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ME DepartmentIC349- Manufacturing project
The Cleaning room
Team member: Yim Chi Pang
Suen Kai Wing
Chan Chun Man
Lam Kin Fung Ryan
Lam Frankie
Leung Pak Ho
Wong Yui Man
Lai Kin fai
Fung Hin Yen
Objective
• To design and manufacture a multi-purpose portable clean room
• Mainly for glass-fiber reinforced plastic (GFRP) fabrication.
• The room size is actually 4m (L) x 3m (W) x 2m (H).
• We decided to have a demo. • Filter is then installed for
keeping low concentration glass-fiber, etc inside the room.
Declaration
• Light in weight, • mobile, • safe to use, • easy to set up• And provide useful function
With reference to the objective required, our team realized that the product should be:
Declaration
The design concept is about the assembly of precise parts to form a room, and is mainly served for glass-fiber reinforced plastic (GERP) fabrication.
Background of clean room
• Used extensively in semiconductor manufacturing, biotechnology, life sciences.
• Clean rooms can be very large
• For examples, the soft-wall clean room
ISO standard
• Worldwide standard of clean room classification is produced.
• ISO Class 1 thru 9 • The numbers in the table
meaning the max. concentration limits (particles/m^3 of air)
• ISO class 1, signify the most “cleaning” area is happened.
The industry recommendation • The ventilation industry has a
“Recommended Air-Changes per Hour” solution.
• Total volume of air in a given room should be removed by a specified timing.
• Work out the required flow rate;
1. Calculate the room volume in m^3
2. Multiply the room volume by the recommended air changes
3. The sum is the total air changes required in m^3/hr
Types of filters
• Two types filter are always used for filtering the dust, which enter a clean room from outside, and the air inside is constantly recycled
HEPA Filter ULPA Filter
Types of airflow patterns
• three types of airflow patterns : unidirectional, non-directional and mix-flow. Non-directional and mix-flow is typical for clean rooms of ISO class 6 and less clean in the operation.
Unidirectional airflow Non-unidirectional airflow
Mixed airflow
Functional requirement
The actual size : 4m (L) x 3m (W) x 2m (H)
The main purpose: glass-fiber blockage to the surroundings
1. Safe to use
2. Light in weight
3. Mobile
4. Useful function
5. Easy to set up
Case Studies
• We need to investigate the actual direction of the airflow.
Turbulent Air Flow
• A clean room differs from air conditioning system in three ways. They are
• Increased air supply, • The use of high efficiency
filters• and room pressurization.
Laminar Air Flow
1. High air velocity is effective to remove large particles
2. Any contaminant can be immediately removed.
Specification Actual situation Prototype
Size (L, W, H): 4m x 3m x 2m 0.5m x 0.5m x 1m
(Depends on working
Situation)
Performance: Class 5 or 6 (0.3micrometer) N/A
Air-flow type: Unidirectional (from top to bottom)
Air flow rate Room size * air changes per hour ~= 200 m^3/hr N/A
Material used: Aluminum alloy, mild steel,PVC
Aluminum alloy, PVC
Assembly method: Modular (wall, ceiling, door)
Operation: Clean room negative pressure
Pressure difference: 5Pa ~ 20Pa
Filter type: HEPA filter N/A
Fan type: Cylinder-type fan Cylinder-type fan
Insulating method: By buckles with 3mm sponge in the gap By buckles with 3mm sponge in the gap
Conceptual Designs
Soft wall type
• Framework is made by aluminum profile
• Plastic curtain covers the framework to make this clean room functional
Advantage:
- It’s easy for storage and transportation. - Waterproof
Disadvantage:
- Relatively weak of framework structure, therefore cannot withstand high winds.
Modular type
• Aluminum square with PVC, which is transparent.
• All of the parts, like door, walls, ceiling are standard parts.
Advantage: - Short manufacturing time, since similar parts.
- Variable room size, depending on the demand or working situation.
Disadvantage: - The room should be sealed to avoid gas
exchange.
Weighted criteria matrix
Objective Tree for the design of a clean room:
Weighted decision matrix for a clean room design:
Result:The decision matrix indicates that design B has the highest rating, so it should be selected. Design B, the hard wall modular type clean room.
Detail design of the demo
•The size of the demo, it’s 0.5m (W) X 0.5m (L) X 1m (H). •It can be assembled from some standard modules such as walls, door and the ceiling.
•the walls and door can be moved to any desirable working area by wheels and setup by pressing down the foot-gate, while it’s used to block the contamination from coming out to the surroundings.
For the walls • There are three
layers of materials mounted at the side; two layers of rubber made and one layer of sponge. for contamination blockage.
buckle
• The buckles It’s installed on our product to keep the standard modules tight together.
• It will be user-friendly while the setup.
The ceiling • For this demo, the
ceiling is one-piece object with two fans.
• There will be lots of modules used to form a ceiling in real size.
• Sponge will fill the gap between the ceiling and the top of the framework.
• The whole ceiling is mainly covered by transparent material
• light can be directly passed to the inside area.
Total cost of the demo
• The total material cost of our demo is around $2200. For the break down cost of each modules. Please refer to our report for more information.
Manufacturing Process• In manufacturing process of the clean
room, several machines and tooling were involved in it. For examples, sawing machine, milling machine and CNC punching machine were used.
Procedure
• This is a hand job to build up a shell by using simple machine.
• Saw, drill, mill
• Rivet gun and rivet to fix a shell.
Procedure
• Welding
Procedure
• Acceptable quality• Horizontal
Procedure
• Horizontal
Procedure• Through the MU project. Learn how to
scheme the work and separate the work. Learn the work flow.
1. Design and modeling2. BOM and drawing3. Separate the parts for suitable machine4. Assembly the parts5. Modify
Assembly
Assembly
Assembly• Set up four wall • Lock the roller• Lock them together
Assembly
• Press Down Cover and lock it by bolt.
Assembly
• Place the ceiling on the top.
Assembly
• Real and modeling
Assembly
• Connect to filter
Manufacture Process
• Major Problems:– Uneven surface of aluminum
tube
– Unexpected size of Aluminum material
– Position error during drilling
Manufacture Process
• Uneven surface of aluminum tube– Cause
• Manufacture process of sawing
• Human error
– Effects• Time consuming
• Solutions– Carefully check work piece– Use the milling machine to
remove the unexpected size
Manufacture Process
• Unexpected size of Aluminum material– Causes
• Different from BOM
– Effects• Joints cannot fit tightly
• Solutions measure the aluminium in
expected size and then sawing it
milling is further needed to ensure the even surface.
Manufacture Process• Position error during drilling
– Cause• The plate too large• Human error
– Effect• Structure not rigid
• Set of solutions
• G-clamp were used to fix the position• boards of the drilling machine were changed to suit the position
Testing
• ISO 14644– Air Flow Test– Air Pressure Test
• Additional Test– Complete enclosure
Air Flow Test
• Objective– Determine number of air
change
• Apparatus– Anemometer
• Procedures
Air Pressure Test
• Objective– Maintain specified pressure
difference
• Apparatus– Manometer
• Procedures
Enclosure Testing
• Objective – Ensure the complete
enclosure
• Apparatus– Soap, water
• Procedures
Conclusion
• Before starting to manufacture the product, we have three problems should be solved.
– how can we let the room to be mobile? wheels
– how can we let the wall stick together more easily? Buckle
– how can we let the room to be closed? sponge
Comment
• divided into three parts– design, – material selection and, – manufacturing part.
• Design– size limitation and budget limitation.
• Demo product instead of the real product
• Material selection– Portable requirement
• Aluminum instead of iron
• Manufacturing– First experience of BOM– Judging teammate’s ability and allocating different tasks
• can increase the efficiency.
Q&A