plastics PTAC 2420 | UPDATED Questions with 100% Verified Answers
Question:
Five pieces of equipment in the dryer/classifier system
Answer:
The scalping box, the dryer and helix, the classifier, the dryer vent fan, and the pellet
divert valve.
Question:
Scalping box (function)
Answer:
The first stage of water separation; scalping bars divert clumps of polymer and trash into
a trash pan while letting the pellet/water slurry pass through toward the helix.
Question:
What the dryer uses to dry pellets
Answer:
Centrifugal force — spinning paddles hurl the pellets outward and upward, and that
mechanical action removes the remaining moisture from the pellet surface.
Question:
Peroxide
Answer:
An additive metered into the homogenizer by peroxide pumps to help control the melt
flow rate (MFR) of the polymer.
Question:
Screen pack
Answer:
A group of 27 horizontal mesh filtering screens, held in a large steel cylinder, that traps
particles or foreign objects out of the polymer stream before it reaches the die.
Question:
Homogenizer
, Answer:
A device that thoroughly mixes the streams of granules, peroxide, and additives by
stirring them with a large spiral auger that also moves the material along a trough.
Question:
Weir (in the homogenizer)
Answer:
A dam on the discharge side of the homogenizer that holds the material at a constant
level to improve mixing before it moves on to the feed chest.
Question:
What melting granules accomplishes
Answer:
It encapsulates the additives within the polypropylene.
Question:
Star feeder
Answer:
A variable-speed feeder at the bottom of each granule blender that governs the rate of
granule flow; it's connected to an air system used to transfer the material.
Question:
Pelletizer
Answer:
A device whose rotating knives cut the strands of polymer as they leave the die holes in
the extruder, producing pellets.
Question:
Classifier
Answer:
A vibrating sieve tub with two stages of screens that separates good pellets from
oversized or misshapen ones.
Question:
Question:
Five pieces of equipment in the dryer/classifier system
Answer:
The scalping box, the dryer and helix, the classifier, the dryer vent fan, and the pellet
divert valve.
Question:
Scalping box (function)
Answer:
The first stage of water separation; scalping bars divert clumps of polymer and trash into
a trash pan while letting the pellet/water slurry pass through toward the helix.
Question:
What the dryer uses to dry pellets
Answer:
Centrifugal force — spinning paddles hurl the pellets outward and upward, and that
mechanical action removes the remaining moisture from the pellet surface.
Question:
Peroxide
Answer:
An additive metered into the homogenizer by peroxide pumps to help control the melt
flow rate (MFR) of the polymer.
Question:
Screen pack
Answer:
A group of 27 horizontal mesh filtering screens, held in a large steel cylinder, that traps
particles or foreign objects out of the polymer stream before it reaches the die.
Question:
Homogenizer
, Answer:
A device that thoroughly mixes the streams of granules, peroxide, and additives by
stirring them with a large spiral auger that also moves the material along a trough.
Question:
Weir (in the homogenizer)
Answer:
A dam on the discharge side of the homogenizer that holds the material at a constant
level to improve mixing before it moves on to the feed chest.
Question:
What melting granules accomplishes
Answer:
It encapsulates the additives within the polypropylene.
Question:
Star feeder
Answer:
A variable-speed feeder at the bottom of each granule blender that governs the rate of
granule flow; it's connected to an air system used to transfer the material.
Question:
Pelletizer
Answer:
A device whose rotating knives cut the strands of polymer as they leave the die holes in
the extruder, producing pellets.
Question:
Classifier
Answer:
A vibrating sieve tub with two stages of screens that separates good pellets from
oversized or misshapen ones.
Question:
