Viscosity Control

Using blended solvents

2012-02-04T05:26:00.000-08:00

Does your printing system use a solvent blend. There are a number of solutions for a viscosity control system to use multiple solvents. One is shown here. When the viscosity rises above the set point then the controller simply opens two valves, each for a different time. The times are based upon the ratio of solvent you desire.

There, it is that simple.

Flexographic Printing Ink Viscosity Control - I Dare You !

2012-02-04T05:23:00.000-08:00

Viscosity control of printing ink. This chart comes from an application note that we offer free of charge to anyone who emails us a request. This comes from a real test on a real flexo press running solvent ink in the UK. Points A-F show the ink viscosity under manual control. H and on show what happens with auto control. J is what happens when an ink attendant adds uncut ink to your ink pail. Our control system brings the viscosity back to where it belongs. BUT the ink man should have pre-thinned the ink before adding it.

If you have no viscosity control then by putting on such a control system you can see savings of between 15 and 60 percent !! Yes you can. Tally up your annual ink cost and look at the numbers.

There is no rational excuse for any printer any place in the world who is running solvent based inks with jobs that last for more than 1 hour not to use viscosity control. The only excuses are that 1. you don't believe, 2. you have had a bad experience with a poorly designed viscosity control system or 3. you like spending more money then you need to.

The pay back is there. You may not believe it but it is. I stand ready to prove this to anyone anyplace in the world. You contact me, we study your system, I give you a quotation, you get approval, you issue a conditional purchase order and I will supply you with three days of free use of a viscosity control system and so long as I prove savings the purchase order becomes validated.

Go ahead - Try me - I dare you.

Making a switch intrinsically safe

2012-02-04T05:12:00.000-08:00

There are times that you may have an industrial application where there is a limit switch in a hazardous location. To connect that switch back to the control system trying to monitor such switch you can use explosion proof conduit, cabling, seals and the like. These cost you lots of money, time and inconvenience.

A wonderful technology is the intrinsically safe barrier. A typical one, as shown in this photo, is mounted with your control system in the NON Hazardous area. The left side of this barrier connects to your controller. The right side is connected to the switch in the Hazardous Location.

The power ( ie voltage * amps ) and the inductance and the capacitance are all limited by special circuits in the barrier so that if the wiring to or in the switch was damaged and the two leads were able to make contact in the presence of some flammable or explosive gases, which in turn have the best ratio of oxygen present to allow for ignition, then the short circuit current would be limited to a level so low that the ignition cannot occur.

This is great technology as it allows you to use ordinary wiring to your switch and you can even use non explosion proof rated switches safely and easily. One caution is that he path that the cable takes from the switch back to the barrier must be such that the gases are sealed off ,so they cannot migrate back to the control system. This is simple to do.

See my posting # 19 as well.

Can Coating % Solids and Film Thickness

2012-02-04T05:02:00.000-08:00

I found this old steel can recently. I wonder if the manufacturer of this had been using viscosity control for their interior varnish and exterior over varnish ? First, all of us in the can coating world know that you need to protect steel from the material it is containing. Second we also know that you need something to protect the printing. Third the percent solids is critical and the best way to measure that is by measuring it's viscosity.

The rusted spikes, around the can did not need any coating. They are just simple iron tools doing their job for a given time. These obviously have served their purpose. Have a great day :)

2012-01-30T07:55:00.000-08:00

Do you have questions about viscosity control ? Send them to sales@viscosity.com and maybe they will make the blog. If you want us to give you credit for the question then please be sure to give us permission to use your name and that of your company ( if applicable ).

2012-01-30T07:50:00.000-08:00

Norcross achieved ISO9001 rating late in 2011. We are proceeding to benefit from the discipline and organization that this brings to bear on our already 75 year history of customer support.

2012-01-30T07:48:00.000-08:00

Greetings, Norcross will be showing new viscosity sensors, ink temperature controllers and other products at this years Drupa. See you there :)

Pizza Box and Tomato Sauce

2012-01-30T07:22:00.000-08:00

Pizza Box and Tomato Sauce

Norcross Viscosity and pH Control to the rescue !!

How might you ask ?

The cans of sauce are made of steel, and need a varnish coating to prevent corrosion. The varnish is applied by a coating machine with both water based and solvent based varnishes. Voila! Norcross viscosity control insures consistent film thickness.

2. Pizza Boxes are often printed directly by in-line corrugated flexo printing presses. The inks used are water based. This means that both viscosity and pH need to be monitored for truly great printing, and minimal ink consumption. Again, Voila! Norcross to the Rescue.

Mix, Mix, Mix

2012-01-26T13:16:00.000-08:00

Mix, Mix, Mix !!!! So often we speak with application engineers having problems controlling viscosity just because the product is not being mixed. Many industries are trying to reduce cleanup time and thus move their pumps from in tank to in line. In doing so the mixing action of the pump, in the tank is lost.

Many mixers run to fast and cannot be throttled to slow flow rates. Often just a little mixing is all one needs.

See the video for an example.

http://www.youtube.com/watch?v=228tGgRkAFM

2012-01-26T13:11:00.000-08:00

Do you make pcb's ? Do you use treaters ? Do you use epoxy with acetone solvent ? Do you need to insure consistent impregnation of the fiberglass base ? Then you need Norcross Viscometers.

Counductive Inks

2012-01-26T13:04:00.000-08:00

Do you use silver or gold ink ? If so you probably have a solvent based suspension. If so you surely pay very dearly for your ink. Most process viscometers cannot measure this because of the metallic content. Norcross can measure and control this with our very clean and easy to use units. If you are printing on medical packaging, flexible electronic circuits or the like then we can help you.

Reactor Viscosity Value - what is it really ?

2012-01-26T05:08:00.000-08:00

We often have inquires from companies using product reactors. In the course of discussions we may be advised that the end point viscosity is 30,000 cps. This may be the case BUT it will be a function of how the product was measured. Usually it has been via a rotating laboratory viscometer on a cooled down sample. The rotating viscometer applies very low shear and most all reactor products are shear sensitive ( ie: thixotropic)
Our viscometers apply a higher shear force and thus what you, our customer, may think is 30,000 cps is only 4,000 cps to us at Norcross. Both values are right.

So often I will ask the customer to pretend they and I are sitting in the reactor having a cup of tea. During the reaction we dip our tea cups into the product and then pour it out. Tell me, does it pour like water ? warm honey ? milk ? or what. Then we can better sense what the viscosity will be like to the falling piston.

Viscosity Control on Gravure Presses

2012-01-26T04:52:00.000-08:00

Just made a YouTube video about viscosity control on gravure presses. See it here.http://youtu.be/-aJtkL_icfI

Why a Perfect pH Level is Key

2011-02-16T13:25:00.000-08:00

When pH levels are too low, the ink could have a faster drying time on the substrate, and increased viscosity, which could lead to filled anilox cells. Also, a difficult clean-up is never fun!

Conversely, when pH levels are too high, ink may not dry at all, in addition to poor water resistance due to entrained amines. Also, odor problems may make for an unpleasant work environment.

Ideal pH and Your Morning

2011-02-15T09:55:00.000-08:00

An example of Trapping, courtesy of paperandprint.com

An example of Adhesion, courtesy of paperandprint.com

pH is very important to print quality. Without it, you could end up with solid chunks of resin and pigments in the bottom of your ink buckets. This occurs because of a phenomenon commonly referred to in the printing industry as "kicking out", which means that because of low pH, the ink drops out of suspension in the solution, falling to the bottom of the ink bucket.

There are two other common problems that exist when pH levels are too low; they are called adhesion, and trapping. Adhesion occurs when the print can be removed by scratching the surface of the material printed.¹ Trapping exists when one color is superimposed onto another, so that the first color does not lay properly before the next color is printed_.²

It is also important to remember that low pH can cause increased viscosity, which could lead to a dark and dirty print, ink drying too slowly, or small random holes in the printed area.

Also with a low pH, you run the risk of your ink pigments and resins not being soluble, and therefore running in the rain. This is bad news for newspapers, and could sour anyone’s morning.

*Additional information and images courtesy of FlexoTech 2007 Compendium, Whitmar Publications, found at www.paperandprint.com

^{1 pg 115}

^{2 pg 137}

How is pH Measured?

2011-02-15T09:51:00.000-08:00

The electrical circuit consisting of two circuits whose compared output indicates pH. The first circuit is a reference source with porous plastic junction. This provides for electrical contact with the ink. The second circuit tracks the exchange of hydrogen ions across a porous glass membrane. The diamond shaped figures are a saline solution, which carries the ions to the wire. The more ions, the more electric flow.

What exactly is pH?

2011-02-14T06:56:00.000-08:00

pH is commonly known as the measurement of how basic or acidic a solution is. The “p” stands for power, or potential, and the “H” stands for the element of hydrogen. The greater the potential a solution has for freeing hydrogen ions, the lower the pH will be.

Generally solutions that have a pH of less than 7.0 are said to be acidic, while those more than 7 are basic, or alkaline. For example, water, which is neutral, has a pH of 7.0.

The pH scale is logarithmic, which means that each whole pH value below 7 is ten times more acidic than the next higher value.

These are the pH measurements of common solutions.

o Lye 13.5

o Bleach 12.6

o Ammonia 11.4

o Milk of Magnesia 10.2

o Swimming Pool Water 7.5

o Orange Juice 4.3

o Vinegar 2.9

o Battery Acid 0.3

Needles Feel Better Because of Norcross

2010-12-01T13:19:00.000-08:00

Do you like getting shots?

If you are like most people, getting shots is not number one on your priority list but nonetheless, it becomes necessary once in awhile.

Aside from the incredible skill of the metal workers who make the needles when they are all done there is one final step they perform. That is the application of a thin layer of silicone.

Why silicone? Because silicone is slippery, like release paper.

How is it applied? Thought you would never ask.

They dip the needles in bath of silicone and acetone and of course they use Norcross viscometers to control the viscosity. This is because the viscosity is a measure of percent solids and they want a certain coating on the needles.

So next time the needle doesn’t hurt you can say "thanks Norcross!". The next time it does hurt then you should say "Where was the Norcross?".

96% reduction in solvent use for lacquer coating

2010-10-01T05:32:00.000-07:00

Greetings

Just last week we had a visit from our agent in Columbia. He brought with him some very interesting news.

In July of 2010 a firm in Columbia was testing the Norcross tank mount viscosity control system.

They apply a lacquer to synthetic seat material, in order to provide proper gloss.

They had never used automatic control before but had always had an operator adding solvent and then lacquer back and forth, during the coating process.

Their operating range is Zahn Cup #4 14 - 35 seconds but normally at 19 seconds.

They installed the Norcross viscosity control system, filled their solvent container and stood by waiting to refill the solvent (as they had become accustomed to doing).

The job ran and ran and when it was all done they had only used 1 quart of solvent, instead of the normal 24 quarts of solvent!!!!!!!! They also did not have to add any extra lacquer, as under manual control when an operator would often over dilute.

Their reject rate dropped, their solvent consumption dropped 96% and their lacquer use dropped.

This is a no brainer - simple viscosity control can pay for itself in a matter of days.

What are you waiting for?

If you would like to talk to someone about viscosity control please visit www.viscosity.com or contact Norcross Corporation at 617-969-7020.

P-o-o-o-f-f Goes the Chemical Reactor

2010-09-14T06:08:00.000-07:00


Norcross M10 Viscosity Sensor

Norcross has been measuring the viscosity of fluids in chemical reactors for many years. This can be done under a full vacuum or under pressure and at a wide range of temperatures and viscosities.

We recently had a very curious issue, with a customer in China. The M10 would be up and running and working fine. After a few batches there would be a build up of vaporized fluid in the head assembly of the M10. This would eventually cause the unit to malfunction. Why is that we thought?

After visiting the customer we found that when one batch was completed they would pressurize the main reactor to 'push' the product out of the reactor.

Then they would pressurize another feed reactor to 'push' the fluid into the main reactor.

These reactors were being pressurized to only about 15psi but their volume was approx 300 cubic feet. This means the total pressure force in the reactor is tremendous. Thus as the fluid reached the bottom of the feed reactor the pressure blew through the fluid into the 4 inch feed pipe connecting to the main reactor. This action vaporized all the remaining adhesive.

This blow through is like a burst of high energy steam but it is high energy vaporized adhesive at high temperature. There are release ports on the main reactor to vent this pressure burst. The "P-o-o-o-f-f" as we named it lasted approximately 1/2 second.

Even with purge gas flowing in through the M10 the pressure spike was so great that it blows back through the purge lines, in addition to blowing out through the release ports. Thus depositing a vapor of adhesive all through the M10.

Conclusion: When a reactor is emptied by pressure, things will work but it must be filled via a pump to avoid the "P-o-o-o-f-f".

Best to you all,

Bob Norcross

24vdc circuits are inherently intrinsically safe - NOT SO

2010-09-08T05:34:00.000-07:00

An intrinsically safe circuit can be of many voltage levels but of only limited power levels with certain limits on resistivity, inductance and capacitance.

Thus just because a circuit is 24vdc does not mean it is Intrinsically Safe.

After all, if you took a 12volt car battery into a factory using acetone based liquids, then attached jumper cables and then touched them together over the tank (i.e. making nice large sparks) it would probably be the last spark you saw.

The energy of that 12volt batter is too large!!! It is low voltage but can generate high current flow (otherwise your engine starter motor would not turn over your engine). Thus there is a lot of power (watts).

Thus there is the very high probability of an experiment such as this turning you over into the hands of a local emergency room doctor.

When Intriniscally Safe IS NOT Intrinsically Safe

2010-09-08T05:25:00.000-07:00

Greetings

In the world of process control of flammable fluids there are many sensors that can be used with intrinsically safe barriers.

However, many individuals do not understand one, of many, technical points.

You cannot run the wires of intrinsically safe circuits in cables or conduits or raceways without special isolation.

We have one version of a viscosity sensor that has integrally mounted valves and a switch. They are all piped to NEC XP standards and the components are all UL Listed.

On occasion a customer will want to use an intrinsically safe barrier for the switch ( which itself is already UL Listed Explosion Proof ). We then point out that the six wires (two from each component) are carried away from the explosion proof junction box in a single cable. Thus making the intrinsically safe effort futile.

If you want to use an intrinsically safe connection to a switch, typically done so that you can avoid hard XP conduit connections. Then wire the switch separate from any other devices, such as valves. Then you have a great Intrinsically Safe Installation.

Norcross Standard in Chinese Text Book on Printing

2010-09-08T05:18:00.000-07:00

Greetings, after many years of testing and working in China Norcross has now been placed in a nationally known text book used by most of the printing colleges in China.

More details to follow.

Water Based Ink - Don't Add Water Until ...

2010-09-08T05:16:00.000-07:00

Caution, many water based inks are not pH stabilized. Thus you can have color and viscosity shifts due to changing pH.

Therefore, do not begin to add water until after you have checked the pH. A small change in pH can cause a large change in viscosity, as well as hinder drying and tack.

The pH Meter Killer :( : Ground Fault Current

2010-08-23T12:53:00.000-07:00

"How come I can measure pH in my ink tank with a hand held pH meter but when I connect a permanent device my readings are either frozen or drifting?"

Odds are it is ground fault current. This wonderful little monster is the incarnation of 'Murphy's Law', you can not measure it, feel it or see it but it can completely distort a mounted pH measuring system.

You can even put the system on a bucket on the plant floor and all will read right but once you put the bucket on the press ##@! watch out - your readings may be great or worthless.

Why you ask? Because big machines have inherent electricity within them. This comes from many sources, to be discussed later. Needless to say when you are trying to measure microamps of flow ( ion exchange ) this can totally throw off your readings.

How do you defeat it ? See the next posting.

Help! I think I need to link my color readings to my viscosity controller!

2010-08-11T10:47:00.000-07:00

Help is not needed!

On a test in Turkey and Colombia we ran our viscosity control system against a favored falling dart system.

Our system showed the falling dart system's inability to reliably measure small changes in viscosity on a repeatable basis (see our water chart below). This means that their control logic cannot provide good control.

After all, if you cannot measure it, how can you control it?

Prior to our arrival the customer was convinced that they needed some kind of 'lockout' linked to their densitometer readings.

We said, "Please be patient, we have almost 80 years of experience in process control, we have seen this before, your problem is that your current control system is not holding viscosity."

Their response was: "Sure it is, just look at the display. The display hardly ever changes."

We said, "Just wait."

They said "OK"

So we installed our demo equipment on the same printing deck that the other viscometer was on and started up.

First we simply measured and showed the customer that while the other viscometer's display kept showing the same cup second, ours showed ongoing variations!

They said, "Woo, what is going on?"

We said, "They need to control their display with some kind of averaging or filtering, because they cannot measure small changes on a repeatable basis."

They said, "But we have used them for years"

We said, "That may be and that is simply years of wasted ink, substrate and time."

(Norcross can do well because we apply shear to the ink. Viscosity is a measure of shear force / rate of shear. Our falling piston really 'feels' the ink and thus we see changes that they cannot.)

So we put the other viscometer's system in manual mode and ours in auto.

Lo and behold the viscosity deviations stopped and so did the changing Delta E (color density).

They said, "Wow, you really do work"

We said, "Yes we do and what saddens us is that so many plants all over the world have tried other viscometers and have had bad experiences or don't even know what they are missing. Thus when we arrive we have to undo the fear and then prove our capabilities. But that is life and we are here to stay."

So the whole matter becomes simple, just use a good viscosity controller from a company that can teach you how to use them and knows about closed loop process viscosity control.

Then you are on your way ink savings of 25% - 40% plus less waste, happier customers and employees.

Win-Win

Best To All

Bob Norcross

What Viscosity Is Not

2010-07-02T12:40:00.000-07:00

That may seem like a very simple question but it is not.

Viscosity is not like temperature, pressure, flow or mass. These other parameters have absolute values that do not change with time, location or method of measurement.

Viscosity is unique - what viscosity value you give a fluid will be a function of how you measure that fluid.

This is because Viscosity is a ratio of shear force to rate of shear and since 99% of all fluids used in printing, coating and other manufacturing processes are Non-Newtonian ( a topic for another entry ) how you measure will determine what you call it.

The goal with process viscosity control is to adjust your process using an independent method of assuring proper output and then instructing a viscosity control system to keep the viscosity where you desire it.

Temperature Compensation - When Not

2010-06-16T18:32:00.000-07:00

There is often talk of temperature compensation of printing inks and some other process fluids. Much of this is mis-information and upon careful examination makes no sense.

If you are operating a printing press with a set ink density and the temperature changes, then with temperature compensation your controller would let the viscosity shift. The idea being that ink density maintains consistency.

What this ignores is that it is the real physical viscosity that impacts ink transfer, in addition to ink density giving color.

I have seen an instance where a latex coating was being applied and due to some improper pump selection the temperature reached 120F. The chief engineer said 'just do temperature compensation'. I said "I can't because your pure undiluted latex coating is too thin at this temperature". He would not listen, would not change his pump and would not cool his latex. His efforts at Viscosity Control Failed.

While the normal process might not see such a large temperature swing, nonetheless, if your process has a changing temperature then CONTROL THE TEMPERATURE separate from CONTROLLING VISCOSITY.

ATEX Approval

2010-06-16T12:03:00.000-07:00

ATEX is a European standard which falls under the Machinery Directive of the EU.

Its purpose is to ensure that devices used in hazardous locations are safe for use.

However, there is massive misunderstanding about this standard.

1. Some devices cannot be listed because they contain no hazard, and the EU has no provision to provide a certificate to show a device is ATEX Exempt.

This includes mechanical pencils, pipe nipples, machine frames, simple temp probes with IS Barriers, fiber optic devices, etc.

2. This happens to us with our inline M51 Viscometer. This is a device which goes directly in an ink line. Thus its interior is Zone 0 and Exterior is Zone 1.

3. While this device contains pneumatic, mechanical and electrical components it has been determined safe by TUV but is not ATEX marked.

4. The reason it is not ATEX marked is because Norcross designed it to avoid the hazards that ATEX is concerned with .

How can this all be ?

Well ATEX is concerned with the following:

A. Does the device have a hot surface ?
B. Does the device emit flames or hot gases ?
C. Are there mechanically generated sparks ?
D. Does the device create stray electrical currents or
can it suffer from cathodic corrosion ?
E. Does the device generate static electricity ?
F. Is the device subject to lightning strikes ( we mount indoors) ?
G. Does the device issue Electromagnetic Waves ?
H. Does the device issue Ionizing radiation ?
I. Does the device use or issue Ultrasonic waves ?
J. Does the device create adiabatic compression and shock waves ?
K. Does the device have any exothermic reaction?
L. Can the device be incorrectly installed such that it might
cause an ignition threat?

While I don't promise that the above list is totally complete I have prepared this from our own TUV report.

Our device presents no hazard under any of these categories and therefore is exempt from the ATEX Seal.

My question to the EU is " Why don't you provide a ATEX EXEMPT seal so that all equipment suppliers can stand on the same ground ? "

That's all for now.

Paint Mixing - High Thixotropic

2010-06-16T09:42:00.000-07:00

Greetings

Today I have a story about a major US cabinet manufacturer who was trying to measure and control the viscosity of their paint, which was being piped out and sprayed onto cabinets.

They had 55 gallon drums with a constant rpm mixer. The mixer was set at a speed so that when the drum was mostly empty, the ink would not foam. When they refilled the drum with new paint (at the same % solvent as what was in the drum) the mixer speed was not changed.

What is wrong here ? What do you think?

Hint: mixing, mixing, mixing.

When the drum was full there was less net mixing energy being applied to the paint and thus its viscosity (by efflux cup) increased. even though it was at the same % solvent.

Thus when automatic viscosity controls were attempted, they would over-dilute. The solution would have been to keep the levels more mid-range and provide more vigorous mixing, plus to only add small amounts of paint to the system. This would give you stability and then you could control viscosity.

With Thixotropic solutions you need to mix them until they reach a point of viscosity where a change in mixing energy does not result in a change of viscosity.

Physical Embodiment of Theory of Measuring Viscosity

2010-06-10T03:50:00.000-07:00

What does this tell you about a reliable way to

measure viscosity in a process application ?

Newtonian Fluid Viscosity - Bend Your Mind

2010-06-10T03:30:00.000-07:00

Dynamic or Absolute Viscosity =

Shear Stress ( the pushing people )/Shear Rate ( the velocity)=

[force/area] / [velocity/gap] = [dynes/cm2] /[(cm/sec)/cm] =

[(gm-cm)/(sec2-cm2)] /[cm/(cm-sec)] =

gm/(cm-sec) =

poise

Thus it is obvious ( joking) that how you measure viscosity will determine what your viscosity value is UNLESS your fluid is Newtonian - like pure motor oil and/or some silicone solutions.
Newtonian Fluids have a linear relationship between the pushing and the velocity.
Most inks, coatings, lacquers, resin and industrial fluids are Non-Newtonian - see the other post for information on that.

Corrugated Glue and Starch Kitchen - End Point Viscosity Control

2010-06-09T13:27:00.000-07:00

Some corrugators make their own glue (starch) to glue paper to each side of the Z flute paper, in order to make a piece of corrugated cardboard.

The preparation of the glue is done in a 'starch kitchen', where they add starch and water to a tank and then heat and mix the solution until the starch and water reach the right viscosity.

This can be a difficult process to measure, unless you use a simple device such as the inverted falling piston of a M8BU. The inversion is used because there can be particles of dry starch which need to be able to fall out of the measuring gap.

The process is typically:

1. Operator adds starch and water to tank.
2. Viscometer is OFF
3. Kitchen starts to heat and mix starch and water mixture.
4. After a period of time, sufficient for the starch to have dissolved, the
M8BU is turned on.
5. Now continue the batch until the Piston Time of Fall(TM) Method gives
you the desired number. This number is determined experimentally.
6. When done remove the glue from the tank,wash out the tank and the equipment in
the tank and you are ready for the next batch.

Is this what they are doing ?

Further along the process stream, there have been a few occasions where the coating being used is circulated and diluted with water on an ongoing basis. In this case
a M8BO can be used in that tank like a regular control system.

Firms such as Ringwood, Serco, Alliance Machine and Vortx have all used this equipment, some going back 30+ years.

I Can Control My pH by Controlling My Viscosity ??

2010-06-08T07:26:00.000-07:00

Not !!

In the trade the rumor has been spread that one can control pH by controlling viscosity. Technically this is totally false and chemically is impossible.

It can be made correct only if the speaker adds " you can control your pH by controlling viscosity only if you add some amine to your water supply.Thus as the viscosity changes and water is added you get a little amine with each water addition. However, this is indirect control and you need to guess how much you contaminate your water supply with amine.

In reality they are two different characteristics of fluid - one is physical and one is chemical. If your pH never changes then you can do just viscosity control, BUT, if you have to hand check your pH and ever need to have an operator add some amine then YOU NEED to control pH separate from Viscosity. To think otherwise is to think counter to science.

pH or Viscosity

2010-06-06T19:01:00.000-07:00

Question:

When using water-based inks is it more important to watch your pH or Viscosity ?

Answer:

Since pH affects the flexiblity of the ink molecule, a decreasing pH can actually make the ink appear to be increasing in viscosity. Therefore, first make sure your pH is correct, then adjust for viscosity.

Viscosity of Water

2010-06-06T18:51:00.000-07:00

There are very few viscometers which can measure the viscosity of water as it is heated from room temperature to near boiling. In fact there is only one process viscometer that can provide this. It is the Norcross(R) Falling Piston(TM) Viscometer.

With the correct configuration we can measure the changing temperature of water by measuring it's viscosity.

I have never seen another process viscometer do this.

This sensitivity is, to my current knowledge, unique to Norcross Corporation equipment and with such sensitivity we can measure solutions as low in viscosity as silicone/acetone solutions of approx .5 cps used to coat hypodermic needles.

So the next time you have a cup of tea, take a look at the water - before putting in the tea bag - and try to guess just how thin it is. Then look at a cup of room temperature water and try to guess.

I know where the answer is, do you ?

Norcross's First Viscosity Control Applications

2010-06-06T18:47:00.000-07:00

Greetings

Austin Norcross was an instructor at MIT, Boston MA in the 1930's and 40's. While working with an instrumentation company he came across a problem in the textile industry.

Sizing, that starch coating applied to the threads ( called a Warp ), needs to be the right viscosity to provide the correct thickness.

If the starch is to thick then the over-coated thread could cause a problem in the loom, if too thin then the coating would provide inadequate protection to the threads from the loom.

First Austin developed the Brass Norcross Cup which is designed to hold the heat of the hot starch and provide a simple manual measuring method.

Then he eventually developed a way to measure automatically and thus alert the operators when the viscosity was out of range.

Viscosity Control in China

2010-06-06T11:00:00.000-07:00

Feel free to visit www.viscosity.cn or www.norcross.cn if you prefer some information in Mandarin.

Turkish Gravure Printer Saves 40% of Ink

2010-06-06T10:40:00.000-07:00

Though it has been known for years it still surprises many manufacturing operations at the incredible savings that a good viscosity control system can provide. A certain printer in Istanbul has a 6 station gravure press using solvent based ink. The operator used to mix 5 containers of ink for each days work, now he only needs 3. He is happy, their quality is up and their ink costs are down 40%.

First Entry www.viscosity.com

2010-06-06T07:01:00.000-07:00

Greetings World

This is the beginning of a process of sharing and offering advice on Process Viscosity Control. My family has been doing this since the 1930's and we have experience in many industries / applications and countries. www.viscosity.com

Welcome One and All