Deck 17: Plastics Systems

Question 1

There are five different pieces of equipment in the dryer/classifier system, which one is not.

A) scalping box
B) dryer and helix
C) classifier
D) melt divert valve
E) dryer vent fan
F) pellet divert valve.

Answer 1

D

Question 2

The __________ separates trash from the pellet slurry.

A) helix
B) scalping box
C) dryer
D) homogenizer

Answer 2

B

Question 3

The dryer dries pellets using ____________.

A) heat
B) centrifugal force
C) high speed air
D) b & c

Answer 3

D

Question 4

Various additives such as _____________ help narrow molecular weight distribution and swell.

A) monoflurophosphate
B) stearate
C) white oil
D) peroxide

Question 5

An __________ is a device designed to prevent damage to equipment and personnel. This is accomplished by stopping or preventing the start of certain equipment functions unless a preset condition has been met.

A) interlock
B) permissive
C) hold-out
D) lock-out

Question 6

A ____________ is a special type of interlock that controls a set of conditions that must be satisfied before a piece of equipment can be started.

A) passive interlock
B) permissive
C) DCS
D) hardwire circuit

Question 7

A _____________ is a polymer filtering device. It comes in a variety of designs and shapes which range from circular, flat multi-layered screens to a group of 27 horizontal mesh filtering screens held in a large steel cylinder is the next area the melt passes through. The _________ traps any particles or foreign objects in the polymer stream.

A) die filter
B) screen pack
C) melt diverter
D) cylinder filter

Question 8

It is the function of the _____________ to thoroughly mix the streams of granules, peroxide and additive(s). The ___________ achieves this by stirring its contents with a large spiral auger as the material is moved along by the auger in a trough.

A) homogenizer
B) ribbon blender
C) feed tank
D) extruder

Question 9

The discharge side of homogenizer is equipped with a _____ to hold a constant level for better mixing.

A) weir
B) ribbon blender
C) feeder
D) pelletizer

Question 10

___________ deal with start up items whereas hardwire interlocks deal with shut down items.

A) passive interlock
B) permissive
C) DCS
D) hardwire circuit

Question 11

Melting the granules:

A) breaks molecular bonds and reduces swell
B) encapsulates the additives in the polypropylene
C) allows the polymer to be cut up into pellets
D) b & c

Question 12

There are two types of interlocks:

A) softwire and hardwire
B) permit and interlock
C) cold and hot
D) open and closed

Question 13

A solids feeder connected to an air system that is used to transfer plastic. When the slide valve is opened under a feed tank, granules drop into a ___________. Granules move through the system without altering pressures on either side of the star feeder with the aid of a vent.

A) air system
B) homogenizer
C) star feeder
D) variable feeder

Question 14

The ____________ rotating knives cut the strands of polymer as they leave the die holes in the Extruder, producing pellets, the product of the Extruder post. The newly formed pellets are carried away and kept from sticking together by a flow of water which is a part of the pellet water system.

A) water tanks
B) homogenizers
C) classifiers
D) pelletizers

Question 15

The ___________ separates good pellets from over-sized or misshapen pellets.

A) star feeder
B) classifier
C) pelletizer
D) homogenizer

Question 16

The __________, the first part of the dryer, is a dewatering device that separates the bulk of the water off by gravity.

A) pelletizer
B) scalping box
C) spirex
D) helix

Question 17

Please sketch a simple flow diagram of a modern plastics finishing facility. Label key equipment.

Question 18

The dryer ___________ removes moisture and heat from the pellets.

A) scalping box
B) inertia
C) vent fan
D) helix

Question 19

The purpose of the extruder is to:

A) melt the granule, flake, pellet mixture
B) pump molten rope through the dryer
C) dry out and mix polymer
D) a & b

Question 20

In its granular and flake form polypropylene has:

A) broad molecular weight distribution and swell
B) inconsistent additive content
C) high melt flow
D) a & b

Question 21

The _________________ system removes pellet water from the pellets and classifies them according to size.

A) dryer / classifier
B) pelletizer / pellet chamber
C) scalping box / helix
D) classifier / homogenizer

Question 22

A complex device composed of a heated jacket, a set of screws or screw, a heated die, large motor, gear box and a pelletizer.

A) rotary gear pump
B) extruder
C) dryer
D) pelletizer

Question 23

Customers will not accept raw granules because of:

A) swell
B) color
C) the danger of dust explosions
D) ppg's