASS
STEP 3 :cutting & painting
• Colored glass is then selected from the supply on hand.
• The pattern is placed on a piece of the desired color, and with
a diamond or steel wheel, the glass is cut to the shape of the
pattern. After the glass has been cut, the main outlines of the
cartoon are painted on each piece of glass with special paint, called
"vitrifiable" paint.
• This becomes glassy when heated.
• The painter might apply further paint to the glass in order to
control the light and bring all the colors into closer harmony.
• During this painting process, the glass is held up to the light to
simulate the same conditions in which the window will be seen.
• The painted pieces are fired in the kiln at least once to fuse the
paint and glass.
• The cutline drawing is spread out on a table and narrow strips of wood
called laths are nailed down along two edges of the drawing to form a right
angle.
• Long strips of grooved lead are placed along the inside of the laths. The
piece of glass belonging in the angle is fitted into the grooves.
• A strip of narrow lead is fitted around the exposed edge or edges and the
next required segment slipped into the groove on the other side of the
narrow lead.
• This is continued until each piece has been inserted into the leads in its
proper place according to the outline drawing beneath.
STEP 4 : glazing & leading
17
18. STEP 4 : glazing & leading
THE MANUFACTURING PROCESS
BLD62003_MAK_GLASS
STAINED
GLASS
STEP 4 : glazing & leading
18
19. THE MANUFACTURING PROCESS
BLD62003_MAK_GLASS
STAINED
GLASS
STEP 5 :finishing
STEP 6 : glazing & leading
• The many joints formed by the
leading are then soldered on both
sides and the entire window is
waterproofed.
• After the completed window has
been thoroughly inspected in the
light, the sections are packed and
shipped to their destination where
they are installed and secured with
reinforcing bars.
• For faceted glass windows, the process begins
the same way, with the cutline and pattern
drawings being made with carbons in a similar
manner.
• The pattern drawing is then cut to the actual
size of the piece of glass with ordinary scissors
since there is no core of lead to allow for.
• The thick glass slabs next are cut with a sharp
double-edged hammer to the shape of the
pattern.
• To give the slab an interesting texture, the
worker then chips round depressions in the
glass with the same hammer. This is called
faceting.
19
22. DEFINITION
COMPOSITION
BLD62003_MAK_GLASS
BEVEALED
GLASS
Modern beveled glass usually is machine
made
Beveled glass is usually
made by taking thick glass
and creating an angled
surface cut (bevel) around
the entire periphery. Bevels
act as prisms in the sunlight
creating an interesting color
diffraction which both
highlights the glass work
and provides a spectrum
of colors which would
ordinarily be absent in clear
float glass.
Textured glass is typically 1/8"
thick and has a distinct visible
texture.
TEXTURE
Beveled glass is typical made from 1/4"
float plate glass but thicknesses up to
1/2" have been used for larger
windows. The width of the bevel also
can vary depending on the desired
effect. The combination of beveled glass
is juxtaposed to the textured glass
creating dramatic visual effects.
HOW IT IS MADE?
GLASS BEVEL EDGES
DEFINITION
22
26. DEFINITION
KILN CASTING
BLD62003_MAK_GLASS
CASTING
GLASS
GLASS CASTING DEFINITION
• glass casting, or kiln casting, is the method
of creating glass sculptures by placing glass
into a mold and letting it take the shape
inside. There are several techniques you can
use to cast glass.
Kiln casting involves the preparation of a mould
which is often made of plaster or plaster mixtures.A
model can be made of any solid material such as
wax,wood or metal and after taking a cast of the
model, (a process called investment), the model is
removed from the mould. One method of forming a
mould is by the Cire perdue or "lost wax" method.
Using this, a model can be made from wax and after
investment the wax can be steamed or burned away
in a kiln. The heat resistant mould is then placed in a
kiln with a funnel like refractory opening which is
filled with solid glass granules or lumps. The kiln is
heated to a high temperature, normally between 800
and 1000 degrees Celsius (1472 - 1832 F), and as the
glass melts it runs, settling into and filling the mould.
Pâte de verre is another form of kiln casting and
literally translated means glass paste. In this process,
finely crushed glass is mixed with a binding material,
such as a mixture of gum arabicand water, and often
with colourants and enamels. The resultant paste is
applied to the inner surface of a negative mould
forming a coating. After the coated mould is fired at
the appropriate temperature the glass is fused
creating a hollow object that can have thick or thin
walls depending on the thickness of the pate de verre
layers
PATE DE VERRE
26
27. DEFINITION
CASTING
BLD62003_MAK_GLASS
CASTING
GLASS
GLASS CASTING DEFINITION
• glass casting, or kiln casting, is the method
of creating glass sculptures by placing glass
into a mold and letting it take the shape
inside. There are several techniques you can
use to cast glass.
Graphite is also used in the hot forming of glass.
Graphite moulds are prepared by carving into them,
machining them into curved forms or by stacking
them into shapes. Molten glass is poured into the
moulds then cooled until hard enough to be
removed and placed into an annealing kiln to cool
slowly.
GRAPHITE CASTING
27
28. CASTING GLASS
BLD62003_MAK_GLASS
METHOD 1: FRIT CASTING
• Fill the mold with frit, which
is small pieces of glass.
• Fire the mold in the kiln to a
temperature between 1,500
and 1,600 degrees
Fahrenheit (820 to 870
degrees Celsius).
• Add more frit and refire the
mold. The frit in the mold will
settle as it melts, so you will
have to add more. Continue
adding frit and refiring until
the mold is completely filled.
• Remove the mold from the kiln
and soak in water until it cools.
Add frit, then return the mold
to the kiln.
• Turn the kiln off and use high
temperature gloves to reach in
and add frit while the mold is
still hot. 28
29. CASTING GLASS
BLD62003_MAK_GLASS
METHOD 2: LOST WAX CASTING
1. Carve the sculpture, also
called the positive form, out of
wax.
2. Cover the wax form with plaster
of Paris to create the mold.
3. Melt the wax out of the mold.
4. Fire the mold in the kiln so it
will be hardened enough, or
annealed, to cast glass in.
5. Fill the mold with frit, then fire
it. Add frit and refire until the
mold is full. 29
30. CASTING GLASS
BLD62003_MAK_GLASS
METHOD 3: GLASS PASTE CASTING
1. Mix very small frit or glass
powder with an adhesive made
for creating glass paste
2. Apply a thin layer of paste to the
mold using a brush or palette knife.
3. Add a second layer, tamping it
down lightly. The combined
thickness of the 2 layers should be
1/8 inch (0.3 cm
4. Fire the mold at
temperatures between 1,300
and 1,500 degrees Fahrenheit
(705 to 820 degrees Celsius).
30
31. CASTING GLASS
BLD62003_MAK_GLASS
METHOD 4: HOT CASTING
1. Create a mold from ceramic
and silica or silica sand, and
resin. Carve a design into the
mold.
2. Don cotton clothing, high
temperature gloves, and eye
protection sufficient for the
temperatures in a furnace.
3. Heat glass in a furnace until it
reaches a temperature of 2,350
degrees Fahrenheit (1,290 degrees
Celsius).
4. Pour the glass into the mold
and allow it to cool.
5. Discard the mold after removing
the cooled and hardened
glass. Molds are destroyed by hot
casting and can't be reused.
31
32. CASTING GLASS
BLD62003_MAK_GLASS
METHOD 5: SAND CASTING
1. Wear cotton clothing, high
temperature gloves, and eye
protection sufficient for the
temperatures in a furnace.
2. Fill a wooden template with
silica sand and carve a design into
it.
3. Ladle molten glass into the mold.
4. Drop small objects that can
withstand the temperature of
the glass onto the top, if
desired. Allow the glass to cool,
remove it, and discard the mold.
32
34. FRAMELESS DOOR
RELIABLE SPACE SAVING
BLD62003_MAK_GLASS
FLEXIBLE LIVING BROADER VIEW
• make a stunning
contemporary design
statement and
• look great in all styles of
home.
• add value to your property
• environmentally friendly
and act as extremely
efficient insulators,
meaning that your energy
bills could be substantially
• can be manufactured to
perfectly fit any space
• can be customised to your
exact specification
In contrast to unwieldy patio doors,
frameless sliding glass doors take up far
less valuable space and have a much
cleaner line. Opening as smoothly as
curtains, they will fit seamlessly into any
space, thus quickly and easily enhancing
the aesthetic of any room in the home.
Frameless sliding glass doors have
literally opened up a whole new world
when it comes to the view we can have
of the garden from our key living spaces.
Heavy bifold doors were once the only
way to achieve a similar effect, but now
a perfect, unbroken view of your garden
is an achievable reality without the
necessity of clunky aluminium frames.
frameless sliding glass doors are an
increasingly common sight in commercial
properties, from office partition walls to
cutting edge shop fronts as it may
conserved space
COMMERCIAL VALUE
can be customised to the
customer`s exact
specifications. They can be
tinted or frosted for privacy
PRIVACY & STYLE WEATHERPROOF
Double glazed doors are thicker
and therefore perfect for fitting
on to outside walls
internal frameless sliding glass
doors are perfect to act as
room dividers, letting in
maximum light, taking up
minimum space and keeping
heat in and noise out
Frameless sliding glass doors
are carefully constructed to
have a minimum of moving
parts, thus making them far less
prone to operating problems
than other door systems.
ADVANTAGESFRAMELESS
GLASS
34
38. DEFINITION TINTED GLASS
ADVANTAGES
BLD62003_MAK_GLASS
TINTED
GLASS
• Residential tinted
• Automotive tinted
• Commercial building tinted
TYPE OF GLASS TINTED
(I) RESIDENTIAL UNIT TINTED
DEFINITION
• Give privacy that the occupants desire,
• Reduces amount of heat entered
building
This term refers to any glass that
has been treated with a material
such as a film or coating that
reduces the transmission of light
through it
Glass can be tinted with various
types of coating, which block
and/or reflect different amounts
and types of light, according to
the needs and preferences of the
consumer.
Residential glass tinting is much easier to
do than automotive tinting. It can even be
done by the homeowner himself, with
some practice.
• limiting ultraviolet light transmission
through windows
• to reduce the fading of furniture and
carpet
• reducing heat gain inside the home by
reflecting solar heat energy
• thereby saving the homeowner money
in cooling costs.
Functions of tinted glass at home
• keep the inside cooler
• giving the outside of a building a more uniform,
aesthetically pleasing appearance.
• different colors of tinting makes the unique and
interesting appearance
• insulated from the sun
Functions of tinted glass in commercial buildings
38
41. Uses or sources of
exposure
to hazard
Potential effects (physical
hazards
or health effects)
Precautions or control
strategies
Overexertion from
manual material-
handling practices ,
poor posture, high
frequency/duration of
tasks involving lifting,
pushing or pulling
Strains and sprains in
skeletal muscular
damage to back, upper
and lower extremities
Excessive physical and
mental fatigue can
cause errors leading to
secondary incidents
· Physical demands
assessments of suspect
job tasks
· Use of material-
handling devices
including lift assists,
powered vehicles
· Process automation or
semi automation
· Education on proper
techniques
Ergonomic stressors; biomechanical hazards
Potential health and safety hazards found during manufacturing of glass, ceramic and related materials
BLD62003_MAK_GLASS 41
42. Potential health and safety hazards found during manufacturing of glass, ceramic and related materials
Uses or sources of
exposure
to hazard
Potential effects
(physical hazards
or health effects)
Precautions or control
strategies
Caught in or struck
by or against fixed or
mobile equipment
Slips, trips and falls
on walking and
working surfaces,
hoses and other
equipment, tools or
materials
Abrasions, cuts,
contusions,
lacerations,
punctures, fractures,
amputations
· Safe work procedures
· Good housekeeping
practice
· Equipment design and
layout
· Job design and structure
· Anti-slip surfaces
Physical hazards
BLD62003_MAK_GLASS 42
43. Potential health and safety hazards found during manufacturing of glass, ceramic and related materials
Noise
Uses or sources of
exposure
to hazard
Potential effects
(physical hazards
or health effects)
Precautions or control
strategies
Pneumatic vibrators,
compressors, mixing
drive motors,
blowers and dust
collectors, conveyors,
packaging
equipment, etc.
Occupational
hearing loss,
communication
difficulty and stress
· Isolation, enclosure,
reflective barriers or sound
absorption materials
· Innovative design of
machine guarding
· Specifying lower-noise
motors or equipment
· Use of hearing protection
and a hearing conservation
programmer
BLD62003_MAK_GLASS 43
44. Potential health and safety hazards found during manufacturing of glass, ceramic and related materials
Uses or sources of
exposure
to hazard
Potential effects
(physical hazards
or health effects)
Precautions or control strategies
Heating or melting
processes during
maintenance or
emergency response
activities
Heat stress
or thermal
burns ,
heat cataracts
· Shielding ,barriers, reflective
surfaces, insulation
· Water-cooled equipment
· Air-conditioned control rooms
· Heat-protective clothing and
gloves
· Acclimatization to hot working
environments, intake of water
and electrolyte beverages,
controlled work-rest regimens
Radiant heat, high-temperature work environment
BLD62003_MAK_GLASS 44
45. Inhalation of airborne from raw material(crystalline silica, clay, lime, iron oxide, nuisance dusts )
Uses or sources of
exposure to hazard
Potential effects
(physical hazards
or health effects)
Precautions or control strategies
Handling, Exposures
during routine
maintenance activities,
rebuilds
non-ventilated equipment
or mixing equipment
Raw materials are
extremely
abrasive, causing
deterioration of transfer
or storage system in
manufacturing processes
Range from
irritation to
chemical burns
to chronic effects
such as decreased
pulmonary
function, lung
disease,
pneumoconiosis
silicosis
·Equipment exhaust ventilation
· Proper material handling
· Isolation of operators
·PPE
· Active leak detection and
repairs
. Periodic medical screening,
surveillance and early
intervention based on
exposure
Potential health and safety hazards found during manufacturing of glass, ceramic and related materials
BLD62003_MAK_GLASS 45
46. Heavy metals particulates or fumes (lead, cadmium, chromium, arsenic, copper, nickel, cobalt,
manganese or tin)
Uses or sources of exposure
to hazard
Potential effects
(physical hazard
or health effect)
Precautions or control strategies
As raw materials or impurities
in glazes, coloring agents
Maintenance and construction
activities involving soldering,
cutting, welding
Grinding, cutting, drilling
structural members or
machinery
Heavy
metal
toxicity
· Engineering controls
· HEPA-ventilated portable power
tools
· Use of ventilated booths for
spray painting & coating activities
· Good work practices to reduce
airborne particulates( wet method)
· Personal hygiene, segregated
laundering of contaminated work
clothes
· Respiratory protection and
protective clothing
· Medical surveillance and
biological monitoring
Potential health and safety hazards found during manufacturing of glass, ceramic and related materials
BLD62003_MAK_GLASS 46
47. Bases (sodium hydroxide) or acids (HCL, sulphuric acid, HF)
Uses or sources of
exposure
to hazard
Potential effects
(physical hazards or health effects)
Precautions or control
strategies
wastewater
treatment and pH
control
Acid cleaning or
etching processes
with HF
.Corrosive to skin or
eyes
Respiratory tract and
mucous membrane
irritant
.HF causes severe skin
burns that can go
undetected for hours
· Process isolation
· Safe handling practices
· PPE use-respiratory
protection, rubber
gloves, faceshield with
eye protection,
eyewash/safety shower
· Exhaust ventilation to
control acid vapours or
aerosols
Potential health and safety hazards found during manufacturing of glass, ceramic and related materials
BLD62003_MAK_GLASS 47
48. Propane, natural gas, gasoline, fuel oil
Uses or sources
of exposure
to hazard
Potential effects
(physical hazards or
health effects)
Precautions or control strategies
Fuels for
process heat
& powered
industrial
trucks
Fire and
explosion
hazards,
Exposure to
CO or other
products of
incomplete
combustion
· Proper design and inspections of
storage and distribution system, and
combustion process controls
· Safe unloading, filling and handling
practice
· Routine testing and control of
combustion processes
Potential health and safety hazards found during manufacturing of glass, ceramic and related materials
BLD62003_MAK_GLASS 48
49. Inhalation of bioaerosols
Uses or sources of
exposure
to hazard
Potential effects (physical
hazards or health effects)
Precautions or control
strategies
Aerosol containing
bacteria, moulds or
fungus generated
from spraying process
or cooling water in
humidification
processes, ventilation
systems
.Waterborne
illness with
systemic non
specific flu-like
symptoms,
.fatigue
.Potential for
dermatitis
· Process design and mist
reduction
· Process and cooling
water treatment with
biocides
· Routine cleaning and
sanitization
· Elimination nutrient
source in water system
· Respiratory protection
· PPE, gloves and good
personal hygiene
Potential health and safety hazards found during manufacturing of glass, ceramic and related materials
BLD62003_MAK_GLASS 49
50. Potential health and safety hazards found during manufacturing of glass, ceramic and related materials
Vacuum lift assist being used to handle
20 to 30 kg packages of textile glass
Walking and working surfaces should be
free from trip and slip hazards
BLD62003_MAK_GLASS 50
51. Potential health and safety hazards found during manufacturing of glass, ceramic and related materials
Machine guarding protects operators from
rotating shafts, belts or drive chains
Robotics used in plate-glass handling
reduces ergonomic and laceration hazards
BLD62003_MAK_GLASS 51
52. Potential health and safety hazards found during manufacturing of glass, ceramic and related materials
Aerosols of reused waste water that is not
treated can cause waterborne illness
Quality-control technician taking glass samples
from furnace and wearing personal heat protective
equipment and IR shielding glasses
BLD62003_MAK_GLASS 52
53. Demographic of injuries & illness case
Nature of occupational injuries and illnesses lost workday cases 1994
BLD62003_MAK_GLASS 53
55. TUTORIAL QUESTIONS
1. Describe the composition of glass. With the
aid of diagram, explain the manufacturing
process of float glass (10 marks)
2. Name two types of hazards during the
manufacturing of glass and describe two
precaution strategies for the named hazards
(6 marks)
3. With the aid of necessary diagram, compare
laminated glass and toughened glass (15
marks)
BLD62003_MAK_GLASS 55
