© 
/JS/AQH fzcJ'Q 
DESIGN OF GREEN TIRE PAINTING MACHINE 
A dissertation submitted to the 
Department of Electrical Engineering, University of Moratuwa 
in partial fulfilment of the requirement for the 
degree of Master of Science ^ 
L I B R A R Y 
UNIVERSITY OF MORATUWA. SRI LANK > 
MORATUWA 
by 
SAMINDA ASELA BANDARA 
Supervised by Dr. Nalin Wickramarachchi 
University of Moratuwa 
— * " ' "" '"' * *"% 
H 
93951 
Department of Electrical Engineering 
University of Moratuwa, Sri Lanka 
August 2009 93 9$/ 
9 3 3 5 1 
DECLARATION 
The work submitted in this dissertation is the result of my own 
investigation, except where otherwise stated. 
It has not already been accepted for any degree, and is also not being 
concurrently submitted for any other degree. 
Saminda'Asela Bandara 
I endorse the declaration by the candidate. 
Supervisor: Dr. Nalin Wickramarachchi 
i 
CONTENTS 
Declaration i 
Abstract iv 
Acknowledgement v 
List of Figures vi 
List of Tables vii 
1. Introduction 1 
1.1 Background 1 
1.2 Tire manufacturing process 2 
1.3 Present method of the green tire painting 7 
1.4 Objective of the project 9 
2. Design Approaches 10 
2.1 Initial attempts and problems 10 
2.2 final approach 12 
3. Detailed Design 14 
3.1 Overview of the design 14 
3.2 Loading Station 16 
3.2.1 Loading station operational flowchart 17 
3.3 Painting Station 18 
3.3.1 Painting station operational flowchart 21 
3.4 Unloading Station 22 
3.4.1 Unloading station operational flowchart 24 
3.5 Main arm rotation circuit 25 
3.5.1 Main arm rotation flowchart 25 
3.6 Clamping disk circuit 26 
3.6.1 Clamping disk rotational flowchart 27 
4. Components Selection 29 
4.1 Pneumatic cylinders selection 29 
4.1.1 Loading/Unloading cylinders 29 
ii 
4.1.2 Clamping cylinder 29 
4.1.3 Main painting cylinder 30 
4.1.4 Inside/Outside painting cylinders 31 
4.2 Pressure switch selection 31 
4.3 Motor selection 31 
4.3.1 Main drive motor 31 
4.3.2 Rotary drive 33 
4.4 Indexing gearbox 34 
4.5 PLC selection 35 
4.6 Proximity sensors / Reflective sensors 36 
4.7 Nozzles 36 
4.8 Encoders 37 
4.9 Rotary air union 38 
4.10 Display 39 
5. Discussion, Conclusion and Future Developments 41 
5.1 Discussion 41 
5.2 Payback calculation 42 
5.3 Future developments 43 
References 44 
Appendix-A PLC Ladder Diagram .• 46 
in 
Abstract 
The tire manufacturing process is a long process that includes lots of hazard 
operations. Manual green tire painting method is also considered in to this category. 
Green tire is the tire which builds according to the tire construction and which is 
ready for the curing process. Before the curing process, it has to apply lubricant inside 
the green tire and flow property improving agent on the out side. This application is 
called green tire painting. The main objective of this project is to design a new 
machine for green tire painting and protect operators from harsh environment, and 
improve the productivity. 
This project is focused more on actual requirements and takes a practical approach. 
When selecting components, it is restricted to select popular brands, which is 
recommended by the company. All the selected components are available in the 
market with reasonable price. As this is an actual machine design, I focused more on 
durability, productivity, safety and budget. 
The green tire painting machine is automated by the control unit which is a 
commercially available programmable logic controller (PLC). The requirement of the 
sensor units for the PLC and the control program is also implemented as part of this 
design. 
IV 
Acknowledgement 
Thanks are due first to my supervisor, Dr. Nalin Wickramarachchi, for his great 
insights, perspectives, guidance and sense of humor. His guidance directed me to the 
success of this project. My sincere thanks go to the officers in Post Graduate Office, 
Faculty of Engineering, University of Moratuwa, Sri Lanka for helping in various 
ways to clarify the things related to my academic works in time with excellent 
cooperation and guidance. Sincere gratitude is also extended to the people who serve 
in the Department of Electrical Engineering office. 
I sincerely gratitude to Mr. Jonas Lundgren, General Manager, Light Industrial Tire 
division, for his approval and guide to perform this project. I must thank Mr. Dian 
Gunathilake, HR Director, who made financial support for the second year of my 
masters studies. Their support directed me to the success of this project. 
Lastly, I should thank many individuals, friends and colleagues who have not been 
mentioned here personally in making this educational process a success. May be I 
could not have made it without your supports. 
List of Figures 
Figure Page 
1.1 Pneumatic tire manufacturing process 2 
1.2 Cross section of a tire 4 
1.3 Green tire 5 
1.4 Green tire with polythin wrap around the bead 5 
1.5 Tire mould in the press with curing bladder 6 
1.6 Cured tire 6 
1.7 Manual green tire inside painting method 7 
1.8 Manual green tire outside painting method 8 
2.1 Basic design of fist attempt 10 
2.2 Basic design of second attempt 11 
2.3 Final design 12 
3.1 Main arm rotation and positions 14 
3.2 Green tire loading-1 15 
3.3 Green tire loading-2 15 
3.4 Loading station operational flowchart 16 
3.5 Clamping disk at painting position 18 
3.6 Green tire at painting position-1 18 
3.7 Green tire at painting position-2 19 
3.8 Painting station operational flowchart 20 
3.9 Unloading position -1 22 
3.10 Unloading position -2 22 
3.11 Unloading station operational flowchart : 23 
3.12 Main arm rotation flowchart 24 
3.13 Clamping disk operation 25 
3.14 Clamping disk operational circuit 26 
4.1 Force distribution between green tire and grabbing arm 29 
4.2 Pressure switch •. 30 
4.3 Indexing gearbox 34 
4.4 Retro reflective sensor 35 
4.5 Paint nozzle 36 
4.6 Incremental encoder 37 
4.7 Rotary air union 37 
4.8 Rotary air union assembly 38 
4.9 TD 200C display 38 
VI 
List of Tables 
Table Page 
3.1 Digital position indication by Arm-1 & Arm-2 switches 15 
4.1 PLC specifications 36 
5.1 Costing 41 
Vll 
List of Tables 
Table Page 
3.1 Digital position indication by Arm-1 & Arm-2 switches 15 
4.1 PLC specifications 36 
5.1 Costing 41 
Vll 
Chapter 1 
Introduction 
1.1 Background 
At present, the increase in the number of vehicles manufactured per year has created a 
higher demand for tires in the world market. Basically, tires can be divided in to two 
main categories. They are Solid tires and Pneumatic tires. From the total pneumatic 
tire production in the world, 95% of tires are used for transportation. Other 5% is used 
for agricultural and farming purposes [1], Tire manufacturing process is a long 
process which includes a number of hazardous operations. It involves lots of 
chemicals that are toxic to the human body. Compared to the solid tire manufacturing 
processes, pneumatic tire manufacturing involves more difficult processes. Pneumatic 
tire manufacturing process includes lots of human interacting hazardous operations 
like Tire building, Green tie painting and curing etc. 
Basic steps in pneumatic tire manufacturing process are chemical mixing, 
Calendaring, Extruding, making beads, tire building and curing process [2], "Green 
tire" is the industrial term used for a half-built tire before the curing process. Green 
tire is the output of the building machine. It is an uncured cylinder shaped tire with 
two beads at the end. Before the curing process, some amount of paint need to be 
applied inside and outside of the green tire. Inside paint is used to reduce friction 
between green tire and curing press bladder [3], and outside paint is used to increase 
the flow properties of the green tire to form lugs accurately as in the mould [4], These 
liquids are highly toxic to inhale. Therefore operators have to wear heavy safety 
equipments to prevent from inhaling the toxic paint [5], However it is very difficult to 
wear such equipments in a hot environment and also the productivity is adversely 
affected. Also it is difficult to get a uniform paint application all over the tire, as it 
depends on the operator's skill and ability. Thus, all above mentioned reasons urges to 
find a solution to increase the productivity, quality and to protect operators from the 
hazardous environment. 
1 
Green tire painting operation is the most hazardous operation among all the operations 
which involve with tire building and curing process [5]. It uses hazardous chemicals. 
Statistically, major reason for serious health damages related to the tire manufacturing 
process is inhaling of toxic chemicals by green tire painting operation [6]. Therefore 
prevention of this hazardous environment in the tire manufacturing process is highly 
important. 
1.2 Tire manufacturing process 
* e 
1 
Mixing 
PROCESS FOR PNEUMATIC TYRES 
I f • 
« f 
.To 
Material Processing 
6 
Inspection 
o 
Curing 
Tire Building 
Tire Painting 
19, 
l a g 1 • ^ < B 
• -
Figure 1.1 Pneumatic tire manufacturing process [2] 
Pneumatic tire manufacturing process is shown in figure 1.1. 
1. Mixing 
As in the first step of tire manufacturing, it has to mix raw materials according 
to the recipe of each respective tire. The recipe is depending on the requirement of the 
2 
customer and the performance of the tire. Main raw materials used for tire 
manufacturing are Natural rubber, Synthetic rubber, Carbon filler, Chemicals and Oil 
[7]. 
2. Material Processing 
Output compound of the mixture has to undergo several processing operations 
to make it suitable for tire building. Inner liner calendaring is used to make inner layer 
of tubeless tires. Also fabric calendaring process is used to cote rubber layers both 
side of the fabric which is used to build a tire. It uses Nylon or Polyester depending on 
the performance and price requirements. Separate steel wire coating operation is used 
to make steel beads and a rubber extrusion process to extrude outer layer (Tread) of 
the tire. 
3. Tire building 
Outputs of the material processing are send to the green tire building machine. 
The operator of the tire building machine winds each plies on expanded or collapse 
drum of the building machine according to the specified tire construction. It is 
basically started with inner liner, several plies from rubber coated fabric, then two 
bead rings at the two edges and finally the thread on the top [8]. 
4. Tire painting 
Then green tire comes to the painting stage. At this stage it has to paint outside 
and inside of the green tire according to the requirements. Inside paint is acting as 
lubricant between green tire and the curing bladder [3]. Outside paint is acting as an 
agent to increase the flow properties of the tread [4], 
5. Tire curing 
Next stage is the tire curing process. In this stage, the green tire is put over the 
bladder which is attached in the middle of the tire mould. Mould is fixed to the curing 
press heated platen. Steam is used to heat up the curing press platen. Firstly apply pre 
shaping steam pressure in to the bladder and then close the mould and apply high 
pressure steam in to the bladder. Then the curing bladder pushes the green tire in to 
the mould. Due to heated mould and bladder inside steam heat, the green tire stats to 
vulcanize. Normally it takes 30 to 60 minutes to cure the tire depending on the tire 
3 
dimension and the compound [9]. In the cuing process green tire takes the shape of the 
mould and the lug pattern. 
6. Quality inspection 
Then it will move to the quality inspection section. If the quality does not meet 
the required level, those tires will be sent to the scrap yard. All the tires which have 
acceptable quality level are sending to packing and warehouse. Those tires will be 
shipped to various destinations according to the customer requirements. 
The basic steps involved with the tire manufacturing process has mentioned as above. 
In this project it is mainly focused on the tire painting process to introduce new 
machine to overcome difficulties faced in the current tire painting manual system. 
Tread Pattern 
Nylon Cap 
Steel Belt 
Valve Cap / 
Figure 1.2 Cross section of a tire [10] 
Inner 
Bead Wire 
Body Ply 
Sidewall Rubber 
4 
Figure 1.3 Green tire 
Figure 1.2 shows a completed green tire which is ready for curing. Figure 1.3 shows 
the green tire with wrapped protective cover over the beads. This is used to prevent 
contamination of the paint on the beads. The paint should not be touched with the 
beads as it will affect badly on the correct bead formation. This protective cover is 
mostly used for big tires. These covers are normally removed before the curing 
process. 
Figure 1.4 Green tire with polyethylene wrap around the bead 
5 
Figure 1.5 Tire mould in the press with curing bladder 
Normally the bladder life time is around 150 tires. There is a separate bladder 
calculation which is used to select suitable bladder for a particular tire. 
1.3 Present method of the green tire painting 
To manufacture a good quality final tire, the attention given to the green tire is utterly 
important. Green tire quality directly determines the quality of the final result. This 
fact clearly shows that the green tire painting plays a significant role in tire 
manufacturing process. A number of inside and outside paint types are available in the 
market. But in this project it is focused on following paint types only. 
Manufacturer Specific gravity 
Inside paint -> Darmex 1.25 [3] 
Outside Paint-> Darmex 1.07 [4] 
Paint quality is an important factor affecting the final tire quality [2], The application 
method and the amount of usage is also affecting to the final outcome. The norm is to 
apply the inside paint as thin layer. It is water based mixture and has to be dry-off 
completely before curing. Otherwise the moisture inside the paint will expand in the 
curing process and will make inside air bubbles in the cured tire. 
The existing method of inside painting is done using a manual operation. Operators 
apply paint according to the specifications as well as their experiences. Therefore it is 
very difficult to get a uniform output from existing method. It highly depends on the 
operators' skill. Also the operator has to rotate the tire manually to apply the paint all 
over the tire, except the beads. 
Figure 1.7 Manual green tire inside painting method 
7 
In this manual method, lots of paint particles are inhaled by the operators. It is very 
hazardous for health. Also this is not economically suitable for long hour 's 
continuous working [11]. Figure 1.6 is showing the manual operation of present green 
tire inside painting method. 
The existing method of outside painting system is also a manual operation. Operators 
use conventional painting brush to apply outside paint. The brush marks give a bad 
appearance on the final tire. The operator has to rotate the tire to apply paint all over 
the tire. Also the amount of paint and the quality of the painting process is highly 
depending on the operator's skill. Figure 1.7 is showing the manual operation of the 
present green tire outside painting method. 
Figure 1.8 Manual green tire outside painting method 
Those two above mentioned operations create bottle necks, which need to overcome 
in order to get high production output. Even, the painting operators cannot work long 
hours as they get sick due to the harsh environment. Sophisticated safety equipments 
need to be used to prevent inhaling the paint. It is very difficult to work with wearing 
heavy safety equipments. This is the utmost requirement behind this project, which is 
to make a machine with capability to paint inside and outside at the same time with 
high production output in a safety environment. 
8 
1.4 Objective of the project 
With the present system, the output is around 650 tires per 8 hour shift when the 
operators are working at their full capacity. In the 8 hour shift routine, they take 
hour meal break. Therefore the painting output is 1.5 tires per minute. Company target 
for the year 2011 is 1500 tires per shift. This equals to 3.3 tires per minute. The 
possibility with the present method to meet that target is to increase the number of 
painting operators. But this will not overcome the safety problems and also not a 
solution for uniform quality output requirement and uniform paint consumption. 
Therefore the main objective of this project is to give permanent solution to fulfill all 
production capacity requirements, quality requirements and to create a safe 
environment to work with. 
Main requirements of the new methodology are, 
1. Efficiency (Maximum 6 to 8 tires per minute) 
2. Easy loading and unloading 
3. Protect operators from toxic paint 
4. Simplify operation and use of standard components 
5. Safety of the operation 
9 
Chapter 2 
Design Approaches 
2.1 Initial attempts and problems 
Basically, three different designs are analyzed as follows. First design is to keep the 
green tire horizontally on horizontal rollers. These rollers are driven by a motor and 
inside and outside paints are applied while the green tire is rotating. 
With the basic experiments it has found that the green tire strength is not enough for 
this method. This means that the green tire gets an oval shape when it kept 
horizontally. The green tire is not a cured tire. Therefore it is more flexible. When it 
gets an oval shape, it is very difficult to rotate the tire with two drive rollers. Also the 
distance from inner painting nozzle to the inner wall is not a constant. Then some 
parts get more paint applied, compared to other parts. All green tires have a joint as it 
is made by winding a fabric and a tread around the drum. It is called as the 'Splicing' 
joint [12]. In this method, the splicing joint is also blocks the free rotation of the green 
tire. Even we overcome these difficulties; tire starts to move left and right when it 
starts to rotate. Then it is difficult to get an even paint distribution all over the tire. 
When these observations from the experiments are taken in to consideration, this first 
attempt was rejected because it does not fulfill the requirements. 
Figure 2.1 Basic design of fist attempt 
10 
observations from the experiments are taken in to consideration, this first attempt was 
rejected because it does not fulfill the requirements. 
The second attempt is to keep the tire vertically. Green tire is kept vertically on the 
loading conveyor and the grabbing disk is placed to grab the tire vertically. After the 
painting process, the tire is placed on the unloading conveyor. 
Figure 2.2 Basic design of second attempt 
With a basic analysis, it has found that this needs a complicated control system. 
Grabbing disk is moving to positions 1-Loading, 2-Painting and 3-Unloading. This 
linier motion has to stop at each position accurately. Green tire is moving from S to E. 
At the point E, green tire and the grabbing disk has to be aligned accurately to grab the 
green tire correctly. Position 2 is also very important as the inside painting nozzle is 
moving within the middle of the green tire. This needs a servo controller to get all this 
positions accurately, and it is very expensive. Also the basic analysis shows that the 
maximum output this can execute is limited to 4 tires per minute. This is because there 
is only one grabbing disk is there to move in all three positions. Though it matches 
with our near future requirement, it will not be suitable with a long term view. Though 
11 
this is a workable model, it is not feasible due to usage of expensive equipments and 
wear and tear caused by extensive movements. Considering these facts, this design 
was rejected and moved to another design which enables a simple logical control with 
high productivity. 
2.2 Final approach 
Third attempt was the final attempt and this was designed by meeting the company 
requirements and budget completely. In this design it has used three rotating grabbing 
disks for Loading, Painting and Unloading respectively. 
Figure 2.3 Final design 
In this design, Position 1 is for loading, Position 2 is for painting and the Position 3 is 
for unloading. Basic operation of this machine is as follows. 
At one instance the grabbing disk 1 comes to the 1st position and grabs the green tire. 
The loading tray of the Is position lifts the green tire to the grabbing disk. Then it 
rotates by 120° which is up to the painting position. Then the painting nozzles paint 
the green tire and rotate another 120° to the unloading position. At the unloading 
12 
position also the unloading tray will lift up to get the green tire. After unloading the 
green tire the same grabbing disk rotates another 120° to the 1st position to grab the 
next green tire. These three operations perform simultaneously. Also 120° indexing 
gear box gives an accurate positioning without any servo control. 
13 
Chapter 3 
Detailed design 
3.1 Overview of the design 
This machine has designed based on the company requirements. That is to increase 
productivity, make hazards free environment for the operators, reduce paint 
consumption and unique paint application all over the green tire. Basic design is a 
simplified logical approach with available components in the market. Other main 
restriction is the company regulations. This is because some of the components have 
to be sourced from the company approved standard suppliers. (Eg: ABB motors, Festo 
pneumatic items, SKF bearings etc.) However these are well established standard 
suppliers with a vast product range. Therefore selecting a suitable component from 
those suppliers is quite an easy task. 
Basically this machine has three positions. Those are. Loading position, Painting 
position and Unloading position. The main rotation arm consists with three clamping 
disks which mounted with 120° angle between each other. These disks named as A, B, 
C and all three rotate with the main arm. For the each operation at each respective 
position, the position has to identify the disk which has aligned with the position. 
Therefore the machine controller needs to identify 9 positions. To get this positions, 
two mechanical sensors are used (named as 'Arm-F & 'Arm-2') which are mounted 
align to the main arm disk A. These sensors are operating by cams which located at 
three positions i.e. Loading, Painting and Unloading and send signals to the PLC. 
Painting Arm-1 -> ON 
Arm-2 -> ON 
Claming disk 
A-Loading Station 
B-Painting Station 
C-Unloading Station 
In the flowchart this position 
Indicated as "PS1" 
Ladder input = 10.0 
14 
position indicated as "PS2" 
Arm-1 ->ON 
Arm-2 -> OFF 
A-Painting Station 
B-Unloading Station 
C-Loading Station 
In the flowchart this 
Ladder input = 10.1 
Painting 
Sensor 1 (Arm-1) 
Sensor 2 (Arm-2) 
Loading Unloading 
A- Unloading Station 
B- Loading Station 
C- Painting Station 
Painting 
Arm-1 ->OFF 
Arm-2 -> ON 
In the flowchart this position 
indicated as "PS3" 
Ladder input = 10.2 
Sensor 2 (Arm-2) 
Sensor 1 (Arm-1) 
Loading Unloading 
Figure 3:1: Main arm rotation and positions 
Loading Painting Unloading 
A 11 10 01 
B 01 11 10 
C 10 01 11 
Table 3.1 Digital position indication by Arm-1 & Arm-2 sensors 
15 
3.2 Loading station 
Loading a green tire on to the loading tray is the first operation in the cycle. Operator 
loads a green tire on to the loading tray manually. When he pushes the loading button, 
loading tray goes up (SW1). 
Loading Encoder 
Arm-1 & Arm 2 
SI • 
I 
I 
I li 
isas 
III 
I ' 
Figure 3:2: Green tire loading-1 
When the green tire came to the clamping position, it will block the loading reflective 
sensor beam (Sen_l). When reflective sensor detects the green tire it will send a signal 
to the PLC. Then PLC stops the loading tray's upward movement and start clamping 
action. Green tire height will depend on the tire size. It is vary from 300 mm to 1400 
mm. PLC counts the pulses of the Loading incremental encoder (Rl ) which starts 
from operator pushes the button till the signal receives from the Loading reflective 
sensor. Then it stores that value in a specific memory register in the PLC (Reg A, 
Reg_B or Reg_3). That represents the height of the loaded tire which is needed for the 
next operations. Then the loading tray is returned to its original position. 
Figure 3:3: Green tire loading-2 
16 
3.4.1 Unloading station operational flowchart 
01 (SW_1) 
I 
02 (LTBLS=1) 
PS2 OR f-
PS3 J 
AND 
No 
03 (LTUM) 
IF 
Sen 1=1 
Yes 
08 (S-LTUM) 
04 (R1) C100 VW100 
IF 
PS3=1 
IF 
PS2=1 
IF 
PS1 = 1 
05 (Reg_B) 06 (Reg_C) 07 (Reg_A) 
X # _ # ' ' 
VW700 VW600 VW500 
09 (SigCC-1) 
10 (SigCC-2) 
T5 Delay 2S 
- * • 11 (LTDM) 
" i ' 
_ 12 IF 
No LTBLS=1 
Yes 
13 (S-LTDM) • 14 (Sig_R1) 
Figure 3:11: Unloading station operational flowchart 
17 
Description: 
Index Description FC Symbol Ladder 
(01) Loading tray lift switch (SW_1) 10.3 
(02) Loading tray bottom limit switch (LTBLS) 10.4 
(03) Start Loading tray upward movement (LTUM) Q0.1 
(04) Read loading encoder pulses (Rl) 10.6 
(05) Store R1 in memory register B (Reg_B) VW700 
(06) Store R1 in memory register C (Reg_C) VW600 
(07) Store R1 in memory register A (Reg_A) VW500 
(08) Stop loading tray upward movement (S-LTUM) 
(09) Send a signal to clamping circuit (SigCC-1) Q0.2 
(10) Receive signal from clamping circuit (SigCC-2) Q0.3 
(11) Start loading tray down movement (LTDM) Q0.4 
(12) Loading tray bottom limit switch (LTBLS) 10.4 
(13) Stop loading tray down movement (S-LTDM) 
(14) Send signal to Main arm circuit (Sig_Rl) Q0.5 
3.3 Painting Station 
The clamping disk can freely rotate about its pivot axis. When it reaches to the 
painting station, the sprocket wheel of the clamping disk is engaged with the drive 
chain which is driven by an electric motor. Then the clamping disk and the green tire 
stars to rotate. The air pressure applied to the clamping disk jacks is supplied though a 
rotary air union. Then the disk can freely rotate around its pivot axis while supplying 
the air pressure to the clamping cylinders. At this point, painting position tire 
detecting sensor (Sen_2) is activated to give the signal to the PLC to activate painting 
position activities. 
This electric motor is a 4 pole three phase motor. Its output rpm is 1500. This motor is 
equipped with a reduction gear box. Selected type is with 25:1 gear reduction ratio. 
Then the output speed of the gear box is 60 rpm. The same number of teeth sprocket 
wheel is attached to the clamping wheel. Then the green tire rotational speed is also 60 
rpm. 
18 
LIBRARY 
UNIVERSITY Of MORATUWA. SRI LANK 
MORATUWA 
Figure 3.5 Clamping disk at painting position 
9 3 3 5 1 
While the green tire is rotating, paint application process also starts to operate. First it 
will move the inside and outside paint nozzles to the top of the green tire. (Activating 
MPCF, IPCF and OPCF). Then it starts to spray inside and outside paint. Inside paint 
nozzle is 360° spraying nozzle. Outside paint nozzle covers 100 mm length paint strip 
at a time. Then the main paint jack starts to move backward (MPCD). 
Figure 3.6 Green tire at painting position-1 
The loading position encoder (Rl) has recorded a value at the beginning of the cycle. 
It represents the height of the green tire. PLC counts the main paint encoder pulses 
(R2) and checks whether it has reached to the bottom of the green tire. If it has not 
reached to the bottom of the green tire with main cylinder full stroke, inside and 
outside separate cylinders start to move backward. When R1=R2 painting operation 
will be stopped and the nozzles will be moved to its original position. 
Main painting 
j ack which is 
attached both 
inside and 
outside painting 
cylinders 
Inside paint ing 
cylinder 
Outs ide painting 
cylinder 
Figure 3.7 Green tire at painting position-2 
Maximum height of the green tire = 1400 mm 
Outside nozzle spray area = 100 mm 
RPM of the green tire = 60 
Rotations need to cover total area of the 'green tire 
with 50% covering from the previously painted area= (1400/100)* 1.5 
= 21 
Max: time need to paint total area of the biggest tire = 21/60 
= 0.35 minutes (21 S) 
Painting process takes much time in the total cycle. Then the rate of painting a biggest 
tire is around 3 tires per minute. This will meet the required output. Normally the 
biggest tire percentage is around 3% from the total production. 
After the painting process, the main arm rotates 120° to the unloading position. 
20 
3.4.1 U n l o a d i n g station operational flowchart 
PS1 
' " T 
PS2 4 OR 
j 
I 
PS3 r 
— • 1 6 (OPCF) 
I 
No 
— 19 (OCFS) 
Yes 
15 (Sen_2) 
AND 
-»• 17 (MPCF) 
No 
20 (MCFS) 
| Yes 
M AND • 
-»• 18 (IPCF) 
No 
21 (ICFS) 
Yes 
22 (IP) 23 (OP) 
No 
r 
- f t — . 
24 (MPCD) 
I 
27 (R2) 
I 
25 (IPCD) 
C101 
VW200 
No No 
1 
IF IF " " IF 
PS3=1 PS1=1 PS2=1 
VW200=VW700 I Yes VW200=VW5001 Yes VW200=VW6001 Yes 
No IF 
R2=Reg_C 
Yes 
28 (SIP) 
31 (OCBS) 
I 
34 (S-OPC) 
No IF 
R2=Reg_B 
i Y e S 
-*> OR 
29 (SOP) 
32 (MCBS) 
I 
35 (S-MC) 
I 
No IF 
R2=Reg_A 
Yes 
33 (ICBS) 
I 
36 (S-IPC) 
- * AND •« 
I 
26 (OPCD) 
n 
30 (RCBV) 
"37 (Sig_R2) 
Figure 3:11: U n l o a d i n g station operational flowchart 
21 
Description: 
Index Description FC Symbol Ladder 
(15) Painting station tire detect sensor (Sen_2) 10.7 
(16) Outside painting cylinder forward (OPCF) Q0.6 
(17) Main painting cylinder forward (MPCF) Q0.7 
(18) Inside painting cylinder forward (IPCF) Q1.0 
(19) Outside painting cylinder front sensor (OCFS) 11.0 
(20) Main painting cylinder front sensor (MCFS) 11.1 
(21) Inside paint cylinder front sensor (ICFS) 11.2 
(22) Start Inside painting (IP) Q l . l 
(23) Start outside painting (OP) Q1.2 
(24) Move main painting cylinder down (MPCD) Q1.3 
(25) Move inside painting cylinder down (IPCD) Q1.4 
(26) Move outside painting cylinder don (OPCD) Q1.5 
(27) Read painting encoder pulses (R2) 11.3 
(28) Stop Inside painting (SIP) 
(29) Stop Outside painting (SOP) 
(30) Release cylinder block valve (RCBV) Q1.6 
(31) Outside cylinder bottom sensor (OCBS) 11.4 
(32) Main cylinder bottom sensor (MCBS) 11.5 
(33) Inside cylinder bottom sensor (ICBS) 
(34) Stop outside paint cylinder (S-OPC) f i 
i 
(35) Stop Main cylinder (S-MC) 
Vss 1 X? \k 
(36) Stop Inside paint cylinder (S-IPC) 
(37) Send a signal to the main arm circuit (Sig_R2) Q1.7 
3.4 Unloading Station 
At the unloading position, the PLC detects the disk using unloading tire detect sensor 
(Sen_3). Then unloading tray moves upward (ULTU). The PLC counts the pulses 
from unloading encoder (R3) till it matches with the loading encoder value (i.e. 
R3=R1). At this point the unloading tray stops its movement after reaching the green 
tire. Then the clamping jacks move backward and release the green tire on to the 
unloading tray. 
22 
Figure 3.9 Unloading position -1 
Figure 3.10 Unloading position -2 
After finishing the unloading operation, the unloading tire detect sensor (Sen_3) 
checks whether the tire is perfectly removed from the clamping disk or not. If the 
reflective sensor is clear, then the arm starts to rotate by another 120° to the starting 
position. Unloading tray moves downward till the activation of the bottom limit 
switch (ULTBS). Then it completes one cycle of green tire painting. Within these 
three steps (Loading, Painting and Unloading) it has to communicate with two other 
main circuits. Those are the Clamping circuit and Main arm rotation circuit. This is 
because; these circuits are mainly related to the green tire position. 
23 
3.4.1 Unloading station operational flowchart 
38 (Sen_3) 
PS2 
PS1 
A / 1 x 
H OR -t -M AND 
t 
PS3 
39(ULTU) 
I 
«'R3» ™ 
No 
IF 
PS3=1 
No 
IF 
PS1=1 
No 
IF 
PS2=1 
VW300=VW700 I Yes VW300=WV500 
No ' IF "N. 
R3=Reg_A 
Yes 
No IF 
R3=Reg_C 
I Yes 
Yes VW300=VW600 
No 
Yes 
• OR k -
T 
41 (S-ULTU) 
IF 
R3=Reg_B 
Yes 
42 (SigCC-3) 
T6 Delay 2S 
-> 44 (ULTD) 
' i 
45 IF 
No ULTBS=1 
43 (SigCC-4) 
Yes 
46 (S-ULTD) 47 (Sig_R3) 
Figure 3:11: Unloading station operational flowchart 
24 
Description: 
Index Description FC Symbol Ladder 
(38) Unloading station tire detect sensor (Sen_3) 11.7 
(39) Start unloading tray upward (ULTU) Q2.0 
(40) Read pulses unloading encoder (R3) 12.0 
(41) Stop unloading tray upward (S-ULTU) 
(42) Send a signal to clamping circuit (SigCC-3) Q2.1 
(43) Receive signal from clamping circuit (SigCC-4) Q2.2 
(44) Unloading tray down movement (ULTD) Q2.3 
(45) Unloading tray bottom sensor (ULTBS) 12.1 
(46) Stop unloading tray down movement (S-ULTD) 
(47) Send a signal to the main arm circuit (Sig_R3) Q2.4 
3.5 Main arm rotation circuit 
Main arm rotation is directly depends on the each station's operations. It will not 
activate till each position is confirmed and a signal is sent to the main arm rotation 
circuit. After it gets the Sig Rl , Sig_R2 or Sig_R3 signals from each position, it 
rotates the main arm by 120° to next position. 
3.5.1 Main arm rotation circuit flowchart 
48 (Sig_R1) 49 (Sig_R2) 50 (Sig_R3) 
• OR 
51 (MAR) z 
Delay 2S 
PS2=1 
PS3=1 
Yes 
52 (S-MAR) 
Figure 3:12: Main arm rotation flowchart 
25 
Description: 
Index Description FC Symbol Ladder 
(48) Signal from loading station ( S i g R l ) Q0.5 
(49) Signal from painting station (Sig_R2) Q1.7 
(50) Signal from unloading station (Sig_R3) Q2.4 
(51) Start main arm rotation (MAR) Q2.5 
(52) Stop main arm rotation (S-MAR) 
3.6 Clamping disk circuit 
When the PLC receives the signal from loading circuit and PS1, PS2 or PS3 signal, 
respective clamping disk pistons start to move forward (A,B or C CDJO). Ends of 
these piston rods are attached to one clamping jaw. That jaw is mechanically 
connected with other three jaws and expands simultaneously. 
Figure 3.13 Clamping disk operation 
Diameters of the green tires depend on the tire size. Required diameters which can be 
handled by this machine are 8" to 22". Therefore the jaws have to stop when they 
touch with the green tire. Three pressure sensors are used (PSA, PSB and PSC) for 
three clamping disks to detect the contact between the green tire and the jaws. These 
are digital adjustable pressure switches. When jaws touch the green tire, the pressure 
inside the clamping pistons starts to increase. It will be detected by the respective 
26 
pressure sensors and a signal will be sent to the PLC. Then the PLC stops the forward 
movement of the clamping pistons and holds it by using a center closed 5/3 way valve. 
3.6.1 Clamping disk operational flowchart 
53 (Sig-CC1) 
IF 
PS3=1 
54 (B-CDJO) 
57 
IF 
PSB=1 
IF 
PS1 = 1 
55 (A-CDJO) 
I 
58 
c i f y 
PSA=1 
/ 
f OR ; 
IF 
PS2=1 
56 (C-CDJO) 
I 
X 5 9 
IF 
PSC=1 
60 (S-B-CDJO) 61 (S-A-CDJO) 62 (S-C-CDJO) 
63 (SigCC-2) 
64 (Sig-CC3) 
IF 
PS2=1 
65 (B-CDJI) 
IF 
PS3=1 
66 (A-CDJI) 
IF 
PS1 = 1 
67 (C-CDJI) 
OR 
68 (SigCC-4) 
Figure 3.14 Clamping disk operational circuit 
27 
Description: 
Index Description FC Symbol Ladder 
(53) Signal from loading circuit (S ig - cc i ) Q0.2 
(54) B-Clamping disk jaws out (B-CDJO) Q3.0 
(55) A-Clamping disk jaws out (A-CDJO) Q2.6 
(56) C-Clamping disk jaws out (C-CDJO) Q2.7 
(57) Pressure Sensor-B (PSB) 12.4 
(58) Pressure Sensor-A (PSA) 12.2 
(59) Pressure Sensor-C (PSC) 12.3 
(60) Stop B-Clamping disk jaws out (S-B-CDJO) 
(61) Stop A-Clamping disk jaws out (S-A-CDJO) 
(62) Stop C-Clamping disk jaws out (S-C-CDJO) 
(63) Send a signal to loading circuit (SigCC-2) Q0.3 
(64) Signal from unloading circuit (SigCC3) Q2.1 
(65) B-Clamping disk jaws Inward (B-CDJI) Q3.2 
(66) A-Clamping disk jaws Inward (A-CDJI) Q3.3 
(67) C-Clamping disk jaws Inward (C-CDJI) Q3.1 
(68) Send a signal to unloading circuit (SigCC-4) Q2.2 
When the clamping operation is finished, it sends a signal to the loading circuit 
(SigCC-2). 
When clamping circuit receives the signal (SigCC-3) from the unloading station, the 
clamping disk jaws attached to the relevant disk starts to move inward. After 
retracting the jaws of the clamping disk, a signal will be sent to the unloading circuit 
(SigCC-4) to start unloading tray movement. 
28 
Chapter 4 
Components Selection 
4.1 Pneumatic Cylinders Selection 
4.1.1 Loading/ unloading Cylinders 
These cylinders are connected with the tire loading and unloading mechanisms. The 
purposes of these cylinders are to lift the loading tray with a tire at the loading station 
and gradual unloading at the unloading station. It has used a pulley mechanism as the 
basis. The sprocket wheel which is connected with the cylinder shaft acts as a pulley. 
Then the lifting tray moves twice for one cylinder shaft movement. This mechanical 
advantage is used to get twice the distance of tray travel relative to the cylinder shaft 
movement. But this will require a doubled force for lifting. 
Maximum weight of the green tire = 80 Kg 
Total weight with the lifting tray and friction = 90 Kg 
Required piston force = 90x2 = 180 Kg = 1800 N 
Required piston stroke = 600 mm (tray travel 1200 mm) 
Selected piston is a custom made, Dia: 63, 600mm Double acting cylinder. The 
standard force at 6 bars is 1870 N. Double acting cylinder is used to get more control 
when unloading. The down movement of the tray is controlled by regulating the 
cylinder output air flow. 
4.1.2 Clamping Cylinder 
Clamping cylinder is only used to move and grab the green tire. Considerable amount 
of force will be required to overcome the friction between chain and sprocket 
mechanism and also to grab and lift the green tire. Maximum green tire weight which 
will be used for this machine is 80 kg. 
29 
: : ' F 
< — Grabbing 
1 • [ — R arm 
Green tire 
\F 
w 
Figure 4.1 Force distributions between green tire and grabbing arm. 
Maximum tire weight [13] = 80 kg = 800 N 
X= 45°C 
Friction between tire and grabbing arm (F) = W Sin x 
= 566 N 
Required arm force (R) = F Cos x 
= 400 N 
Required piston force (Used two cylinders) = 400 / 2 
= 200 N 
Required piston stroke = 200 mm 
(For the range of 8" to 23") 
Used Festo, [14] DSW-32-200-PPV-A-B, Dia: 32, 200mm Double acting cylinder. The 
maximum standard forward force is 483 N at 6 bar pressure. 
4.1.3 Main painting cylinder 
Main painting cylinder is used to lift the two inside and outside painting cylinders and 
nozzle assembly. Weight of this piston and nozzle assembly is approximately 10 kg. 
Weight of the piston nozzle assembly = 10 Kg 
Required stroke = 6 5 0 mm 
(650 mm of total 1100 mm will travel by this piston) 
Selected piston is custom made Dia: 32, 650mm Double acting cylinder. Standard 
force at 6 bars is 483 N. 
30 
4.1.4 Inside / Outside painting cylinders 
These two pistons only use to lift the paint nozzles. Therefore it is not required to have 
a great force for this movement. But in order to get a high speed operation, 25 mm 
diameter piston has been selected. 
Selected piston is custom made Dia: 25, 450mm Double acting cylinder. Standard 
force at 6 bars is 295 N. 
4.2 Pressure Switch selection 
Green tire diameter depends on the tire dimension. This machine is designed for tires 
which are having a diameter range from 8" to 23". Clamping j a w arm's movement has 
to stop after it touches the green tire and should apply a considerable force to grab and 
lift the tire. Supply air pressure to the clamping cylinder can be used as a parameter to 
identify this position. This pressure will be measured by a pressure sensor and it will 
pass a signal to the PLC when it reached to the set value. 
Selected pressure switch is SMC, ISE30-01-25-M-L-D, [15] which is an adjustable 
digital pressure sensor. 
Figure 4.2 Pressure switch 
4.3 Motor selection 
Mainly two motors are required for this machine. One is to drive the main arm which 
is connected with the three clamping disks is called as the 'Main drive motor. The 
second one is used to rotate the green tire disk assembly. It is called the 'rotary drive 
motor ' . Also the motor selection has been restricted to select only ABB motors. ABB 
is the standard motors which permitted to use in this factory. 
4.3.1 Main drive motor: 
The arm which is connected with the three clamping disk is called "Main arm' . We 
can consider the main arm with a lifted green tire, as one assembly unit for this 
calculation. 
31 
Total maximum mass of the main arm with 3 tires = 85+80x3 kg 
= 325 kg 
Distance of the arm from axis to the mass end = 920 mm 
As this mass is kept parallel to the rotary mechanism axis, the motor needs to 
overcome only the inertia of the mechanism and friction. Center bearing is a friction 
less thrust bearing. Then in practice, the axis friction will have a very low value and 
can be neglected for calculations. As these three masses are equal and placed around 
the axis with a 120° distance, we can assume this mechanism as a uniform disk with 
325 kg weight. Then, 
The inertia of the assembly (I) = V2*m*xA2 [16] 
= '/2*325*0.92A2 
= 137.54 kg-m2 
Where, m=Mass of the assembly, r=distance from the main arm pivot point to the 
clamping disk mounting position 
Expected total time to rotate 120° (one position to next position) is 6 seconds. 
2S - Acceleration - 30° 
3S - Constant velocity - 70° 
1S - Deceleration (Braking) - 20° 
Therefore velocity at 30° = 70/3 
= 23.3 Degree/S = 0.41 rad/S 
Therefore required angular acceleration = 0.4112 rad/S2 
= 0.205 rad/S2 
The Newton 's second law of motion when applied to rotating bodies state, the torque 
is directly proportional to the rate of change of angular moment. [16] 
Then, 
Required torque to accelerate main arm = la 
= 137.54 x 0.205 x 10 
= 281.96 Nm 
Where, I = Inertia of the assembly, a = Angular acceleration of the assembly. 
(Assumed acceleration of gravity as 10 m/s2) 
32 
Selected Indexing gearbox reduction = 150:1 
Motor torque required =281.96/150 
= 1.88 Nm 
By considering neglected friction of the main bearing and the gear box, 
Selected Motor is -> [17] ABB, M2QA 80 M4A, 0.55kW ,4-poles = 1500 r/min 400 V 
50 Hz, Torque ->3.37 Nm, Starting torque-> 2.4 x TN Nm 
4.3.2 Rotary Drive: 
Main purpose of the rotary drive is to rotate clamping disk with a grabbed green tire. 
Same as previous calculation, we can consider this as one solid cylinder assembly 
with a mass of 95kg. (Clamping disk + Maximum green tire weight = 15+80 kg) 
Distance to the mass can be taken as the radius of biggest green tire which can be 
handled by this machine. 
Radius to the effective mass = 1 1 " = 279.4 mm 
The inertia of the assembly (I) = '/2*m*rA2 [16] 
= !/2*95*0.28A2 
= 3.724 kg-m2 
Expected rotational speed of the green tire for painting is 10 rpm. 
Therefore angular velocity of the green tire = 360 x 10/60 
= 60 Degree/S 
= 1.05 rad/S 
Time for one revolution = 60/10 
= 6 S 
Expected angular velocity in one revelation, 
Therefore required angular acceleration = 1.05/6 
= 0.175 ras/S2 
The Newton 's second law of motion when applied to rotating bodies state, the torque 
is directly proportional to the rate of change of angular moment. [16] 
Then, 
33 
Required torque to accelerate the green tire = la 
= 3.724 x 0.175 x 10 
= 6.517 N m 
Where, I = Inertia of the disk green tire assembly, a = Angular acceleration of the 
assembly. 
(Assumed acceleration of gravity as 10m/s 2 ) 
This clamping disk and green tire assembly will get connected with the rotary drive 
motor at the painting position, though the chain and sprocket wheel assembly. The 
selected sprocket ratio of the green tire assembly and the rotary drive is 25:1. 
Then, 
Effected gear reduction = 2 5 : 1 
Motor torque required = 6.517/25 
= 0.26 N m 
By considering neglected friction of the bearings and getting a safety factor, 
Se lec t ed M o t o r - > [17] A B B , M2QA 71 M4A, 0.37kW ,4-poles = 1500 r/min 400 V 50 Hz 
Torque -> 1.71 Nm, Starting torque-> 2.1 x TN N m 
4.4 Indexing gearbox 
Main arm needs to stop at three positions, which are loading, painting and Unloading 
positions. That means it stops for every 120° position of one rotating circle. Also the 
main arm and the drive motor have to be connected though a reduction gear box to get 
the required speed and torque. In this case, the ' Indexing gearbox' is the perfect 
solution. Those are available in the market with predefined gear ratios and indexing 
positions. For the purpose of this machine it has defined the required main arm 
rotation speed as 10 rpm. 
Drive motor speed = 1500 rpm 
Required gear box out speed = 1 0 rpm 
Selected gear ratio = 150:1 
34 
Selected indexing gear box is Boneng, H4DHA150 with internal electrically activated 
brake. This electrically activated brake is an added advantage which can be used to get 
a perfect stop at required positions. 
Figure 4.3 Indexing gearbox 
4.5 PLC selection 
Basically this machine 's main controller is a PLC (Programmable logic controller). 
Different kinds of PLCs are available in the market. Basically all the PLCs are 
programmed by a ladder diagram programming method. Different kinds of PLC 
manufacturers are using their own software for their PLC programming. In the PLC 
selection, the first one is to determine the required number of input and output 
terminals. 
Required digital Inputs = 26 + extra 10 
= 36 
Required digital Outputs = 20 + extra 10 
= 30 
Other requirements, 
3 high frequency inputs for encoders (25 Hz), 24 V DC outputs, Easy programming, 
Flexibility to trouble shooting, memory capacity, after sales services and should be a 
company recommended product. 
According to the above requirements the selected PLC is 'S7-200 PV 224 Xpsi C P U ' 
(I/P-14 digital, 2-analog O/P-IO digital, 1-analog) with 'EM223 24V ' (I/P-32 digital, 
O/P-32 digital) expansion module [18]. Total digital input is 46 and 42 outputs. Two 
analog inputs and one analog output are kept aside for future requirements. 
35 
Program memory 12288 bytes 
Data memory 10240 bytes 
Memory backup 100 hours 
High speed counters 4 at 30 kHz 
Real time clock Built-in 
4.6 Proximity sensors / Reflective sensors 
Here reflective sensors are used to detect the green tire, to stop the loading t ray ' s 
upward movement, and to detect the green tire at unloading position. When the sensor 
beam which reflected by the reflector is cut by the tire, the sensor passes a signal to 
the controller. The reflective sensor which is used is 'Baumer ' N P N F P A M 18N 3151 
due to its high reliability in harsh environment and low impedance. Maximum sensing 
distance of the sensor is 4m. 
connection diagram 
Figure 4.4 Retro reflective sensor 
4.7 Nozzles 
To get a perfect uniform paint application it needs to use a perfect atomization nozzle. 
The specific gravity of the inside paint is 1.25 and outside paint is 1.07. World famous 
brand for this kind of applications is Binks nozzles. Selected nozzle is a USA made 
'Binks ' B-125-LS nozzle as the inside painting nozzle. It is 360° atomization nozzle. 
This is the nozzle which is used for manual operations also. But this nozzle has 25" 
diameter 360° covering area. Then this nozzle can be used for automated process also. 
36 
For the outside painting propose, the selected nozzle is 'Binks ' A54-72R 8/06, M A G 
HVLP automatic spray nozzle. 
High transfer 
efficiency in a 
manifold mounted 
HVLP compliant 
spray gun 
Figure 4.5 Paint nozzle 
This nozzle can be pneumatically activated and can apply 100 mm wide paint strip on 
the painting surface with a 150 m m distance. Working air pressure is 6 bars and 
required fluid pressure is 8 bars. Actuating pressure is 3.4 bars. Specific gravity is up 
to 1.25. These are the available inputs in the factory. 
4.8 Encoders 
For the paint application process, controller needs to know the green tire height which 
can be hanged on the clamping disk. Then the controller can limit the paint application 
distance along the green tire without any losses. Encoder reads the upward movement 
of the loading tray and the controller gets the green tire height by substituting this 
value f rom the total height which is from the bottom to the clamping disk. At the 
unloading position also, controller counts the unloading tray encoder signals and stops 
it, when it reaches to the desired value as given in the loading tray encoder. 
Selected encoder is HS25 Incremental Optical Encoder. As the operations o-f this 
machine do not need high precision, we do not need to use expensive absolute 
encoders. Therefore an incremental encoder is selected. Also these encoders have to 
37 
rotate several times for each tray movement. Then it can use low resolution encoder as 
those are very cost effective. Selected encoder has 100 pulses per revolution. 
Figure 4.6 Incremental encoder 
Lift ing jack stroke 
Diameter of the sprocket wheel 
Average lifting jack speed 
Max rpm of the sprocket wheel 
Max: output frequency of the encoder 
= 600 mm 
= 130 mm 
= 100 mm/S 
= 600/(22/7* 130)/6 
= 14.67 rpm 
= 0.244 rpS 
= 0.244 x 100 
= 24.4 Hz 
This frequency can read by the PLC easily. 
4.9 Rotary air union 
The main arm with three disks is rotating around the center point. Also three clamping 
disks are rotating around its pivot axis. It has to supply compressed air though these 
rotary joints. The equipment used for this purpose is a rotary air union. For the main 
arm pivot joint 6 port rotary union is used and for each disk 4 port rotary unions are 
used. 
38 
* 
Figure 4.7 Rotary air union 
Figure 4.8 Rotary air union assembly 
4.10 Display 
For easy operation and user friendliness, the electronic display is acting a major role. 
It does not need to input any parameters though display device in this machine. Also 
the selected display needs to be perfectly compatible with the PLC. By considering 
these factors, selected display is Siemens TD 200C display. It is compatible with the 
selected PLC. It has two lines of text output display with 20 characters per line, for 
about total of 40 characters. 
39 
Figure 4.9 TD 200C display 
Chapter 5 
Discussion 
5.1 Discussion 
The main objective of industrial automation is to increase productivity, quality, 
efficiency and also to improve the working conditions in a particular industry. Thus, 
industrial automation can facilitate number of activities currently in use in the tire 
industry for further improvements. In this project my main focus was on the Green tire 
painting system. Machine operators are directly benefited from this machine. This 
machine will facilitate a safer working environment with minimized hazardous 
operations. Also it is very easy to load and unload the tire and operators do not need to 
pay attention on the size of the tire. 
In the company point of view they can increase the productivity without any head 
count increment. Evenly panted tires will reduce the scrap percentage. Also improve 
the appearance of the tire will be improved ultimately resulting a good quality output. 
That will give a competitive advantage for the company when competes in the 
international markets. 
Component M. imifactmei Code Description Oty Unit Price Price |Rs:( 
Loading Cyl: Custom made Dia:63, 600mm Double acting 2 19,000.00 38,000.00 
Clamping cylinder Festo DSW-32-200-PPV-A-B Dia:32, 200mm Double acting 4 11,000.00 44,000.00 
Paint Main Cyl: Custom made Dia:32, 650mm Double acting 1 17,500.00 17,500.00 
IP Cyl: Custom made Dia:32, 450mm Double acting 1 15,500.00 15,500.00 
OP Cyl: Custom made Dia:32, 450mm Double actinq 1 15.500 00 15,500.00 
Pressure sensor SMC ISE30-01-25-M-L-D Adjustable diqital pressure sensor 3 11,000 00 33,000.00 
Main drive A B B M 2 Q A B 0 M 4 B 0.75kW ,4-poles = 1500 r/rnin 400 V 50 Hz 1 45,000.00 45,000.00 
Rotary Drive A B B M2QA BO M4A 0.35kW ,4-poles = 1500 r/min 400 V 50 Hz 1 110,000 00 110,000.00 
Indexing Gear box Boneng H4DHA150 150:1 GRwi th internal brake 1 225,000.00 225,000.00 
PLC Siemens S7-200 PV 224 Xpsi CPU l/P-14, 0 /P-10 digital 1 55,000.00 65,000 00 
Expansion Siemens EM223 24V l/P-32, Q/P-32 digital 1 26,000.00 26.000.00 
Contactors Telemechanigue 6 7,500.00 45,000.00 
Pneumatic Valves SMC B 6,500.00 52,000.00 
Display Siemens TD200C 2 line text display 1 36,000 00 36,000 00 
Rotary air union 1 Rotation Rotation 994514 4 Port rotatable air connector 3 28,000.00 B4,000.00 
Rotary air union 2 Rotation Rotation 112569 2 Port rotatable air connector 1 19,000.00 19,000.00 
IP nozzle Binks B-I25-LS 380 degree atomization nozzle 1 58,000.00 58,000.00 
OP nozzle Binks 77-2797 R-5 MAG A A automatic spray gun 7 25,000.00 175,000.00 
Inc encoder Baumer HS25 Incremental Optical Encoder 500 cyl/turn 3 54,000.00 162,000.00 
Retro-ref: sensors Baumer FPAM 1BN3151 Retro-reflective sensor 4m 2 9,000.00 1B,000.00 
Bearings SKF 24 6,000.00 144,000.00 
Linear Bearings SKF PCM 252B50 M 6 12,000 00 72,000.00 
Other Pneu: i tems Tubes, Connectors, FRL etc 150,000.00 
Other Elec: Items Cables, Connectors, Push Buttons 200,000.00 
Mechanical Clamping Jig, Frame, mountings 800,000.00 
Machining 200,000.00 
Other expenses 400.000.00 
Total 3,249,500.00 
Table 5.1 Costing 
41 
Basically this machine is designed with the components which are available in the 
market. Therefore manufacturing of this machine is not a tricky operation. Also the 
design is free with any complicated customized components. Therefore it can be 
easily replaced with available matching components when it is broken or worn out. 
There are various types of machines which are available in the market for green tire 
painting process. But most of the machines are made only for inside painting. Also the 
maximum diameter range that they can handle is limited to maximum of 6". In other 
words, even a Chinese machine will cost around 8 million rupees. Apart from that the 
payback period of this machine is considerably less when compared with other 
available machines in the market. Also this machine has advanced capabilities. 
5.2 Payback calculation 
Total cost for the machine 
Current production tonnage per day 
Planned production tonnage per day in 2009 
More operators need to meet this production 
Extra cost need 
Cost for extra accessories and paint booth 
Average value of the scrap tires per year due 
to operator painting defects 
Average customer clams value per year due to 
Painting defects = R s : 540,000/= 
Rough payback period of the machine 
(3,249,500-628,000)/ (960,000+(600,000+540,000)*3/4) 
= 1.5 years 
• Assumptions: 
Assume 75% of customer clams which are related to the painting defects and 
painting operator defects can be solved by this machine. 
= Rs: 3,249,500/= 
= 16 Tones 
=18 Tones 
= 1 per shift (4 for 4 shifts) 
= 20,000 x 4 x 12 
= Rs: 960,000/= 
= Rs: 628,000/= 
= Rs: 600,000/= 
42 
5.3 Future Developments 
As this machine is designed in-house, we have more flexibility for further 
developments and modifications depending on the company requirements. One of the 
future developments will be to design outside paint nozzle to move forward and 
backward. Then we can reduce the paint wastage when painting small tires. In this 
case the PLC has to read the tire diameter. To read the diameter of the tire it can use 
the clamping jaw movement. By measuring the clamping jaw movement, PLC can 
identify the diameter of the tire. Then outside nozzle can be moved accordingly. 
43 
References: 
[ 1 ] Martin A Carree, A Roy Thurik, "The Life Cycle of the World Tire Industry," 
Southern Economic Journal, vol. 2, pp. 68-69, October 1, 2000. 
[2] Marvin Bozarth, " Today's Tire Industry," Lakisha Pindell Publication, Pointer 
Ridge Place, Bowie, vol. 3, pp. 28-29, 2003. 
[3] "Darmex inside tire release technical data manual," Technical Bulletin, 
Darmex, Argentina, vol. 2, pp. 27-29, 2007. 
[4] "Darmex Outside tire antiblemish technical data manual," Technical Bulletin, 
Darmex, Argentina, vol. 2, pp. 18-22, 2007. 
[5] K.J. Stevenson, "Safety in tire industry," John Wiley & Sons, Inc. pp. 268-273, 
2002. 
[6] Kevin Rohlwing, "Commercial Tire Service Today," Tire Industry Association 
Publication, Louisville, Kentucky, USA, vol.8, issue no.l, pp.2, 2003. 
[7] http://www.maxxis.com/AutomobileLight-Truck/How-a-Tire-is-Made.aspx 
webpage. (Appeared on 14/08/2009). 
[8] http://en.wikipedia.org/wiki/Tire manufacturing webpage. (Appeared on 
15/08/2009). 
[9] http://www.enotes.com/how-products-encyclopedia/tire webpage. (Appeared on 
18/08/2009). 
[10] http://www.maxxis.com/Repository/Files/lavered_tire.pdf webpage. (Appeared 
on 18/08/2009). 
[11] L.S. Larsson, "Hidden challenges in Tire industry," Lawrence & Wishart Ltd, 
Wallis Rd, Hackney, E95LN, pp. 143-145, 2003. 
[12] "ETRTO-Engineering Design Information-2006," Technical bulletin, European 
tire and rim technical organization, vol. 1, pp. 248-249, 2006. 
[13] "Tire and Rim data book 2008," Technical Bulletin, The Scandinavian Tire & 
Rim organization, vol. 2, pp. 23-31, 2008. 
[14] "FESTO Products 2004," Digital product catalogue, Festo AG & Co.KG, 
Germany, vol. 10, pp. 902.FIF-1,2003, (CD ROM). 
[15] "SMC Pneumatic Catalogue," Digital product catalogue, SMC Co.Ltd, Tokyo, 
Japan, vol 8, pp. 16-2-37, 2007, (CD ROM). 
[16] R.S. Khurmi, J.K. Gupta, "A Textbook of Machine Design," Eurasia Publishing 
House, India, pp. 341-348, 2001. 
44 
[17] http://www.clrwtr.com/PDF/ABB-Motors/ABB-Cast-Iron-Motors.pdfwebpaae, 
motor catalogue. (Appeared on 18/06/2009) 
[18] '-Products for Automation and Drives," Interactive Catalog CA 01, Siemens AG, 
vol 10, pp. 4N-48-2, 2008, (DVD ROM). 
APPENDIX-A: PLC ladder diagram 
A.l Loading tray ladder diagram 
Circuit2 / MAIN (061) 
POU Comment 
Network 1 
Loading Tray Ladder Diagram 
(0.3 I0 4 
f 
10,5 
Q7.1 
10.1 
10 2 
Q0.1 
< ) 
10.5 00.2 
< ) 
Q0.1 i0.6 
Q0.2 
c u CTU 
i 
i 
VW100" PV 
I0.0 I0.5 MOV W 
I I EN ENO \ i I I A 
VW100- l l i • OUT -VW500 
10.1 
J I 
I0.5 
j ! 
MOV_W 
EN ENO i i I I A 
VW10Q- IN OUT -VW6Q0 
I0.2 
I 
I0 5 
! | EN 
MOV_W 
ENO \ J I I \ A 
VW100- OUT -VW700 
46 
Circuit2 I MAIN (061) 
GO.3 
+20 
10,4 
T5 
IN TON 
PT 
Q7-2 
S1 OUT 
SR 
R 
QG.4 
< ) 
GO,5 
< ) 
47 
A.2 Painting station ladder diagram 
Circuit? / MAIN (081) 
Network 2 
Painting Station Ladder Diagram 
I0.0 
1 I — ! 
10.1 
IQ.2 
11.0 
1 
10.1 
I0.2 
11.1 
— I 
IO.O 
10.1 
I0.2 
11.2 
11.0 
10.0 
10.1 
11.1 
I0.7 
I0.7 
H h 
VW500 
VW200 
vwsoo 
H - H 
VW200 
I0.7 
11.2 
Q7.3 Q0.6 
S1 OUT 
Q74 Q0.7 
S1 OUT 
SR 
h K ) 
Q7.5 Q1.0 
S1 OUT 
SR 
Q7.6 
S1 OUT 
SR 
R 
Q1.1 
< ) 
^ Q1.2 
Cifcuit2 / MAIN (0B1) 
10.2 
1 
11.0 
11.5 
11.0 
11.6 
11.0 
11.4 
Q1.3 
01 6 
11.4 
VW700 
H - h WV200 
11.1 
11 1 
11.3 
11,5 
I 1 h 
11 .2 Q7.7 
S1 OUT 
SR 
11,2 Q7 7 
11.2 
I 1 h 
VW200-
S I 
SR 
OUi 
R 
G7.7 
OUT 
SR 
R 
C101 
CU CTU 
R 
PV 
11.6 
i h 
01 6 
< ) 
Q1.3 < ) 
01.4 < ) 
01 5 
< ) 
Q1.7 
< ) 
49 
A.3 Unloading station ladder diagram 
Circuits / MAIN (OB1) 
Network 3 
Unloading Station Ladder Diagram 
I0.0 Q8.1 Q2.0 
Q2.1 
< ) 
02.3 
< ) 
Q2.4 
< ) 
50 
A.4 Main arm rotation ladder diagram 
Circuits / MAIN{0B1) 
Network 4 
Main rm rotation Ladder Diagram 
Q0.5 
Q1.7 
Q2.4 
02.5 
Q25 
| 1 
10.0 
10.1 
10.2 
+20-
IN TON 
PT 
Q8.3 
A.5 Clamping disk ladder diagram 
Circuit2 / MAIN (OB t) 
Network 5 
Clamping disk Ladder Diagram 
Q0.2 10.0 
1 
12.2 
Q0.2 
12.3 
Q0.2 
12.2 
12.3 
— ! 
02.1 
Q21 
11.7 
I / 
I0.2 
Q8.4 
SI OUT 
SR 
R 
QS.5 
S1 OUT 
SR 
Q 8 . 6 
S1 OUT 
SR 
R 
Q8.7 
S1 OUT I I I 
SR 
11.7 
R 
Q91 
S1 OUT 
•SR 
R 
Q2.6 < ) 
Q2.7 
< ) 
Q3.0 < ) 
Q0.3 
< ) 
03.1 
< ) 
03.2 
< ) 
52 
( > zzo 
ft 0 
ZED 
TED 
c > ceo 
a 
as 
xno is 
/ 
ru 
Z'6D Z'Oi I'ZD 
U90> NIWI / ZHTOJIO