3.5 Compression Molding Report

3.5 Compression Moulding.

Compression Moulding Machine.
The 7 layer Glass Fiber Reinforced Plastic is pressed in the mold is pressed in compression molding at a temperature of 135C. The pressure is maintained to 120kg/cm2. The pressure is relieved and termed as breathing. The breathing is for half a minute and the volatile material in the resin is evaporated out and pressure with heat is reapplied for 12 minutes and cross-linking takes place.

Chapter-4
Testing
4.1 Viscosity

It is a quantity that describes fluid’s resistance to flow or the viscosity of a fluid is a measure or parameter of its resistance offered to gradual deformation by shear stress or tensile stress to material .It is measured with instrument named as

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Specimen for tensile test
Test Procedure:-
Test specimen was conditioned for minimum 24 hrs. At 23 ± 2°C and 50 ± 5% RH before testing.
The UTM was switched on and programme was selected for tensile properties
Two marks 50 ±1 mm apart were made, on the entire test specimen from the centre of narrow portion of the test specimen.
The width and thickness was measured by vernier to the nearest 0.01 mm.
The value of width and thickness entered into the programme of the machine.
The specimen was placed in the grip of the testing machine and the grips were tightened.
The extensometer was attached on the marks made on the test specimen.
The initial load was tare.
The speed of the testing machine was set and the machine was started at 5 mm/min.
The load vs. extension curve of the test specimen was recorded.
The load and extension at the break point was

Schematic Diagram of Universal Testing Machine for Tensile Test

Tensile Strength as per satisfactions = Force Load/ Cross Sectional Area
Tensile strength at Yield Point (MPa) = Max. Load noticed (N)/ Cross section Area of specification (mm2)
Tensile strength at Break Point (MPa) = Load at break noticed (N)/ Cross section Area of specimen (mm2)
Tensile strain ratio = Change in Length of specification /Original Length of specification (gauge length)
Elongation at yield point (Δ L) = ɛ (the recorded value at the yield point on the x- axis) X L point .
Percent elongation at yield point = change in length X 100

Stress- strain