Apparatus confined to obtain melt flow properly of thermoplastics such as polyethylene’s, polypropylene, etc. by means of weighing cut –offs obtained manually at different intervals.
Principle: All thermoplastics are melted at a specified temperature and can flow from a jet at a specified load/pressure. Therefore, melt flow index is a property which in obtained by measuring the rate of extrusion through an orifice of a specified length and diameter under specified condition of temperature and pressure.
Signification: By this apparatus one can check the quality of polyethylene (thermoplastics) generally having low melt viscosity’s. By this property it quite significant to know whether the polythene is injection moulding or blow moulding grade. Generally polyethylene’s of lower MFI (> 1.o gm/10min.) are used in cable/pipe manufacturing.
Apparatus:Extrusion Plastometer: Temperature controlled by P.I.D. temperature indicator cum controller possessing set value as well as prouss value on the display panel with an accuracy of o.1 º C. essential part of the apparatus are
Cylinder of hardened steel: – Fixed in a vertical position and possessing internal diameter of 9.550 +o.025 mm. and uniform its length. Total length more than 115mm. Heaters winded helically over the entire circular surface and isolated with asbestos bricks. This cylinder kept in hard chromed chamber.
Piston: – Made of mild steel and of sufficient length (more than cylinder) so that specified load 2.16 Kg. Can also mount over it easily without touching the surface of cylinder. Piston have lead of length 6.35 + o.1 mm. and diameter less than of cylinder. Piston is made of an ebonite plastic stud pacing between the piston and load.
Load: – Total mass on the melted polythene which acts as load to exert a pressure equivalent to 2.16 Kg. Load provided.
Jet: – made of harden steel with a length of 8.000 + o. 025 mm and internal diameter 2.095 +o.005 mm. cylinder is designed to sustain the jet so that it is not projecting beyond the base of
The cylinder. All essential parts are hard chromed and barrel cleaning devices etc., are provided.
Apparatus confirms to: IS: 2530 – 1968, IS: 10810 (Pt-23) – 1984, BS: 2782.