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MC12 manual
8
System performance
The following variables may influence the accuracy and repeatability of the system:
1.
Material properties. Easy flowing, non-sticky and non-static material that comes in the form of small
regular shaped granules or powder can be dosed very accurate and regular.
2.
Periodical cleaning of the dosing cylinder and seals is necessary for proper operation.
3.
Extreme vibrations and shocks can have negative influence on system performance.
4.
An unstable relay signal has a negative influence on the repeatability.
5.
With injection molding the shot to shot accuracy depends, besides the variables mentioned so far, on
the shot time in combination with granule size and weight. If relatively big and heavy granules have to
be dosed in a very short time, it will influence the shot accuracy and repeatability, because if only a
few granules are dosed during the shot, one granule more or less makes a big difference on the total
shot weight.
6.
Vacuum or overpressure in the neckpiece caused by driers or hopper loaders.
7.
Bridging or rat holing of the material inside the hopper can happen if the material is not free flowing.
8.
Bridging or rat holing of the material inside the hopper can happen if the material is extremely static.
9.
Extremely static material can contaminate the dosing cylinder.
10.
In case of water cooled neckpiece, check if there is material build up around the dosing cylinder and
the water cooled pipe. Check also the water supply to the neckpiece.
