• Standard Pulp & Paper Terminology - Physical Properties
• How much do you know about your testing lab?
• Econotech Reburned Lime Analyzer
• We're Listening to You!
• Save money by knowing about trace metals in your machinery oil and fluids
• "Waxing" poetic about stickies
• Econotech is Working in Indonesia
• HurStory

Bursting Strength
This is one of the oldest tests used in the paper industry. Bursting strength and tensile strength are highly correlated. The instrument used to measure burst is the Mullen tester. Despite its popularity, there does not seem to be strong correlation between bursting strength and any end use requirement. Although often believed to be indicative of the resistance of paper to puncture, which is especially important for bag and some building papers, its suitability for this use is limited because of large differences between puncture forces and the forces applied in the burst test. Bursting strength is an indication of fiber-to-fiber bonding forces. The more bonding, the higher the burst. In most cases, the burst test is used as an indication of the strength or toughness of the paper.

Tear Strength
The tearing strength is an out-of-plane tear test. The instrument used to measure the tearing strength is the Elmendorf tear tester. Tearing resistance is the work done to tear paper through a fixed distance after the tear has been started. This property reflects the general nature of the fibers present in the paper as well as the degree of refining they have been subjected to. Tearing strength correlates well with fiber length - the longer the fiber the higher the tearing strength. Southern pines with fiber lengths of over 3 mm have very high tearing strength. This property is important for papers such as bags, wrapping papers, tissue, books and magazines.

Stiffness
Stiffness is an extremely important property for many uses of paper. It may also be referred to as bending stiffness or flexural stiffness, as the resistance to a force causing a member bend. This is an indication of the ability of the paper to resist deformation under stress. Stiffness is important to the use performance of papers. For example, file folders and index cards must support themselves upright during use. The stiffness of tabulating cards ensures that they will be read properly by card reading dividers. Playing cards, posters, cups and plates are also examples of paper that must have good stiffness in use. A certain degree of stiffness is necessary for proper feeding in sheet-fed presses and office copying equipment. Stiffness is also important to the proper functioning of laser printers.

Lab techs are a special breed. Share a twinkie with one, and you'll get exactly half. Fifty percent, by weight and by volume, not 50.1 or 49.9 per cent. Including the filling. These are very precise people. They don't pour anything out of a container without reading the label three times. Lab techs check and recheck calculations. They make diamond cutters look sloppy.

One drop of water too many can dilute a sample to the wrong consistency and throw off all the calculations. Let a stirring rod touch the counter top, and the next time it's picked up it could contaminate the whole sample. Unthinkable!

Who else do you know who would soak glassware overnight in nitric acid, rinse it four times in distilled water, then rinse it again in water treated by reverse osmosis? Only a lab tech testing for metals.

So why do you need to know this?

Let's say there's a dust in the air giving your staff sore throats. Or your product is coming off the line with orange spots. Your effluent has to meet new permit regulations. Or your health and safety committee makes a recommendation to test the air in the workplace. All of these mean collecting samples and sending them to the lab for testing, but you've never dealt with an analytical laboratory before. Who are those people in the white coats? What are they doing behind those laboratory doors? Before you pick up that phone or start up that air pump, you may want to know the things that will help you understand the peculiar world of the lab tech and the testing laboratory.

1. The whole and some of its parts
You ask the lab how much sample they need. They tell you. But be careful, they say it needs to be representative. Of what? Of the whole.

There are entire books written on how to take a representative sample. The simplest way to get one is to make sure what you are sampling is well mixed. If it's something like a dirt sample, it's easy. Spread it out and mix it. Draw in sections from the outside of the pile and scoop them toward the middle. Go into the middle and scoop toward the outside. Repeat many times. Once well mixed, take a sample not just off the top, not just from the bottom, not from just the inside or the outside, but from the top all the way down to the bottom, inside to outside. Otherwise, you may get just the lighter material on the top, or the denser material on the bottom. The sample you have taken represents the whole.

When you are sampling from a very large source, such as an effluent, sample intermittently. Take the same amount every hour, half hour, or whatever makes sense. The testing procedure itself may have guidelines on sampling. Ask the lab doing the testing, or check with the body setting the regulations. The test results are only as good as the sample you've taken. Or, to put it another way, if the sample you submit is not truly representative of the whole, the test results ­ though accurate for the sample ­ will be worthless.

2. Size matters and other lab truths
If there's one ongoing request from a lab, it's to send more sample. There are times when you only have a little bit of sample, or you only had one opportunity to sample and took all you could, and they understand that. But if you have more, send two or three times what they need.

It's not uncommon to have companies that produce 500 tons per day of product not want to part with 28 grams. That may sound like a lot, but it's only one ounce. Surely you can spare one ounce? Please?

If it's a water sample, send a lot. What is a lot of metal by drinking water standards is not a lot by testing standards. They'll need a lot of water to get a sample they can measure accurately.

There are reasons why the lab may need more. Some methods require results reported on an oven-dry weight basis. This means the lab must use a portion of the sample to determine the weight after oven drying to remove moisture. That 10-gram sample you sent may only be six grams after oven drying.

Lab techs are only human, and occasionally a sample gets spilled. (Of course it's never happened to anyone I know.)

You may need to run additional tests. All indicators may point to the sample containing metals. Through analysis, the lab finds no significant metal contamination, so they dig a little deeper and come up with another potential contaminant. If you've shipped extra, they can go ahead with the analysis. And it didn't cost any more to send 25 grams instead of 10 grams.

The lab may wish to run a duplicate. This will give you and the lab peace of mind should the results be higher or lower than you expected. Often times lab personnel will do a duplicate without your knowledge, as part of their ongoing quality assurance program. Occasionally, they have been known to do a repeat test on your sample when the results are out of line with previous work they have done for you. They anticipate your questions.

And if you think that the result is unusual, please ask. You're not insulting them. Lab managers are professionals, and they don't mind questions. They'll do their best to explain their confidence in the result.

3. Precisely accurate
Precision and accuracy. Like the Baldwin brothers, you know they're different but you can't remember which is which.

Accuracy is how close you are to the true result. If you take a sample and spike it with 5.25 milligrams per gram (mg/g) of lead, how close the result comes to 5.25 mg/g is the accuracy of the test.

Precision is how small an increment you can read. Is your result 5 mg/g or 5.2, or 5.25? Precision is a big thing in lab testing. Two things limit precision. Sample size, as mentioned above, and the sensitivity of the testing equipment.

Think of the precision of the testing equipment as a timepiece. With a sundial, you can estimate time to the nearest five or 10 minutes. The clock on your VCR is probably accurate within a minute or two. A quartz wristwatch can tell the time to the nearest second. Stopwatches can get you down to fractions of a second. As technology advances, instruments get more and more precise.

If the lowest an instrument measuring oil and grease can detect is two parts per million (ppm), and your sample is one ppm, there is no way of knowing that exact amount. The instrument will read it as < 2 ppm oil and grease. It could be 1.5 ppm, 0.5 ppm, or none at all. But, with the precision of that instrument, this is all they can tell you. That is why lab reports never say there is "none", only less than the detection limit.

4. What the blank do you need to run that for?
Blanks and standards confuse a lot of people. You thought all you had to do was take a sample, but now the lab wants a "blank" or a "standard" sample. Why?

When you take in four dirty shirts to the cleaners, do they make you take in a clean one for reference? No. But the lab may ask you for a "clean" filter paper when you bring in a filter you have used to take an air sample. There are a few reasons for this.

The blank filter can be used as a measure of the whole process. Has your supplier given you "clean" filters? Have you stored them properly to avoid contamination? Have they been contaminated on the trip to and from the sampling site? Your blank will tell you this. Imagine you're testing the air for fibres, asbestos fibres perhaps, in an area where asbestos is being removed. Now, just imagine that there is a source of contamination where you are unpacking your equipment. An unexpected source of fibres, unrelated to asbestos. Before you even sample, your filter is filled with fibres. If you sent this sample to the lab, your results would be sky high, not reflecting the true hazard. Now, send a blank filter to the lab, and they'll see the same high results there. Using this knowledge, they can work on removing the source of contamination, and getting accurate results. The lab needs a blank to calibrate their instruments. The blank sets the baseline, telling the instrument where zero is.

Standards serve a different purpose. A standard is a sample of the material you are trying to quantify. If you are testing for something common like zinc, you won't need to supply a standard. The lab will have one. But, if you are testing for contamination from oil X lubricating your machinery, the lab does not have oil X on hand. Oil X is probably a blend of different materials, oil A, oil B, binder Y and whatever else those brilliant oil chemists have mixed together. The testing instrument will have been given measured does of oil X in a range of dilutions. The lab may also need a sample of your original uncontaminated product to further isolate your contaminant.

5. They're good, but they're not that good
You've got dust. You've got complaining workers. Get this tested, your boss says, see if it's bad. So you call the lab. Can you tell me if this is harmful? And before you get started, can you tell me how much this will cost?

Unfortunately, there is no machine that tests for toxic materials. The lab needs to have an idea of what they're looking for. That's why you may be asked a whole string of questions. The lab manager is not being nosy, he's narrowing down the list of suspects. If he asks about other work being done in the area, he's looking for clues, not company secrets. Part of being a testing lab is a strict code of confidentiality.

And when you ask when the results will be ready, please be aware that sometimes five days means five days. That is how long it will physically take for the tests to be completed. For example, a five-day BOD (biochemical oxygen demand) measures the amount of dissolved oxygen in your effluent consumed by micro-organisms in five days.

Chances are your lab doesn't work weekends unless you've arranged it in advance. If timing is critical, ask. But be warned, your lab techs may get cranky if you submit a sample dated February 10 on July 28 and ask for rush service!

6. It's hard to tell you what isn't there
Logic may tell you that if there's no contaminant X in your sample, analysis should be easy. After all, what do they have to do? Just tell you it's not there. They don't have to isolate, identify, or quantify. Easy, right? Not always.

Imagine it this way. You're looking for your friend Mr. X at a crowded party. If you spot him right away, it's easy. He's there. If you don't, you have to go room to room and confirm that everyone you see isn't Mr. X. Only then can you say for certain, "This party contains no Mr. X". Some analyses are like that, and a good technician keeps looking until he or she is sure.

7. SOS, save our shipper
Shipper/receiver is one of those under-appreciated jobs. Every specimen is identified, counted, logged, preserved and sent to the correct department for analysis. Opening packages all day, it's a little like Christmas and a lot like Russian roulette.

Scanning the pile of boxes and envelopes, the shipper can tell from the courier labels what company the package is from. Some days that's invaluable. Some days the box contains a few samples and nothing more. Now, we know you are the lab's favourite customer, and they love hearing from you, but their system gets clogged up with all these other customers. So when they don't know which of the 500 people at company X has sent this sample, or what test they want, all the shipper can do is get out the Ouija board and hope for help from beyond.

I don't want to nag, but packing is important. If you're sending a dust, please put it in a container, then into an envelope. The shipper's just not expecting to open an envelope with a cloud of dust and a note saying "please test for asbestos". It makes her nervous. So do wet sample bottles put into a cardboard box. The box gets wet, a bottle falls through, the bottle breaks. This may be an effluent that you are required to test weekly. If the sample's gone, it's gone. And you have no results.

I know you heard this already from your third grade teacher, but write the sample description clearly. Otherwise, you may get a report on a sample named "flaw cream" instead of "flow stream". Oh, and permanent ink is ideal. It's hard to read the sample description backward and smudged from the palm of your hand.

When shipping dangerous goods you need, well, a dangerous goods label. You are required by law to fill it out yourself. The lab shipper would love to help you by telling you what the pH of your sample is over the phone, but she can't. Check it out with the Department of Transport. There's a short course you can take. Your boss will give you the day off, and I think they serve you lunch.

And remember, if you jam the sample into a small-necked container using a screwdriver, your lab tech will need a coat hanger and a stick of dynamite to get it out. (Plus, the results you end up with may be for the screwdriver, not the sample.)

8. Talk to us. Please.
Lab work doesn't begin and end with testing. You can call any time for help suggesting and find procedures, and recommendations for other facilities if the test is outside the lab's expertise.

The lab manager will give you an idea of when your results will be ready, so you can plan your next move. Sometimes samples need to be shipped immediately after sampling. He'll warn you.

If you have an in-house procedure, let them know. They can adapt to your needs. If you have your own testing lab, an outside lab can provide cross-checks for your own quality control.

You may need special containers to sample into, or specially prepared containers. A lot of the time, the lab can provide you with these. Just ask! If you're sampling for oil and grease, not only is a clean glass container essential, but a little nitric acid in the bottom will ensure the sample is at the required pH.

And don't think you can use those plastic containers you've got sitting around to ship your chemical oxygen demand test sample. The plastic will breathe and affect the amount of oxygen in the samples. Your results will be meaningless.

You may not realize how much time your lab spends ensuring quality results. An average of 12 to 15 per cent of the lab technician's time is spent on duplicate testing, or other quality assurance work. Some testing procedures require two quality assurance samples for every one sample tested!

Some labs check their results in a round-robin sample exchange with other labs, often the only option for non-environmental testing. Or, a lab may keep a large supply of sample on hand to run monthly checks, to make sure results are consistent.

9. Confidentially yours
Remember, your lab is impartial. They don't make the regulations, and they don't enforce them.

If your results indicate a problem, they are there to let you know. They don't tell anyone else, it's all strictly confidential. Think of your lab contact as a psychiatrist. Sit back, tell them your problems. You'll feel much better.

10. Worse than a blind date?
The phone book's open to "analytical laboratories". Now what? The biggest ad? The most technical sounding name? How do you pick a quality lab?

A few things are universal to any profession. How long have they been in business? What education or experience do the laboratory managers have? Don't sell experience short, it's just as important as education. Working your way through "real world" problems is invaluable.

Ask about the lab's accreditation. How do they check the accuracy of their results? One respected standard for analytical laboratories in Canada is CAEAL, the Canadian Association of Environmental Analytical Laboratories. There are other standards, such as the ISO, or International Organization for Standardization. These independent companies certify quality. They come to the lab, inspect the lab's procedures, people and performance. The lab receives suggestions, which are then implemented and the lab is re-examined. This may be repeated several times until the lab meets the evaluation standards, giving them the "seal of approval" in the form of laboratory certification. But, the lab cannot then rest of its laurels. It must consistently achieve acceptable results for samples supplied by the certifying body. The lab is supplied with a chart that identifies its ranking with other labs in the program.

Of course, there are exceptions to certification and quality assurance. Some tests are subjective, meaning the person doing the test is making a judgment based on his or her experience. An example of this would be unknown contaminant identification. Your lab person may look at a small white particulate and know it's starch. She can show you how she's looked at it under the microscope under certain light conditions and seen the distinctive "church windows" that confirm starch. She can't offer you certification results, only her experience and certainty.

No, most lab techs can't leap tall buildings in a single bound, but how many superheroes would have the patience to watch a thermometer creep up one degree at a time?

The hardcopy version of this quarter's newsletter featured an article on our Reburned Lime Analyzer. Here's a link to our website page describing this very useful apparatus. (Use your browser "back" button to return here.)

As a result of requests from several clients, Econotech has purchased a Britt Drainage Jar. This instrument is designed to measure the fines content of paper stock and pulp samples. A modified procedure allows the apparatus to measure the tendency of the fines fraction to be retained by the fiber fraction under graduated turbulent conditions. What can Britt Drainage Jar analysis reveal to you? Give Don McDermid a call at 800-463-5700 or 604-526-4221, or email him at don@econotech.com.

In today's cost conscious business climate, progressive companies are implementing predictive maintenance programs since they are more cost effective than the traditional preventative maintenance approach. Predictive maintenance makes use of periodic tests on equipment to establish the condition of the system, thus setting maintenance work to the specific needs of the equipment. This approach alerts one to impending trouble before it occurs and scheduled maintenance can be done on targeted areas with minimal unexpected downtime. Savings are also realized by exploiting the full service lifetime of consumables such as lubricants, hydraulic fluids and coolant fluids.

Lubricating oil is a very useful medium for diagnosing the general state of well-being for machinery. In addition to its role as a constantly renewable surface between moving parts, lubricating oil carries debris away from wearing surfaces in machinery. The debris present in lubricating oil can tell the informed user a great deal about the condition of the machinery - such as the degree of wear of various components of the machinery. The presence of abnormal levels of trace metals in lubricating oil may be used to diagnose component wear in machinery.

In addition to component wear, leaks into a machine's lubrication system can be an insidious source of mechanical problems. The presence of abnormal levels of certain elements in lubricating oil may also be used to diagnose internal leak problems in machinery.

In the typical predictive maintenance program, samples of lubricating oil from various machines are collected at predetermined sampling intervals and sent to the laboratory for analysis. The lubricating oils are usually analyzed for metals as well as other parameters such as color or viscosity. Results for each machine are examined, compared with previous data as well as other measurements relevant to specific machinery such as noise, vibration or bearing temperature. Departures from normality usually indicate potential problems, and in many situations well in advance of component failure.

Cooling fluids also carry information relevant to the overall health of machinery and process plant components. Over time, cooling fluids may become corrosive or contaminated with deleterious substances, they may also carry debris from wearing pumps or valves. Monitoring changes in the concentration of metals present in cooling fluids is a useful diagnostic tool in a plant's predictive maintenance program.

If you are maintaining or developing a predictive maintenance program, consider sending your lubricating oil and cooling fluid samples to Econotech for metals analysis. Our highly skilled analysts use state-of-the-art instrumentation and validated methods for determining trace elements by AA and ICP in lubricating oils and cooling fluids. Our ISO Guide 25 compliant quality system assures reliable data that you can use as an integral part of your predictive maintenance program. Please contact Bill Warning or Tom Yuen for details on how our services can benefit your company.

The Microscopy Department continues to 'count the ways' they have heard of to measure stickies, or adhesive residue, in pulp. Inquire about our methods or tell us about yours.

*PSAs (pressure sensitive adhesives) make up a large percentage of stickies.

back to the top

A Canadian company has hired Econotech to help improve the equipment, standard test methods and training at the Institute of Research & Development of Cellulose Industry in Bandung, Indonesia. Our team - Dr. Paul Thomas (Director of International Projects), Kevin Lam (Technical Specialist-Pulping) and Don McDermid (Manager-Pulp & Paper Testing) spent the month of November at the Institute, helping to install and start up a new pilot plant digester and other equipment. The Econotech staff also provided extensive training on laboratory pulping, bleaching and paper testing.

In mid-January, Paul Thomas, Lori Granger (Senior Technologist-Bleaching), Yolanda Kerr (Group Leader-Pulp & Paper Testing) and Sumesh Putra (Senior Technologist-Pulping) returned to Bandung to continue monitoring and implementation of additional procedures and practices. Econotech was chosen to do this work because of our reputation for very high standards for quality and reliability.

Hur Begum has worked in our Environmental Department for over ten years and has gained a great deal of knowledge working with effluents, wastewaters, oil, dustfall and air-laid tissue samples. Her clients are not limited to pulp and paper mills, but include food manufacturing and processing plants, utilities, chemical producers, as well as environmental and engineering consultants and other laboratories.

Hur completed two years of a Bachelor of Science Studies Program at the University of South Pacific in Fiji in 1987, and shortly thereafter, moved with her family to Vancouver. Hur was an avid scuba-driver in Australia and Fiji, but has yet to stick her toe in the comparatively frigid waters of BC. She still enjoys swimming regularly (indoors) and jogging and teaching her bilingual cat, Princess to speak Hindi.

As a Senior Technologist, Hur performs quality control, water and soil analyses; operates HPLC/IC with chromatography software, UV-VIS Spectrophotometer and is responsible for instrument maintenance, repair and calibration. She ensures statistics and record keeping are within compliance (SCC/CAEAL Certification) and is involved in method development. Whether it is EPA or a BC Government requirement for tests such as sulfides, chlorides or oil and grease, Hur has the capability to research and analyze the samples to meet your requirements. As with all Econotech analyses, samples are tested with known standards and strict quality control.

Should you have any type of special testing requirements, please contact me or Hur - we're here to help you!