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REDUCE IN HOUSE REJECTION INCR CHECK VALVE
BITS ZC423T: Project Work
by
M CHELLAPANDI
ID No - 201118TS128
Project Work work carried out at
M/S MEGA RUBBER TECHNOLOGIES PVT LTDHosur – Tamil Nadu, India.
BIRLA INSTITUTE OF TECHNOLOGY & SCIENCEPILANI (RAJASTHAN)
1
April 2014
REDUCE IN HOUSE REJECTION INCR CHECK VALVE
BITS ZC423T: Project Work
by
M CHELLAPANDI
ID No - 201118TS128
Project Work work carried out at
M/S MEGA RUBBER TECHNOLOGIES PVT LTDHosur – Tamil Nadu, India.
Submitted in partial fulfillment of B.S. Engineering
Technology degree programme
Under the Supervision ofG GOUTHAM, SENIOR ENGINEER,
M/S MEGA RUBBER TECHNOLOGIES PVT LTDHosur – Tamil Nadu, India.
2
BIRLA INSTITUTE OF TECHNOLOGY & SCIENCEPILANI (RAJASTHAN)
April 2014
CERTIFICATE
This is to certify that the Project Work entitled REDUCE INHOUSE REJECTION IN CR CHECK VALVE by M.CHELLAPANDI havingID-No. 201118TS128 for the partial fulfillment of therequirements of B.S. ENGINEERING & TECHNOLOGY degree of BITS,embodies the bonafide work done by himr under my supervision.
______________________ Signature of the Supervisor
Place : HOSUR
Date : 04.04.2014
3
G GOUTHAM, SENIOR ENGINEER,COMPOUNDING,MEGA RUBBER TECHNOLOGIES PVT LTDHOSUR-635114.
Name, Designation & Organization Location
ABSTRACT
The Project is concerned with the identification of the major contribution in high
1.Process Rejection
of CR CHECK VALVE and to reduce the same. The analysis has been done based on the data of the past 1 year and various parameters related to the problem have been analysed and solutions taken.
The identified problem has been Defined, the parameters affecting have been measured, key parameters have been analysed and then they have been Improved based on its criticality.
____________________Signature of the Student
4
Name: M CHELLAPANDI Date: 04.04.2014
Place: HOSUR
______________________Signature of the Supervisor
Name: G GOUTHAM
Date: 04.04.2014 Place:HOSUR
BIRLA INSTITUTE OF TECHNOLOGY & SCIENCE, PILANIWORK-INTEGRATED LEARNING PROGRAMMES DIVISION
Second Semester 2013-2014
ID No. : 201118TS128
NAME OF THE STUDENT : M CHELLAPANDI
EMAIL ADDRESS : [email protected]
NAME OF THE SUPERVISOR : G GOUTHAM
PROJECT WORK TITLE : REDUCE IN HOUSE REJECTION IN CR CHECKVALVE
Project Work Final Evaluation (Please put a tick ( ) mark in the appropriate box)
5
BITS ZC423T Project Work EC-3 Final Evaluation Sheet
S No. Evaluation Component Excellent Good Fair Poor 1. Final Project Work Report 2. Final Seminar and Viva-
Voce
S.No.
Evaluation Criteria Excellent Good Fair Poor
1 Technical/Professional Competence
2 Work Progress and Achievements 3 Documentation and expression 4 Initiative and Originality D5 Research & Innovation 6 Relevance to the work
environment
Please ENCIRCLE the Recommended Final Grade: Excellent / Good / Fair / Poor
Supervisor Additional ExaminerName G GOUTHAM S SUDARSAN
Qualification BE – Polymer science B Tech. – PolymerTechnology
Designation Senior Engineer Senior EngineerEmploying Organization &Location
M/S MEGA RUBBER TECH. (P) LTD,Hosur
M/S MEGA RUBBER TECH. (P)LTD, Hosur
Mobile Number 08870275667 09500784452
Email Address [email protected] [email protected]
Signature
Place & Date HOSUR & 04-04-2014 HOSUR & 04-04-2014
ACKNOWLEDGEMENTS
It is my privilege to solicit my heartfelt thanks to theBirla Institute of Technology and Science for allowingme to undergo the project
6
Remarks of the Supervisor:
It is my privilege to solicit my heartfelt thanks to theManagement of Mega Rubber Technologies Pvt Ltd forpermitting to execute the project
It is my great pleasure that, I record my indebtednessto my academic mentor Mr. G Goutham , Senior engineer -compounding , Mega Rubber Technologies Pvt Ltd,Hosur,Tamilnadu-635114, for his counsil, content supportand guidance during the project period and thepreparation of this report.
I am indebted to thank my colleagues of compoundingdept., Production & Planning dept., and QAD of MegaRubber Technologies Pvt Ltd, for their support inproviding the information related to the process and forextending their help whenever required during theexecution of the project.
7
TABLE OF CONTENTSChapter Descriptions
Page No
1 DETAILS OF ORGANISATION 1.1 About organisation 1 1.2 Facilities 2 1.3 Organisation structure 5 1.4 Conclusion 5
2RUBBER TECHNOLOGY AND SCIENCE
2.1 About process 8 2.2 Mixing 10 2.3 Preforming 11 2.4 Calendering 11 2.5 Moulding 12
3 PROBLEM DEFINITION
3.1Background of the problem 16
3.2 Scope of the project 17 3.3 Data collection 18
4PROBLEM ANALYSIS & CORRECTION
4.1 Rejection phenomena 20 4.2 Pareto diagram 21 4.3 Process flow 22 4.4 Measure of problem 23 4.5 Analyze of problem 25 4.6 Cause & Effect diagram 28 4.7 Action 29 4.8 Standardisation 32 4.9 conclusion 32 4.1 Biblography 33
8
CHAPTER 1
1.1 About the organisation
Mega Rubber Technologies Pvt Ltd manufactures rubber compounds, rubber moulded parts and rubber-to-metal bonded parts for the automobile industry. It also imports syntheticrubber and rubber chemicals. Mega Rubber Technologies, a private limited companyestablished in 1995, is a part of Sujan Group which is aMumbai-based manufacturer of compounded, moulded andextruded rubber products. Sujan Group operates with eightholding companies, including Mega Rubber Technologies, thatmanufactures and exports engine mounts, bellows, hose pipes,silent blocks, valves, small fasteners and othermiscellaneous products. Mega Rubber Technologies operateswith 2 plants located at Thane, Maharshtra and Hosur,Tamilnadu. BothThe plant has production capacity of 4,350tons p.a. of rubber compounds and 200 mn units p.a. ofmoulded parts. More than 75% of the total revenue isgarnered from the OEMs of the domestic market. Year ofOperation 1995
Major customers
TVS Motor Company
Wabco India Limited
9
Mann Humal india Limited
MGM Brakes
Bendix Commercial Vehicle Systems LLC
Minda Nabtesco Limited
Toyota Kirloskar & MNR filters
Honda motor cycles
1.2Facilities
Mega rubber technologies pvt ltd having made a big impact in
the manufacturing and production of vital rubber components,
it was time for sujan to take their capabilities to the next
level. the group decided to apply their experience and
insight to the innovation and
design of new products. and their new component development
and design cell was born and has a well laid out factory
equipped with following manufacturing facilities.
1.2.1.Mixing facilities
10
• Mixing facility comprising of automatic (k4) Internal-
mixer volume 84 liter & a Versatile Mixing mill (22*60”)
fitted with Stock-blender capacity of 80 kg .
Intermixer –K4 MIXING MILL -22*60”
Size
Figure 1
1.2.2.Moulding Facilities
• Cure-preparation facility, which include Calendaring
facility comprising of a 4 Roll calendar fed by cold feed
extruder and two roll mill.
• Preforming facility with Barwell preformer fed by a
warming mill.
• Moulding facility which include
11
1. Vacuum chamber type moulding presses
2. Vertical Injection moulding presses
3. Conventional Compression moulding machines
MOULDING SECTION MOULDING PROCESS
1.2.3Hose manufacturing facility comprising
1. Braiding machines
2. Cold-feed combination head extruder
3. Dual layer Extruder
4. Vulcaniser (Autoclave)
1.2.4Testing facilities:
1. Rheometer for testing of the Rleological properties
2. Mooney Viscometer
3. IRHD - Micro-hardness tester
4. Laboratory press
12
CHIEF EXECUTING OFFICER
MANAGING DIRECTOR
5. Hose testing station-for proof as well as burst test.
6. Diaphragm endurance testing rig.
7. Tensile testing machine
8. Low temperature cabinet
9. Universal Testing Machine
10. Densimeter
RHEO METER DIAPHGRAM ENDURANCE TESTING M/C
1.3 Organisation structure
13
DEVELOPMENT SALES OPERATION
Purchase
FINANCE HUMAN RESOURCES
compounding QAD DespatchP M D P E D PRODUCTION
1.4 Conclusion:Mega Rubber Technologies Pvt. Ltd is a QS-9000
and ISO-9001 certified company, manufacturing automobile and
two-wheeler anti-vibration moulded rubber parts for world
wide OEM applications. They are certified OEM suppliers to
European and Indian vehicle manufacturers and have a
14
technologically advanced production plant spread over 20000
sq. ft.
CHAPTER .2
Rubber Science and Technology
Before going to the details of the project, here is a brief
about the properties of rubber, selection criteria for
rubber, general manufacturing methods followed.
Elastomers or rubbers are classes of materials like metals,
fibers, concrete, wood, plastics, or glass. Without which
modern technology would be un thinkable. At present the
annual consumption of rubber amounts to 13 million tons and
assed to this an equal amount of compounding additives are
added and the consumption is raising at a rate of 4% over
year to year. About one third of total rubber usage is
Natural Rubber. Natural rubber is predominantly produced in
Asia, West Africa and South or Central America. The remaining
two thirds of the required rubber is produced synthetically
by a great number of industrial countries. Natural rubber
15
comes from the rubber tree (Hevea brasillinsis). When a tree
natures at the age of six or seven years, the latex is
collected from a diagonal incision in the tree trunk. The
tapping process does not effect the health of the tree and
the tree wound later heals itself. Synthetic is made by man
from petrochemical deedstocks. Crude oil is the principal raw
material. The most important property of elastomers is the
elastic behaviour after deformation in compression or
tension. It is possible for an instance to stretch an
elastomer ten times its original length and after removal of
the tension, it will return to its original shape and length.
The Indians of Central and South America were the first to
utilize rubber's unique properties. Christopher Columbus
watched them play a game called "Tlacahtlic", a vigorous
cross between basketball and football, with the object of
directing a rubber ball through a stone ring. In England,
Joseph Priestley, best known for his discovery of oxygen,
noted that pencil marks could be "rubbed out” by the
16
substance. From this early use, rubber derived its nameOther
than that rubbers are also capable of exhibiting greater
toughness under static and dynamic stresses, an abrasion
resistance that is higher than that of steel, good
impermeability to air and water, high resistance to solvents
and chemicals. These properties are exhibited at room
temperatures and above and are retained under certain
conditions, retained under most climatic conditions and in
ozone rich atmospheres. Rubbers are also capable of adhering
to textile fibres and to metals. In combination with fibres
such as rayon, polyamide, polyester, or steel cord and
depending on the properties of the reinforcing member the
tensile strength is increased considerably with an attending
reduction in extendibility. This use in composite increases
the range of application of rubbers considerably. At Mega
Rubber Technologies pvt ltd, we are manufacturing both kinds
of rubber parts i.e. solid rubber articles and textile
reinforced articles.
17
About our process:
Rubber products are produced by three main processes:
• Compounding
• Mixing
• Preforming – Barwel blanking and Calandaring
• Vulcanisation – Moulding, Autoclave curing
2.1.Compounding
Compounding is the development of rubber mixes which will
effectively perform in service. At the same time, the mixes
should be capable of being processed in the factory without
much difficulty and at minimum cost. Chemically speaking, a
rubber "compound" is not a compound, but is merely a mixture
of rubber and compounding ingredients, ready for
vulcanization. The simplest of all compounds, rubber plus
vulcanizing agent, is of little use in most applications.
Since it is the basic structure for most compounds, we have
to consider how it can be compounded with reinforcing agents,
18
anti-oxidants, and plasticizers to give the best combination
of properties for a particular application.
Table 1 RUBBER PROPERTIES CHAT
PROPERTIES NR SBR NBR EPDM CR SILICON VITON
Cost Factor 1 1.5 2 2.5 3 8 15
Hardness, A 30 –95 40 – 95 40 – 95 30 -
85 30 – 90 40 – 80 50 – 95
PhysicalStrength
Excellent Good Good Good Good Poor Good
CompressionSet Good Good Good Good Good Good Good
Tear andabrasion
Excellent Good Good Good Good Fair Good
Resilience Excellent Good Good Very
Good Very Good Fair Poor
Low tempResistance -60 -85 -20 -50 -35 -60 -20
GasesPermeability Poor Fairly
low Good Fairlylow Very Good Good Very Low
Heatresistance 75 85 100 130 100 205 205
OxidationResistance Fair Fair Good Excelle
nt Very Good Excellent
Out-standing
Ozone andWeathering Poor Fair Fair
Out-standin
g Very Good Out-
standingOut-
standing
OilResistance Poor Poor Excelle
nt Fair Good Excellent Excellent
Solvent-Alcohol Good Good Good Good Good Good Good
Fair Fair Poor Good Fair Fair Poor
19
- Acetone
- Benzene Poor Poor Poor Poor Poor Poor Good
Chemical -Acids Good Good Good Good Good Fair Excellent
-Bases Good Good Good Good Fair Fair Good
WaterResistance
VeryGood Fair Good Excelle
nt Good Good Good
General Compounding Principles
The scope of compounding consists of specifying the type and
amount of various ingredients in a mix, the manner of mixing,
the processing of the mixed compound, and the method and
details of vulcanization. This essentially covers the
requirements of end-use and service properties,
processability, and cost. The three major decisions to be
made by the compounder, considering all these factors in
designing a compound, are connected with the choice of
rubber, the level of reinforcement, and the type of
vulcanization system to be employed. In general, these
factors determine cost, mechanical and visco-elastic
properties, resistance to degrading influences,
20
processability, and special requirements such as flame
resistance, low temperature flexibility and non-toxicity for
application in contact with food-stuffs.
2.2.Mixing
The mixing process is usually performed in heavy internal
mixer, capable of processing 65 kg batch weight in five
minutes. This process has two functions: firstly, to soften
the rubber (this is often known as mastication) and,
secondly, to admix the rubber with the compounding
ingredients, which may include fillers, vulcanizing agents,
protective agents and blends with other rubbers (which are
usually synthetic rubbers). This technique is known as
compounding.
After mixing, the compounded rubber is plastic and is now
ready to be shaped. After the internal mixing the rubber is
passed through mixing mills and either sheeted out or striped
out for further usage.This is done in a variety of ways and
is frequently combined with vulcanization in which the rubber
21
undergoes a chemical reaction at a high temperature, becoming
converted from the plastic state into a strong, highly
elastic material.
2.3.Preforming – Barwel Blanking
The most common performing method is the barwel blanking
method almost all the solid mouded products require preformed
blanks for moulding. Here the solid rubber is extruded
through a ram extruder and the output is cut into small
blanks by a revolving cutter. This machine produces blanks
with 2% accuracy.
2.4.Calendaring
In the calendaring process, rubber is passed through a three-
or four-roll calendar either to produce a sheet of controlled
thickness or to force the rubber into close contact with a
textile or metal cord. At HRP a four-roll calendar is used
for topping the Nylon fabric, which is used in the diaphragm
manufacture.
22
2.5.Vulcanisation (Moulding)
The most common shaping process is by molding under pressure
in a heated mould in which vulcanization also occurs. There
are three important variants of the process: compression,
transfer and injection molding. Other important shaping
techniques include extrusion and calendaring. Bonding of
rubber to metal (or thermoplastic/glass fabric, etc) normally
takes place as part of the molding process. The metal
component will require pretreatment to clean it and the
application of a bonding agent.
2.6. a)Compression-Molding
A blank of appropriate weight is shaped in a steel mould
within a heated press. This process makes the majority of
rubber articles. It is
• Cheap
• Rapid
• Capable of long or short runs
23
• Gives a fair degree of precision if care is taken
High rates of production are possible in multi-daylight
presses in which downtime is reduced to a minimum by using
alternately each of two separate sets of moulds,
mechanically handled. The compression presses are further
upgraded by the application of vacuum during the degassing
operation and hence improve the efficiency of regular
compression moulding. HRP uses these types of presses in the
manufacture of Diaphragms.
2.6.b)Transfer Molding
A slug of rubber compound is put into the upper cavity of the
transfer mould. When placed in the press the rubber is
squeezed through a small aperture to fill the second cavity,
having the required shape, in the rubber is vulcanized. This
method is used for precision work, which justifies the high
mould cost and relatively slow throughput. Short runs are
feasible and the method is particularly useful for components
having metal inserts (such as engineering components).
24
2.6.c)Injection Molding
This is a semi-continuous process in which rubber is extruded
from a heated barrel of a screw or ram machine through a
nozzle. The work of extrusion produces a further rise of
temperature, before the rubber is forced into a heated mould
where the rubber is vulcanized. Because the rubber reaches
the mould at a high temperature, vulcanization times are
short and thick articles are homogeneously vulcanized. The
high capital cost is justified by the use of the machine for
long runs of articles of good quality, particularly those
which are difficult to mould by compression molding.
2.6.d)Extrusion
During extrusion compounded rubber is passed from a short
screw extruder through a die of appropriate shape.
Vulcanization is a separate process, and can be performed in
a variety of ways: (i) batch wise in a steam or air
autoclave, or (ii) continuously in steam or hot air, or (iii)
25
in a bath containing a eutectic mixture of molten metal salts
or in a fluidized bed. Simple or complex sections, either
solid or sponge, may be extruded.
Extrusion is used for the manufacture of hose, weather-strip
seals for automobiles and cables. Parts of tires are also
extruded, notably the sidewalls.
CHAPTER 3: DEFINE
26
Define the Goals of the Improvement Activity. At the Project
level goals might be to reduce the defect level and increase
output.
Problem Definition
In this project the CR CHECK VALVE (SC05Z08DA) has been taken
for study due to its high rejection trend in the last 6
months. The top three problems related to the rejection will
be summarized and one problem will be solved using the DMAIC
concept.
The following tabulations show the rejection trend of each
component; the cost wise rejection details and an exhaustive
rejection trend of CR CHECK VALVE (SC05Z08DA). The Process
flow diagram for the CR CHECK VALVE has also been given below
to know the overall Production sequence and the product
27
characteristics varying due to the incoming sources of
variation. The diagram also shows the Process characteristics
for each and every stage of production.
The Cause and Effect diagram for the CR CHECK VALVE has also
been given below. The sources of variation due to Man.
Machine, Material and Method have been depicted.
Product Diagram:
28
3.1 BACKGROUND OF THE PROBLEM:
1. High tearing rejections in CR Checkvalve.
2. High Rejection % in CR Checkvalve-28.8% avg/month.
3. Rejection Value is very high (for the last 6 months is
2.22 lakhs).
4. It is come in top most rejection parts.
5. Affecting the delivery rating.
6. Volume of the part also increasing trend.
3.2 SCOPE OF THE PROJECT
Scope of the this project is to reduce the Process Rejection
percentage in CR Checkvalve by taking proper corrective
action against major problem.
DMAIC concept is taken as a base to reduce the Process
Rejection.
1.DEFINE
2.MEASURE
3.ANALYSE
29
4.IMPROVE
5.CONTROL
EXPECTED BENEFITS :
1. PRODUCTIVITY INCREASE
2. CUSTOMER SATISFACTION
3. ON TIME DELIVERY
4. EFFECTIVE UTILISATION OF RESOURCES
5. OVERALL EFFICIENCY WILL INCREASE
6. COST SAVING
7. REDUCTION OF MANUFACTURING COST/TIME.
3.3 DATA COLLECTION
REJECTION PERCENTAGE & VALUES IN VALVE FAMILY
For supplying to WABCO
Part NoPart Name Customer Rejection
%
RejectionValue in
Rs
SC05Z08DA CR CHECK VALVE WABCO 33.9 40633.0
SC05E12D0 M311980 VALVE WABCO 2.3 25300.0
30
SC05E15D0M 310880 WABCO 2.5 12000.0
SC05E13D0M 311680 WABCO 2.0 12000.0
SC05E11D0M 312050 WABCO 2.6 6500.0
WABC
O
WABC
O
WABC
O
WABC
O
WABC
O
CR CHECK VALVE
M311980 VALVE
M 310880
M 311680
M 312050
SC05Z08DA
SC05E12D0
SC05E15D0
SC05E13D0
SC05E11D0
0.05000.0
10000.015000.020000.025000.030000.035000.040000.045000.0
Rejection %Rejection Value in Rs
CHAPTER .4. ANALYSIS
REJECTION DETAILS FOR THE CR CHECK VALVE – SC05Z08DA
Part No Part Name Month
Cumulative
production
Rejection
Rejection %
Rejection
Valuein Rs
SC05Z08DA
CR CHECK VALVE June-13 62349 21201 34.0 49822.
4
SC05Z08DA
CR CHECK VALVE July-13 50154 10854 21.6 25506.
9
31
SC05Z08DA
CR CHECK VALVE August-13 47062 12081 25.7 28390.
4
SC05Z08DA
CR CHECK VALVE
September-13 54465 13009 23.9 30571.
2
SC05Z08DA
CR CHECK VALVE
October-13 45270 18837 41.6 44267.
0
SC05Z08DA
CR CHECK VALVE 13-Nov 60190 15745 26.2 37000.
8
June
-13
July
-13
Augu
st-1
3
Sept
embe
r-13
Octo
ber-13
13-N
ov
CR CHECK VALVE
CR CHECK VALVE
CR CHECK VALVE
CR CHECK VALVE
CR CHECK VALVE
CR CHECK VALVE
0.020000.040000.060000.0
Rejection %Rejection Value in Rs
COST ANALYSIS:
Average Rejection Value of the month in Rs - 36709.7
Rejection Value of the year in Rs -
440516.9
32
4.1.REJECTION PHENOMENA FOR CR CHECKVALVE REJECTIONS
Part Name:CR CHECKVALVE Part No: SC05Z08DA
Month ProducedQty
Rejected Qty
Type of Rejection
Air Pocket
Tearing
Cut mark
Undercuring
less weight
Flowmark
Foreign matter
September-13 54465 13009 20 10407 350 182 800 1200 50
October-13 45270 18837 60 14848 235 20 1500 2100 74
13-Nov 60190 15745 88 12860 212 330 980 1225 50
Hence, I am going to analyze the Major contribution of
Tearing, Less weight and Flow mark rejections
4.2.PARETO DIAGRAM FOR CR CHECK VALVE REJECTIONS
33
Tearing
less weight
Flow mark
Cut mark
Under curing
Foreign
matter
Air Pocket
02000400060008000
1000012000
0102030405060708090100
82.489.5
96.4 98.1 99.3 99.6 100
REJECTED QTY
4.3Organisation Process Flow Diagram
34
Tearing
less weight
Flow mark
Cut mark
Under curing
Foreign
matter
Air Pocket
02000400060008000
1000012000
0102030405060708090100
82.489.5
96.4 98.1 99.3 99.6 100
REJECTED QTY
4.4 MEASURE
Measure the existing system. Establish valid and reliable
metrics to help monitor progress towards the goal(s) defined
at the previous step. Begin by determining the current
baseline. Use exploratory and descriptive data analysis to
help you understand the data.
Component tearing root causes:-
1. Compound rheological properties variation(Torque of
compound and cure characteristics of compound)
2. Compound shelf life variation
3. Mill warming time variation,
4. Compound heat buildup variation( While loading more
compound when warming compound getting scorch)
35
5. Base polymer – CR (Chloroprene Rubber ) Used(As per the
customer materials reference)
6. Volume of components are in increasing trend( Ex.
20000/month to 100000 / month –Requirement for the
customer.
7. Properties of Chloroprene Rubber
NEOPRENE RUBBER:
(Poly chloroprene)
One of the first synthetic rubbers developed in the search
for oil resistance rubber. Widely used due to its combination
of useful properties and comparatively low price.
Properties :
* Resistant to a wide range of hostile environments.
* Resistant to Oil and chemicals
* Weather and water resistant
* Can withstand temperature from –30°c to 95°c
* Easy to process and compound offering cost benefits
36
* Flame retardant
* Can be produced in any colour required.
* Compound scorch safety is low
* It will give better ozone and oil resistance with
blend of NVC rubber.
* Very high heat sensitive Rubber.
Limitations:
* Unsuitable for applications requiring contact with
fuels.
* Tendency to tear once there is initial damage.
* Some Neoprene may crystallizes during storage or use
causing temporary stiffening (increase in
modulus/hardness).If parts are deformed during
crystallization, they may take a set. However crystallization
is a readily reversible phenomenon and can be removed by
warming over 80°c.It can be prevented by the use of special
grades.
Typical Applications
37
* Most general mechanical applications without contact
with fuel.
* Particularly useful in marine environments due to
good ozone resistance.
4.5 : ANALYSE
Analyse the System to identify ways to eliminate the gap
between the current performance of the system or process and
the desired goal. Apply statistical tools to guide the
Analysis.
The various statistical tools that can be implemented for
analysing the problems are shown below:
A. Root cause analysis
B. Why Why Analysis
C. Genba Observation
CAUSE EFFECT DIAGRAM – I
38
4M PROBLEM COUNTERMEASURERELEATIONSHIP
39
MAN Warming timetoo high
Opertor educated tomix SC6510 compound LOW
ImproperMixing of
compound (SC6510)
Opertor educated tomix SC6510 compound MEDIUM
MACHINE
High heatbuild up in
Barwellblanking
Opertor educated toensure the barrel
heatMEDIUM
Cooling watercirculation
nil
Opertor educated toensure the coolingwater circulation
LOW
Temperaturevariation
Electricianensuring thetemperaturefluctuations
LOW
METHODLower Batch
size only canbe processable
Lower batch sizeonly to beprocessed
MEDIUM
Compound notable totroubleshooting
Compound no scorchsafety HIGH
CompoundSticking onthe millroller
Operator educatedto mix the compound
when mill iscooling
MEDIUM
Compound req.increased
Lower batch sizeonly to beprocessed
HIGH
MATERIAL Nature of basepolymer (CR)
CR base polymeronly used HIGH
No scorchsafety incompound
To be modified therecipe HIGH
40
Basic compoundrecipe design
To be modified therecipe STRONG
Compound
internal heatbuidup
To be modified therecipe HIGH
TABLE: 4M ANALYSIS
41
4.6 CAUSE & EFFECT DIAGRAM - II
42
4.7ACTION FOR MAJOR CAUSES
We have found the following root causes for tearing rejectionin CR Check Valve. From 4M analysis.
1. Poor processability of CR Check valve(SC 6510)
2. No scorch safety of compound (SC 6510)
3. Basic compound recipe design for Cr Check valve
4. Compound Sticking on the rollers.
ACTION 1
SC 6510 Rubber compound having the 100 PHR of Chloroprene
Rubber, In that recipe 5 PHR of replaced by Poly Butadiene
Rubber out of 100 PHR.
43
BILL OF MATERIALS
COMPOUND CODE SC 6510 SC 6510 TSL No RAW MATERIAL
WT INKG PHR
WT INKG PHR
1 CHLOROPRENE RUBBER 32 100 30.4 952 POLY BUTA DIENE RUBBER 0 0 1.6 53 MGO 1.28 4 1.28 44 STEARIC ACID FLAKES 0.16 0.5 0.16 0.55 OCD 0.96 3 0.96 36 MICROFFIN 63 WAX 0.64 2 0.64 27 MBI 0.64 2 0.64 28 FEF - N550 4.8 15 4.8 159 GPF - N660 11.2 35 11.2 3510 THEMAX FLOFORM N990 8 25 8 2511 DOP 6.4 20 6.4 2012 ZINC OXIDE (WHITE SEAL) 1.6 5 1.6 5
13 NA -22 (ETU) 0.220.687
5 0.220.687
514 MBTS 0.096 0.3 0.096 0.3
Total67.99
667.99
6
Concultion:
Tearing rejection reduced but Compound not meeting the oil
swell resistance properties in compound evaluation.
44
ACTION 2:
Again we are developed new recipe for improving the oil Swell
properties and scorch safety in the SC6510T compound. In that
formula Polybutadiene rubber replaced by NVC Rubber .
Compound codeSC 6510 T
SC 6510 A
RAW MATERIAL PHR RAW MATERIAL PHRCHLOROPRENE RUBBER 95 CHLOROPRENE RUBBER 75POLY BUTA DIENE RUB 5 NVC 573 25MGO 4 MGO 4STEARIC ACID FLAKES 0.5 STEARIC ACID FLAKES 0.5OCD 3 OCD 3MICROFFIN 63 WAX 2 MICROFFIN 63 WAX 2MBI 2 MBI 2FEF - N550 15 FEF - N550 25GPF - N660 35 GPF - N660 45THEMAX FLOFORM N990 25 THEMAX FLOFORM N990 0.0DOP 20 DOP 20ZINC OXIDE 5 ZINC OXIDE 5NA -22 (ETU) 0.687 NA -22 (ETU) 0.687MBTS 0.3 MBTS 0.3
SULPHUR 0.2
45
Conclusion:
Compound meeting the properties as per the customer material
reference, And Tearing cut mark rejections are reduced from
33.9% to 7.7 %
Action implemented.
4.8 STANDARDISATION
46
4.9: CONCLUSION
The DMAIC concepts has been used in the CR CHECK VALVE
for reducing the Process Rejection due to tearing rejection.
Problem has been targeted and solutions taken. The
Improvements
are and the analysis done during the Project. The Control
Plan has been formulated.
PROCESS REJECTION TREND AFTER IMPROVEMENT
47
June
-13
July
-13
Augu
st-13
Sept
embe
r-13
Octo
ber-
13
13-N
ov
Dece
mber
-13
Janu
ary-14
CR CHECK VALVE
CR CHECK VALVE
CR CHECK VALVE
CR CHECK VALVE
CR CHECK VALVE
CR CHECK VALVE
CR CHECK VALVE
CR CHECK VALVE
0.010.020.030.040.0
Chart Title
Rejection %
BIBLIOGRAPHY
SUNG .H. PARK, Six Sigma for Quality and Productivity,Asian Productivity organization - Japan, Second Edition 2003.
AMITVA, Fundamental of Quality Control Improvement,Mitra Publishers, Second Edition 2001.
Rubber Materials And Their Compounds, 1978, LONDON, JA BRYDSON.
Hand Book Of Rubber Technology, Mourice morton.
Checklist of items for the Final Project Work ReportThis checklist is to be attached as the last page of the report.
This checklist is to be duly completed, verified and signed by the student.1. Is the final report neatly formatted with all the elements
required for a technical Report?
Yes / No
2. Is the Cover page in proper format as given in Annexure A? Yes / No3. Is the Title page (Inner cover page) in proper format? Yes / No
48
4. (a) Is the Certificate from the Supervisor in proper format?
(b) Has it been signed by the Supervisor?
Yes / No
Yes / No5. Is the Abstract included in the report properly written within
one page? Have the technical keywords been specified properly?
Yes / No
Yes / No6. Is the title of your report appropriate? The title should be
adequately descriptive, precise and must reflect scope of the
actual work done. Uncommon abbreviations / Acronyms should not
be used in the title
Yes / No
7. Have you included the List of abbreviations / Acronyms? Yes / No8. Does the Report contain a summary of the literature survey? Yes / No9. Does the Table of Contents include page numbers?
(i). Are the Pages numbered properly? (Ch. 1 should start on
Page # 1)
(ii). Are the Figures numbered properly? (Figure Numbers and
Figure Titles should be at the bottom of the figures)
(iii). Are the Tables numbered properly? (Table Numbers and
Table Titles should be at the top of the tables)
(iv). Are the Captions for the Figures and Tables proper?
(v). Are the Appendices numbered properly? Are their titles
appropriate
Yes / No
Yes / No
Yes / No
Yes / No
Yes / No
Yes / No
10. Is the conclusion of the Report based on discussion of the
work?
Yes / No
11. Are References or Bibliography given at the end of the Report?
Have the References been cited properly inside the text of the
Report?
Are all the references cited in the body of the report
Yes / No
Yes / No
Yes / No
12. Is the report format and content according to the guidelines?
The report should not be a mere printout of a Power Point
Presentation, or a user manual. Source code of software need
not be included in the report.
Yes / No
Declaration by Student:I certify that I have properly verified all the items in this checklist andensure that the report is in proper format as specified in the course handout.
49
Place: HOSUR Signature of the Student
Date: 04.04.2014 Name: M CHELLAPANDI
ID No.: 201118TS128
50
