Industrial training report on spray technicics, its various sheet metal operations and paint booth

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INDUSTRIAL TRAINING REPORT
STUDY OF MACHINES, MECHANICAL OPERATIONS OF
SHEET METAL
Submitted By
Dipjyoti Deka
SUBMITTED TO:
SPRAY TECHNICS, Ecotech III, Greater Noida (UP)
Plant Manager: Mr. Hari Om Vishnoi
And
Department of Mechanical Engineering
Assam Don Bosco University
DATE OF INDUSTRIAL TRAINING:
27th
December to 12th
January 2019

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DECLARATION
I hereby declare that the Industrial Training Report entitled “Study of machines,
mechanical operations of sheet metal” is an authentic record of my own work as
requirements of Industrial Training during the period from 27th
December to 12th
January 2019 for the award of the degree of B.Tech. (Mechanical Engineering),
Assam Don Bosco University, Airport Road, Azara, under the guidance of Mr.
Deepak Negi and Mr. Hari Om Vishnoi.
Signature
Dipjyoti Deka
Date:

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PREFACE
The knowledge of Sheet Metal Fabrication is very useful in our day-to-day life and
one needs to know at least the basics of the same. The content of this report includes
an overview of the whole manufacturing fundamentals and the processes to be
followed in this category in order to obtain the required final product. The report
contains the description of various processes to be followed and their analysis for
their better understanding. The various processes included in the report are the
Punching (CNC & LASER), Bending, Welding, Grinding. The operation study,
machine study, and material information are clearly mentioned out there.

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ACKNOWLEDGEMENT
Before initializing the industrial report, we want to accomplish a vital task. First
of all, I would like to thank god for giving us strength and courage to successfully
complete such a beneficial industrial training. For my under graduate career, this
is the last industrial training.
It is my great privilege to express hearty thanks to Mr. Satyam Sharma for giving us
such a nice opportunity and his kind encouragement throughout this project.
My sincere thanks to the director and CEO of Spray Technics for allowing us to get
an exposure in the sheet metal industry.
I gratefully thank my guide Mr. Deepak Negi (Training Head) and Mr. Hari Om
Vishnoi (Plant Manager) who guided us throughout the project.
I sincerely thank all the operators and staff of Spray Technics for their immense help
during the course of the project.

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TABLE OF CONTENTS
Sl. No Page Title Page No.
1. Ch. 1
Introduction of Company 8
2. Chapter 2
Literature Survey
Punching process 9-14
Bending Process 14-16
Welding process 16-20
Drilling Process 20-22
Lathe Machine 22-26
3. Chapter 3
Conclusion on Study of machines, 27
Mechanical operations of sheet metal

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LIST OF FIGURES
Fig. 1 Punching Process
Fig. 2 Amada CNC Punching Press
Fig. 3 Finn Power CNC Punching Press
Fig. 4 Punched Workpiece
Fig. 5 Blanking Process
Fig. 6 Workpieces of punching process
Fig. 7 Nibbling in a cylindrical Punch
Fig. 8a Amada Laser Punching Machine
Fig. 8b Amada Laser Punching Machine tool
Fig. 9 Press brake (bending machine)
Fig. 10 Flanges with guidelines
Fig. 11 Amada Press brake machine
Fig. 12 Hindustan Hydraulics Press brake machine
Fig. 13 TIG welding Gun
Fig. 14 TIG welding while working
Fig. 15 TIG welding workpiece
Fig. 16 TIG welding process
Fig. 17 TIG weld joints
Fig. 18 MIG welding Gun 3D Model
Fig. 19 MIG welding Gun
Fig. 20 MIG welding process
Fig. 21 MIG welding gun with assembly
Fig. 22 Spot Welding Process
Fig. 23 Spot Welding machine Prima Italy
Fig. 24a Drill Bit
Fig. 24b Drilling cum tapping machine
Fig. 25 Working of Drill
Fig. 26 Block Diagram of the drilling assembly
Fig. 27 Lathe Machine
Fig. 28 Lathe Machine Headstock
Fig. 29 Lathe Machine Carriage
Fig. 30 Lathe Machine Tailstock

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CHAPTER 2
LITERATURE SURVEY
The objective of Literature Survey: It is the detailed study of each process that
comes under the sequential production. It is much needed to understand the
manufacturing thoroughly.
Various processes are as follows:
1. PUNCHING PROCESS:
Punching is a metal fabricating process that removes a scrap slug from the metal
workpiece each time a punch enters the punching die. This process leaves a hole in
the metal workpiece.
CNC Punching and Blanking:
Punching is the process of forming metal components using a punch. The punch is
usually the upper member of the complete die assembly and is mounted on the slide
or in a die set for alignment (except in the inverted die). The punching process forces
a steel punch, made of hardened steel, into and through a workpiece. The punch
diameter determines the size of the hole created in the workpiece.
The illustration that follows provides a two-dimensional look at a typical punching
process. Note how the workpiece remains and the punched part falls out as scrap as
the punch enters the die. The scrap drops through the die and is normally collected
for recycling.
Fig. 1

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Fig. shows two CNC turret machine used for punching purpose:
The Computer Numerical Control (CNC) fabrication process offers flexible
manufacturing runs without high capital expenditure dies and stamping presses.
High volumes are not required to justify the use of this equipment. Tooling is
mounted on a turret which can be as little as 10 sets to as much as 100 sets. This
turret is mounted on the upper part of the press, which can range in capacity from 10
tons to 100 tons in capacity. The turret travels on lead screws, which travel in the X
and Y direction and are computer controlled. Alternatively, the workpiece can travel
on the lead screws, and move relative to the fixed turret. The tooling is located over
the sheet metal, the punch is activated, and performs the operation, and the turret is
indexed to the next location of the workpiece. After the first stage of tooling is
deployed over the entire workpiece, the second stage is rotated into place and the
whole process is repeated. This entire process is repeated until all the tooling
positions of the turret are deployed.
The illustration that follows shows a few common punches and die configurations
and the workpieces that would be formed by this combination. Multiple punches can
be used together to produce a complete part with just one stroke of the press.
Fig. 2 Fig. 3
Fig. 4

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There are 20 different tools and die, holders, on which various tools with their
specific dies can be mounted. There are certain dies for thin and thick sheets,
depending upon sheet thickness. Mainly there are three stations, B, C and D
depending on the tool and die size
Blanking is a metal fabricating process, during which a metal workpiece is removed
from the primary metal strip or sheet when it is punched. The material that is
removed is the new metal workpiece or blank. The blanking process forces a metal
punch into a die that shears the part from the larger primary metal strip or sheet. A
die cut edge normally has four attributes. These include:
• burnish
• burr
• fracture
• roll-over
The illustration that follows provides a two-dimensional look at a typical blanking
process. Note how the primary metal workpiece remains and the punched part falls
out as scrap as the punch enters the die. The scrap drops through the die and is
normally collected for recycling.
Like many other metal fabricating processes, especially stamping, the waste can be
minimized if the tools are designed to nest parts as close together as possible.
The illustration that follows shows the workpieces that could be created through the
blanking process using either sheet or roll as the parent material.
Fig. 5
Fig. 6

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Quite often, curves and other difficult features are produced by punching out small
sections at a time. This process is called nibbling. This leads to triangular shaped
features. These triangular shaped features give the edge a scalloped look. This
scalloping can be pronounced if the nibbling pitch is coarse. The amount of
scalloping that can be accepted is a function of tooling and product cost. Clamp
marks are cosmetic in nature, and if objectionable, can be so positioned to cut them
away in subsequent processing.
The limitations for CNC turret: Maximum limit for various materials: Aluminum-
5mm, Mild steel- 3mm, Copper- 4mm and Brass- 3mm.
Continuous cooling is required for proper and safe operation. An oil tank is also used
to provide oil for extensive lubrication that is necessary to avoid wear of job and
tool. Mostly all jobs can be done on CNC for punching purpose, but there are some
limitations of it, due to which there arises the need of Laser CNC machine.
Laser Punching:
Fig. 7
Fig. 8a
Fig. 8b

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Laser cutting machines can accurately produce complex exterior contours. The
laser beam is typically 0.2 mm (0.008 in) diameter at the cutting surface with a
power of 1000 to 2000 watts.
Laser cutting can be complementary to the CNC/Turret process. The
CNC/Turret process can produce internal features such as holes readily whereas
the laser cutting process can produce external complex features easily.
Laser cutting takes direct input in the form of electronic data from a CAD
drawing to produce flat form parts of great complexity. With 3-axis control, the
laser cutting process can profile parts after they have been formed on the
CNC/Turret process. Lasers work best on materials such as carbon steel or
stainless steels. Metals such as aluminium and copper alloys are more difficult to
cut due to their ability to reflect the light as well as absorb and conduct heat. This
requires lasers that are more powerful.
Lasers cut by melting the material in the beam path. Materials that are heat
treatable will get case hardened at the cut edges. This may be beneficial if the
hardened edges are functionally desirable in the finished parts. However, if further
machining operations such as threading are required, then hardening is a problem.
A hole cut with a laser has an entry diameter larger than the exit diameter, creating
a slightly tapered hole.
The minimum radius for slot corners is 0.75 mm (0.030 in). Unlike blanking,
piercing, and forming, the normal design rules regarding minimum wall
thicknesses, minimum hole size (as a per cent of stock thickness) do not apply.
The minimum hole sizes are related to the stock thickness and can be as low as
20% of the stock thickness, with a minimum of 0.25 mm (0.010 in) up to 1.9 mm
(0.075 in). Contrast this with normal piercing operations with the recommended
hole size 1.2 times the stock thickness.
Burrs are quite small compared to blanking and shearing. They can be almost
eliminated when 3D lasers are used and further, eliminate the need for secondary
deburring operations.
As in blanking and piercing, considerable economies can be obtained by nesting
parts and cutting along common lines. In addition, secondary deburring operations
can be reduced or eliminated.
The limits associated with laser cutting –Maximum sheet thickness preferred:
Aluminum- 1 mm, Mild steel- 8mm, Stainless Steels- 6mm.

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The minimum flange width should be at least 4 times the stock thickness plus the
bending radius. Violating this rule could cause distortions in the part or damage to
tooling or operator due to slippage.
Fig. shows a hydraulic press (Bending machine):
The machine has a stationary bed or anvil and a slide (ram or hammer) which has
a controlled reciprocating motion toward and away from the bed surface and at a
right angle to it. The slide is guided in the frame of the machine to give a definite
path of motion.
A form of open-frame single-action press that is comparatively wide between the
housings, with a bed designed for holding long, narrow forming edges or dies.
Used for bending and forming strip, plate, and sheet (into boxes, panels, roof
decks, and so on).
Fig. 10
Fig. 11 Fig. 12

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Dies used in presses for bending sheet metal or wire parts into various shapes. The
work is done by the punch pushing the stock into cavities or depressions of similar
shape in the die or by auxiliary attachments operated by the descending punch.
Various types of machinery equipped with two or more rolls to form a curved sheet
and sections.
3. WELDING PROCESS:
Welding is the process of permanently joining two or more metal parts, by melting
both materials. The molten materials quickly cool, and the two metals are
permanently bonded. Mainly used welding types are Argon (TIG) welding and
MIG welding.
TIG welding:
TIG welding is a slower process than MIG, but it produces a more precise weld
and can be used at lower amperages for thinner metal and can even be used on
exotic metals. TIG welding is a commonly used high-quality welding process. TIG
welding has become a popular choice of welding processes when high quality,
precision welding is required. The TIG welding process requires more time to
learn than MIG.
Characteristics:
• Uses a non-consumable tungsten electrode during the welding process,
• Uses a number of shielding gases including helium (He) and argon (Ar),
• Is easily applied to thin materials,
• Produces very high-quality, superior welds,
• Welds can be made with or without filler metal,
• Provides precise control of welding variables (i.e. heat),
• Welding yields low distortion,
• Leaves no slag or splatter.
In TIG welding, an arc is formed between a non-consumable tungsten electrode
and the metal being welded. Gas is fed through the torch to shield the electrode
and molten weld pool. If filler wire is used, it is added to the weld pool separately.

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The illustration that follows provides a schematic showing how the TIG welding
process works.
The following illustration shows the TIG-welded joints:
MIG welding:
The "Metal" in Gas Metal Arc Welding refers to the wire that is used to start the arc.
It is shielded by inert gas and the feeding wire also acts as the filler rod. MIG is fairly
easy to learn and use as it is a semi-automatic welding process.
Welding gun
GMAW torch nozzle cutaway image: (1) Torch handle, (2) Molded phenolic
dielectric (shown in white) and threaded metal nut insert (yellow), (3) Shielding gas
diffuser, (4) Contact tip, (5) Nozzle output face
Fig. 13 Fig. 14 Fig. 15
Fig. 16
Fig. 17

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Characteristics:
• Uses a consumable wire electrode during the welding process that is fed
from a spool,
• Provides a uniform weld bead,
• Produces a slag-free weld bead,
• Uses a shielding gas, usually – argon, argon - 1 to 5% oxygen, argon - 3 to
25% CO2 and a combination argon/helium gas,
• Is considered a semi-automatic welding process,
• Allows welding in all positions,
• Requires less operator skill than TIG welding,
• Allows long welds to be made without starts or stops,
• Needs little cleanup.
The illustration that follows provides a look at a typical MIG welding process
showing an arc that is formed between the wire electrode and the work piece.
Fig. 18 Fig. 19
Fig. 20 Fig. 21

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During the MIG welding process, the electrode melts within the arc and becomes
deposited as filler material. The shielding gas that is used prevents atmospheric
contamination from atmospheric contamination and protects the weld during
solidification. The shielding gas also assists with stabilizing the arc which provides
a smooth transfer of metal from the weld wire to the molten weld pool.
Versatility is the major benefit of the MIG welding process. It is capable of joining
most types of metals and it can be performed in most positions, even though flat
horizontal is the optimum.
The most common welds are illustrated below. They include the:
• lap joint
• butt joint
• T-joint, and the
• edge joint
MIG is used to weld many materials, and different gases are used to form the arc
depending on the materials to be welded together. An argon CO2 blend is normally
used to weld mild steel, aluminium, titanium, and alloy metals. Helium is used to
weld mild steel and titanium in high-speed process and also copper and stainless
steel. Carbon dioxide is most often used to weld carbon and low alloy steels.
Magnesium and cast iron are other metals commonly welded using the MIG process.
Spot Welding
Spot welding works by sending an electrical current through two metal surfaces and
thereby welding the surfaces together at that spot, hence the name. Spot welding
requires the use of two copper electrodes and a thorough knowledge of how the
thickness and density of the joining metals will react to the electrical current. If too
little power is sent through the copper electrodes, then the metal will not adhere. If
too much electricity is sent through the electrodes, they will burn a hole through the
metal.
To create heat, copper electrodes pass an electric current through the work pieces.
The heat generated is expressed by the equation: E=I2
*R*t
Where E is the heat energy, I is the current, R is the electrical resistance and t is the
time that the current is applied.
Spot Welding occurs in three stages:
• Electrodes seated in a weld head are brought to the surface of the parts to be
joined and force (pressure) is applied

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Construction:
The design of lathes can vary greatly depending on the intended application;
however, basic features are common to most types. These machines consist of (at
the least) a headstock, bed, carriage, and tailstock. Better machines are solidly
constructed with broad bearing surfaces (slide-ways) for stability, and manufactured
with great precision. This helps ensure the components manufactured on the
machines can meet the required tolerances and repeatability.
● Headstock
The headstock (H1) houses the main spindle (H4), speed change
mechanism (H2,H3), and change gears (H10). The headstock is required to be made
as robust as possible due to the cutting forces involved, which can distort a lightly
built housing, and induce harmonic vibrations that will transfer through to the
workpiece, reducing the quality of the finished workpiece.
Fig. 27
Fig. 28

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The main spindle is generally hollow to allow long bars to extend through to the
work area. This reduces preparation and waste of material. The spindle runs in
precision bearings and is fitted with some means of attaching workholding devices
such as chucks or faceplates. This end of the spindle usually also has an
included taper, frequently a Morse taper, to allow the insertion of hollow tubular
(Morse standard) tapers to reduce the size of the tapered hole, and permit use
of centers. On older machines (50's) the spindle was directly driven by a flat
belt pulley with lower speeds available by manipulating the bull gear. Later
machines use a gear box driven by a dedicated electric motors. A fully 'geared head'
allows the operator to select suitable speeds entirely through the gearbox.
● Beds
The bed is a robust base that connects to the headstock and permits the carriage and
tailstock to be moved parallel with the axis of the spindle. This is facilitated by
hardened and ground bedways which restrain the carriage and tailstock in a set track.
The carriage travels by means of a rack and pinion system. The leadscrew of accurate
pitch, drives the carriage holding the cutting tool via a gearbox driven from the
headstock.
● Feed and lead screws
The feedscrew (H8) is a long driveshaft that allows a series of gears to drive the
carriage mechanisms. These gears are located in the apron of the carriage. Both the
feedscrew and leadscrew (H7) are driven by either the change gears (on the quadrant)
or an intermediate gearbox known as a quick change gearbox (H6) or Norton
gearbox. These intermediate gears allow the correct ratio and direction to be set for
cutting threads or worm gears.
● Carriage
In its simplest form the carriage holds the tool bit and moves it longitudinally
(turning) or perpendicularly (facing) under the control of the operator. The operator
moves the carriage manually via the handwheel (5a) or automatically by engaging
the feed shaft with the carriage feed mechanism (5c). This provides some relief for
the operator as the movement of the carriage becomes power assisted.

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● Cross-slide
The cross-slide (3) rides on the carriage and has a feedscrew that travels at right
angles to the main spindle axis. This permits facingoperations to be performed, and
the depth of cut to be adjusted.
● Compound rest
The compound rest (or top slide) (2) is usually where the tool post is mounted. It
provides a smaller amount of movement (less than the cross-slide) along its axis via
another feedscrew. The compound rest axis can be adjusted independently of the
carriage or cross-slide. It is used for turning tapers, to control depth of cut when
screwcutting or precision facing, or to obtain finer feeds (under manual control) than
the feed shaft permits.
● Toolpost
The tool bit is mounted in the toolpost (1) which may be of the
American lantern style, traditional four-sided square style, or a quick-change style
such as the multifix arrangement pictured.
● Tailstock
The tailstock is a tool (drill), and centre mount, opposite the headstock. The
spindle (T5) does not rotate but does travel longitudinally under the action of a
leadscrew and handwheel (T1).
Fig. 29
Fig. 30

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Operation performed on lathe:
1. Centering: It is center drilling.
2. Turning: A machining operation for generating external surfaces of
revolution by the action of cutting tool on a rotating workpiece.
3. Chamfering: It produces beveled egde at a specified angle on the end of a
turned diameter.
4. Thread cutting: It consists in producing a helical form or thread on revolving
work pieces.
5. Polishing: It produces polished surface by removing excessive metal from
work piece.
6. Knurling: It produces depression or indentations of various shapes into the
work piecesbt the use of revolving hardened steel wheels against the work
pieces.
7. Grooving: It produces grooves on the surface of workpiece.
8. Keyway cutting: It produces keyway by the help of cutting tool.

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CHAPTER 3
CONCLUSION
We conclude from this training that the various processes as applied are dependent
on various parameters. A good co-ordination is the key to get best efficiency and
high productivity.
• Each and every process depends on factors such as the method used to carry
out the process, the type of the material used (whether Aluminium, Mild Steel,
GP, etc.) and the thickness of the material (or sheet).
• At the process of development of surfaces, the allowances are to be increased
as per the thickness of metal.
• The operations are varied based on the type of workpiece and type of sheet.
In the technical aspect, we conclude that nothing can be understood thoroughly
without practical knowledge and practice. We observed almost each process related
to sheet metal fabrication that we had just studied in books. It was really a fruitful
training for us to enhance our knowledge and confidence level.
END OF STUDY OF MACHINES, MECHANICAL OPERATIONS OF
SHEET METAL IN SPRAY TECHNICS

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INDUSTRIAL TRAINING REPORT
Study of Paint Booth and the various processes involved in fabrication of it
Submitted By
Dipjyoti Deka
SUBMITTED TO:
SPRAY TECHNICS, Ecotech III, Greater Noida (UP)
Plant Manager: Mr. Hari Om Vishnoi
And
Department of Mechanical Engineering
Assam Don Bosco University
DATE OF INDUSTRIAL TRAINING:
27th
December to 12th
January 2019

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Table of Contents
Sl. No Page Title Page No.
1. Abstract 32
2. Chapter 1.
Introduction to paint booth 33
Types of paint booth 33-34
3. Paint booth components 35-37
4. Chapter 2
Safetry mechanisms 37-38
Heating the paint booth
5. Chapter 3
Operating cycles of paint booth 38-40
Managing airflow in the paint booth 40-41
6. Chapter 4
Practical Session 42-45
Brief working of
Spray Technics Paint Booth 45
Chapter 5
3D Model of a typical 46
Paint Booth
7. Chapter 6
Conclusion
References

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LIST OF FIGURES
Fig. 31 Downdraft paint booths
Fig. 32 Semi-downdraft paint booths
Fig. 33 Side downdraft paint booths
Fig. 34 Crossdraft paint booths
Fig. 35 paint booth components
Fig. 36 intake
Fig. 37 CNC Program for punching process
Fig. 38a Sheet stack 1
Fig. 38b Sheet stack 2
Fig. 39 CNC program for bending of sheet
Fig. 40 Operator during bending process
Fig. 41 MIG welding in paint booth turbine chamber 1
Fig. 42 MIG welding in paint booth turbine chamber 2
Fig. 43 MIG welding in centrifugal fan chamber
Fig. 44 Assembly of turbine chamber side view 1
Fig. 45 Assembly of turbine chamber side view 2
Fig. 46 Insulation in Paint booth panels
Fig. 47 3D Model of Paint Booth (front view)
Fig. 48 3D Model of Paint Booth (side view)

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CHAPTER 1
INTRODUCTION TO PAINT BOOTH
Introduction: A Paint Booth is primarily a pressure-controlled enclosure that is
employed for spraying paints in vehicles, furniture, parts or in any other equipment.
To ensure that this booth is functioning it is very important to guarantee air flow,
humidity, and temperature that are outfitted with all possible ventilation system. It's
mainly made up of sheet metal. The most basic thing about Paint booth is an
excellent air supply. All Paint booths require a fantastic amount of air that can be
pumped for efficient and better results.
Paint booths come in many different conjurations. The biggest difference among
those configurations is the air flow.
There are four main air flow designs for paint booths:
DOWNDRAFT PAINT BOOTHS
The best air flow style, downdraft paint booths do an excellent job controlling
overspray and contamination. Air enters the booth through a full-length, filtered
ceiling plenum or intake chamber and flows vertically over the product or vehicle
and into the filtered exhaust pit in the floor. The intake and exhaust filter layout is
designed for even air velocity throughout the working area.
SEMI-DOWNDRAFT PAINT BOOTHS
Semi-downdraft paint booths are a hybrid, combining features of cross draft and
downdraft booths. Air is introduced to the booth through the ceiling or an intake
Fig. 31

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plenum in the first 25 to 30 percent of the booth. It is then pulled across the working
chamber, over the product or vehicle and into the filtered exhaust chamber at the
rear of the booth.
SIDE DOWNDRAFT PAINT BOOTHS
Side downdraft paint booths are an economical solution for shops that are not able
or do not want to install an exhaust pit. Air comes into the booth through a full-
length, filtered ceiling plenum or an intake chamber and flows downward over the
product or vehicle. The intake and exhaust filter layout is designed for even air
velocity throughout the working area. When air reaches the floor, it’s pulled into
floor-level, filtered exhaust plenums on both sides of the booth.
CROSSDRAFT PAINT BOOTHS
The simplest, most cost effective one, in cross draft paint booths air flow starts at
the front of a cross draft paint booth, with air entering the booth through filtered
product doors or an intake chamber. Air flows horizontally, parallel to the floor and
over the product or vehicle. The intake and exhaust filter layout is designed for even
air velocity throughout the working area. Air exits the booth through an exhaust
plenum at the rear of the booth.
Fig. 32
Fig. 33

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PAINT BOOTH COMPONENTS
All paint booths are designed to move air through a working chamber which is made
of sheet metal before exhausting it. They have three common components:
• Intake chamber
• Working chamber
• Exhaust chamber
INTAKE
INTAKE PLENUM
Located at the front or top of the booth, the intake plenum is the point at which air
is brought into the spray booth. The plenum may be vertical and located at one end
of the paint booth, or horizontal, using part or all of the ceiling inside the paint booth
as an aperture. Air entering the spray booth through the plenum may flow parallel to
the floor, or it may flow downward from an overhead plenum at the top of the
chamber.
INTAKE FILTRATION
Dust, dirt and other airborne particles in the supply air are a major cause of
contaminated paint jobs. A set of filters, located in the intake plenum, helps trap
these particles before they enter the paint booth’s working chamber.
WORKING CHAMBER
Since the paint booth’s working chamber encloses the spray operation, it should be
large enough to contain the product and provide the painter room to move around
Fig. 34
Fig. 35
Fig. 36

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the product. The recommended working depth in a paint booth is usually a minimum
of 5 to 6 feet wider and deeper than the largest product to be coated. Lighting and
vehicle movement are also considerations when designing a spray booth for painting
and coating operations.
EXHAUST
EXHAUST FILTRATION
All dry filter spray booths use filters to capture overspray produced by the spray
application. Filter materials are usually configured in one of two ways:
• Pads are suitable for operations in which overspray is concentrated in less than
50 percent of the filter area. Pads can be changed individually, as needed,
reducing replacement costs.
• Filter rolls are a better choice when overspray is distributed across a majority
of the filter surface. Filter rolls are purchased as bulk media and are
traditionally cheaper than purchasing individual filter pads.
In some applications, water is used as the filtering medium. In water wash booths, a
recirculation system continually cycles specially compounded water through a series
of sluices and baffles, creating a water curtain to capture overspray.
EXHAUST CHAMBER
In cross flow booths, the exhaust chamber is a plenum behind the exhaust filtration
and is often the same width and height as the working depth. In this configuration,
the exhaust air moves parallel to the floor as it enters the exhaust filters. In booths
using downdraft airflow, the exhaust plenum is either a pit or a basement. Air from
the working chamber is drawn down through filters under the booth to be exhausted
or recirculated during a bake cycle. These exhaust systems typically use an air make-
up unit to move air through the system.
AIR MAKE-UP UNITS
During paint spray operations, the spray booth’s exhaust system removes a
significant amount of air from the facility. A typical spray booth exhausts more than
10,000 cubic feet of air per minute (CFM). To combat this, shops may pull
replacement air from outside the building. In colder environments, this replacement
air can cool the interior of the building to an unsuitable temperature. An air
replacement system, which supplies filtered, conditioned air to the booth, may be
required. This minimizes temperature variations and removes particles that
compromise finish quality.

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CHAPTER 2
SAFETY MECHANISMS
Automatic Safety Shut-Down Systems: Automatically interrupts compressed air
to the spray equipment (i.e. spray gun) when the accumulation of overspray in the
filters exceeds a preset limit.
Limit Switch: Electronically operated switch that shuts down painting operations
when a paint booth’s doors are opened.
Manometer: Monitors air pressure within the working chamber. Also provides a
visual indication of when dirty filters should be replaced.
Motors: All AC, induction motors should be mounted on standard frame bases and
should be explosion-proof and totally enclosed, fan-cooled types. They should
conform to state and local fire and safety regulations.
Pneumatic Start/Stop: Activates a pneumatic-electric interface, turning an exhaust
fan on and off. A non-sparking pneumatic switch is located inside a paint booth,
allowing the operator to enter and leave the booth with the exhaust fan turned off
and preventing dirty, unfiltered air from entering the paint area.
Safety Air Valve: A three-port, two-position safety air valve prevents spraying with
air assist systems when booth exhaust is off.
Compressed air between the valve and spray equipment is vented out when the
exhaust is shut off.
Variable Frequency Drive (VFD): Automatically adjusts fan motor speeds based
on actual airflow conditions and maintains an air balance within the paint booth,
preventing paint fumes from escaping and dust from entering. Also provides
optimum air pressure, consistent exhaust and consistent temperature.
HEATING THE PAINT BOOTH (BAKING MODE)
The spray booth is maintained at a temperature of 90 degree centigrade.
In addition, many coatings require a heat-enhanced curing period (bake cycle) after
application to reach their final finished state. This heat is applied through a heater or
burner unit.

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CHAPTER 1
INTRODUCTION OF COMPANY
Name: Spray Technics
Address: Plot No. 49-50, Toy City, Ecotech III, Greater Noida, GB Nagar
(U.P)
About: Spray Technics has the knowledge, experience and capabilities
required to meet and exceed sheet metal fabrication needs of large and small
companies alike. Spray Technics, sheet metal fabricators, provide "turnkey—
design & build" fabricating capabilities for producing individual sheet metal
component parts, assemblies, cabinets and enclosures in both prototype and
production quantities. Utilizing steel, aluminium, brushed stainless, and pre-
painted metals SPRAY TECHNICS turns customer ideas into functional
realities through cutting edge metal fabrication technology and unsurpassed
customer service.

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CHAPTER 3
A curing paint booth provides four successive operating cycles:
1. Spray mode
2. Flash-off
3. Bake mode
4. Cool down
PHASE 1: SPRAY MODE
The spray mode is the period of time in which the paint material is being sprayed
onto the vehicle. The operating cycle ensures the correct air pressure and
temperature for the painter, as well as excellent air filtration for proper results of the
paint application.
The operator turns on the power to the paint booth, then sets the appropriate switch
on the control panel to “spray.” The spray cycle is as Follows:
The damper positions itself automatically to allow the intake blower assembly to
draw in only fresh air. All of the air passes through the pre-filter, then through the
burner or around the heat exchanger. The outside air is heated to the preset
temperature on the control panel and enters the plenum of the paint booth
Here the air passes through the ceiling filters, enters the paint booth and is evenly
distributed throughout the paint booth cabin. The air is then exhausted beneath the
floor through the paint arrestor filters, where most of the overspray is removed. It
then enters the exhaust side of the mechanical unit, where it is expelled through the
duct exhaust to the outside.
PHASE 2: FLASH-OFF
The flash-off phase is the period of time between two applications of paint or
between the last application and the bake cycle. This time is necessary to allow the
paint to flow out and release solvents before the final cure.
This is an extremely variable phase, which may or may not be necessary, depending
upon the type of paint and application method used. The time setting will be
determined in each case by the painter and the paint product recommendations.
PHASE 3: BAKE MODE
The bake mode is the period of time required for the curing of the paint applied to
the vehicle. In this phase, the control unit maintains the operator’s pre-selected
temperature (up to 200 degrees Fahrenheit) for proper results. For code compliance,
no one should enter the spray booth during bake mode.
The operator switches the control console to “bake.” This automatically activates the
bake timer, which should have been set in advance with the correct cure time. The

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bake time counter starts when the spray booth reaches the preset temperature for this
phase.
The operating cycle is as follows:
The damper automatically positions itself to permit the intake blower assembly to
draw a portion of the air from the outside (10 to 15 percent) and re-circulate the
remaining air (85 to 90 percent)
All of the air then passes through the pre-filter and around the burner or heat
exchanger
It is heated to the preset temperature on the control panel and enters into the plenum
of the paint booth
Here the air passes through the ceiling filters, then enters the paint booth and
is evenly distributed throughout the booth cabin
The air is exhausted beneath the floor through the paint arrestor filters, then it enters
the exhaust chamber, where 10 to 15 percent of the air is expelled outside and the
remaining 85 to 90 percent is re-circulated.
PHASE 4: COOL DOWN
The cooling phase is the period of time required to cool down the heating unit and
the interior of the paint booth. This phase starts automatically upon completion of
the bake period. The length of this phase is preset and controllable via a thermostat.
A sensor is located above the burner or heat exchanger and close to the connecting
duct between the spray booth and the mono block. If the thermostat temperature
setting is too low, making it impossible for the outside air to cool the paint booth to
the preset temperature, a preset timer will interrupt the cooling, even though the
preset temperature has not been reached.
The operating cycle is similar to the spray mode, in that the dampers automatically
position themselves to draw 100 percent fresh air from the outside, like in the paint
cycle. Never turn off power to the paint booth when it is operating in the cooling
cycle. Doing so will stop the blower assembly, thus preventing the proper cooling of
the combustion chamber, which could overheat and be damaged. If it is absolutely
necessary to interrupt the cooling cycle due to an emergency, turn off the main power
switch.

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MANAGING AIRFLOW IN THE PAINT BOOTH
Managing the airflow is probably the most important element of a spray booth and
its design. Creating a laminar airflow envelope in the spray area at an engineered
velocity separates a “spray booth” from a “tin box”. This managed airflow enables
a painter to get maximum efficiency of the paint sprayed while directing overspray
away from the painted finish. In a superior design, air is controlled to flow in
unidirectional layers, either in horizontal, semi-downdraft or downdraft flow
patterns, while maintaining an even velocity. Velocity must be evenly maintained
and balanced!
BOOTH AIR REQUIREMENTS
A critical step in selecting a spray booth system is establishing the minimum air
velocity and volume requirements. The spray booth should be located to allow for
proper air entry and flow through the booth.
The graphic at below shows that an open-faced booth should be located with the face
at least booth height dimension from any wall. Booth “a” is too close to the building
walls. The front of booth “b” is placed at a distance from the wall that is equal to the
height of the booth. When this placement is not possible, air input plenums can
provide adequate airflow. Booth “c” can be placed next to the wall because it has a
direct-connected air input plenum.
A spray booth requires a minimum air draft or velocity, measured in feet per minute
(fpm), to carry overspray through the booth, past the operator or the automatic
equipment, and deposit it into either the filter pads or water curtain. The high-
pressure atomization equipment used to break up higher solids materials, for
example, produces high atomization pressures and consequently, high fluid stream
velocity, at the tip of the spray gun. This can cause overspray to rebound and may
expose the operator to toxic materials present in the paint. Velocity should always
be sufficient to carry the overspray away from the operator and into the exhaust
chamber.
The velocity possible in a booth depends on the fan size. Most standard booths
offered in the market come equipped with fan and motor packages sized to deliver
the necessary draft. Draft requirements take into account real world static pressures;
that is, resistance to airflow from entry losses, stack filters and ductwork.
The static pressure of any filter is determined by how much air will pass through that
filter. Air intake filters for downdraft spray booths are denser and pass less air than
air intake filters for either cross-draft or semi-downdraft booths. Consequently, air
intake filters for downdraft spray booths have a higher static pressure rating than the
air intake filters for other booths.

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When intake or exhaust filters become clogged with dirt or material overspray, the
amount of air that can pass through the filter decreases.
When airflow is restricted, the filter’s static pressure or resistance to airflow
increases. Air intake and exhaust ducts also influence static pressure.
Air volume and velocity are decreased when elbows, reducers, transitions and long
runs are added to ducts. Elbows introduce angles and increase resistance to airflow.
Reducers and transitions also increase the static pressure in ductwork. The ideal
situation is to keep ductwork to a minimum.

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CHAPTER 4
PRACTICAL SESSION
My whole training session was under the guidance of Mr. Deepak Negi and
Mr. Hari Om Vishnoi, who helped me in preparing the report everything from
beginning of paint booth design to end of paint booth manufacturing.
The ordered paint booth to be made is received by Spray Technics in the form
of drawings on paper, CAD drawing, or in any soft document files else design
engineers of Spray Technics prepare the CAD or drawing based on customer’s
requirement .These drawings are firstly studied by the Designing Engineer regarding
the type of the material required by the ordering company, the possibility of the paint
booth to be made well with that type of material, the amount of material required in
accomplishing the task, the type operations to be performed on respective machines,
etc.
After reading the drawing by Engineer, the final part list is made. The operator
is given a CNC program to feed to the required machine for operation and a drawing
or just the figure and the final dimension of sheet that is required of raw material for
paint booth work. The workers prepare the specific blank sheet for further
processing.
Fig. 37

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Then the required sheet metal is collected from store, the paint booth then
moves to the CNC Press where the sheet metal gets cut into desired requirement.
Here the operator understands the paint booth and its diagram to check whether the
CNC press brake machine is working according program given to the machine. The
operator starts the pressing operation by pressing the start button on the machine
control panel. The sheet is then proceeded for further operations.
The sheet then moves to the bending shop. Here the operator understands the
diagram to carry on the required process with a given CNC program. The symbols
like BUP and BDN shows about the direction of bend to be applied on sheet. The
operator starts bending operation by pressing the start button on the control panel.
The sheet is then proceeded for further operations.
Fig. 38a Fig. 38b
Fig. 39 Fig. 40

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The sheet is taken to the welding area. The sheet and its edges are properly
cleaned to avoid any inclusions at the time of welding. The required type of welding
needed for the sheet to join is decided. The sheet is then kept on an anvil or support
frame to weld. The bend edges are then welded by MIG/TIG or Spot Welding. The
sheet is then left idle to get cooler.
If the sheet needs finishing then the sheet is further proceeded for finishing
process. Here the edges and the weld portioned is grinded/finished with the help of
grinder or any other finishing operation. Also the weld foul appearance is improved
a lot by this finishing processes.
After that different parts (made from sheet metal) are sent to the assembly area
where the parts are assembled. If any defect on the parts are detected by the operators
during assembly then the information is forwarded to the engineers. Else the
assembled parts moves to the electrical shop where the different electrical systems
are provided to the parts or the paint booth.
Fig. 41 Fig. 42 Fig. 43
Fig. 44 Fig. 45 Fig. 46

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After the final inspection is done on the assembled parts of a paint booth the
order is then ready to dispatch to the customer.
A brief working of Spray Technics Paint Booth
The spray booth maintains downward draft velocity of 0.2 to 0.3 m/s. The entire
overspray is trapped in the overspray arrestors which are either on the sidewall.
The spray booth has four levels of filtration particles smaller than 15 micron pass
through the main filter which filters up to 5 micron.
The fresh air is passed through the spray booth with the help of a direct mounted
air turbine. It can filter up to 15 microns at the pre-filter stage.
Particles smaller than 5 micron which passed through the main filter are not
significant and do not create any issue while painting the object.
After painting, the components are pushed into the drying oven, the drying oven
can go up to a temperature of 90 degree Celsius.
The drying oven also filters the air up to the same level and releases hot air into
the drying chamber. After recycling air inside the air handling unit, this results
in a massive economy of energy. Hot air is recycled and only five to ten percent
of fresh air is introduced in the drying oven to unable the oven to breathe, this
results in a very efficient safe and low-cost paint drying.
The pressure manometer informs the operator of the filter clock in stage. There
is a backup filter in the extraction unit which does not allow even a single paint
particle to be released in the environment.
The objects are now ready for further assembly or dispatch and are pushed out
the drying oven.

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Chapter 5
3D Model of a typical Paint Booth
Fig. 47
Fig. 48

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References
• www.spraytechnics.com
• www.gzguangli.com
• www.finishingacademy.com
• www.autokabina.pl

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