Amit Nitharwal report

IN-PLANT TRAINING REPORTAt

(17th July to 14th August 2014)

Product Application and Research Centre, Chembur,Mumbai

Degree of Bachelor of Technology in petroleum

Engineering

Submitted by:

Amit nitharwal

B.Tech 2nd year in petroleum EngineeringCollege roll no. -12/385

University college of engineering, Rajasthan Technical University,kota

Acknowledgements

A summer training is a golden opportunity for learning and self development.I consider myself very lucky and honored to have so many wonderful people lead me through in completion of this training.

I wish to express my indebeted gratitude and special thanks to Mr. S.V.Raju, Head of the Department - Product Application and Research Center (PARC), Reliance Industries Ltd (RIL) who in spite of being extraordinarily busy with her duties,took time out to hear for extending its training facilities and giving me an opportunity to gain an insight into the working of an industry.

I express my deepest thanks to Dr. Nitin Joshi, my guide for his vital encouragement and keep me on the correct path and allowing me to carry out my industrial training work at their estmeed organization and extending during the training.I do not know where I would been without him. I choose this moment to acknowledge their contribution gratefully.

I am highly indebted to the executive & technical officers of PARC for their everyday guidance and help. I pay special thanks to Mr. Anant Pawar , Mr. Lalit Pathaskar,Mr. Ajit Gate for their help in the processing centre.

I would specially like to thank Mr. Tushar Dongre, Mr. Kunjan Mhatre and Mr. Kulkarni for their support and co-operation throughout the training period in spite of their busy schedules.

It is my glowing feeling to place on record my best ,deepest sense of gratitude to Mr. Anshul Rajgarhia, Mr. Ashish Sharma, Mr. Jigar Palecha, Mr. Ravi Kute, Ms. Parul Sachdeva and Ms. Smita Kumbhare, Mr. Rupesh Rhane for their continuous help during the training.

Finally I would like to thank all the office and support staff for extending their cooperation throughout the course of this training.

Amit nitharwal 13 th august 2014

Contents Company profile

Manufacturing facilities

Introduction to PARC

Testing division

Processing division

1. company profile

Reliance Group, founded by Shri Dhirubhai H. Ambani (1932-2002), is India's largest private sector enterprise, with businesses in the energy and materials value chain.

Reliance Industries Limited (RIL) is an Indian conglomerate holding company

headquartered in Mumbai, Maharashtra, India. The company currently operates in five

major segments: exploration and production, refining and marketing, petrochemicals,

retail and telecommunications. The company is ranked 99th on Fortune Global 500 list

of the world's biggest corporations for the year 2012. RIL is one of the largest publicly traded companies in India by market capitalization. It is the second largest company in

India by revenue after Indian Oil Corporation. RIL’s revenue is US$ 68.4 billion as of FY 2012-2013. Reliance enjoys global leadership in its businesses, being the largest polyester

yarn and fiber producer in the world and among the top five to ten producers in the world

in major petrochemical products.

RIL manufactures Polypropylene (PP), Polyethylene (PE) and Polyvinyl Chloride (PVC) sold under the brand names Repol, Relene & Reon respectively.

Diverse applications across packaging, agriculture, automotive, housing, healthcare, water and gas transportation and consumer durables.

Repol PP can turn any of your 'plastic' ideas into a reality. Relene PE has completely transformed the concept of packaging. Reon PVC is a versatile polymer with applications ranging from soft to rigid. RIL has manufacturing sites at Hazira, Nagothane, Jamnagar, Baroda, and

Gandhar. RIL is the largest producer of PE & PP in India. RIL manufactures LDPE which no other Indian manufacturer produces.

Reliance's polymer business is integrated with its cracker facility at Hazira, as well as its

refinery at Jamnagar, ensuring feedstock availability at all times. The company operates

world-scale plants for Polyolefins and PVC with state-of-art technologies from global

licensors like Novacor, Geon and Union Carbide. Along with IPCL, Reliance is among the

world's top 10 plastic producers.

Reliance Industries Limited is Asia's largest manufacturer of Polypropylene (PP).

Reliance figures the Fifth largest Polypropylene producers in the world. Reliance holds a

67% share of the Indian Market and caters to 3% of the world’s consumption of PP. The

four production sites offer a wide range of Homopolymer, Random and Impact copolymer

grades. These can cater to the entire spectrum of Extrusion, Injection & Blow molding

processes.

“Relene” HDPE is available in densities ranging from 0.941g/cc to 0.965g/cc & melt flow

index from as low as fractional to 20. Relene HDPE is widely used for numerous extrusion

& molding applications. Specially formulated HDPE Raffia grade has placed "Relene" way

above the competing materials for this application. The grade has excellent processability

on high output raffia lines & exhibits superior balance of tenacity / elongation.

Reliance LLDPE grades are marketed under trade name "Reclair" & is available in density range of 0.916 to 0.935 g/cc & MFI range from fractional to as high as 50g /10min.

2. Manufacturing facilities

PP

PE

3. INTRODUCTION TO PRODUCT

APPLICATION & RESEARCH CENTRE

The product application & research centre (PARC), Reliance Industries Limited

petrochemical division was established in 1990 at Chembur, Mumbai as a technical wing

of the polymer marketing division. It is deeply involved in the development of new grades

& the optimization of the existing grades in terms of cost & properties. It also carries out

continuous valuation of various lots produced at Jamnagar & Hazira plants. PARC is

committed to deliver value addition to polymer business of Reliance Industries Limited by

providing technical service, constant product up gradation and initiating market

development with the sole objective of total customer satisfaction. It also carries out testing

and trials of various modified and developmental grades.

PARC is a conduit between business enterprises and their vendors, converting basic needs

into commercially viable technology and helping to produce useful products. To fulfill

these objectives, sophisticated analytical & processing facilities have been established at

PARC.

PARC is recognized by the department of science and industrial research as an in-house research & development wing of reliance-plastic & petrochemical division.

Functions of PARC:

Product development

Process development

Customer Support / Technical service

Co-ordination with plant & marketing department for benchmarking exercises

Training & manpower development

The Activities of PARC can be divided into:

Testing

Processing

4. Testing Division

Testing of raw material is absolutely necessary for quality control & characterization. The analytical laboratory is involved in the analysis & testing of resin and product samples received from the customers as well as from the PARC division.

Testing for resin:Melt Flow Index

Ash Content Bulk Density Funnel Flow Time(FFT) FTIR Spectroscopy Measurement of Colour Density

Testing for plastic films: Shrinkage Test for films Tear Strength Coefficient of Friction (COF) Haze Dart Impact Strength Tensile Properties

Testing for Moulded samples: Tensile properties

Scanning Electron Microscope(SEM) Izod-Impact strength Shrinkage Test

TESTING FOR RESIN

Melt Flow Index Determination

Reference: ASTM D1238

Machine Make: Davenport Flow Indexer.

Summary: For this, molten polymer is extruded through a die and flow of polymer is measured under a specified load and at particular temperature per 10 min

Scope: This procedure is used to determine melt flow properties of resins with the help of Davenport Flow Indexer. Melt Index is an inverse measure of molecular weight. Since

flow characteristics are inversely proportional to the molecular weight, a low molecular polymer weight polymer will have a high melt index value and vice versa.

Apparatus: (I) Melt Flow Indexer (Davenport make) with accessories:

Temperature: PE: 1900C

PP: 2300C

Prheating time :

PP: 6 min

PE:5 min

Barrel diameter= 9.5504 0.0016 mm

Die diameter= 2.0955 0.0016 mm

Die Length= 8 0.025 mm

Weight= 2.16 kg, 6.48 kg ( 0.5% of the total weight)

Procedure:

1. Manual

A small amount of the polymer sample (around 4 to 5 grams) is taken as per the expected MFI of material in the specially designed MFI apparatus. The apparatus

consists of a small die inserted into the apparatus, with the diameter of the die being around 2 mm.

The material is packed properly with the help of suitable piston inside the barrel to avoid formation of air pockets.

A piston is introduced which acts as the medium that causes extrusion of the molten polymer.

The sample is preheated for a specified amount of time: 5 min at 190°C for

polyethylene and 6 min at 230°C for polypropylene.

Push the piston a little above the mark to ensure good packing (known as purging).

After the preheating a specified weight is introduced onto the piston. Examples of standard weights are 2.16 kg, 5 kg, etc.

The weight exerts a force on the molten polymer and it immediately starts flowing through the die.

A sample of the melt is cut in regular intervals of time and is weighed accurately.

MFI is expressed as grams of polymer/10 minutes of flow time.

2. Automatic

Weigh the specimen and put it in the apparatus as per the expected MFI. Select remote control on apparatus and start the computer. In the computer start console software. Feed polymer type, melt density, cut-off length and file name. Start the test. Purge after 3 minutes just before the mark on piston.

Put the arrester of 71mm or 81mm height depending on whether the material is Hi-Flow or Low-Flow.

Put the weight on plate above the apparatus. Record the output.

ASH CONTENT

Reference: ASTM D2584, D5630

Machine Make: Mettler Balance, Bunsen burner

Scope: This test is used to measure the ash content and filler content of plastic samples

Sample specification: 3-5 g of sample

Procedure

1. The sample weight and the weight of the empty crucible are note.2. In case of PVC sample (self-extinguishing in nature) the sample is now wetted completely

with 98% sulphuric acid and it is again heated to give out CaSO4. After

heating, the PVC sample is now put in the oven for 1 hour at 850C.

3. For other samples, after burning is completed they are put in an oven maintained at 550C

4. Now the sample is kept in a desiccant (containing silica gel) for ½ hour to absorb all the moisture.

5. It is then weighed and the ash content is found.

6. Calculation : % Ash Content = Wt. of Ash x 100

Wt. Of Sample

Fourier Transform Infrared Spectroscopy (FTIR)

Reference: ASTM E1252

Machine make- Perkin Elmer, spectrum 100 series

Principle:

FTIR utilize an ingenious device called Michelson interferometer, which was developed many years ago by A. A. Michelson for making precise measurement of the wavelengths of electromagnetic radiations.FTIR instruments contain no dispersing elements and all wavelengths are detected and measured simultaneously. Instead of a monochromator an interferometer is used to produce interference patterns that contain the infrared spectral information.In FTIR when an infrared spectrum is introduced to a sample stretching and bending of various bonds takes place and due to different bond energies, each molecule absorbs energy at a different frequency.One of the components of an electromagnetic wave is a rapidly reversing electric field(E). This field alternately stretches and compresses a polar bond. When the electric field is in the same direction as the dipole moment, the bond is compressed and its dipole moment decreases.

When the field is opposite the dipole moment, the bond stretches and its dipole moment increases. If this alternate stretching and compressing of the bond occurs at the frequency of the molecule's natural rate of vibration, energy may be absorbed. The energy is absorbed by a molecule only when there is a change in dipole moment.

1. The Source: Infrared energy is emitted from a glowing black-body source. This beam passes through an aperture which controls the amount of energy presented to the sample (and, ultimately, to the detector).

2. The Interferometer: The beam enters the interferometer where the “spectral encoding”

takes place. The resulting interferogram signal then exits the interferometer.

3. The Sample: The beam enters the sample compartment where it is transmitted through or

reflected off of the surface of the sample, depending on the type of analysis being accomplished.

This is where specific frequencies of energy, which are uniquely characteristic of the sample, are

absorbed.

4. The Detector: The beam finally passes to the detector for final measurement. The detectors used are specially designed to measure the special interferogram signal.

The Computer: The measured signal is digitized and sent to the computer where the Fourier transformation takes place. The final infrared spectrum is then presented to the user for interpretation and any further manipulation

Procedure:

1. Take small amount of material on a glass slide and place it on a hot plate. Ensure the material melts and press it into a uniform film by applying steady pressure by means of another glass plate. If material is already in film form it can be used directly.

2. Once the background scan has been completed the spectroscopy of the material is carried out.

3. Place the film sample on the Universal Attenuated Total Reflectance Cell and scan it for background radiation.

4. The interference pattern of the material is obtained which is converted by the Fourier analyser into a spectrum

5. . The graph obtained is of % transmittance v/s wave number.

A typical FTIR spectrum

Determination of Density


Apparatus:

Weighing Balance (METTLER )

Density meter assembly: Beaker stand, Beaker (500mL), a frame attached to the weighing pan and a sample holder which facilitates weight in air and in liquid.

Sample Specification:

1 cm x 1 cm smoothly cut sample is used for density determination. The sample should

not have any sharp edges.

Procedure:

The weight of the sample was measured in air and then in a liquid (n-butyl acetate) of known

density. The density of the liquid used was less than the expected density of the sample. The

ratio of weight in air to loss of weight in liquid was used to calculate the density of the sample.

Calculation:

Density of sample at Tm =Wa

sWa Ws

Where:

Tm = Temperature of measurement Wa = Weight in air

Ws = Weight in the liquid

s = Density of the liquid at Tm

TESTING FOR PLASTIC FILMS

Shrinkage Test for films


Scope: This test method covers determination of the degree of unrestrained linear thermal shrinkage at given specimen temperatures of plastic film and sheeting of 0.76 mm [0.030 in.] thickness or less.

Sample specification: 150mm x 10mm

Requirements: Constant temperature bath, Silicone oil, Free Shrink Holder, Stop-watch

Procedure:

1. Cut the specimen as per required dimensions in both machine direction (MD) & transverse direction (TD).

2. Start heating the silicone oil and set its temperature to 130 degrees Celsius.

3. Now hold the sample with free shrink holder in the upper 50 mm length.

4. Place the specimen in the bath for 20 seconds.

5. Now observe the change in length.

6. Repeat the same procedure for other direction.

7. Calculate the % change in length.

(Application of shrink wrap films)

Determination of Tear Strength of films


Machine Make: CEAST Italy

Scope: Used to measure the tear strength of plastic films.

Principle:

The force to propagate a tear across a film or sheeting specimen is measured. The force necessary to propagate the tear is measured.

Apparatus: CEAST ED 30 machine, Digital micrometer

Sample Specification:

The specimens shall be of the single tear type and shall consist of strips 76 mm long by 64 mm wide. The thickness of the specimen is noted along the path where tear will occur. The samples are cut in the machine direction (MD) and the transverse direction (TD).

Procedure: Different weights available are 4000mN, 8000mN, 16000mN, 32000mN, 64000mN,

50N, 100N. The weight is selected such that the film reading lies between 20-90% of the weight.

The blank reading is taken and the machine is calibrated. The sample is inserted in the pneumatic

sample holder. The cover is shut and the film tears. The reading is noted from the display.

Calculation: Tear Strength (in g/ m) = Force in cN / thickness ( m)

Determination of Coefficient of friction of Plastic Films


Machine Make: Davenport

Scope: Used to find coefficient of friction between a plastic film with respect to other films and metal surfaces.

Principle:

Frictional force f is related to the normal force acting on a body at rest as follows: f = N

Where is the coefficient of friction. The COF associated with the force required to start a body from rest is known as coefficient of static friction and that associated with a moving body is known as the coefficient of kinetic friction.

Apparatus: Davenport friction measuring apparatus, template, vacuum pump

Sample Specification: 675 mm x 255 mm should be attached to the testing plane and 6.5 mm x 6.5 mm minimum for sliding.

Analytical Procedure:

The vacuum is switched on and the film is placed on the plane, without wrinkles. The film is

attached to the 200g sled with cellophane tape taking care to avoid wrinkles. The cord is attached

to the sled and placed gently on the plane at two fixed points parallel to the machine direction.

The speed is selected to be 15 cm/min.

Calculation:

COSF = Static force/ weight of the sled

COKF = Kinetic force/ weight of the sledDetermination of Dart Impact Strength for Plastic Films


Apparatus: Dart Impact Testing apparatus (International Engineering Industries), Weights

Sample Specification: Greater than the diameter of the specimen holder

Scope: Used to measure the dart impact strength of plastic films

Principle:

Dart Impact strength values are very important for plastics packaging. They theoretically give the

impact strength of the plastic film. In the test, falling weights from a specified height are made to

fall on the film until fracture occurs. The weight at which 50% of the samples fail is the dart

impact weight value. This value divided by thickness in microns gives dart impact strength.


The two different types of dart used are:

A: 38.1 0.13 mm of 55g weight

B: 50.8 0.13 mm of 283g weight

Vacuum applied is 700 mm of Hg

A: Dropped from 66 cm and is used for films requiring masses of about 50g to 2 kg to fracture

B: Dropped from 152 cm and used for films requiring masses of 0.3 to 2 kg to fracture

10 samples are tested on each weight level and the weight at which 50% failure occurs is

reported.

Calculation:

Dart Impact Strength (g/m) = Weight to cause 50% fracture (g)/ thickness (m)

Determination of Tensile Properties of Plastic Films


Machine make: Lloyd, LRX plus

Sample specifications: The width of the sample should be 15 mm - 25 mm and the gauge

length should be 5 cm.

Principle:

Plastic products when subjected to tensile force initially resist deformation, get elongated and

finally break. Tensile elongation and tensile modulus measurements are amongst the most

important indications of strength in a material and are the most widely specified properties of the

plastic materials. Tensile test, in a broad sense, is a measurement of the ability of the material to

withstand forces that tend to pull it apart and to determine to what extent the material stretches .

Procedure:

The film is cut in exact dimensions making sure that the sides are uniform. The sample is

clamped carefully and the thickness of the film is measured using a digital micrometer. The

dimensions and batch references are entered in the software. The initial load is tare and the speed

of testing is set to 500 mm/min and the machine is started. The stress vs. extension curve of the

specimen is recorded and the required values are taken.

TESTING FOR MOLDED SAMPLES

Determination of Tensile Properties of Moulded Plastics


Scope: This test is used to determine the tensile properties of moulded polymer samples.

Principle:

Plastic products when subjected to tensile force initially resist deformation, get elongated and

then finally break. Tensile elongation and tensile modulus measurements are among the most

important indications of strength in a material and are most widely specified properties of plastic

materials. Tensile test in a broad sense is a measurement of the ability of a material to withstand

forces that tend to pull it apart and to determine to what extent the material stretches before

breaking. Tensile modulus, an indication of the relative stiffness of a material can be determined

from a stress-strain diagram.

Apparatus:

(i) Universal Testing Machine

(ii) Grips for mounting the specimen

(iii) Vernier Callipers

Sample Specification: Five specimens are tested as per the following specifications:

Sample PE PP

Sample Type ASTM D638 Type IV Type I

Grip separation rate 50mm/min 50 mm/min

Distance between the grips 64 5 mm 114 1 mm

Procedure:

The testing machine is switched on and the program for determining the tensile properties is

selected. Test samples, previously conditioned are used for testing. Two marks, 1.0 0.1 inches

apart are on all the test samples at the center of the narrow portion of the sample. The width and

thickness of the sample is measured to the nearest 0.001 mm and entered as data. The specimen

is placed in the grips of the testing machine and the grips are tightened. The extensometer is then

attached on the marks made on the sample. The initial load is tare. The speed of the testing

machine is set and the machine is started. The load vs. extension curve of the specimen is

recorded and the load and extension at the yield point and the point of rupture are noted. Tensile

strength at yield (TYS), UTS, % elongation at break and % elongation at yield were directly

displayed on the screen.

Calculations:

Tensile modulus was calculated from the points on the stress-strain curve

Tensile Modulus = Difference in stress/difference in corresponding strain

Tensile strength= force/ area

Scanning Electron Microscope (SEM)

Scope: This test is used to see the finer details of the surface of polymeric sample. It finds

application when the dispersion and size of rubber droplets in Impact co-polymer

polypropylene (ICP) is to be found or surface defects are to be evaluated.

Principle:

A scanning electron microscope (SEM) is a type of electron microscope that produces images of a sample by scanning it with a focused beam of electrons. The electrons interact with electrons in the sample, producing various signals that can be detected and that contain information about the sample's surface topography and composition. The electron beam is generally scanned in a raster scan pattern, and the beam's position is combined with the detected signal to produce an image. SEM can achieve resolution better than 1 nanometer. Specimens can be observed in high vacuum, low vacuum and in eenvironmental SEM specimens can be observed in wet conditions.

In a typical SEM, an electron beam is thermionically emitted from an electron gun fitted with a tungsten filament cathode. Tungsten is normally used in thermionic electron guns because it has the highest melting point and lowest vapor pressure of all metals, thereby allowing it to be heated for electron emission, and because of its low cost. Other types of electron emitters include lanthanum hexaboride (LaB6) cathodes, which can be used in a standard tungsten filament SEM if the vacuum system is upgraded and FEG, which may be of the cold-cathode type using tungsten single crystal emitters or the thermally assisted Schottky type, using emitters of

zirconium oxide.

The electron beam, which typically has an energy ranging from 0.2 keV to 40 keV, is focused by one or two condenser lenses to a spot about 0.4 nm to 5 nm in diameter. The beam passes through pairs of scanning coils or pairs of deflector plates in the electron column, typically in the final lens, which deflect the beam in the x and y axes so that it scans in a raster fashion over a rectangular area of the sample surface. When the primary electron beam interacts with the sample, the electrons lose energy by repeated random scattering and absorption within a teardrop-shaped volume of the specimen known as the interaction volume, which extends from less than 100 nm to around 5 μm into the surface.The size of the interaction volume depends on the electron's landing energy, the atomic number of the specimen and the specimen's density. The energy exchange between the electron beam and the sample results in the reflection of high-energy electrons by elastic scattering, emission of secondary electrons by inelastic scattering and the emission of electromagnetic radiation, each of which can be detected by specialized detectors. The beam current absorbed by the specimen can also be detected and used to create images of the distribution of specimen current. Electronic amplifiers of various types are used to amplify the signals, which are displayed as variations in brightness on a computer monitor (or, for vintage models, on a cathode ray tube). Each pixel of computer video memory is synchronized with the position of the beam on the specimen in the microscope, and the resulting image is therefore a distribution map of the intensity of the signal being emitted from the scanned area of the specimen. In older microscopes image may be captured by photography from a high-resolution cathode ray tube, but in modern machines image is saved to computer data storage.

Procedure:

1. Cut the sample by microtoming if Tg of polymer is below room temperature it is cut by cryogenic microtomy (i.e. in an atmosphere of Nitrogen because of its low boiling point) else its microtomed at ambient conditions.

2. Put the double stick carbon tape on sample stub.

3. Place the sample on the stub.

4. Now take out the rod and watch the indicator where green signifies vacuum and red indicates air, as air enters the current increases.

5. Now control and regulate the voltage and filters to observe the specimen.

(An image formed SEM)

Determination of Izod-Impact Strength of Plastics


Machine Make: Resil Impactor

Scope: This procedure is used to determine the impact strength of molded polymer

samples.

Summary: Notched specimens were subjected to impact with the help of a striking pendulum hammer. Energy required for the sample to break was noted.

Principle:

Impact test indicates the energy required to break standard test specimens of a specified size. Energy lost by the pendulum during the breaking of the specimen was noted.

The objective of the Izod Impact test is to measure the relative susceptibility of a standard test

specimen to the pendulum-type impact load. The results are expressed in terms of energy

consumed by the pendulum in order to break the specimen. The energy required to break a

standard specimen is actually the sum of the energies needed to deform it, to initiate its fracture

and to propagate the fracture across it, and the energy needed to throw the broken ends of the

specimen.

Apparatus: Izod Impact Tester- CEAST (Resil-25)

Notch cutter with micrometer-screw gauge Vernier Calipers- Accuracy 0.01 mm

Notch cutter

Sample specification: Molded specimens have width between 3.17 and 12.7 mm. The depth of

the plastic material remaining in the bar under the notch was 10.16 0.05 mm and the distance

of the notch from the end was between 31.5 to 32 mm.


1. Hammer was selected along with the relevant range and installed by means of the range selector and the range switch.

2. The hammer was manually checked so as to ensure that it could be swung freely between the anvils.

3. The hammer was initially released without the specimen and the value displayed indicated the amount of energy lost due to friction, wind age, and other factors.

4. This value was subtracted from each of the final sample readings.

5. The hammer was positioned on the anvil and the test samples (conditioned for 40 hours at 23 2 C) were positioned and tightened with the torque wrench.

6. The hammer was then released and the breaking energy value on the digital display was noted down.

7. If the display exceeded 70% of the 2.75 J, then the hammer was replaced by a higher energy hammer and the above steps were repeated again.

Calculation:

Izod Impact Energy required to break the specimen – Air resistance

Energy = Thickness

Determination of Flexural Properties of Plastics


Scope: This procedure is used to determine the flexural properties of plastic materials

Principle: Plastic Products when subjected to flexural strain resist deformation. Flexural strength

is the ability of the material to withstand bending forces applied perpendicular to its longitudinal

axis. The stresses induced due to the flexural load are a combination of compressive and tensile

stresses. Flexural properties are reported and calculated in terms of the maximum stress and

strain that occur at the outside surface of the test bar. Many polymers do not break under flexure

even after a large deflection that makes determination of the ultimate flexural strength

impractical for many polymers.

Apparatus:

(i) Universal Testing Machine (Lloyd)

(ii) Loading noses and supports

(iii) Vernier Callipers (Mitotoyo make)

Sample specification:

Five samples of the following dimensions are tested:

Length = 127 5mm

Width = 12.7 1mm

Thickness = 3.2 0.4 m

Support span length is 16 times the specimen thickness (Tolerance +4 or –2 mm)


An appropriate load cell (depending upon the type of material) is mounted on the machine. The

loading nose is attached to the load cell and the supports to the stationary crosshead. The parallel

alignment of the loading nose and supports is critical here. The machine is switched on and the

following instrumental parameters are set:

Speed of testing for the PP samples = 1.3 mm/min

The appropriate program for flexural properties is selected. Previously conditioned (Maintained

at 23 2C for 40 hours) test specimens are used. The width and thickness of the samples being

tested are entered as data and the support span is set at 50 2mm for PP. The specimen is

entered on the supports. The experiment was performed and the load deflection curve was

displayed and the program gave the flexural yield strength, modulus of elasticity, and 1% secant

modulus directly.

Calculation:

Eb=L3F/ (4bh3Y)

σf =3FL/ (2bh2)

F: Force @ midpoint

L: Span

b: Width

h: ThicknessMeasurement of Colour of Plastics

Reference: ASTM E313

Machine make: Color quest II, Hunterlab

Scope: This test is used to measure the L*, a*, b* values of the given sample and also the Yellowness Index, Whiteness Index, and colour differences between the standard and sample.

Sample specifications: Typically a 50 mm (2") or 100 mm (4") disk, although any flat sample that the specimen holder will grasp can be tested.

Procedure:

The instrument is first standardized for color measurements and the instructions in the computer are followed to get the required values.

L* indicates brightness,

a* indicated greenness or redness,

b* indicates blueness or yellowness.

ΔE= ((L* )2 (b* )2 (a* )2 )

Standardization includes selection of specular reflectance mode with large area of view and UV filter out.

The standard light trap is then inserted followed by the standard white and the standard gray tiles.

The test sample is inserted into the specimen holder, and the spectrophotometer takes the

reading

The result obtained is in the form of L, a, b values, whiteness index (WI) and yellowness index (YI).

Color analysis can be used to match adjacent parts molded from different materials, or to

evaluate color change due to outdoor exposure. Visual color and Spectrophotometer readings can

also be affected by surface texture, molding parameters, processing method, and viewing light

sources.

5.Processing Division

Brief Description of Processing Machines:

Injection Moulding

Principle:

In the process the material is plasticized and melted by the heat added through barrel heaters and friction due to shearing.

Then the material is injected through nozzle into a relatively cold mold to get the desired shape. After the shape is formed, the ejector pins push the specimen out of the mould.

The process is used to make solid articles like caps, plugs, bobbins, furniture & house ware products, industrial & automobile parts etc.

Mould:

Machines available:

Klockner Windsor FR 110

Klockner Windsor SP 180 (Family mould machine)

Arburg 320C All-rounder (ASTM standards)

Parts of a moulded specimen:

Injection moulding machine detail specification

Specifications Units DGP Klockner Arburg

Windsor Windsor All rounder

SP180 FR110 320 C 500-100

Screw diameter Mm 50 45 30

Injection pressure Bar 1800 1900 1550

L/D - 18:1 19:1 20:1

Clamping force KN 1800 1100 500

Min mould height Mm 350 250 200

Max mould height Mm 900 700 200

The theory of injection moulding can be reduced to four simple individual steps:

Plasticizing, Injection, Cooling, and Ejection. Each of those steps is distinct from the others and correct control of each is essential to success of the total process.

The steps are as follows:

Plasticizing - describes the conversion of the polymer material from its normal hard granular form at room temperatures, to the melt necessary for injection at its

correct melt temperature.

Injection - is the stage during which this melt is introduced into a mould to completely fill a cavity or cavities.

Cooling - is the action of removing heat from the melt to convert it from melt back to its original rigid state. As the material cools, it also shrinks.

Ejection - is the removal of the cooled, moulded part from the mould cavity and from any cores or inserts.

Limitations of Injection Moulding

High initial equipment investment

High start-up and running costs possible Part must be designed for effective moulding Accurate cost prediction for moulding job is difficult

Application: PARC uses injection moulding machine for manufacturing of spiral flow test sample, tensile testing sample, flexural testing sample, Izod testing sample, disc shape sample and colour testing sample.

Blown Film Plant

PE Monolayer Blown Film Plant:

Blown film extrusion process and salient features:

Blown film extrusion is the process by which most commodity and specialized plastic films are

made for the packaging industry. In this process extruded material flows through the tubular die,

which is like a combination of an offset die and a pipe die in that the material turns as it flows

into the die. The upward motion is preferred as it makes gravity uniform over the entire part. The

melt exits the die in the form of a tube. A cooling ring is placed at the exit of the die to give the

tube some dimensional stability since the material is air cooled. Air is then introduced through

the back of the die and flows upward inside the middle of the tube. This air pushes the tube

outward creating a bubble. The bubble thus formed continues to expand, cool and crystallize.

The bubble is then forced into a flat sheet by collapsing guides and moved into the nip rolls.

The nip rolls are present at the apex of the flattening planes. One of them is made of rubber and

other is made of steel, which draw the film through the take-off. They are about 15 to 30 cm in

diameter, with even larger diameters needed for widest films .The rpm of the nip rolls is

modified as per the thickness of the film is required.

Generally single layered films of 7-200 microns can be made on a monolayer blown film plant.

The line on the bubble that marks the onset of close-packed molecular arrangement can be identified by loss of clarity and is known as the frost line.

The tube size is specified as the lay-flat size which is the width of the finished roll i.e. half the circumference of the expanded tube.

Tubular films show excellent toughness as they are a mild form of biaxial orientation. Tubular lines produce products which can be easily made in to bags, edge-trimming can be frequently avoided and a film width is easily changed simply by blowing a bigger tube.

Machine Specifications:

LDPE/LLDPE plant HM/HDPE plant

Make Rajoo Engineers Limited Rajoo Engineers Limited

Model No RELL-4040 LAB REHD-4040 LAB

Screw diameter 40mm 40mm

Screw length 1200mm 1200mm

L/D ratio 30:1 30:1

Screw speed range 10-100rpm 10-100rpm

Die diameter 110mm spiral type 75mm spiral type

Die gap 1.2, 1.5,1.8mm 0.8,1.2mm

Parts of a tubular blown film plant:

ExtruderExtruders comprise of hopper, barrel/screw and dies. Fig shows the component of a

modern extruder.

Hopper:

All the extruder has an opening in the barrel at the driven end, through which the plastic graduals

enter the extruder. The hopper, a simple sheet –metal enclosure, is mounted above the opening

and holds about a hopper’s capacity material. Hopper is provided with heating system, if the

material has to be preheated before entering the extruder.

Screw:

This is the heart of the extruder. Screw conveys the molten polymer to the opening of the die after properly homogenizing the molten polymer.

There is considerable variation in the design of the screw for various materials, the most

important variable being the depth of the channels. Despite much desire for universal screw, it is

advisable to use a different design for each material to achieve the best results. PE screw is

designed to have shallow channels, sudden compression and long metering join.

Screw dia : 20-250mm,CR: 2.5-3: 1,L/D: 24-33: 1

Mixing Heads

The metering section of a standard is not a good mixer. Smooth laminar flow patterns are

established in the channel, which do not mix dissimilar elements in the melt. Mixing devices are

frequently installed in screw to disrupt these flow patterns and improve melt homogenization.

Breaker plate/screen pack:

Breaker plate with screen packs inserted is kept in the adapter, which connect the dies and extruder barrel. This assembly has several functions.

1. Arrest the rotational flow of the melt and convert into axial flow.

2. Improves melt homogeneity by splitting and recombining the flow.

3. Improves mixing by increasing backpressure.

4. Remove any contamination and unmelt.

Screen packs are made up of series of screen of differing mesh. With the coarse screen placed against the breaker plate to support the finer screens.

Die

The dies used for tubular extrusion are centre-fed or side-fed. Centre fed dies are better as all the

points on the lip are equidistant from the feed-entry point. This gives uniform flow and uniform

thickness. The spider arms of the centre-fed die always divide the flow into separate paths which

must come together and weld completely before leaving the die or else weld lines are formed,

which are lines of weakness.

Die gap is also a very important parameter as too small die gap may cause increase in die resistance and cause overheating in extruder and reduce output rate. And if the gap is too large resistance becomes so less that weld lines may appear.

For the processing of PE, a die with spiral is used as shown in the figure. As the plastic flows

from the entry point it spirals around the mandrel section of the die. The land depth between the

spiral section and wall increases as the wall increases as the material progress through the die, .as

a result, the distribution around the die periphery made uniform in order to control the gauge of

extruded tube.

Corona Treatment

Many plastics, such as polyethylene and polypropylene, have chemically inert and nonporous surfaces with low surface tensions causing them to be non-receptive to bonding with printinginks, coatings, and adhesives. Although results are invisible to the naked eye, surface treating modifies surfaces to improve adhesion.

Corona treatment (sometimes referred to as air plasma) is a surface modification technique that

uses a low temperature corona discharge plasma to impart changes in the properties of a surface.

The corona plasma is generated by the application of high voltage to sharp electrode tips which

forms plasma at the ends of the sharp tips. A linear array of electrodes is often used to create a

curtain of corona plasma.

Parameter of blown film extrusion:

Temperature:

A lower temperature is needed for tubular film (e.g., 170oC for PE of 2.0 MFI) since the cooling capacity often limits the output as a higher temperature may mean lower output. The other possible disadvantages of higher temperature are:

Increased blocking

Reduced bubble stability

Promotion of decomposition in the die with resultant impaired appearance

Possible bubble breaks.

Blow up Ratio:

The blow-up ratio is defined as the ratio of the bubble diameter to the die diameter and is one of

the important factors to determine the final film size and properties. A high blow ratio means that

a smaller and less expensive die is needed for any given film size, but a high blow-up ratio yields

the strongest film as the increased stretching has an orientation effect. However, high blow-up

ratio also encourages bubble instability, requires more drawdown and magnifies all the

imperfections in the die, thus a compromise blow-up ratio is needed. Bubble instability is a

major problem in tubular film extrusion as it produces wrinkles, thickness variation, and

“walking” of the film along the windup roll.

The blow-up ratio is determined in advance, when a die is selected to do a given job. Die gap

also has significant effect on the film properties. Increasing die gap will increase machine

direction orientation which then results in lower machine direction tear strength, lower machine

elongation, improved transverse direction tear strength, & improved machine direction tensile

strength.

Frost-Line Height:

The area of change, where the viscous fluid is changed to solid film, is called the "frost-line"

because here the hardening film first appears "frosty" in some films. An irregularity here

indicates that something is wrong with the filmmaking process, and this may result in poor film.

Increasing FLH will decrease machine direction orientation with slower quenching rates resulting in higher film crystallanity. Optical properties will reach an optimum & then start to decrease.

The frost line can be raised or lowered by means of extruder output, take-off speed, and the

volume of cooling air blown against the bubble. When the screw speed goes up the distance

between the die and the frost line is increased; when more cooling air is blown against the

bubble, the frost line drops. The frost line can be change by adjusting the cooling-air volume.

The frost line in the bubble can effectively be raised by means of a so-called annealing chamber

(or "chimney") placed between the die and the air ring.

Start-up & shutdown of the process:

The first minutes of the production always yield scrap material as the system much yield

equilibrium. The die bolts may have to adjust to get the uniform thickness, and the extrusion

speed and the winder speeds must be balanced to get the desired overall thickness. The process is

started quite cool in order to minimize formation of decomposed material in the system, which

could subsequently contaminate the film and cause streaks. Once the screw is turning and plastic

is running through the die, the temperatures are raise to normal values. As the tube is being

formed, air is introduced through the die in small amounts to keep the tube slightly blown. After

the threading is complete, more air is blown in to bring the bubble to the desired size. Care must

be taken to keep the die faces clear of the molten resin as this may later be decomposed and

cause die lines.

Shut down is one of the most vital steps in blown film extrusion in order to avoid damage to

the head and the die. Such decomposition can be caused by the degradation, oxidation of hot

plastic in contact with air, or by both. For all materials degradation and decomposition may

produce hardened bits of material which can break off and lodge in the die lips. Such bits

form weld lines which are not only unsightly but are also lines of weakness.

When the film line is shut down, material is kept moving as the zones cool to about 130oC

(LDPE) then the extruder is stopped and the die and head are cooled with air as fast as possible to inhibit decomposition. Polyethylene is often left in the extruder barrel as well as inside the die to prevent air from entering the system and oxidizing any bits of plastic left. Likewise, before start-up the die is not left hot any longer than absolutely necessary.

Winding:

Winding is the final operation in the film manufacturing process. In blown film, because there

are two sides of the tube, two winders are requires. Film is wound on a spiral wound paper core

which is supported by the winding shaft. This shaft is attached to the winder at the ends. The

core is secured to the shaft using either a cable lock mechanisms or lugs which are pneumatically

protruded from the shaft surface.

Two basics techniques used for winding films are: driving the winding roll from the centre using a driven wind up shaft, or applying a driven roll directly to the surface of the winding roll of the filmCentre winders : Centre winders have the advantage in that the tension in the film can be

controlled as the diameter of the film increases. This is done by sensing the diameter of the film

& decreasing the tension of the film as the diameter of the film increases. Tension is controlled

by controlling the differences in speed between the nip rolls & the winding rolls Tension can also

be controlled by a pneumatically activated idler roll that applies pressure on the film web. This

roll is called the dancer since it pivots up& down as it maintains the constant pressure in the web.

With the higher force required to move the dancer roll, more tension will be applied to the film.

Decreasing the tension as the roll diameter grows up, helps to keep the film roll form winding

too tight. Tight winding will cause the film to block & make it sensitive to shrink as it cools on

the toll. If winding is too tight, the shrinking film will become distorted & difficult to print or

laminate.

Surface winders : Surface winders are easy to operate since they don’t have the

complex methods of tension control. In case of surface winders, tension is applied to the

film by winding the film faster than the nip rolls. However, this does not allow for the

finer adjustments in tension as in a dancer-bar arrangement. Surface winders rely on the

pressure of the drive roll to control the roll hardness. Therefore, because some pressure is

required to drive the roll, they tend to wind harder rolls than centre winders. However,

because there is not the variation in tension & because there is no dancer rolls, some

processors believe that surface winders can wind flatter rolls than centre winders. It is

difficult, however, to change the direction of the wind on a surface winder compared to

the centre winder.

Compression Moulding Machine

Machine Specifications: Compression cylinder: 6 inch diameter

Make: Carver Inc. LMV 50H-15-C (50T)

Process: The process of compression molding may be simply described by reference to Fig.

Two-piece mold provides a cavity in the shape of the desired molded article. The mold is heated,

and an appropriate amount of molding material is loaded into the lower half of the mold. The two

parts of the mold are brought together under pressure. The compound, softened by heat, is

thereby molded into a continuous mass having the shape of the cavity. The mass then must be

hardened, so that it can be removed without distortion when the mold is opened.

Advantages

Compression Moulding Mould costs tend to be lower because the moulds are simpler.

Low volume jobs are better suited to compression moulding because start up is usually quicker, easier and generates less scrap. Cycle times for compression moulded is more than injection moulding

Disadvantages of Compression Moulding

Compression molded parts usually are more labour intensive. Preforms must be made, heated and loaded into the mold by an operator or a robot. Across parting line dimensions can be more difficult to control.

Application: PARC uses compression moulding for manufacturing of thermoplastic

sheet (testing sample are punch from sheet)COMPOUNDING

A) Single screw compounding extruder:

Make: Thermo Electron Corporation


Screw diameter: 19mm

L/D ratio: 25:1

Application : Single screw compounding extruder is use for checking the decrease in properties of material after no. of passes.

B) Twin screw compounding extruder:

Type: Co-rotating twin screw extruder

Make: Omega 30 STEER


Screw diameter: 30mm

Application : Twin screw extruder is use mainly for PVC

C) Pulverizing Unit:

The pulveriser unit is capable of pulverizing polymer granules 500μm to 1.75mm.

Make: Fixopan Machines Pvt Ltd.

Model no: FP14-SGL

Capacity: 40-60 kg per hour

Grinding teeth: Multiple (Over 250)

References

Organic Chemistry (6E 2005) L. G. Wade

PSLC-The Polymer Science Learning Centre

ASTM Standards Handbook

Polymer Science and Technology- V. Gowarikar

J. Heo, K. J Lim, Member, IEEE, J. N. Lim and E. H. Jung, AC Insulation Performance of HDPE Mixed with EVA Applied for Power

Cable Insulation, page no.1-5

BRYDSON, J. A. (1999) Plastics Materials (7th edition)

Handbook of Plastics Testing and Failure Analysis 3rd edition (2007)

Stress crack resistance of structural members in Corrugated High Density Polyethylene pipe, John M. Kurdziel, P.E. and Eugene F. Palermo, page

No 1-2

Documents

Amit Nitharwal report