1.3mm isn't a large hole by any means, but why not try to clamp one end of the pipe and pressurise the cleaning fluid through the length of the pipe?

A couple of bar with a thin solvent should easily pass through to give it a good clean from any oil remains.

John.

I agree. This would seem to be the most practical approach since it guarantees contact of the cleaning fluid with the oil. I have never found Ultrasonics to be effective in such an enclosed environment.

For the Have you tried ultrasonic bath.

I don't know if it would help but this is what we used to remove traces of oil.

We were drilling test holes into the dam wall of a big dam to test the water pressure in the rock formation underneath.

The drilling process left traces of oil and we could not fix an adaptor in the hole (it kept on leaking).

We then used petrol to dissolve the oil and then ether to remove the petrol (leaded).

The cleaning ensured a perfect bond.

I am sure a better 2 or 3 step process will be available by now. For the small bore I think the chemical need to be assisted by ultrasonic and /or pressure.

1mg of water equals 1mm3.

0.03mg equals 0.03mm3.

Depending on the specific gravity of oil the oil will be a little bigger than that.

Try a solvent bath in a vacuum chamber. It seems that the solvent can't break the surface tension at the ends of the tube and doesn't flow through. There is a bubble of trapped air inside. Vacuum will take care of that. The solvent can then do its job.

I have an automatic paint roller with a pressure feed over a plastic (see through) hose. It was a devil to get the still wet paint out of afterwards, till I cut a small piece of plastic sponge out, slightly larger than the hole at its thickest point and cone shaped. I then forced it through with normal tap water pressure. It cleaned out the paint with one usage!!

Maybe you could modify this idea and make it smaller and the pressure higher?

Also use a detergent or soap at the same time.....washing up liquid works well on oil deposits....

Sterilize before final use!

I think you need to add some soft mineral, an insoluble carbonate for example as a fine powder to the bath.

These will abrade the surface and dislodge the oil and not abrade the surface.

Hi oak51

Why not heat the tube to a temperature were the oil turns to carbon and then remove the carbon. Shouldn't be much carbon left if only 0.03mg of oil is to be transformed. Being such a small tube it wouldn't take long either. The ultra sonic treatment should do the rest. Hope this helps. Ky

You should add more way: install one more pump and build jig that can pump alkaline through your small pipe with vertical position.

Good luck.

First, make sure that the solvent you use will dissolve the lubricant, then force the solvent through the tube. A pumping arrangement may be a challenge, but will be better than a customer reject.

Many thanks for everybody's input, It would appear as I had expected that the best solution will be to pump something through the tube. Is there a possibility that a chemical could be added to reduced the surface tension and allow the bubbles to escape from the tube, as I understand ultrasonic cleaning it relies on microscopic bubbles forming on the surface, these are building up in the tube and forming big bubbles which then cant escape.

Would a higher temperature help closer to boiling point?

Surface tension can be reduced with a surfactant (surface acting agent) that is effective with the oil and the cleaning liquid you chose. I can't advise on which surfactant, a chemist should be able to help there especially as you don't want to leave any other contaminants. For a start, washing up liquids contain all sorts of surfactants but probably contain salts and other chemicals that you don't want.

I don't understand about surfactant.

I just suggest you some way that, base on your current system. Therefore If it is successful, it will be the best effective. Please to combine pump alkaline detergent through the pipe with ultrasonic cleaning and reducing temperature to 40~45 degree C.

I think you use mineral cutting oil? If so try to use Synthetic cutting oil, and you just use ultrasonic cleaning with water and without alkaline detergent.

Surfactant as related to water and oil.

Water will not remove oil because water and oil won't mix of course.

A surfactant will mix with both water and oil and allow the oil to be removed.

I'm sure a chemist would be able to give a much more elaborate definition but basically that is about it.

If Alconox is available, that is made for ultrasonic use.

Soap is one as are detergents I believe and the result would be an emulsion I would guess....

Exactly.

Dear Jaguar,

Had you used coolant (or cutting oils) in metal fabrication processes?

I am sure, you did'nt.

Here, I mentioned to "synthetic" cutting oils. Because our factory is using it in stainless steel pipe production processes with "water ultrasonic cleaning" process to remove that oil. It is made by Noritake-Japanese company, therefore I think "Synthetic cutting oils are popular in other countries.

Mr.Oak51 is using alkaline detergent to remove oil (I thinked cutting oil in pipe cutting process), so i think it is the best choice now and no need to change it.

In the Pharmaceutical environments I have worked in, ultrasonics was relegated to lab bench cleaning of small parts at best. Ultrasonics are used in cleaning to provide a non-contact mechanical scrubbing action. The same could be done with a good spray system.

I really don't recommend cooking the oils out since tubes of such small diameter and thin walls will inevitably deform in some way due to non-uniform heat distribution.

The day to day washing has pretty much been done exclusively with dedicated spray wash systems that use multiple wash and rinse stages to deal with the initial contaminants and leave a clean neutral surface at the end of the process. The right choice of cleaning agents will do wonders.

So if you already have a washer for cleaning small stainless parts all you would really need is to add a specific adaptor and appropriate filters and screens, to the spray system to pump your wash fluids through your tubes in a batch process. Washer suppliers will be more than happy to help design a viable answer to your cleaning issue. Adaptors and cleaning agents included.

Dear Friend,

I am not from the Engineering background but m from chemistry. I think since ur medical device tube is with very small diameter u must try carbon tetrachloride as it is an organic solvent, it can remove oil and yet the traces of it will not appear because it is volatile. It is a good cleaning agent for oil, specially for the rolling and cutting oils. Do try it and let me know if it is successfull.

Regards.

Most chlorinated hydrocarbons have been banned for use in industry, except under special conditions.

The carcinogenic properties of Carbon tetrachloride are well known and in the UK it has been banned for 40 years.

Trichlorethelene or 'trike' as we called it was the stuff to use but only up to the early 90s after that it was banned due to its greenhouse effect and other dangers...

I think now we're only left with isopropnol alchohol based cleaning agents, methelated spirits etc...

So don't go using carbon tet' as its dangerous and illegal...

John.

Again many thanks for all your input.

Just to update where we are the oil has been tested and 3 chemicals have been identified that dissolve it;- chloroform,ethyl acetate and toluene. Chloroform and toluene have been rejected for health and safety reasons. which leaves us with ethyl acetate samples are going to be processed in this using an ultrasonic bath. The general consensus is that we will have to pump the fluid through the tube to have total confidence that the bore is clean. One other chemical has been sugested but not tested all I know is it is refered to as IPA may be someone can put me right on this but I thought this was a beer!!

Errrm well yes it is a beer (India Pale Ale) and very nice it is too.... especially the one on the handpump in my local real ale bar rated at 9% alcohol

YES!! 9% lethal!!

But it also stands for Isopropanol Alcohol which is what I suggested earlier... But not good to drink!!

John.

I work in a medical manufacturing environment, and we use IPA (Isopropyl Alcohol) almost exclusively, both full strength and in a 70% IPA/30% Deionized Water solution. We use Methonal in some of our other applications, mostly in cleaning out vacuum chambers. Both work extremely well.

Dam I thought I was onto a good one there, Just imagine the fun to be had trying to get purchase authorisation for Green King IPA!! I wonder what would be on the MSDS especially at 9%

Warning - this may make you feel tired or drowsy, if affected do not operate machinery or drive.

Do not attempt to wake early to go to work tomorrow!

For internal use only!

John

Have you tried steam in place?

Capillary action

From Wikipedia, the free encyclopedia Jump to: navigation, search This article is about the physical phenomena capillary action. For the band, see Capillary Action. This article needs additional citations for verification.
Please help improve this article by adding reliable references. Unsourced material may be challenged and removed. (August 2007) Capillary Flow Experiment to investigate capillary flows and phenomena onboard the International Space Station

Capillary action, capillarity, capillary motion, or wicking is the ability of a substance to draw another substance into it. The standard reference is to a tube in plants but can be seen readily with porous paper. It occurs when the adhesive intermolecular forces between the liquid and a substance are stronger than the cohesive intermolecular forces inside the liquid. The effect causes a concave meniscus to form where the substance is touching a vertical surface. The same effect is what causes porous materials such as sponges to soak up liquids.

A common apparatus used to demonstrate capillary action is the capillary tube. When the lower end of a vertical glass tube is placed in a liquid such as water, a concave meniscus forms. Surface tension pulls the liquid column up until there is a sufficient mass of liquid for gravitational forces to overcome the intermolecular forces. The weight of the liquid column is proportional to the square of the tube's diameter, but the contact length (around the edge) between the liquid and the tube is proportional only to the diameter of the tube, so a narrow tube will draw a liquid column higher than a wide tube. For example, a glass capillary tube 0.5 mm in diameter will lift a theoretical 2.8 cm column of water. Actual observations show shorter total distances.

With some pairs of materials, such as mercury and glass, the interatomic forces within the liquid exceed those between the solid and the liquid, so a convex meniscus forms and capillary action works in reverse.