Swinburne University of Technology Sarawak campus Swinburne University of Technology Sarawak campus
MEE30001 Materials and Manufacturing 2 MEE30001 Materials and Manufacturing 2
Lab 1: Polymer processing and testing Lab 1: Polymer processing and testing 1.
1. CompreCompressssion ion moldinmolding of g of polypropylene spolypropylene sampleamples for s for memechanichanical tcal teesstiting ng ..
Introduction
Introduction
The methods by which sample materials are prepared and molded influence the mechanical The methods by which sample materials are prepared and molded influence the mechanical properties
properties of of the the specimen. specimen. Unlike Unlike injection injection molding, molding, the the objective objective of of compression compression molding molding is is toto produce test specimens
produce test specimens or sheets that or sheets that are both hoare both homogeneous and mogeneous and isotropic. Molded isotropic. Molded specimens mayspecimens may be
be made made from from powder powder or or pellets pellets such such as as are are received received directly directly from from a a material material manufacturer,manufacturer, particles produced in a
particles produced in a recycle recovery operation, recycle recovery operation, or from a milled preform or from a milled preform or sheet prepared on or sheet prepared on aa two-roll mill. The powder, pellets, particles, preform, or sheet are melted and molded in a mold two-roll mill. The powder, pellets, particles, preform, or sheet are melted and molded in a mold designed to produce a finished specimen of a given geometry, size, and thickness, or melted and designed to produce a finished specimen of a given geometry, size, and thickness, or melted and molded in the form of a smooth plaque or sheet of uniform thickness from which desired molded in the form of a smooth plaque or sheet of uniform thickness from which desired specimens are cut, punched, or machined.
specimens are cut, punched, or machined.
Procedure Procedure
Compression molding is a procedure where a molding material is placed in an open, heated mold Compression molding is a procedure where a molding material is placed in an open, heated mold cavity. The mold is closed with a top and pressure is applied to force the material to contact the cavity. The mold is closed with a top and pressure is applied to force the material to contact the entire mold area. Heat and pressure are maintained until a desired cure time. Different materials entire mold area. Heat and pressure are maintained until a desired cure time. Different materials require different cure times, temperatures, pressure, and cooling. The compression molder in lab require different cure times, temperatures, pressure, and cooling. The compression molder in lab 1115 is a 30 ton
1115 is a 30 ton Hydraulic Hot Press LS-22071 (Lotus Scientific, Malaysia).Hydraulic Hot Press LS-22071 (Lotus Scientific, Malaysia).
1.
1. Close the guard door.Close the guard door. 2.
2. Turn the Disconnect switch (Red knob on yellow panel on the right/west top side of theTurn the Disconnect switch (Red knob on yellow panel on the right/west top side of the compression molder) to the On (closed position).
compression molder) to the On (closed position). 3.
3. Ensure the EMERGENCY STOP BUTTON IS PULLED OUT.Ensure the EMERGENCY STOP BUTTON IS PULLED OUT. 4.
4. Press CONTROL POWER ON button and the green Press CONTROL POWER ON button and the green light will illuminate.light will illuminate. 5.
5. Press the HYDRAULIC PUMP ENABLE button and the green Press the HYDRAULIC PUMP ENABLE button and the green light will illuminate.light will illuminate. 6.
6. Press the PLATEN HEAT ON button and the Press the PLATEN HEAT ON button and the green light will illuminate.green light will illuminate. 7.
7. Select the MANUAL position of the MAN/SEMIAUTO selector switch.Select the MANUAL position of the MAN/SEMIAUTO selector switch. 8.
8. Adjust the temperature controller to the desired setpoint.Adjust the temperature controller to the desired setpoint. 9.
9. When desired temperature is reached, open the guard door and place mold in between theWhen desired temperature is reached, open the guard door and place mold in between the two platens then close the guard d
two platens then close the guard door.oor. 10.
10. Press and hold the two CLAMP CLOSE buttons. The hydraulics should move the twoPress and hold the two CLAMP CLOSE buttons. The hydraulics should move the two platens
platens together. together. a. a. If If Air Air cooling cooling is is required required for for your your procedure, procedure, pull pull the the AIR AIR button button toto activate the air cooling feature.
activate the air cooling feature.
11.
11. When the clamp is sealed, you can adjust the pressure with the CLAMP PRESSUREWhen the clamp is sealed, you can adjust the pressure with the CLAMP PRESSURE ADJUSTMENT knob. The max is 15 tons.
ADJUSTMENT knob. The max is 15 tons. 12.
12. Leave the mold in place under pressure and heat for your cure time.Leave the mold in place under pressure and heat for your cure time. 13.
13. After your cure time, if water cooling is needed pull the WATER ON button to activateAfter your cure time, if water cooling is needed pull the WATER ON button to activate water cooling.
water cooling. 14.
14. When temperature reaches between 70-80 degrees, press the CLAMP OPEN button.When temperature reaches between 70-80 degrees, press the CLAMP OPEN button. 15.
15. It is now safe to open the guard door and remove the mold.It is now safe to open the guard door and remove the mold. 16.
Health and safety information for materials used: This machine operates under high temperatures and immense pressure. Never place any body parts in the machine while it is warming up, loading, or unloading. Pay attention to the warning tags on the machine. Never try to bypass any safety features of the machine. To ensure safety, keep the front door closed when the machine is operating.
Hazard Control Measures: • Safety glasses
• Lab coat
• Heat Resistant Gloves
2.Mechanical testing of polypropylene samples.
Tensile testing of thermoplastics
Standards: AS 1145 (Australian standard), ASTM D 638 (US standard)
Testing equipment
Universal testing machine (T-Machine) Electronic digital caliper Pro-max.
Method
Measure and record the dimensions of the cross sections of the test specimen;
Clamp up specimen in the crossheads of machine and run the test. Set distance between grips 100 mm
Perform five tensile tests.
Determine the mean and standard deviation of the samples tensile strength (maximum stress from stress-strain curve)
Save all your data on a USB data key for later analysis
R 76 10 20 60 G 105 150
TESTING OF PP: RESULTS
Table 1. Measured, recorded and calculated results for tensile testing of PP
Specimen number 1 2 3 4 5 Mean S.D. Width (d), mm Thickness (b), mm Maximum load, N Maximum stress, MPa
Discussion (Factors effecting reproducibility of tests results).
Determination of polypropylene Melt Flow Index Standards: ASTM D 1238 (US standard)
Testing equipment: CEA7024F CEAST (Italy) Settings: Temperature 230 °C, weight 2.16 kg
Method
Prepare 6 g of PP in granular form.
Prepare the correct weight and place next to the instrument. Insert the piston in the barrel for a few minutes (preheating). Press start on the main menu.
Fill in the field operator your group number. Press start.
When the temperature is reached the set value insert material in the barrel and manually compact it using a provided tool.
Insert the preheated piston.
Preheat the material without weight till the acoustic signal. Manually place the test weight on the piston.
The instrument automatically begins measurements when the set position is reached. Cut the extruded filament at the end of the test.
The instrument will guide the operator by emitting an acoustic signal at the beginning and at the end of each test.
Measure weight of the extruded fillament and insert data. Print out the results
Clean the piston, barrel and the die.Remember to wear thermally insulated gloves. Polypropylene MFI (MFR)
Mean
Standard deviation
Discussion (factors effecting reproducibility of test results). Conclusion
