THE PRESS SECTION
Quiz
There are 17 questions in this quiz. Complete it at your leasure and mail me with your score. Good Luck!
What are the two primary objectives of pressing?
- To remove water, consolidate the sheet
- To smooth and consolidate the sheet
- To smooth the sheet and to remove water.
- To smooth the sheet and reduce bulk
Name two secondary objectives of pressing
- To smooth and consolidate the sheet
- To remove water, consolidate the sheet
- To smooth the sheet and reduce bulk
- To smooth the sheet and to remove water.
Which of the four phrases below best describes the pressing process?
- The process designed to reduce calliper
- A continuation of the water removal process
- The cheapest way to remove water from the web
- The first water removal step
Excluding the press rolls, how many different types of rolls are there in a traditional press section?
- 2
- 3
- 4
- 5
Consistency or % dryness can be used to express differences in moisture content of the sheet. What is a better indicator?
- Water to Fibre ratio
- % wetness
- Absolute wetness
- Absolute dryness
Whose theory of pressing dominates today understands of the process?
- Wallstrom
- Wahlstromberg
- Brickstrom
- Wahlstrom
How many phases does the pressing theory consider?
- Two
- Three
- Four
- Five
What is recognised as a serious limitation to idealised water removal?
- The surface tension of water
- The viscosity of water
- Re-absorption of water from the felt in Phase 3
- Re-absorption of water from the felt in Phase 4
There are two distinct limiting situations to pressing. What are they?
- The flow limited situation - The temperature limited situation.
- The flow limited situation - The pressure limited situation.
- The temperature limited situation - The pressure limited situation.
- The flow limited situation - The humidity limited situation.
Excessive pressure applied to the sheet in a flow limited situation leads to what type of problem?
- Crushing
- Creasing
- Watermarking
- Blow marks
If pressing is carried out in a series of nips, which of the following statements is true?
- The first nip is usually flow limited and the last nip pressure limited
- The first nip is usually pressure limited and the last nip flow limited
- The first nip is usually flow limited and the last nip flow limited also
- The first nip is usually pressure limited and the last nip pressure limited also
The sum of the mechanical loading plus the weight of the top bowl, divided by the nip length, is known as what?
- Linear Pressure
- Absolute pressure
- Press pressure
- Running pressure
The pressure applied to the top press bowl is resisted by two things. What are they?
- The fibres resistance to deformation. - The roll bearings
- The roll bearings - The felt
- The fibres resistance to deformation. - The resistance to flow of the water
- The bottom press roll - The felt
What is the definition of camber?
- The curvature resulting from the higher diameter of the centre of the roll compared to the edge of the roll
- The curvature resulting from the smaller diameter of the centre of the roll compared to the edge of the roll
- The curvature resulting from the difference in the diameter of the centre of the roll compared to the edge of the roll
- The curvature resulting from the deflection of the roll under pressure
When a load is applied to the ends of a press roll, what happens to the middle of the roll
- It deflects, (usually rises)
- It deflects, (usually falls)
- It applies more pressure to the bottom roll
- Its linear velocity decreases
What 4 things influence the calculation of roll camber?
- Machine speed, Roll width, Applied load, Type of felt used
- Machine speed, Roll width
Type of felt used, Materials of construction - Machine speed, Length of felt used, Applied load, Materials of construction
- Machine speed, Roll width, Applied load, Materials of construction
How has press roll design overcome the problem of a wide range of speeds on a machine?
- By the development of direct drives
- By the development of the variable camber roll
- By the development of a new generation of roll bearings
- By the development of triplex felts