50 PET Plus User Manual
7.12 CLEAN THE DIE BORE
The die bore can only be cleaned by blowing through with high-pressure nitrogen.
Do NOT try to clean the die bore by pushing wire etc through it. If the wire breaks inside the die, then
a new die may be required.
Always clean the die immediately after use even if another test is not going to be performed after-
wards.
Place the die into the recess of the die retaining nut with the end containing the O Ring facing up-
wards.
Screw the die retaining nut with the die to the bottom of the barrel and hand tighten using the tightening
tool.
Loosen off by about 1/10th of a turn (about 30 degrees) otherwise it will be very difficult to remove
once it has heated up and expanded.
Fit the top cap to the top of the barrel and tighten securely using the tightening tool to seal the barrel.
Press the key under FULL to apply the nitrogen gas to the barrel. Wait until the gas can be heard
flowing freely through the die, noting that the sound will change when the die is clean.
Press the key under GAS OFF to release the gas pressure, check that the display shows nominally
zero then remove the top cap using the tightening tool.
7.13 STORING THE DIE
If another test is not going to be performed, remove the die from the barrel using the barrel cleaning
tool and store safely.
Note that the die will be hot after cleaning!
Do NOT leave the die in the barrel for long periods when not in use.
7.14 CLEANING THE FOLLOwERS
The followers are cleaned by heating to burn off the excess polymer.
Note that polymer fumes may be emitted from the followers during the heating / burning process so
this should be carried out in a fume cupboard or an enclosed laboratory oven.
There are 3 ways that they can be heated.
1
Heated on a hot plate.
2
Placed on a wire gauze on a tripod stand then heated using a bunsen burner under the gauze
3
Placed in a muffle furnace using a maximum temperature of 450ºC.
Do not handle the hot followers with tweezers or tongs as this might damage them by causing
distortion or indentation, which would render them useless.
After the followers have cooled, brush off the film of ashed polymer using a brass wire brush.
