Polymer Engg Lab

POLYMER ENGINEERING LAB

EXPERIMENT NO:-1 AIM : IDENTIFICATION OF PLASTICS BY PHYSICAL METHODS EXPERIMENT 1.Cutting test Try to cut the sample with a knife

2. Scratch test (distinguish between PE & PP) Try to scratch with finger nail 3.Dropping Test Drop the sample on a hard surface & note the sound 4. Melting & Odour Test Heat a metal plate & place a small piece of plastic material on it.

5.Burning test Hold a small piece of sample in a flame, if it ignites, with draw it from the flame

6. Solubility test Add approximately 0.1g of finely divided plastic to a test tube with 5-10 ml of the solvent. Over the course of several hours thoroughly shake the test tube and observe of possible swelling of the

OBSERVATOIN a) A shaving can be pared

b) pare but instead flakes or powder a) easily scratched b) can not be scratched a) Metallic sound b) Dull sound Melt behaviour:a) Softens, remains hard, b) Flows, bubbles, wells, c) Dose not char but melts, d) Melts & chars. e) Burning rubber, candle f) Marigold, Sweet fruit, g) Lubricating oil, vinegar h) Rancid butter. a) Degree of flammability:burn, self extinguishing, does not burn. b) Colour of flame c) Type of flame (steady, tall, short) d) Smoke ( black, sooty, etc) Swelling of the sample

INFERENCE a) probably thermoplastics o b) probably f thermoset

a) may be PE b) may be PP a) PS PC, SAN, ABS, PPCP, thermoset. b) Cellulose acetate, PVC, PTFE, PP, PE Check results against the table given in table no. 1

Check results against the table given in table no. 2

compare the observed result with the respective table no. 3

POLYMER ENGINEERING LAB sample. This can often take quite a long time if necessary heat the test tube gently with constant agitation. This can be done with a Bunsen burner but a water bath is better. Precaution: Avoid sudden boiled of the solvent boiling of the solvent as it may spill out of test tube. And most organic solvents are flammable. 7.Pyrolisis test Add a small sample to a pyrolysis tube gripping the end of the tube with a pair of tong. At the open end of the tube hold a moistened litmus paper or pH paper. Heat the test tube in the flame of a Bunsen burner that has been reduced to minimum heat taking care to point the open end of the tube away form the face (preferably wear safety glasses) Heating should occur so slowly that the change in the sample and in the smell of the decomposition gas can be properly observed. Classify the vapour acidic, basic or neutral by moistened litmus paper 8.Identification of plastics film by tear test :Cut a piece of the film about (12mm x 50mm) make a short starting out at one end with a pair of scissors. Pull and attempt to tear the film. Repeat the test in a direction at right angle

9. Bending test Take a plastic sample of (10mm x100mm x 2mm) size and perform the bending test

smell of the decomposition gas and colour of litmus paper

Tearing behavior:a) Tough, stretches before tearing. b) Tough, stretches a lot before tearing c) Stretches and then tear ruggedly d) Tear easily and straight e) Stretches and then pull apart Bending behaviour

confirm the sample from the respective table no. 4

a) may be PE b) may be PP c) may be PVC d) may be CA, PS or cellophane e) may be PVOH Check the observed fact against the table given Table No.5

Table no. 1: MELTING AND ODOUR CHARACTERISTICS Plastic Materials Melting Behaviors (Thermoplastics) Polyethylene Melts& bubbles fiercely waxy around the edges

Burning candle

Polypropylene

Waxy

Becomes soft, tends to waxy Form a ball

Odour

smell

including

POLYMER ENGINEERING LAB

PTFE PS ABS PVC Cellulose acetate

Does not melt Melts & bubbles around edges Becomes soft but not fluid Soften & forms a ball, Chars at the bottom melts & emits white Smoke, dangerous (moth balls) CAB melts & chars at the edges PMMA Boils & bubbles Polycarbonate Bubbles, develops a cellular structure before decomposing Nylon Melts, round edges & chars Casein Swells & chars on ignition Acetyls polymers Melts ,forms drops & copolymers PET Melts, pacifies, blackens PVAc Softens Phenol resins Does not melt Urea resins Does not melt Melamine Resin Does not melt Epoxy Blackens & softens

Table no. 2: TYPICAL RESULTS Plastic Colour of Flame PE Blue with yellow PP PTFE PS ABS PVC CN CA PMMA Nylon Acetal Casein Phenolic Epoxy

Lubricating oil smell None Marigold Burning rubber smell of chlorine Pungent Vinegar smell Rancid butter fruity, floral smell None Burning wool of vegetable Burning milk pungent smell of formaldehyde. Pleasant elusive odour Vinyl acetate smell Carbolic smell Fishy smell Fishy smell pleasant like burnt flower

OF BURNING TESTS Type of Smoke Other features Almost absent flaming plastic off Tends to drip yellow with blue Base -do-doDoes not burn none none Orange yellow Sooty Heavy, black Spurting, burns easily Orange yellow -doStrong smell of styrene and rubber Yellow with green at bottom Some white smoke Burns with difficulty self extinguishing edges Hot white None Burns furiously very dangerous Yellow turns Brown at Some light Strong smell of vinegar base smoke Blue base yellow tipped A little black Not self extinguishing ,bubbles at base smoke Blue with yellow tip none material drips, self-extinguishing Pale blue none Burns readily Yellow Almost absent self extinguishing yellow with light blue edge none Burns with difficulty, swells & cracks, Yellow orange Smoky burns continuously

POLYMER ENGINEERING LAB Polyester -do-

-do-

-do-

PYROLYSIS TEST LITMUS TEST OF PYROLYSED GAS Table No. 4:- Litmus and pH test for vapour of plastic.

Litmus paper becomes Red

pH 0.5-4.0 Halogen containing Polymer, Polyvinyl esters Cellulose esters PET Novolacs PU elastomers Unsaturated Poly ester resins Fluorine containing Polymers Vulcanised fibre Polyalkylane sulphide

Blue

Essentially unchanged

5.0- 5.5 Polyolefin Polyvinyl alcohol Polyvinyl acetate Polyvinyl ether Styrene polymer (including SAN)** Polymethacrylate POM PC Linear PU Silicones Phenolic resins Epoxy resins Cross linked PU

8.0-9.5 Polyamide ABC PAN Phenolic and Cresol resin Amino resin (Aniline, Melamine Urea formaldehyde)

Table No. 5:- TYPICAL RESULTS OF BENDING TESTS

Thermoplastics PE PP PS ABS RPVC (Rigid PVC) CA PMMA Nylon

Bending Behavior Bends tend to stay Unbends most of the way Cracks but retains bend Bends tends to remain Bends easily and springs back quickly (plasticized PVC is more flexible) Bend tends to remain Cracks and splinters difficult to bend Springs back

Flame Test Film (Density, gm/cc) PE (LDPE=0.9-0.94) HDPE=0.94-0.965) PP (0.9-0.915) PS

Colour Top yellow Bottom Blue

When held on a flame of a bunsen burner Behaviour Odour White smoke melts and drips like Burnt wax wax

-do-

Melts and drips

-do-

Yellow orange

Black soot, no drips, Softens

Pleasant

POLYMER ENGINEERING LAB (1.04-1.09) PVC (1.20-1.30) Cellophane (0.48) Polyester (1.30) PC (1.2) Nylon (1.06-1.14)

Yellow Orange, green edge Yellow orange gray Yellow Yellow orange Blue with yellow top

Decomposes

Chlorine

Smoke, fast and complete burning Burnt paper Black smoke, no dripping, burns Not aggressive steadily Black smoke, no dripping, Not aggressive Decomposes Melts, drips, and froths rigid drips Burnt hair

POLYMER ENGINEERING LAB EXPERIMENT NO:-2 AIM:-DETECTION OF ELEMENTS IN POLYMERS AND SOLUBILITY OF POLYMERS DETECTION OF NITROGEN, CHLORINE AND BROMINE, FLUORINE AND SULPHUR

BY SPECIFIC WET TEST PREPARATION OF SODIUM FUSION EXTRACT A small piece of clean sodium (about 0.02g) is placed in –an ignition tube warmed and small quantity (about 0.1g) of the sample to be tested is added. The tube is gently heated until reaction subsides and then strongly until the glass is red hot. The tube is then plunged into distilled (10ml) contained in a china dish. The filtrate is divided into four equal portions which are used for the detection elements. A. Test for Nitrogen Two ml of the sodium fusion extract is boiled with 3 drops of freshly prepared aqueous ferrous sulphate and then cooled , after acidification with acid , a drop of 0.5N aqueous Silver nitrate is then added. A blue precipitate confirms the presence of nitrogen. B. Test for Chlorine and Bromine Two ml of the sodium fusion extract is acidified with 5N nitric acid, the solution is boiled for 2 min.0.01N aqueous silver nitrate is then added. A white precipitate which is soluble in ammonia confirms the presence of chlorine whereas a yellow precipitate which is insoluble in ammonia confirms the presence of bromine. C. Test for fluorine Acidify the original solution with dilute HCl or acetic acid and then add a 1(N) CaCl2 solution. A gel like precipitate of Calcium fluoride indicates the presence of Fluorine. D. Test for sulphur Two ml of sodium fusion extract is added to added to three drops of freshly prepared aqueous Sodium Nitropruside (Approx 0.5%).A violet indicated the presence of Sulphur.

Table No. 1: Solubility of plastics Polymer Solvent Polyethylene P-Xylene. Trichlorobenzene, Polybutene Decane, Decalin Isotactic PP Atactic PP Hydrocarbon, Isoamylacetate Polyisobutylene Hexane, benzene carbon tetrachloride, Tetra hydrofuran Polybutadiene Aliphatic and Aromatic hydrocarbon Polyisoprene PS Benzene. Toluene, Chloroform,

Non-solvent acetone, Diethyl ether,lower alcohol

Ethyl acetate, Propanol Acetone, Methanol Methyl acetate Acetone. Diethyl ether, lower Alcohol Lower alcohol Diethyl ether (Swells)

POLYMER ENGINEERING LAB

PVC

Polyvinylfluoride PTFE Polyvinyacetate Polymethacrylate PAN

Polyvinyl alcohol

Cellulose

Aliphatic Polyester Polyethylene glycol terephthalate Polyamides

Polyurethanes (uncrosslinked) Polyoxymethylene Polyethyeneoxide Polyethylsiloxane

Cyclohexane, Butyl acetate, carbon disulphide Tetra hydro furan, cyclohexane, methylethyl- Ketone, dimethyl formamide cyclohexanone, dimethylfomamide Insoluble Benzene, chloroform, methanol, acetone, Butyl acetate tetrahydrofuran, toluene Dimethyl formamide, dimethylsulfoxide, Conc. Sulfuric acid water,dimethyl formamide, dimethylsulfoxide Aqueous cuprammonium hydroxide, Zinc Chloride, aqueous calcium thiocyanate Chloroform,formic acid,benzene

methanol, acetone heptane

Aliphatic hydrocarbon, methanol Diethyl ether, petroleum ether, Butanol petroleum ether Alcohol, diethyl ether, water

Hydrocarbon, methanol acetone, diethyl ether Methanol, acetone

Methanol,diethyl ether,aliphatic hydrocarbon m-cresol,o-chlorophenol nitrobenzene, Methanol,acetone aliphatic trichloroacetic acid hydrocarbons Formic acid,conc.sulfuric Methanol,diethyl ether, acid,dimethylformamid, Hydrocarbons m-cresol formic acid,y-butyrolactone,dimethyl methanol,diethyl ether, formamide,m-crecol hydrocarbons y-butyrolactone,dimethyl formamide , Methanol, diethylehter, aliphatic benzylalcohol hydrocarbons water benzene dimethylformamide Aliphatic hydrocarbons, diethylether Chloroform, heptane benzene diethyl Methanol, ethanol ether

Experiment No. 3

POLYMER ENGINEERING LAB Aim: Determination of unknown polymer sample Procedure: Based on Experiment 1 and 2, you have to identify the unknown polymer sample.

POLYMER ENGINEERING LAB Experiment No.- 4 AIM: Synthesis of Poly(methylmethacrylate) by bulk polymerization technique and determination of viscosity average molecular weight. THEORY: PMMA is a transparent and colorless thermoplastic with high softening point. It is available in molding and extrusion composition, cast sheets, rods and tubes. PMMA is obtained by chain polymerization of the monomer PMMA using suitable catalyst. REACTION:CH2= C(CH3)COOCH3

Bz2O2

-(CH2 – C(CH3)COOCH3) -

REAGENTS REQUIRED : Methyl methacrylate (MMA) Benzoyl Peroxide Sodium hydroxide APPARATUS REQUIRED: 1 Conical Flask 2 Constant temperature water bath 3 Funnel 4 Beaker ( 250 ml) 5 Petridish with lid 6 Separating funnel (250 ml.) PROCEDURE: 1. Purify 25ml. (MMA) monomer by washing with 2% aqueous NaOH Solution. 2. Take equal volume of NaOH Solution and MMA in a Separating funnel and mix by tumbling . Separate the aqueous phase and take the monomer (clear layer ) in the conical flask . 3. Add Catalyst (Bz202) to this monomer and mix . 4. Reaction is to be carried out in an inert atmosphere. 5. Place the reaction flask on the water bath, and carry out the reaction at 800C until completion of the reaction . RESULT:- Report the % yield Cast the film by film casting method Characterization of the film be FTIR spectroscopy

Experiment No. 5

POLYMER ENGINEERING LAB Aim: Determination of molecular weight of a polymer by viscometric method. Apparatus 1. Ubbelohde viscometer 2. stop watch 3. pipette(10ml) 4. Measuring cylinder 5. Clamp with stand 6. Filter paper 7. Sucker Principle The viscosity of a polymer solution is considerably higher compared to the pure solvent. The increase in viscosity imparted by the macromolecules in solution is a direct function of the hydrodynamic volume and hence the molecular weight of the macromolecule. The ratio η/ηo is Known as relative viscosity, where η = viscosity of polymer solution and ηo= viscosity of pure solvent. This and other terms related to viscosity measurements are given below: Relative viscosity= η/ηo = t/to = ηr. Specific viscosity = (η-ηo) / ηo = (t - to) / to = ηr-1 = ηsp. t and to are the times (in sec) for the flow of the equal volume of solution and solvent respectively. Reduced viscosity = ηsp/c = ηred, dl/g, where c = concentration of the solution in g/dl Inherent viscosity =In ηr/c = ηin, dl/g. Intrinsic viscosity = ( ηsp/c)c-o = ln (ηr/c)c-o = [η], dl/g [Or Staudinger Index or Limiting viscosity number] Molecular weight of polymer is related to [η] by the following equation known as Mark –Houwink equation: [η] = KMva-------- (1) Where K and a are constants for a particular polymer/solvent/temperature. A plot of (ηsp/c) Vs conc. for a series of polymer solution of different concentrations will help one to find out the (ηsp/c)c=0 or [n]. Then by using the following equation(2) Mv of the Polymer can be found out. ln[η] = lnk + a ln(Mv)-----------(2)

POLYMER ENGINEERING LAB Procedure: 1.Wash and dry the viscosity (with chromic acid and water). 2.Clamp the viscometer vertically. 3.Introduce about 20ml of pure solvent(supplied)into it by ppt. At the end of the right limb. 4.Suck the liquid the upper mark.

in the

middle limb with the help of the sucker till it reaches

5.Allow the liquid in the middle limb to flow though the capillary and note the time (to)(in sec) taken by the liquid to flow from the upper mark to the lower mark. 6.Now repeat the same (from 3 to 5) for the supplied solution. 7.Introduce required amount of solvent though the right limb to dilute the solution in the viscometer to the next concentrations. 8.Repeat the procedure as mentioned in point(5). 9.Report the results in tabular form as below:Sl.No.

Conc (c )g/ml

Time(t), sec

ηr

ηsp

ηred= ηsp/c

10.Plot ηsp/c vs. conc and find out [η]. 11.Calculate mol. Weight (Mv) using corresponding values of k and a at the temp. of experiment. 12. Usefulness of Experiment and Limitations: -

POLYMER ENGINEERING LAB

Experiment No.: 6 TITLE: Effect of Filler on Natural Rubber Compound Rubber in its uncompounded state is a tacky material with allows values of physical properties and is dimensionally unstable. Thus it needs to be properly compounded with various compounding ingredients and properly cured or vulcanized to meet the specified requirements for its contemplated end use. Thus it can be inferred that compounding and subsequent curing of a particular grade of rubber has become an integral part of rubber technology.

MATERIAL REQUIREMENT: Rubber, various compounding ingredients, moulds releasing agent. PROCEDURE: 1) Masticate NR in Two Roll Mill for one minute. 2) Add filler and masticate for around 3 minutes. 3) Add other ingredients according to the sequence and write the usefulness of each. COMPOUNDING FORMULA Compounding ingredients Content, phr NR 100 Calcium carbonate [Filler] 0,10, 20, 5, 15, 25 Zinc Oxide [Activator] 5 Stearic acid [Activator] 2 Paraffin wax [Lubricant] 1 Sulphur [Cross-linking agent] 2 4) Cure at 145°C for 15 minutes in hot press in sheet form (size) 5) Determine tensile strength, modulus, elongation at break (As per ASTM D638), hardness(As per ASTM D2240) by Durometer. 6) Cut specimen for tensile testing by punching die and keep for conditioning at 23°C & 50% RH overnight 7) Tensile test conditions (UTM, Instron): Crosshead speed 50 mm/min, Load 10 KN, at least three specimens are to be tested for each reading. RESULTS: 1) Tensile strength, 2) Modulus at 300% elongation, 3) Elongation at break % 4) Hardness in Shore –A

POLYMER ENGINEERING LAB

Experiment No.: 7 TITLE: MELT FLOW INDEX – Determination of MFI (ASTM D 1238) Melt flow index of thermoplastic material is defined as the rate of flow in gram per ten minutes of extrudate of molten resins from a cylindrical cavity inside a heated metallic barrel through a jet of specified length and diameter under prescribed conditions of temperature, load, and piston position. MFI value is used as a production control assessment of the average molecular mass as well as viscosity or flow ability. However the data obtained by this test does not necessarily correlate with the process ability of the polymer. Never the less the reported values help to distinguish between different grades of materials. Typical MFI range are in g/10 min at 190oC, and under 2.16 kg load for polyethylenes: Typical MFI range Injection moulding grade 5 – 100 Rotational moulding grade 5 – 20 Film extrusion grade 0.5 - 6 Blow moulding grade 0.1 – 1 Profile extrusion grade 0.1 – 1 Factors affecting the test results: a) Preheat time b) Moisture c) Packing d) Volume of sample DETERMINATION OF DIE SWELL As polymer melts are viscoelastic, a typical phenomenon in polymer melt extrusion is the swelling of the extrudate as it leaves the die. This is due to the elastic recovery of the deformation that the polymer melt was exposed to in the die. Degree of die swell is given in terms of a swell ratio: Extrudate diameter Swell ratio = --------------------------Capillary diameter The elastic recovery is time dependant. The critical parameter is the time of polymer melt is constrained within the capillary If this is decreased (by decreasing capillary length or by increasing wall shear) then the swell ratio must increase. Procedure: 1. Preheat the Melt Index apparatus to a specified temperature 2. Fill the cylinder within one minute with a weighed portion of the sample according to the specification of the material under test. Fill the cavity initially up to approximately one third of its length followed by pressing down with the packing rod. Repeat this till whole of the charge is filled inside the cavity.

POLYMER ENGINEERING LAB 3. Place a specified weight on the piston. 4. Start the stopwatch to note the preheat time. Allow the charge to preheat for a period of 4 minutes to enable it to attain the desired test temperature. 5. As soon as the lower scribed mark on the piston shank reaches the top of the piston guide, reset the stopwatch to zero and restart it immediately. Simultaneously cut off the extrudate at the lower face of the jet using the cutting tool provided. Collect separately cut-offs obtained after each successive test time. 6. Allow the remaining charge in the cavity to discharge through the hole in the jet. 7. Remove the disc weight and piston, Proceed for cleaning. 8. Allow the cut-offs to cool down to room temperature. Discard the first cut-off and any subsequent cut-offs showing presence of air bubbles. Weigh the remaining cut-offs to nearest 1 mg. Report data in g/10 min. 9. Determine MFI of one sample at one temperature, using different loads. Measure diameter of extrudate. For polyethylene 1) Temperature: 190°C 2) Load: 2.16kg, 5.00kg Determine the followings 1) MFI at two different loads and find melt flow ratio (MFR; ratio of MFI at two different loads) 2) Extrudate swell ratio

POLYMER ENGINEERING LAB

Experiment No.: 8 TITLE: Preparation of general purpose Phenol Formaldehyde (PF) moulding powder. Novolak Resin - The novolaks are prepared by reacting phenol with formaldehyde in a molar ratio of approximately 1 : 0.8 under acidic conditions. Stage 1:

Stage 2:

Stage 3:

Novolak Resin (typical structure) Hardener for Curing

Hexamethylene tetramine Structure of PF resin after curing

FORMULATION: Ingredients

Composition(phr)

POLYMER ENGINEERING LAB Novolak resin Hexamethylene tetramine [Crosslinking Agent/Hardener] MgO [Accelerator] Magnesium Stearate [Lubricant] Wood flour/ Rice husk [Filler]

100 12.5 0.3 0.2 70, 80, 90, 100, 75, 85

EQUIPMENT: - High speed mixer Process: 1. Add finely ground novolak resin to the mixer. 2. Add the other ingredients too at once and mix for 15 minutes. 3. Collect the blend from mixer 4. Make sheets of this and cut test specimens as instructed in your class. Testing Prepare tensile specimen and find out its tensile properties (tensile strength, tensile modulus) Graph Plot tensile strength vs glass content, and tensile modulus vs glass content

POLYMER ENGINEERING LAB

Experiment No.: 9 TITLE: INJECTION MOULDING – WINDSOR ST25 Study the ST 25 Injection moulding machine. Note machine ratings. 1. Study the hydraulic mechanism of the machine. Note location and function of the hydraulic cylinders. 2. Define: Closing speed, Opening speed, Slow down, Locking force, Injection speed, Injection pressure, Injection temperature, Locking period, Reduced injection pressure, Injection period, Screw refill, Suck back, Reaction pressure, Cooling period, Sprue break, Cycle delay. 3. Identify location and function of various limit switches. 4. Practice Injection Moulding in semi automatic mode. Note the procedure for semi – automatic operation of the Injection Moulding machine. 5. Report the cycle time. Study trouble shooting. Give causes and remedies for short shot flashing, sink flow mark, weld line, void, Black streak, warping & poor mould Release. OBSERVATIONS CYCLE TIME DETERMINATION Material : Process Parameters: Temperatures; Pressure: Injection Rate: Clamping End Injection End Time Time Mould close and lockInjection time, s Injection, packing, part Screw dwell(Packing time), s cooling Injection unit retraction time, s Mould Open- Ejection Refilling/plasticating time, s and mould open dwell Injection unit forward time, s Total Total Cycles per hour: Cycles per 24 hour: TROUBLE SHOOTING Trouble Cause Remedy Short shot Flashing Sink mark Flow mark Weld line Void Black streak Warping Poor mould Release

POLYMER ENGINEERING LAB

Experiment No.: 10 TITLE: Preparation of FRP sheets of different fiber loadings AIM : Preparation of FRP sheets of different fiber loadings. Polyester Resin: Condensation of polyhydroxy compounds with polybasic acids, e.g. a glycol with a dicarboxylic acid:

Unsaturated Polyester Resin: made by polycondensations involving varied proportions of a saturated acid (phthalic anhydride, isophthalic acid, adipic acid, etc.), an unsaturated acid, which is most invariably maleic anhydride and a glycol (ethylene glycol, diethylene glycol or I, 2propylene glycol), whose chemical structures are given below: Saturated acid

Unsaturated acid

Glycol

The unsaturated nolyester resins are prepared by heating the component acids and glycols for 1012 h at about 160-200°C, under stirring conditions usually under a blanket of nitrogen. The resin is then cooled to below the boiling point of styrene and pumped into a blending tank when it is appropriately blended with right proportions of styrene containing suitable inhibitors. CURING OF USP RESIN

POLYMER ENGINEERING LAB

Materials requirement for FRP Sheet: 1) GP Unsaturated Polyester Resin – Rest quantity 2) Catalyst; Methyl ethyl ketone peroxide (MEKP) - 2% of GP Unsaturated Polyester Resin 3) Accelerator; Cobalt Napthenate - 2% of GP Unsaturated Polyester Resin 4) Solvent; Acetone – As required 5) Glass fibre matt – 40%, 50%, 60%, 45%, 55%, 65% Other Ingredients: PVA solution, Waxpol, polyester sheet GENERAL PROCEDURE: 1. Clean the surfaces of both the polyester sheets. 2. Apply thin layer of mould releasing agent (WAXPOL). 3. Apply a thin layer of Polyvinyl Alcohol solution (prepared by dissolving PVA in boiling water). 4. Prepare resin by mixing properly first the accelerator (2%) and then catalyst (2%).[General Resin requirement is twice the weight of the fiber] 5. Apply one layer of resin on one of the sheets placed on a smooth surface. 6. Place a layer of chopped strand mat. 7. Apply a layer of resin and wet the mat. 8. Repeat steps 6 and 7 once more, or as required. 9. Place the other polyester sheet above the CSM layers. 10. Place a metal plate on the cast sheet and allow to cure. Testing Prepare tensile specimen and find out its tensile properties (tensile strength, tensile modulus) Graph Plot tensile strength vs glass content, and tensile modulus vs glass content