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