1. The Concept of the Basic Liquid
技術研討資料
Millipore Corporation has always been at the forefront of filter membrane development and characterization for the Microelectronics industry. We are focused on continuing improvements to test methods in an effort to provide solutions to our customers' contamination controls problems.
Retention of particles is the most fundamental require- ment of any chemical filter. Any filter must be capable of removing the majority of particles from the liquid stream
This presentation will review our latest progress in particle retention testing of Teflon filters, as well as test results from third party studies.
主講人 : 龍仁生

2. Topics The key point to the filter Filter Cartridge Filter type
Depth fiber, Membrane, Hollow Fiber…
Filter Device
Membrane, Support…
Membrane Characteristic
Retention
Wet-ability --- De-wet
Filter Housing
SS, PFA, PVDF,PP…
How to choice an optimal filter

3. The key to filter in Chemica
The Filter pore size / Retention
How much ? 0.1um, 0.2um…
Lower filtration rate, Higher retention
The Chemical Compatibility / Pre-wetting
PTFE
UPE PP
Nylon
Cleanness
Low Hold Volume

4. Typical Depth Filter Structure

5. Manufacturing Process
Stretched Polymeric Membranes e.g. PTFE

6. Manufacturing Process Cast Polymer Membranes e.g. PVDF

7. Manufacturing Process
Membranes Track Etched e.g. Polycarbonate

8. Membrane Characteristics
"Pore size" (maximum pore size = "retention rating )
The largest sized pores in a filter
"Porosity"
A measurement of the openness of a filter
i.e. 80% porosity equates to 80% open volume, 20% material
"Pore size distribution"
The range and frequency of pore sizes which make up a the filter
That is why HA

9. Typical Filtration Devices:
Pleated Cartridges
Permeate
Flow Path
Inlet Flow Path
Filter "pack" contains membrane, plus upstream & downstream fibrous supports.
Supports can be a source of particles .
Pulse pressure is a potential shedding source
It is not easy to prewet and flush.

10. Typical Filtration Devices: Stacked Disk Cartridges
Downstream components are rigid and cleaner than other membrane supports.
Excellent in pulse pressure shedding.
Horizontal disks prevent efficient gas venting
Fluid
Flow
Path
Permeate

11. Typical Filtration Devices: Hollow Fiber Cartridges
Filter area can be greater than pleated structure
Benefits of self-supporting, high surface area, high flow.
Used mostly in water filtration and photochemical.
Low pressure drop

12. Filtration Retention Mechanisms:
Capture by
Sieving / Interception ---
Hard Particle--- Bridge/ Cake effect
Soft –Gel/Micro-bubble
Hard Particles
Soft Particles

13. Retention Mechanisms:
Capture by Adhesion / Adsorption +
Very small particles in liquids have a negative charge and can be captured by attraction to a positive charge in a filter

14. 過濾在時間的變化
particlel
Time 壓差
Time

16. Hydrophobic Vs Hydrophilic
Wetting smoothly with, water.".
No pre-wetting
Hydrophobic:
Fear of water;
Tending not to combine with water.
Requires pre-wetting.

17. Hydrophobic Vs Hydrophilic
Contact Angle is the measure of Wettability
i.e.
Low contact angle = Hydrophobic
High contact angle = Hydrophilic
Hydrophobic
< 90?
Hydrophilic
No contact angle
90?
> 90?

19. What is Dewetting and how can it
impact a process?
SC1
SC2
H2O2
NH4F
Piranha

20. Non-Dewetting Technology
QuickChange Filters are Non-Dewetting
SC1
SC2
H2O2
NH4F
Piranha
Non-Dewetting Technology

21. Prewetting Flow in one direction (prevents air entrapment)
Drain
Flow in one direction (prevents air entrapment)
Flow from upstream side into core
60:40 IPA water solution
Flush with DI water

22. Filter Housing POU typically single 10" filter housing
Materials of construction:
PFA, PVDF, PP, SS

23. Filter Cartridge Housing
Inlet
Outlet
Typical Flow Path
T-Line Design
In-line Design
Inlet
Outlet

24. Filter Cartridge Housing
Inlet
Outlet
Typical Flow Path
T-Line Design
In-line Design
Inlet
Outlet

25. T-Line Mounting Considerations
Bowl Down (top of the head points toward ceiling)
Easier to drain upstream side of filter
Air does not get trapped in core
Liquid remains in core after drain
20" can be difficult to mount filters
Inlet
Outlet

26. T-Line Mounting Considerations
Bowl Up (top of the head points towards the floor)
Complete draining of filter core
Easy filter installation
Recommended configuration for 20" housings
Liquid drains from upstream side of filter
Must vent downstream side of housing
Vent
Drain

27. Reduced Tool Space Required
A typical tool design requires enough space to lower the bowl below the cartridge for filter changeout.
With Chemlock, the bowl only needs to be lowered below the head, then the cartridge and bowl can be removed as a single unit.
Tool Space Savings - Approx. ~ 8 inches!
18” in space savings with 20” bowl

28. Typical Disposable Filter Assembly
outlet
Vent
Drain
Internal Filter Element
inlet
Connections : Flartek, Butt Weld, etc.

29. Disposables Vs. Housings
Traditional design
Flexibility - 4" - 40"
Requires O-ring change
Increased contamination risk
Greater material selection
Easier customization
Limited Temp ( ~100C )
Disposables
More compact footprint
Cleaner
no o-rings/seals
no handling of element
Easier for prewetting
Improved safety
Higher Temps ( 180C )

30. Variables Which Effect Retention
Membrane
Contaminant
Fluid
Conditions
Structure
- cast
- stretched
- irradiated
Charge
Pore size & pore size distribution.
Porosity*
Thickness
Etc.
REF.<C01>
Type:
- solvent
- acid
- base
- mixture
Viscosity*
Flow rate/face velocity
Temperature
Pressure:
- pulse
- differential

31. Summary Two major filter types Filter Wetability
Five major filtration mechanism
1.Cake filtration 2.Size exclusion 3.interception 4.adhesion 5.adsorption
Two major filter types
Depth filter—Pre filter-dirty process
Membrane filter – Final filter-precision filtration
Filter Wetability
Hydrophobic membrane – used for solvent
Hydrophilic membrane –Not need to prewet for water base chemical
Filter Retention
Defined by pore size and LRV
Affected by Pore size distribution and pore size definition