Surface UV Fluorescence Detection

Question: Can UV Fluorescence be used for soil detection?

Answer:

Surface Ultraviolet (UV) Fluorescence—Many organic and some inorganic contaminants will fluoresce under UV light. Shining a UV light on the surface makes residues more visible, particularly in a slightly darkened or dark room. The higher the intensity of the light used, the lower the level of contaminants easily detected. Note, however, that the typical black light found in novelty or specialty gift stores may not be strong enough to cause much residue to fluoresce. More powerful UV lights, available from scientific supply houses or industrial suppliers, will provide far better results. The test is performed by shining the light on the surface and observing an easily seen, fluorescent—typically a yellow, orange or green, sometimes red—color which glows under the light.

Contact Alconox technical support for selecting the right aqueous critical cleaner!

Alconox, Inc manufactures a range of aqueous critical cleaners from powder to liquid, acid to alkaline, highly emulsifying to low foaming. GMP compliant brands are available globally. Downloadable certificates of analysis (COA), MSDS, technical bulletins and trace analysis from the Alconox website at www.alconox.com

Nonvolatile Residue Inspection

Question: What is a nonvolatile residue inspection?

Answer:

Nonvolatile Residue Inspection (NVR)—involves extraction of soil from a dirty surface into a solvent. The solvent is then evaporated onto a coupon of known weight after the solvent is evaporated off the coupon, any residue will be deposited on the coupon. The coupon is then re-weighed and any weight increase detected is attributed to the nonvolatile residue. Many solvents can be used for this purpose. It is important to use a solvent that can dissolve the soil being detected. (Isopropyl alcohol, methylene chloride, acetone and other solvents have been used for this purpose.)

To get more information on how to measure cleanliness, contact Alconox Critical Cleaning Experts at cleaning@alconox.com

Water Break Test

Question:
Is a water break test similar to an atomizer test?

Answer:
Water-break test- uses running water, allowing it to form a sheet, across the surface. Breaks in the water indicate the presence of hydrophobic (water-fearing) residues. (See "The Hydrophobic Surface Film by the Water Break Test," ASTM Method F 22-65-found at astm.org) The water break test is a fairly crude test which is suitable for detecting films of process oils and heavy fingerprints. It does not readily detect non-hydrophobic residues. This test is often used for parts washing and may not be suitable for precision cleaning applications.

Atomizer test- a variation of the water-break test, involves a gently sprayed water mist. Any areas, where water repulsion occurs, indicate the presence of a hydrophobic soil. The atomizer test is slightly more sensitive to hydrophobic soils than the water break test in which the kinetic energy of the flowing water may overcome a hydrophobic residue. In contrast, the atomizer test allows you to see a small droplet of water being repelled by a hydrophobic contaminant.

With over 60 years of experience in detergent manufacturing, talk to the critical cleaning experts at Alconox to solve your most difficult cleaning challenges. Contact the Critical Cleaning Experts at cleaning@alconox.com.

Tape Test

Question:
Need a simple method that will aid visual inspection?

Answer:
The Tape Test is a simple method that aids visual inspection and is well suited for testing the cleanliness of smooth metal and plastic parts. It involves attaching transparent adhesive tape to the surface being measured, firmly pressing it down, carefully removing it and then placing it on a sheet of clean white paper. Visually comparing the sample with an adjacent piece of white paper is a fast, easy way to monitor particulates and sometimes even film residues.

Need to get your hard surfaces cleaner? Alconox, Inc manufactures a range of aqueous critical cleaners from acid to alkaline, powder to liquid, highly emulsifying to low foaming. Brands are available globally with consistent formulations and are GMP compliant. Certificates of analysis, technical bulletins, MSDS, trace analysis, and inhibitory residue testing are downloadable from the Alconox website.

Measuring Cleanliness - Low Tech Detection Methods

Question:
What low tech and easy to perform detection methods can be used to measure cleanliness at 0.01 grams per square centimeter?

Answer:
Visual inspection is best used to detect residues of contrasting color or texture. Good lighting can enhance visual inspection. Magnification and fiber optic lighting, which throws light across a surface, improve detection.

Low-power microscope inspection is a quick and efficient way to verify cleanliness of residual oils and greases, flux residues, particles and surfaces.

Wiping with a white wipe provides a contrasting surface with which to detect dark residues (the white glove test).

For more information on how to measure cleanliness, request a free copy of The Aqueous Cleaning Handbook. Entire chapter dedicated to Measuring Cleanliness! To get your FREE copy, simply email request to cleaning@alconox.com.

Methods for Measuring Cleanliness

Question:
What methods can be used to detect cleanliness at 0.01, 0.01 to 0.001, and below 0.001 grams of soil per square centimeter?

Answer:
Depending upon method selected, cleanliness can be detected to varying degrees or levels.

Cleanliness can be detected to 0.01 grams per square centimeter levels by using visual inspection, low power microscope inspection, wiping and visual inspecting, water break tests, atomizer tests, nonvolatile residue inspection, surface UV Fluorescence detection, tape test.

The level of cleanliness typically suitable for automotive, aerospace, electrical and many surface preparations is between 0.01 to 0.001 grams per square centimeter. This level of detection can be achieved through Millipore filter measurement techniques such as optical microscopy, extraction, oil evaporation, oil soluble Fluorescence, gravimetric analysis, surface energy tests, contact angle measurement, particle counting.

The highest level of cleanliness measurement, below 1 microgram per square centimeter, is suitable for use in semiconductor, disk drive, and medical device applications. Techniques that are used for this level of precise cleanliness measurement include carbon coulometry, electron spectroscopy for chemical analysis (ESCA), Fourier transform infrared (FTIR), Gas chromatography/mass spectrophotometry (GC/MS), Ion chromatography (IC), Optically stimulated electronic emissions (OSEE), Particle counting, scanning electron microscopy (SEM) and Secondary ion mass spectroscopy (SIMS).

Need to get your surface cleaner? Need help selecting an aqueous critical cleaner to best meet you critical cleaning needs? The Critical Cleaning Experts at Alconox, Inc. can help, click here to “Ask Alconox”.

Cleaning parts with complex geometries

Question:
What is the best way to clean parts with complex geometries such blind holes so that optimal cleaning is achieved?

Answer:
When cleaning parts with complex geometries, you should pay particular attention to any blind hole that can trap air, particles or cleaning solution during the cleaning and rinsing process. Air trapped in a blind hole interferes with cleaning and rinsing. Blind holes that face up and trap solution can potentially trap particles and cleaning solution that would otherwise rinse away if the hole was able to drain. To clean a blind hole, you need to make sure that cleaning and rinsing fluid gets in to the hole and back out. If blind holes are all on one axis of a part, and you are cleaning under immersion such as with ultrasonics, then one way to assure this is to put the parts in with the blind holes horizontal so that they fill up with solution and release any trapped air, then under immersion, rotate the part so that the blind holes face down, which allows gravity assisted release of any particles or residues that are removed during the process. Reverse the process to remove the part from the tank to allow the cleaning solution to pour out from the blind holes in a horizontal position. Repeat for immersion rinsing, or better yet, rinse with running water being sure to flush the blind holes. If a part has blind holes on multiple axis, then for immersion cleaning, you would want to rotate the part under immersion in order to release all trapped air and fill the holes with cleaning solution. If practical, it is desirable to further rotate the part during cleaning to pause for a period of time so that each axis of blind hole faces downwards for part of the cleaning cycle. In some cases it can even be worth creating a basket or bracket system that continually rotates the parts during cleaning and rinsing if rinsing is done under immersion. For spray cleaning of parts with blind holes, you want to pay attention to the orientation of the spray to make sure it penetrates and flushes the blind hole during cleaning and rinsing.

Alconox, Inc manufacture’s a range of aqueous critical cleaners from acid to alkaline, powder to liquid, highly emulsifying to low foaming. Brands are available globally with consistent formulations and are GMP compliant. Downloadable certificates of analysis, technical bulletins, MSDS, trace analysis, and inhibitory residue testing are available from the Alconox website at Alconox.com.

Title: Standard Operating Procedure (SOP)

Question:
Can Alconox, Inc provide an example of a standard operating procedure for cleaning glassware?

Answer:
The following is an example of a standard operating procedure (SOP) for cleaning a glass substrate:

To clean glass substrates: Make a 1% solution of Alconox detergent (10 g/L) in hot (50 deg C) deionized water in an ultrasonic tank. Remove glass from supplier packaging. Place the glass in a rack and immerse for 5 minutes. Rinse for 1 minute under running deionized water making sure to contact all parts of the glass for at least 10 seconds. Dry for 2 hours in a drying oven with HEPA air filtration. Allow cooling to ambient temperature for 20 minutes in a clean bench before use.

To download an Alconox technical bulletin click here

Standard Operating Procedure (SOPs) For Cleaning

Question:
What are important items to include in standard operating procedures for cleaning?
Answer:
A large part of successful cleaning relies on having a sound, reproducible procedure. In general, a good SOP should present a list of materials and people involved, the surface being cleaned should be identified, and the eight key variables for cleaning effectiveness should be defined:

1) precleaning handling

2) cleaning chemistry/concentration

3) time

4) temperature

5) type of agitation

6) rinsing conditions

7) drying conditions

8) postcleaning handling

Where cleaning solutions are re-used in baths or sumps, the control parameters and equipment used should be defined (such as conductivity or pH) the limits should be defined, the person responsible for monitoring the baths should be defined, the type of report or logbook entry should be defined, the trigger points and alert levels should be defined, actions taken in response to these levels and finally the conditions under which the bath is dumped should be defined.



Alconox cleaners are available globally with consistent formulations and are GMP compliant. Downloadable certificates of analysis, technical bulletins, MSDS, trace analysis, and inhibitory residue testing are available from the Alconox website at www.alconox.com

Silicone Oil Removal from Polyimide Surface

Question:
How do you clean residual silicone oils from polyimide film surfaces during a lamination process (polyimide bonded to Inconel metal foils)? The oil is only contacting the polyimide. What can be used to clean this polyimide surface that will leave behind no residue?

Answer:
You have a very challenging problem here. Silicone oils are very tenacious and difficult to remove. Polyimides are somewhat delicate and some do not like water, so you will have to confirm these factors prior to using water based cleaners, which is what Alconox sells. Moreover, polyimides often don’t tolerate alkalinity or high temperature. Typcially silicone oils are removed by high emulsifying alkaline cleaners at very high temperatures. For most silicone oil cleaning we recommend 2% Alconox at 170 deg F under immersion cleaning. Assuming the polyimide being cleaned is thermoset, you should be ok with high temperature, however since there may be a problem with alkalinity compatibility, so our recommendation is an acid cleaner, Citranox. Specifically 4% Citranox at 170 deg F using immersion cleaning, ideally in an ultrasonic tank if that is available or alternatively by soaking and using some sort of devise to mechanically clean with, i.e. a wipe or soft brush. Citranox is a high emulsifying mild acid (pH 2.5) cleaner that has the best chance to clean silicone oils. We suggest that you try 10 minutes in an ultrasonic tank or 30 minutes of soaking followed by some sort of mechanical cleaning. If the polyimide can not withstand heat, then the only reasonable thing to try is the hottest temperature 2% Alconox solution that the polyimide will tolerate. Ideally use ultrasonic cleaning or the same soaking/scrubbing process stated above with triple the soak times.

Alconox cleaners are available globally with consistent formulations and are GMP compliant. Downloadable certificates of analysis, technical bulletins, MSDS, trace analysis, and inhibitory residue testing are available from the Alconox website at Alconox.com.

Residual Solvent Statement

Question:
Do Alconox brands contain class 1, class 2, class 3 or class 4 residual solvent ingredients? Where can an official statement concerning the residual solvent content be found, as it is required to have on file to comply with current USP guidelines.

Answer:
Alconox brands do not contain no class 1, class 2, class 3 or class 4 residual solvent ingredients. In the lower left hand corner all certificates of analysis (COA) have the statement "Contains no class 1, class 2, class 3, or class 4 residual solvent ingredients as defined by ICH Q3C guidelines."

The COAs are available online at www.alconox.com at the top center of the page by using a valid product lot number.

Spots on Glassware

Question:
I have an under the counter glassware washer and I keep finding spots on the glassware after each cleaning. I am fairly certain that the detergent is responsible. At this point I want to replace the detergent but I don’t know what product would work better. What is the difference between an acidic and alkali detergent? Is a neutralizer necessary? What does having an ionic and anionic detergent do for you?

Answer:
The three most common causes of spots on glassware are: heavy metal hydroxide/oxide deposits; water spots from hard tap water rinsing; and water spots from improper glassware loading with wash water holding cups such as the upturned bottoms of large graduated cylinders that are not loaded at an angle to allow proper drainage.

If you have any glassware residues of heavy metals that form insoluble hydroxides/oxides at alkaline pH, then you need an acid rinse to remove these. Citrajet is the recommended product. Hopefully your washer has some provisions for dosing a liquid acid rinse during a rinse cycle.

If you have hard tap water that is being used to rinse with, then you need to take precautions to assure that this tap water does not dry on to your glassware and leave mineral deposits. This can be achieved by putting in deionized water rinsing, eliminating the heated drying cycle and manually rinsing in deionized water, skipping the heated evaporating drying cycle and doing some kind of manual water removing drying process (wiping, blowing, or isopropanol dipping off the tap water and not allowing it to evaporate and form spots),

You can open the machine during a wash cycle and inspect the glassware to see if there is any significant volume of wash water that is trapped due to the way it is loaded in the racks. Change the angle at which you load problem glassware to allow drainage, or wash the problematic glassware by hand to avoid this problem.

If you suspect that the residues are simply dried on detergent due to incomplete rinsing, you could confirm this by doing a quick cursory water rinse of the problem glassware. If the residue comes off quickly and easily in water, then you may well have simple detergent residue. This would indicate something wrong with the rinsing. Check the programming to make sure multiple rinse cycles are running. Open and inspect the washer during rinse cycles to make sure water is actually getting in to rinse with. Consider running any empty cycle with Citrajet acid rinse (just dump a few ounces in to the bottom of the chamber at the start of a wash cycle if there is no way to dose in an acid rinse - this will unclog any clogged up spray jets inside the washer. Note this type of failure is fairly unusual, but I wanted to address it because you indicate that this is what you think is happening.

Neutralizers or acid rinses are required when any metal residue is present that can cause the formation of an insoluble metal hydroxide or oxide. As a generalization, you should use nonionic detergents. You need to use low or non foaming detergents in a washer. The most common low or non foaming detergents are nonionic.

Alconox, Inc manufactures several brands of detergents for under the counter machine washers, our customer recommendations for "http://www.alconox.com/static/section_customer/ind_lab.asp">Laboratory.



Alconox cleaners are available globally with consistent formulations and are GMP compliant. Downloadable certificates of analysis, technical bulletins, MSDS, trace analysis, and inhibitory residue testing are available from the Alconox website at Alconox.com.

Rinse Aids

Question:
What are rinse aids? Are rinse aids found in Solujet?

Answer:
There are basically three kinds of rinse aids:

1. Hydrophobic rinse aids that deposit on a substrate that repel the water off the surface, but leave themselves behind as a residue

2. Surfactants that wet surfaces and allow rinse water to sheet off a surface without leaving behind droplets that will cling and evaporate, potentially leaving water spots

3. Acid rinses that dissolve insoluble alkaline salt residues (typically calcium, magnesium and iron salts) that can be formed during the first alkaline cleaning cycle in a washer.

Alconox, Inc does not make any of the first type of rinse aid, because we are all about residue free cleaning. This type of rinse aid is what you get with household rinse aids available at the grocery store.

Solujet contains the second type of rinse aid denoted, surfactants that act as the second type of wetting and sheeting rinse aid.

Alconox does make an acid rinse aid, the third type listed known as Citrajet , which also contains wetting and sheeting rinse aids. If you are washing with tap water, especially water with high hardness, or if you have any heavy metals present on the substrates you are cleaning, you can greatly reduce water spots and hardness residues by using an acid rinse such as Citrajet.

Alconox cleaners are available globally with consistent formulations and are GMP compliant. Downloadable certificates of analysis, technical bulletins, MSDS, trace analysis, and inhibitory residue testing are available from the Alconox website at Alconox.com

Liquinox

Question:
Is Liquinox phosphate free cleaner filtered before bottling?

Answer:
Liquinox as sold in the standard package is filtered to 25 microns, but packaged in new but unwashed containers in an open air reasonably clean liquid detergent factory that is certainly not a clean room. We do not certify or test for particle content. You can reasonably expect fewer larger than 25 micron particles than an unfiltered liquid detergent. We know that the occasional bottle (anecdotally about 1 in 1,000 to 1 in 10,000) has visible particles in it which typically either trace to the bottle manufacturer or our manufacturing environment.

We do not offer a further filtered or controlled version of Liquinox. If something more filtered were required, on various occasions we have evaluated doing this. Relatively smaller quantities would best be packaged by an outside contract packager with clean room filtering and packing experience and capability. For high volume use, we in principle could consider doing this, although the volume and price would have to be sufficient to support investments of many hundreds of thousands of dollars. In the past when we have evaluated this, the final price for the filtered Liquinox was extremely high.

Most people today who require filtered Liquinox, filter it at the point of use rather than buying or manufacturing a filtered package.

Click here http://www.alconox.com/downloads/pdf/techbull_liquinox.pdf for Liquinox technical bulletin.

Alconox cleaners are available globally with consistent formulations and are GMP compliant. Downloadable certificates of analysis, technical bulletins, MSDS, trace analysis, and inhibitory residue testing are available from the Alconox website at Alconox.com.

Replace Chlorinated Solvents with Aqueous Cleaner

Question:
Can an aqueous cleaner or degreaser be used to replace chlorinated solvents? If so what Alconox brand is recommended?

Answer:
Chlorinated solvents clean by solvating residues. Many polar organic and inorganic residues are soluble in chlorinated solvents. The solvents are typically used in baths where the residue is dissolved in to the bath; or the solvents are used with rags or wipes where the residue is dissolved and transferred to the rag or wipe; or in some cases the solvents are used in vapor degreasers where the solvent condenses on to the substrate and drips off in to the tank carrying the residue with it. In all cases, you typically keep cleaning to the point where enough residue is removed and you are now left with clean enough solvent on the substrate. In effect, these solvents are self rinsing. Once cleaning and rinsing are completed, then the last of the solvent evaporates away to dryness.

Aqueous cleaners can quite easily be used to remove polar organic and inorganic residues. In fact depending on what cleaner is used, aqueous cleaners can additionally remove particulates, oxides and a range of non-polar and other organic residues that are not soluble in chlorinated solvents. The method of use and cleaning mechanisms for using aqueous cleaners are quite different from solvent cleaning. Aqueous cleaners work by emulsifying, dispersing, wetting, chelating, dissolving, and saponifying residues. The big difference is that aqueous cleaners need to be rinsed with water. Aqueous cleaners also benefit from using heat, whereas for safety reasons, you usually do not heat chlorinated solvents except in vapor degreasers. You typically need to change the cleaning procedures to switch from a chlorinated solvent to an aqueous cleaner.

If you were using soak tanks to clean with chlorinated solvent, you can typically use a soak tank with warm 1% Liquinox followed by a thorough water rinse to get comparable or better cleaning. If you are using a vapor degreaser, typically you would use a warm or hot 1% Liquinox solution in an ultrasonic tank followed by a thorough water rinse to get comparable or better cleaning. If you were using chlorinated solvents with rags, you can often use rags of warm 1% Liquinox to clean with, followed by whatever best rinse is practical using other rinse water rags or ideally a running water rinse. The kinds of residues that are best removed by chlorinated solvents can typically be readily removed by Liquinox.

One other key difference between aqueous cleaners and chlorinated solvents is that the rinse water used can cause rust on certain kinds of tool steel, mild steel and iron. Since Liquinox is a residue-free cleaner, there are no corrosion inhibiting residues that will survive the rinse process. Once the detergent is rinsed away, any dissolved oxygen in the rinse water can attack the steel and cause rust. Typically rusting will not occur during cleaning, but during rinsing. You can minimize and control any rusting by being sure to rinse with cool ambient temperature water and the drying promptly by a water removing process rather than a water evaporating process. Water removing drying processes include wiping, blowing off with air or gas jets, dipping in isopropanol or other drying solvents. On stainless steel, plastics, ceramics and most other substrates there are not corrosion concerns with mild aqueous cleaners like Liquinox.

Alconox cleaners are available globally with consistent formulations and are GMP compliant. Downloadable certificates of analysis, technical bulletins, MSDS, trace analysis, and inhibitory residue testing are available from the Alconox website at Alconox.com.

Medical Device Cleaning

Question:
What is the most common cleaning technique used in medical device manufacturing?

Answer:
The most common cleaning technique in medical device manufacturing is to use heated ultrasonics followed by suitable purity of water rinsing. Depending on the types of residues, sometimes an alkaline clean is used first to remove all oily residues, followed by a brief rinse to prevent dragout and then an acid cleaner to remove alkaline insoluble inorganic residues. This two step cleaning is then followed by a thorough rinse.

The critical cleaning experts at Alconox, Inc have specially formulated brands for this two step process: Liquinox, an alkaline cleaner, followed by Citranox, an acid cleaner. These brands are fast acting and penetrating ultrasonic cleaners that rinse away residue free.

Alconox cleaners are available globally with consistent formulations and are GMP compliant. Downloadable certificates of analysis, technical bulletins, MSDS, trace analysis, and inhibitory residue testing are available from the Alconox website at Alconox.com. For biocompatibility & toxicity data, shelf life information, residue sampling techniques, validation information and ingredient disclosure please contact validation support.

Agitation and cleaning

Question:
What important parameters need to be considered when selecting a cleaning method and detergent?

Answer:
Time constraints and volume of parts being cleaned affect choice of cleaning method and with it detergent. When a large number of parts must be cleaned quickly, then a fast, high-agitation method, such as spray washing, with an aggressive cleaner is preferable. Likewise, when cleaning fewer parts or batch-continuous quantities of smaller batches rather than the large quantities from continuous manufacturing of parts, ultrasonic soak cleaning with a milder cleaner is more appropriate for the wetting and emulsifying mechanisms.

Alconox, Inc has both high emulsifying and low foaming cleaners for your selected cleaning method. We also offer alkaline to acidic cleaners to target a range of residues. Sizes of liquid and powder detergents range from single unit (gal or 4 lbs box) to large bulk sizes (55 gal or 300 lbs drums).

Visit Alconox.com to find an appropriate cleaner.

Agitation and cleaner selection

Question:
Does agitation in a given cleaning method impact the cleaner or detergent used?

Answer:
Yes, agitation used in a particular method does impact the cleaner or detergent used! In fact, agitation is a factor in detergent choice. High emulsifying, high foaming cleaners are more effective for cleaning processes with low levels of agitation and longer cleaning time. These include the manual, soak and ultrasonic processes. Likewise, low foaming, high dispersing cleaners are suitable for high-agitation cleaning with short contact time as found in spray washing, parts washing and when using spray CIP systems, etc.

Alconox, Inc has both high emulsifying cleaners as well as low foaming cleaners. Visit Alconox.com to find an appropriate cleaner for your application.

Cleaning Insecticide Components

Question:
What Alconox brand cleaner is best to clean carbamates and synthetic pyrethroid off of stainless steel?

Answer:
Carbamates and synthetic pyrethroids are commonly used in insecticides and can be cleaned off stainless steel using an alkaline cleaner that targets the ester groups. The alkaline cleaner used will be determined by the method of cleaning. Our recommendation for manual cleaning is Liquinox and for machine cleaning is Solujet.

For downloadable Technical bulletins, MSDS and trace analysis on Liquinox or Solujet, visit Alconox.com.

Alconox and unstressed polycarbonate

Question:
Is Alconox Powdered Precision Cleaner compatible with unstressed polycarbonate?

Answer:
Alconox is compatible with unstressed polycarbonate. If there is stress in the polycarbonate, then any low surface tension solution such as Alconox will act as a stress cracking agent, especially with the addition of a little heat. Warm solutions of Alconox will cause stress cracking on stressed polycarbonate. The same warm solutions of Alconox will not attack unstressed polycarbonate.

Stress cracking is a surface attack causing fogging, crazing, or slight surface cracks. This stress cracking does not particularly affect the mechanical properties of the polycarbonate, but it does make the polycarbonate less transparent and it does make the surface of the polycarbonate rougher.

For downloadable Technical Bulletin, MSDS and trace analysis on Alconox, visit Alconox.com