DESIGN AND FABRICATION OF PAD PRINTING

MACHINE FOR FINISHED PAPER PRODUCTS

A PROJECT REPORT

Submitted by

NAVNEET KUMAR MISRA 71606114077

PREM KUMAR.M 71606114086

SUHAIL MUHAMMAD 71606114104

SURAJ.S 71606114106

In partial fulfillment for the award of the degree

Of

BACHELOR OF ENGINEERING

In

MECHANICAL ENGINEERING

PARK COLLEGE OF ENGINEERING AND TECHNOLOGY,

COIMBATORE-641659

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ANNA UNIVERSITY: CHENNAI 600 025

APRIL 2010

ANNA UNIVERSITY: CHENNAI 600 025

BONAFIDE CERTIFICATE

Certified that this project report “ PAD PRINTING MACHINE FOR

FINISHED PAPER PRODUCTS” is the bonafide work of NAVNEET

KUMAR MISRA, PREM KUMAR.M, SUHAIL MUHAMMAD, SURAJ.S

who carried out the project work under my supervision.

SIGNATURE SIGNATURE

Prof.S.PARANJOTHI B.E, M.Sc. (Engg) Prof. R. GOVINDANKUTTY M.Tech (IITM)

SUPERVISOR

HEAD OF THE DEPARTMENT PROF. & VICE PRINCIPAL DEAN OF MECHANICAL ENGINEERING

Dept. of Mechanical Engineering Dept. of Mechanical Engineering

Park College of Engineering & Technology Park College of Engineering & Technology

Kaniyur, NH 47, Coimbatore-641659 Kaniyur, NH 47, Coimbatore-641659

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INTERNAL EXAMINER EXTERNAL EXAMINER

ACKNOWLEDGEMENT

At the foremost we prostrate before the almighty GOD and

praise his honour, glory and pay our contribution of thankfulness to him for

blessing we with all knowledge required us for doing this successful project.

We thank our chairman Dr. P.V.RAVI, Chief Executive

Officer Ms. ANUSHA R. MAHESH, B.E, M.S (US) and Executive Officer

Mr. T.NITHYANANDAM, B.E, MS (Res), MBA, MISTE who helped us

indirectly to know what engineering deals with and also we extend hearty

thanks to our Principal Dr. G.MOHAN KUMAR, M.E, PhD, MBA,

PGDMRM, MIE, MISTE who provided us with all the facilities to accomplish

this project in college premises itself.

We wish to express our deep sense of gratitude to our Vice

Principal, Dean and our Supervisor Prof. R.GOVINDAN KUTTY, B.Sc.

(Engg), MTech (IITM) for his valuable support for providing us for all the

facilities required to build up this project work.

We express our gratefulness to our head of the department

Prof. S.PARANJOTHI, B.E, M.Sc (Engg) for his incredible advice in the

completion of this project. We also express our thanks to our project

coordinator Mr. K.S.SATHISH KUMAR, B.E, M.S (Res), MBA (HR),

MISTE for providing us with the necessary details about the project and its

proper schedule.

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Finally we thank all the faculty members of mechanical dept for their

cooperation and insistence.

TABLE OF CONTENTS

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TABLE OF CONTENTS

CHAPTER NO. TITLE PAGE NO

ABSTRACT 8

LIST OF TABLE 10

LIST OF FIGURES 12

LIST OF SYMBOLS 14

1. INTRODUCTION 16

2. LITERATURE SURVEY 18

COMPANY PROFILE 21

3. DESCRIPTION OF COMPONENTS

3.1 Compressor 27

3.2 Pneumatic Cylinder 28

3.3 Printing pads 29

3.4 Substrate 31

3.5 Ink cup 32

5

3.6 Printing ink 33

3.7 Image plate and print plate making 34

4. DESIGN CALCULATIONS 45

FIGURES

Fig.1 :Manual Pad Printing machine. 18

Fig.2 :Pad Printed Products. 19

Fig 3 : A single acting compressor. 27

Fig 4 :A reciprocating Compressor. 28

Fig 5 : Double acting Pneumatic Cylinder. 28

Fig 6 :Printing pads. 31

Fig 7 :Paper Plate. 32

Fig 8 : Medicine capsule box 32

Fig 9: New Generation Closed ink cup. 33

Fig 10: Image Plates. 34

Fig 11: Laser printing plate maker. 35

5. WORKING PRINCIPLE 50

5.1 Working

5.2 Features of pad printing

6. ADVANTAGES AND DISADVANTAGES 52

6.1 Advantages

6.2 Limitations

7. APPLICATIONS 56

6

8. COST ESTIMATION 58

9. CONCLUSION 60

10. REFERENCES 62

ABSTRACT

7

ABSTRACT

In our day today life its quite common that we are using lots of products which

are made attractive and informative through textual and pictorial impressions

made by pad printing. But out of its all scopes, the printing on the finished

paper products was still untouched at a gross level. Here forth, we came up with

an idea for the same and started the project on the “DESIGN AND

FABRICATION OF PAD PRINTING MACHINE FOR FINISHED

PAPER PRODUCTS”.

Pad printing is used for printing on various substrates like Plastics, Metals,

Glass and Ceramics, Paper and Cardboard, Leather. But it is primary used in

places where the printing area is small and / or the contour or surface of the

object is not flat or hard to reach by other printing process. We tried to give

emphasis on the pad printing on the finished paper products which is quite yet

not achieved so easily at larger scales.

We achieved the pad printing on the finished paper products with a minimum

operating pressure of 5 bar and by utilizing pneumatic and electrical systems.

The machine is being developed for a paper products manufacturing company at

Coimbatore.

It is a fully automated machine working with the help of pneumatic cylinders

for its horizontal and vertical movements. The sealed ink cup, silicon printing

pad and an etching plate are the major components of our pad printing machine.

Our project has the current applications in the company itself being developed

for and for its flexibility and efficient working.

8

LIST OF TABLES

9

LIST OF TABLES

S.NO PRACTICALS PAGE NO

1 COST ESTIMATION 66

10

LIST OF FIGURES

11

LIST OF FIGURES:

S.NO PARTICULARS PAGE NO

1. Rubber Pad Holder 38

2. Guide Rod 39

3. Top Plate 40

4. Print Head Front View 41

5. 3D View 42

6. 3D Wire Frame 43

7. Pneumatic Circuit 44

12

LIST OF SYMBOLS

13

LIST OF SYMBOLS:

P= Working Pressure in N/mm2

D= Diameter of barrel in mm

T= Thickness in mm

Pd = Direct load

Ft1=Hoop stress

Ft2 =Longitudinal stress

p= Pitch (mm)

σy=yield stress

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INTRODUCTION

15

CHAPTER 1

INTRODUCTION:

Pad printing is used for printing on various substrates like Plastics, Metals,

Glass and Ceramics, Paper and Cardboard, Leather. But it is primary used in

places where the printing area is small and or the contour or surface of the

object is not flat or hard to reach by other printing process.

Pad Printing is finding increasing favour in a host of commercial and

industrial applications.

Any way you look at it, Pad Printing is an unlikely imaging process. It

"borrows" a unique amalgamation of features from gravure, screen printing and

rubber stamp printing, yet its most frequent industrial decorating competitor is

none of these processes. Instead, Pad Printing most often encroaches on jobs

once dominated by Hot Stamping. Even the process itself is somewhat

befuddling. If the ink is so attracted by the silicone pad that it leaves the

recessed areas of the printing plate, why does it abandon the pad so completely

upon touching the substrate? Unlikely as it may be however; this process is

finding increasing favour in a host of commercial and industrial applications.

It is adaptable to a variety of shapes and contours on parts with a variation in the

surface, yet fine detail and precise copy can be achieved. Four color processes is

obtained with exact registration. Pad printing is ideal for decorating toys, plastic

house wares, and injection molded components. This technology also lends

itself to marking electronic components such as resistors, canisters, and

connectors. Any part, plastic, ceramic, or metal can be production marked by

16

this process. The equipment can be semi or fully automated, yet remains a low

capital expenditure technology.

LITERATURE SURVEY

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CHAPTER 2

LITERATURE SURVEY:

Pad Printing is a printing process that can transfer a 2-D image onto a 3-D

object. This is accomplished using an indirect offset (gravure) printing process

that involves an image being transferred from the printing plate (cliché) via a

silicone pad onto a substrate (surface to be printed). Pad printing is used for

printing on otherwise impossible products in many industries including medical,

automotive, promotional, apparel, electronics, appliances, sports equipment and

toys. It can also be used to deposit functional materials such as conductive

inks, adhesives, dyes and lubricants.

Fig.1 Manual Pad Printing machine

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Physical changes within the ink film both on the cliché and on the pad allow it

leave the etched image area in favour of adhering to the pad, and to

subsequently release from the pad in favour of adhering to the substrate

(material being printed).

The unique properties of the silicone pad enable it to pick the image up from a

flat plane and transfer it to a variety of surface (i.e. flat, cylindrical, spherical,

compound angles, textures, concave surfaces, convex surfaces).

In the early 1960’s the pad printing machines were manually operated type,

which are like shown in fig below. Later only the hydraulic, pneumatic and

Electrical drive system types of machines were manufactured. After that in the

recent years highly automated machines were developed.

Fig.2 Pad Printed Products

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COMPANY PROFILE

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COMPANY PROFILE

K.U.Sodalamuthu

Founder

Creative thinking and an innate sense of observation are vital ingredients for

any successful business venture. The Late Mr. K.U.Sodalamuthu had them in

him when he observed the potential in Paper Conversion Machinery. He chose

an uncommon industry which was largely related to a common one - Textiles. It

is a laudable fact that an innovative brand of industry has its origin in a city

popularly known as "Manchester of South India".

The Brand - Sodaltech holds an amazing 96% of the Indian Market for its paper

Conversion Machinery. The Company has more than 500 installations to its

credit worldwide, with 36.5% of the international market.

The Industry has continued to climb the ladder of success steadily over the past

37 years. The three sons of the founder have been actively involved in the

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Company's remarkable success. The eldest Son Mr.K.S.Viswanathan handles

the Production Department .The second son Mr.K.S.Subramaniam is

responsible for the Marketing while the third son Mr.K.S.Balamurugan takes

care of the Administration. Sodaltech has maintained its tempo throughout

meeting the challenges thrown out by the rapidly advancing technology, head

on.

New enhancements are a permanent part of the show based on research and

surveys. Rich in experience and always on the lookout for challenge, Sodaltech

is a versatile brand which can meet any form of requirement adapting itself to

different levels of economy and technology.

Paper Cone Production Line

Automatic Paper Cone Making Machine

Partially Automatic Paper Cone Making Plant

Paper Cone Flocking Machine

Automatic Paper Cone Finishing Machine

Paper Tube and Core Production Line

Pulp Moulding Plant

Edge Protector Production Line

Paper Core Polishing Machine

Paper Core Shredding Machine

Parallel Tube Winder

Baling Press

Paper Traffic Safety Cones

Rebuilt Machines

Automatic Core Cutter

High Speed Core Winder with Multi-Cutter

Fiber Drum Making Machine

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Contact Information

We have a country wide network of sales and service offices all over India to

enable our valued customers to reach us easily.

Our Head Office and Factory Unit # 1:

K. U. SODALAMUTHU AND CO. PVT. LTD.,

# 428 Mettupalayam Road,

Coimbatore - 641 043.

Tamilnadu, India.

Phones: + 91-422-2438346,

+ 91-422-2441223,

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+ 91-422-2441805.

Fax : + 91-422-2431279

E- Mail: sales@sodaltech.com

Our Factory Unit # 2:

K. U. SODALAMUTHU AND CO. PVT. LTD.,

SF # 73 /1 - A, Solavampalayam Post,

Kinathukadavu - 642 109.

Coimbatore District

Tamilnadu - India

Phone: +91-4259-242383, 241417, 200462

PRE & AFTER SALES OFFICES IN INDIA LOCATED AT

• NEW DELHI

• MUMBAI

• KOLKATA

• CHENNAI

OVERSEAS PRE & AFTER SALES OFFICES IN

USAUNITED

KINGDOMRUSSIA BANGLADESH

MALAYSIASOUTH

AFRICASYRIA SPAIN

TURKEYSAUDI

ARABIABRASIL ITALY

24

 KUWAIT IRAN

 

We have a market share of 96.5% in India and 36% worldwide in paper

conversion machinery. More than 500 of our machinery and plants have been

manufactured and supplied to various parts of India and abroad. Hence, it is not

surprising that accolades and awards have been coming our way for more than a

decade now. In recognition of this performance we have been awarded the

EEPC (Engineering export Promotion Council) awards for Export

Excellence,

The Indian Institute of Packaging PACMACHINE awards for

Excellence in Packaging Machinery Design for SODALTECH

Composite Can Making Plant, SODALTECH Spiral Paper Tube Plant,

SODALTECH Fiber Drum Making Plant, SODALTECH Automatic

Paper Cone Plant and SODALTECH Paper Tube / Composite Container

Making Plants.

Our machinery and plants have been exported to several countries

25

including Mexico, Brazil, Finland, Turkey, Nigeria, Kenya, Zambia, Ghana,

Russia, Sudan, South Africa, Egypt, Iran, Saudi Arabia, Kuwait, Syria, Sri

Lanka, Bangladesh, Thailand, Singapore, Malaysia, Libya, Lebanon, United

Arab Emirates etc.

DESCRIPTION OF PARTS

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CHAPTER 3

DESCRIPTION OF PARTS:

The project consists by following parts:

Compressor

Pneumatic Cylinder

Printing pads

Substrate

Ink cup

Printing ink

Image plate and print plate making

The pneumatic cylinder and piston arrangement holds the Printing pad. The

compressor provides highly pressurized air to the cylinder. The power will be

transmitted to the piston rod and the printing pad is actuated. Thus the pad is

absorbing ink in shape of art made on the cliché and due to reciprocating motion

of the horizontal cylinder it spreads the print on the substrate.

3.1COMPRESSORS

RECIPROCATING COMPRESSOR

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Fig 3: A single acting compressor

A reciprocating compressor or piston compressor is a positive-

displacement compressor that uses pistons driven by a crankshaft to deliver

gases at high pressure.

The intake gas enters the suction manifold, then flows into the compression

cylinder where it gets compressed by a piston driven in a reciprocating motion

via a crankshaft, and is then discharged. We can categorize reciprocating

compressors into many types and for many applications. Primarily, it is used in

a great many industries, including oil refineries, gas pipelines, chemical plants,

natural gas processing plants and refrigeration plants. One specialty application

is the blowing of plastic bottles made of Polyethylene Terephthalate (PET).

Fig 4: Reciprocating Compressors

3.2 PNEUMATIC PISTON CYLINDER:

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Fig 5: Double acting Pneumatic cylinder

Pneumatic cylinders (sometimes known as air cylinders) are mechanical

devices which produce force, often in combination with movement, and are

powered by compressed gas (typically air).

Double acting cylinders

Double Acting Cylinders (DAC) use the force of air to move in both extends

and retract strokes. They have two ports to allow air in, one for outstroke and one for

in stroke. To perform their function, pneumatic cylinders impart a force by

converting the potential energy of compressed gas into kinetic energy.

Operations:

General

Once actuated, compressed air enters into the tube at one end of the

piston and, hence, imparts force on the piston. Consequently, the piston

becomes displaced (moved) by the compressed air expanding in an attempt to

reach atmospheric pressure.

3.3 PRINTING PADS:

Pads are three dimensional objects typically molded of silicone rubber. They

function as a transfer vehicle, picking up ink from the printing plate, and

transferring it to the part (substrate). They vary in shape and durometer

depending on the application.

There are three main shape groups: "round pads", long narrow pads called "bar

pads", and miscellaneous shapes (square, rectangular, etc.) called "loaf pads".

Within each group there are three size categories: small, medium, and large size

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pads. It is also possible to engineer custom-shaped pads to meet special

application requirements.

CHARACTERISTICS & PAD CHOICE:

The pad is made with special silicone rubber with the following

characteristics:

Excellent absorption and detachment of the ink; perfect transposal of the

image to be printed.

Tear strength and resistance to solvents and inks; pad long life.

Hardness and form stability; possibility of being used several times.

 Easy to be cleaned; quick maintenance.

The choice of the pad depends on many elements, including the following:

     Shape of the printing surface: flat or uneven.

     Dimension of the printing surface: printing area.

     Type of printing surface: smooth, rough, etc.

     Number of the colors to be printed.

These elements determine the pad's size, shape and hardness, expressed in

durometer. Our pads are available in durometer ranges between 10 and 75.

Important:

The size of the pad depends on the printing surface. 

 It is necessary to use pads whose dimensions are at least 20% greater than

the printing area.

The data of the pads listed in this catalogue refer to the max printing possibility.

Cylindrical Pads

Square & Rectangular Pads

Linear Pads

Special & Compound Pads

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Fig 6: Printing pads

3.4 SUBSTRATE:

Substrate is the technical name used to address any parts or materials to be

printed, and it is critical to match substrates and ink series as to their chemical

compatibility. Please consult the substrate compatibility chart for proper ink

selection. Typically you will need a "fixture" to hold and support your substrate

in order to ensure good quality printing. Fixtures vary in materials and

complexity depending on the application.

One of the most interesting examples of fixture making creativity is the use of

Lego for short run printing. This began in a eureka moment of inspiration when

Cliff Rowell, a small print shop owner and grandfather in Calgary, Canada, was

playing with his grandson. This innovation has begun making its way through

the industry in recent years and saves the time and expense of building job

specific custom fixtures. Note that substrates need to be clean and free from

surface contamination to allow proper ink adhesion.

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Fig 7: Paper Plate Fig 8: Medicine capsule box

3.5 INK CUP:

Open inkwell system (older technology)

Open ink well systems use a trough (ink well) for the ink supply, located behind

the printing plate. A flood bar pushes a pool of ink over the plate, and a doctor

blade removes the ink from the plate surface, leaving ink on the etched artwork

area ready for the pad to pick up.

Sealed ink cup system (latest technology)

Sealed ink cup systems employ a sealed container (ink cup), which acts as the

ink supply, flood bar and doctor blade all in one. A ceramic ring with a highly

polished working edge provides the seal against the printing plate.

ToughCup has a proprietary micro-surface coating designed to repel inks and

solvents. This low-tension surface provides complete release of inks and

drastically simplifies cleaning. It improves productivity by reducing changeover

time when switching colors. 

ToughCup is ideal for people who use 2-component inks as there is a good

chance you will be able to clean the cup even if the ink and hardener mix is

accidentally left in it for an extended period of time. 

Because of the unique coating, this ink cup is also more resistant to attacks from

solvents, to pigment abrasion and mechanical wear. It is Tough! The ink cup is

32

also environmentally friendly: it significantly reduces the use of solvents needed

for cleaning.

Fig 9: New Generation Closed ink cup

3.6 PRINTING INK:

Ink is used to mark or decorate parts. It comes in different chemical families to

match the type of material to be printed (please consult the substrate

compatibility chart for selection).Pad printing inks are "solvent-based" and

require mixing with additives at the time of use. UV inks will not fully cure

until UV light hits the ink. UV curable ink can be wiped off many substrates

when mistakes are made. They can be cured with UV light in as fast as 1 second

of light exposure.

This depends on the ink, substrate and the light power and spectrum. UV inks

can be reused as the pot life can be high as long as the ink stays clean, blocked

from UV light and hasn't broken down from sitting. Also there are heat curable

inks too, which work in much the same way as UV in the sense that there is a

"trigger" for curing at your convenience. Two part inks usually have a pot life of

only a few hours or so. They must be disposed of when they cannot be revived

(by means of retarders etc..) Ink choices are available in many convenient and

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time savings forms, but for some substrates you will have to use the type of ink

that best adheres to the surface.

Climatic conditions will significantly affect the performance of any pad printing

ink, especially the open ink well style printers. Too dry conditions can lead to

faster evaporation of solvents causing the ink to thicken prematurely and too

much moisture can lead to ink issues of "clumping" or something alike. Also the

climate can affect other aspects of the printing process such as ink pick up and

release from the plate to the pad to the substrate, as well as polymer plate to

blade chattering or binding due to humidity. Keep this in mind when planning

the location of your pad printer. Use any necessary heater, air conditioner, and

humidifier or dehumidifier as needed. Always consult Federal, State and local

regulations regarding proper handling, storage and disposal of inks.

3.7 PRINTING PLATE MAKING:

3.7.1 Image plate

Image plates are used to contain the desired artwork "image" etched in its

surface. Their function is to hold ink in this etched cavity, allowing the pad to

pick up this ink as a film in the shape of the artwork, which is then transferred

to the substrate.

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Fig 10: Image Plates

There are two main types of printing plate materials: photopolymer and steel.

Photopolymer plates are the most popular, providing a good do-it-yourself

option. These are typically used in short to medium production runs. Steel plates

come in two choices: thin steel for medium to long runs, and thick steel for very

long runs. Both steel plate types are generally processed by the plate supplier as

it involves the use of specialized equipment.

3.7.2Printing plate making:

There are two main techniques used to create a printing plate. The traditional

technique requires a UV exposure unit and involves photo exposure with film

positives and chemical etching of a photopolymer plate. A second technique

known as "computer to plate" requires a laser engraver and involves laser

etching of a specialized polymer plate. Although the latter technique is

convenient for short run printing it does have several disadvantages over the

former.

Laser plate making is a process that requires the use of a very soft, low quality

polymer coated plate. Thus, the standard cycle life that can be expected out of a

laser etched plate is quite low (10,000 impressions on the high end). By

comparison, a hardened steel plate can easily last for over 1 million

impressions.

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Fig 11: Laser printing plate maker

Ink cups Now introduces the revolutionary Cobalt 250 laser etching and plate

making system to its lineup of laser engraving machines – a lower cost

alternative to the highly successful Cobalt 1000 laser etcher. The Cobalt 250

laser uses CO2 laser technology and specially designed Imperial Printing Plates

(Patent Pending) to produce high resolution pad printing plates directly from the

computer, without the use of film positives.

The Cobalt 250 laser etcher is an extremely simple and powerful laser

engraving machine system to operate. Just add the Cobalt software to your

standard PC and begin “printing” images to the Cobalt 250 laser. Within

minutes you can etch high resolution pad printing plates without the use of

chemicals, films or concern about depth control. The XY motion of the laser

prints head enables etching of very large images (up to 8” x 12”) making the

Cobalt 250 a highly flexible machine for both engraving Imperial pad printing

plates as well as promotional products.

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FIGURES

37

2-D VIEWS

38

39

40

41

42

3-D LABELLED VIEW

43

3-D WIREFRAME VIEW

44

PNEUMATIC CIRCUIT DIAGRAM

45

DESIGNING CALCULATIONS

DESIGN SPECIFICATIONS:

46

No of color = 1

Cup type ( closed cup ) = 60mm

Image Plate size = 100 X150 mm

carriage movement = 300mm

Pad piston stroke on plate = 50mm

Pad piston stroke on product = 50mm

Power required = 230V, 50/60Hz, Single Phase

Power consumption = 20W

Controller : PLC(Applicable)

Plc voltage = 24V DC

Drive system : pneumatic

Operating pressure = 5 bar

Air consumption = 60 lit/min

CYLINDER DESIGN:

Cylinder:1

Diameter of cylinder = 50mm

Stroke of cylinder = 50mm

Operating Pressure = 5 kgf/(cm^2)

Cylinder :2

Diameter of cylinder = 50mm

Stroke of cylinder = 300mm

Operating Pressure = 5 kgf/(cm^2)

Maximum operating pressure = 13.5 kgf/(cm^2)

Total load = Pressure * Area

=13.5*(3.14/4)*(5^2)

= 264.93 kgf

= 2649N

Printing Force = Operating pr * Area

47

= 5 * (3.14/4)* (5^2)

= 981 N

GUIDE ROD DESIGN:

Diameter of rod = 20mm

Length of rod = 250mm

Material selected is C 25

Yield stress for C 25 = 280 kgf/(mm^2)

Printing force acting = 981N

Self wt acting = 400N

Stress = load/area

= (981+ 400)/((3.14/4)*(20^2))

= 4.395N/(mm^2)

= 0.439kgf/(mm^2)

Stress created is less than the allowable yield stress.

Therefore, material selected is c 25 with diameter 20mm.

DESIGN OF NUT AND BOLT:

Longitudinal and Hoop stress:

Ft2 = p*d/4*t

Where,

P = working Pressure = 0.5 N/(mm^2)

d = Diameter of barrel = 50mm

t = thickness of barrel = 1.2mm

Maximum allowable tensile strength for brass = 280 N/(mm^2)

48

Hoop Stress = Ft1 = p*d/2*t

= 0.5*50/2*(1.2)

= 10.416 N/(mm^2)

Longitudinal stress = Ft2 = p*d/4*t

= 0.5*50/4*(1.2)

= 5.208N/(mm^2)

Both loop & longitudinal stress are less than the allowable stress.

Therefore, the selected cyilnder and piston is safe under working condition.

Force on piston = Pressure*Area

= 5.208*3.14*(50^2)

= 40906N

This force is Shared or Divided by the 4 nuts and bolts.

Therefore, Force shared by each bolt = 10226.53N

Area of core = Ac = (60*Pb/σy)^(2/3)

= (60*10226.53/280)^(2/3)

= 168.7 mm^2

From PSG design data book Pg.no 5.42 ,for Ac = 168.7 mm^2

Fine Series M16*1.5 can be selected

Pitch = 1.5 mm

Major diameter of Nut = 16 mm

Minor diameter of nut = 14.376 mm

Minor diameter of Bolt = 14.16 mm

Depth of thread = 0.920 mm

49

WORKING PRINCIPLE

50

5.1 WORKING PRINCIPLE:

WHAT DOES THE PROCESS REQUIRE?

Artwork i.e. the image that is to be printed. Because Pad Printing is often

used for its ability to print very fine detail Artwork can be quite

specialized.

A film positive, which is produced from the artwork.

A printing plate, which is either a "plastic" or steel printing plate, referred

to as a cliché. Onto this cliché we have etched an image (from the film

positive) into the surface. So the image is said to be in relief rather than in

profile as in letterpress printing.

A Pad Printing machine to facilitate the inking and doctoring of the

image, the pick up of the image from the cliché and the put down of the

image onto the item being printed.

A Tampon or Pad, which is moulded from silicone rubber.

Specialist Pad printing ink

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5.2 FEATURES OF PAD PRINTING:

Following are the unique features of the Pad Printing process.

Can print on convex, concave, curved, recessed and discontinuous

surfaces allowing product designers a substantially broader range of

shapes and designs.

Pad printing is able to print shapes and surface structures well outside the

capabilities of Screen Printing and Hot Stamping opening up a way to

decorate a whole new range of products.

Allows wet-on-wet multicolour printing (without intermediate drying) on

non-absorbent surfaces - therefore much reduced down time.

Is capable of 90 degree wraparound on three-dimensional objects.

Offers better edge definition and higher resolution than most other

printing systems therefore offering a method of decorating high quality

high priced items.

Is a relatively inexpensive printing system particularly for multi-colour

and process colour printing which means reduced capital outlay.

52

ADVANTAGES AND DISADVANTAGES

6.1 THE MANY ADVANTAGES OF PAD PRINTING:

53

Variety of substrates - Almost any material including glass, ceramic,

metal can be printed with suitable inks.

Ability to print fine details - Resolution is far better than that of screen

printing in fact up to 120 lines / Cm (300 lines per inch)

High resistance of printing inks - Depending on ink type used extremely

high resistance against mechanical abrasion or chemicals can be

achieved.

Easy handling and little maintenance - Compared to other printing

processes pad printing is easy to learn

Multi-colour printing: wet on wet - Possibility to apply multiple prints

without intermediate drying

Short tooling-up times - Plates and inks can be exchanged within a few

minutes

Low set up cost - Plates can be produced in-house

Relatively low space requirement - Compared to other printing machines

pad printing equipment is space efficient

Low drying cost - In the most simple case air drying at room temperature

is sufficient.

Integration into complex systems, inline production and assembly lines -

For years now there has been a successful combination of pad printing

systems with injection moulding equipment or assembly lines.

6.2 LIMITATIONS OF PAD PRINTING:

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Size of motive - Motive sizes are limited by plate, pad and efficiency of

the pad printing machine. The diameters of the largest efficiently printed

motives are currently approx. 30 cm.

Layer thickness of ink film - The pad process uses plates up to a depth of

approx. 20-25µm (at the most 35µm). Thus conventional inks will result

in printed ink films of approx. 7µm. This layer thickness can be increased

correspondingly by multi-layer printing. Rough particles (e.g. glitter

pigments) are difficult to print in an efficient manner

Printing speed - Even substrates can be printed a lot faster with other

printing processes.

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APPLICATIONS

APPLICATIONS:

Common applications of normal pad printing:

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Medical devices (surgical instruments, etc)

Implantable & in body medical items (catheter tubes, contact lenses,

etc.)

Golf ball logos/graphics

Decorative designs/graphics appearing on Hot Wheels or matchbox

toy cars

Automotive parts (turn signal indicators, panel controls, etc.)

Letters on computer keyboards and calculator keys

Identification labels and serial numbers for many applications

Pad Printing is finding increasing favour in a host of commercial and

industrial applications

Baseballs,bottles, light bulbs, clips, handles and knobs.

Industrial parts and industrial pumps

Containers, appliances, control buttons and automotive parts.

Injection molded parts

Furniture accessories

Toys and hobby parts

Promotional products

Name plates

Special applications of our project:

Printing on capsule boxes for pharmaceuticals.

Printing on paper cups and paper plates.

Printing on paper egg holders.

Printing on paper cones for textile industries.

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COST ESTIMATION

COST ESTIMATION

Components Price (Rs)

Base plate 700

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( Mild Steel, 12mm thick)

C-Frame

(Mild Steel)

3000

Top plate

( bearing sleeve, mild steel, machined)

650

Pad Holding plate

( Mild steel)

535

Guide rod

( 2 No’s , Polish rod)

300

Pneumatic cylinder

1. (50x50)

2. (50x300)

1000

1500

Vice

(stroke=300mm)

2200

Ink cup 950

Screw rod 350

Surface plate

(200x300, 10 mm thick)

1500

Etch plate

(100x600mm)

1250

Pad

(115x 65mm)

3200

Direction Control Valve 1500

Fasteners 500

TOTAL 19135/-

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CONCLUSION

CONCLUSION:

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Eventhough pad pritning is already existing for the

solid substrates like plastics and metal,but it had a limitation of not using it for

the paper products. Now with our project it s possible to obtain prints on paper

products with minimum working pressure and compact design.

The machine can lead to minimize lots of error in the printing industries letting

an error free printing on the finished paper products also. The printing can be

easily done after the manufacture of the products irrespective of its shape, size

and material.

Hence leading to the great success , this pad printing machine can develop

impressions of any type on any typical components including the finished

paper products.

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REFERENCES

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REFERENCES:

BOOKS:

1. Pad Printing Technical Guidebook: John P. Kaverman

2. The stamp-pad printing book: Florence Harvey Pettit – 1979

3. The Complete Book on Printing Technology: Niir Board

PATENTS:

1. BS Adner, DP Bouchard - US Patent 5,806,419, 1998 - Google Patents

2. DWM Ho - US Patent 5,237,922, 1993 - Google Patents

3. PAD PRINTING MACHINE :  Claus Morlock  Wilfried Beron

WEB:

1. http://www.sodaltech.com/

2. http://en.wikipedia.org/wiki/Pad_printing

3. http://www.kinnariprintingmachines.com/

4. http://www.padprinters.com/

5. http://www.padprinting.in/

6. http://www.padprintingplatesonline.com/

7. http://www.inkcups.com/

8. http://www.freebase.com/view/en/pad_printing

9. http://www.halfbakery.com/

10.http://www.howstuffworks.com/

11.http://www.ritapad.com/

12.http://www.packmark.com.au/Pad%20Printing/

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