Tinius Olsen MP1200 Extrusion Plastometer Page 14-10
Operation Manual # 02002215
TEST TIP: When testing materials with high melt flow rates (> 10g/10 minutes), the
weight platform of the WLD can be used to prevent excessive polymer from running out of
the cylinder prior to the end of the preheating period. The actual position of the weight
support platform will vary with flow rate. One example is to lower the weight platform so
that the top surface of the platform is approximately 25 mm (1 inch) above the 46 mm
(1.81 inch) start position of the test measurement. The weight platform will now catch the
weight as it falls and support it, temporarily reducing the load on the material in the
cylinder. When the Release Time reaches 420 seconds (or other time entered above in
13.2.13), the weight platform will lower fully and allow the test to continue. Note that to
achieve the total preheat time of 420 +/- 30 seconds, it may be necessary to reduce the
Release Time. The total time from start of test to the start of test measurement can be
observed by watching the elapsed time “ET” display.
14.3.9 The Elapsed Time (ET) display will reset to zero and begin to count up, in
seconds. Material will begin to extrude through the orifice.
CAUTION: If the optional WLD is being used in the automatic mode, and the Weight Support
has been programmed to run to a height less than its maximum height, the weight platform
will automatically begin to lower the weight(s) when the [START] button is pressed. Keep
hands clear!
14.3.10When the elapsed time (ET) reaches the “Release Time” (Preheat Time) that
was entered in 14.2.10, an alarm will sound (if enabled). The first (lower)
scribe line on the ASTM piston rod should now be close to entering the guide
collar.
14.3.11 The WLD will automatically begin to lower the weight(s) at the end of the
preheating period (Release Time), provided that it has not already been
lowered all the way at the start of the test. Keep hands clear!
Note: ASTM D 1238 requires the test measurement to be started at 46+/-2 mm (1.81+/-
0.079 inches) above the top of the orifice and 7+/-0.5 minutes (420+/-30 seconds) after
starting the release (preheat) time. If the preheat time criteria is not met, the amount of
material charged and/or the release time used should be changed accordingly.
14.3.12When the weight drives the arm of the PPDT to the “Start Capture 1” Height, a
momentary alarm will sound. The MP1200 will automatically start recording
the time it takes for the piston to travel the programmed “Piston Travel CAP 1”
distance entered in 14.2.18.
NOTE: There is no need to cut off the extrudate during a typical Procedure B test when the
Melt Density value has been entered.
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