Synthetic FIltering Media/Total Surface Area?

[Johnny_Law]

I am a student at CSU Fresno and my Graduate Report is on the Evaluation and Testing of Automotive Oil Filters. In conducting the research, it became obvious that oil filters with either a synthetic or synthetic/cellulose blend almost always seem to have a smaller total surface area for their filtering media.

It seems logical that a synthetic filtering media could have a smaller filtering media and still capture smaller micron particles than a cellulose media, but it also seems logical that the total holding capacity of the synthetic media would be less due to the smaller total surface area.

The synthetic media oil filters are also generally recommended for longer drain intervals which is worrisome due to the smaller synthetic filtering medias total surface area, and the fact that the synthetic fibers will capture and hold smaller particles. Thus it is likely that the filter will become clogged faster with debris which would result in the oil bypass valve opening and defeating the purpose of the filtering element functioning as intended.

For example the Amsoil EAO 20 oil filter having the smallest filtering surface area of the test sample seems contradictory to Amsoil’s claim that their filter can last up to 25,000 miles. In fact their total surface area is 2.84 times smaller than the OEM Hyundai oil filter which it is a replacement for. Amsoil technical support also claims that all holding capacities of their oil filters are Proprietary information so I can not compare the holding capacity in grams from a full synthetic Amsoil Filtering Media to a standard cellulose filtering media.

Hear is a picture of a graph showing the cost to total surface area of the filtering element:

In conclusion, my question is how can a smaller total surface area of synthetic filtering media have the ability to hold more total contaminant assuming the oil bypass valve on a synthetic and cellulose oil filter open at the same PSI?

If there is a study I missed in my research, please provide a link or article title.

Thank you for your help.

 

[tom slick]

Is the synthetic media thicker?

 

[Johnny_Law]

Attached is the email showing that Amsoil's total contaminate holding capacity is proprietary information:

Thank you for contacting AMSOIL with your questions.



Here is the information that at this time I can share with you:



· Filter Burst pressure: approx. 300 psi

· We determine efficiency via ISO 4548-12: 98.7% at 15 microns, minimum 50% at 7 microns

· No specific EaO20 capacity data is available that isn’t proprietary



Please feel free to let me know if I can be of further assistance.



Regards,



Bryan Kershaw

AMSOIL Product Specialist

Filtration/Aftermarket

 

[Johnny_Law]

Originally Posted By: tom slick
Is the synthetic media thicker?


There is no direct correlation as you can see.

Note: For the Fram Extended Guard the metal screen backing was factored in to the total thickness of the filtering media. The thickness of the Fram's Screen was 0.010 in. The metal screen was not factored into the thickness of the filtering media for the Amsoil or SynLube oil filters as it is just for support of the filtering element and does not actually filter particles to any measurable degree.

 

[Johnny_Law]

Originally Posted By: tom slick
Is the synthetic media thicker?


I could see how a thicker filtering media would improve micron filtering capacity, but not the total holding capacity in grams. As soon as the filtering media traps a small layer of contaminant over the entire filtering element and the pressure differential becomes greater than the spring pressure of the bypass valve, it will open and bypass valve and the engine oil will not travel through the filtering media.

In the picture below the black line indicates the filtering media while the blue line indicates the contaminant. A larger surface area would seem to hold a larger holding amount of contaminant.

What other variables am I missing?

 

[Fester]

The answer to how Amsoil EAO filter media achieves the holding capacity, has been posted before, I think its due to the way the synthetic media traps dirt, it doesn't just do it on the surface like paper, it holds dirt all through it, it works to trap more small particles as the filter gets more use, it does it without plugging up. At least thats how I understood it, I could be wrong.

They use Danoldson media, uses smaller fibers than cellulose media.
http://www.amsoil.com/StoreFront/elf.aspx

 

[Johnny_Law]

Originally Posted By: Fester
The answer to how Amsoil EAO filter media achieves the holding capacity, has been posted before, I think its due to the way the synthetic media traps dirt, it doesn't just do it on the surface like paper, it holds dirt all through it, it works to trap more small particles as the filter gets more use, it does it without plugging up. At least thats how I understood it, I could be wrong.

They use Danoldson media
http://www.amsoil.com/StoreFront/elf.aspx


Thanks for your reply, as my drawing was over simplified, but I am not the best drawer

. I will contact Donaldson about the filtering media and its holding capacity characteristics.

 

[Newtonville]

It is hard for me to understand how media thicknesses can be measured to 1 mil accuracy. I would say the measuring variation would be as great as the difference between the highest and lowest values shown, 22-31 mils.

Also, to me at least, something looks askew in the surface area measuring department.

 

[Johnny_Law]

Originally Posted By: Newtonville
It is hard for me to understand how media thicknesses can be measured to 1 mil accuracy. I would say the measuring variation would be as great as the difference between the highest and lowest values shown, 22-31 mils.

Also, to me at least, something looks askew in the surface area measuring department.


The measurements are in thousandths of an inch and not millimeters. The measurement is taken three times and if any one out of the three measurements is off by more than 0.001 of an inch then all the measurements are discarded and retested again. Micrometer can measure up to 0.0001 of an inch with good accuracy and repeatability. At 0.001 the margin of error due to the Micrometer accuracy is almost zero.

Click hear for more info:

http://en.wikipedia.org/wiki/Micrometer

 

[Johnny_Law]

Originally Posted By: Newtonville


Also, to me at least, something looks askew in the surface area measuring department.


Any Specifics?

 

[wileyE]

If contaminant was allowed into the media it's be apt to clog?

If the media was fine enough not to allow it to enter, but to pile up on the outside, the containment could posibly act as additional filter media. Assuming it's size doesn't restrict the media exposed media pours?

As far as amsoil claims, think I would also look at their flow ability. If they claim more flow, finer media, and have less media surface? something doesn't add up.

 

[glenncof]

Do some research on synth media (I did awhile ago). The term 'depth' is frequently used.

Read the description here: http://www.purolator-facet.com/media2.htm

As I understand, a multi-layer polymetric filter media with different coarseness can be constructed using Exxon Melt Blowing process(eg Stratapore). This is outlined in a http://www.turbodieselregister.com issue #27.

Yes, surface area directly correlates to filter holding capacity.

The only the filter maker and their supplier will really know holding capacity. I don't believe holding capacity will be significantly different based on media thickness. Also mechanically measuring glass-based media may crush the media so optical measurements may be need.

 

[Johnny_Law]

Originally Posted By: glenncof
Do some research on synth media (I did awhile ago). The term 'depth' is frequently used.

Read the description here: http://www.purolator-facet.com/media2.htm

As I understand, a multi-layer polymetric filter media with different coarseness can be constructed using Exxon Melt Blowing process(eg Stratapore). This is outlined in a http://www.turbodieselregister.com issue #27.

Yes, surface area directly correlates to filter holding capacity.

The only the filter maker and their supplier will really know holding capacity. I don't believe holding capacity will be significantly different based on media thickness. Also mechanically measuring glass-based media may crush the media so optical measurements may be need.



Thanks for the links, as there is a lot of good information on the purolator site. I am a TDR member, but do not have issue 27, nor can I seem to find it on the website?

Good job for thinking of crushing the media using a calipers. I will have to mention that in my report.

 

[Johnny_Law]

Originally Posted By: wileyE
If contaminant was allowed into the media it's be apt to clog?

If the media was fine enough not to allow it to enter, but to pile up on the outside, the containment could posibly act as additional filter media. Assuming it's size doesn't restrict the media exposed media pours?

As far as amsoil claims, think I would also look at their flow ability. If they claim more flow, finer media, and have less media surface? something doesn't add up.


Good post, generally a oil filter will filter better as it nears its holding capacity, as the build up of debris helps to trap smaller debree that might have already gone through previously.

Since the Amsoil oil filer can filter the following:

98.7% @ 15 microns
65.0% @ 10 microns
50.0% @ 7 microns

It seems logical that it would gather more contaminant (in grams) faster than a cheep oil filter that is only 95% efficient at 35 micron. Since the Amsoil filters smaller particles it will have to hold more material in a shorter period of time over a cheep oil filter. It seems that it should then have a greater surface area and not the smallest out of the test sample in order to keep the bypass valve closed and the filtering element functioning during 25,000 miles of use.

 

[jldcol]

Is this a question of the media itself and not a distortion of same to get more effective media into a given can? First corrogate/fold for more surface area and then if not enough make the thin media thicker via construction and material selection to make the filtrate easier to catch but keeping pressure drop low and flow thru high? Whether stuck in or on media, filtrate accumulation should block up the smaller pores first, and the size passable thru media will change also with usage. Also agree general ability of filter to filter will go up as flow thru goes down to some workable lower limit.

 

[Johnny_Law]

Originally Posted By: jldcol
Is this a question of the media itself and not a distortion of same to get more effective media into a given can? First corrogate/fold for more surface area and then if not enough make the thin media thicker via construction and material selection to make the filtrate easier to catch but keeping pressure drop low and flow thru high? Whether stuck in or on media, filtrate accumulation should block up the smaller pores first, and the size passable thru media will change also with usage. Also agree general ability of filter to filter will go up as flow thru goes down to some workable lower limit.


Basically the question is as follows:

How does a oil filter with almost 3 times less total surface area than the OEM hold more total contaminant and can last 25,000 miles?

 

[wileyE]

they count the area between the pleats? I don't know? who's making the claim, consider the source?

I use a 3593a on my hyundai cause it fits and is bigger than stock, guess I'm good for 50k, LOL

 

[wileyE]

There was a study done that showed more engine wear right after an oil change. Part of it was the decreased efficiency of the new filter. Dirt in the new oil, and fresh detergent additives making the ep adds less effective.

 

[Newtonville]

The term mil is commonly used as .001" in labs, shops, industry, etc. A micron is .001 millimeter.

It is sensitive to measure accurately ,0001" even on a hard sample, with a quality mike. Filter media is soft and variable. .001" has no meaning in this case.

The amsoil filter element spread out next to the hyundai is supposed to be about 1/3 the size. That should be verified.

 

[wileyE]

Is filter media rated before or after it's folded into pleats? The bends could really change it's rating. Making some pores wider and some tighter, elongating others.

Also don't they rate after a certain amount of passes of the fluid? not just single pass.