There are No Silver Bullets, Kemosabe!

We’ve all seen it before…

The salesperson sits in front of us and spouts all of the benefits of their products:

“It’ll save you money!”

“It’ll reduce your defects!”

“It’ll increase your throughput!”

“It’ll make your wife beautiful!”

“It’ll make your kids behave!”

OK, maybe those last two are a little over-the-top, but…

The Cascade Effect

Often, control systems have a “cascade effect”.  By controlling one factor in our process, we affect other parameters that we hadn’t originally targeted – often for the better (fortunately)!  For instance, we stabilize our pressure regulation, and oscillation in our control valve decreases.  This decrease in oscillation allows us to increase the gain in our control loop and improve our response time!  It’s a natural chain-of-events – a normal system reaction – but our salesperson hypes it all as huge benefits!  And we start to wonder…

Stacking the Deck

So lets’ look at it from the other side…

As salespeople, we all want to put our offerings in the best light.  Often, we feel it’s up to us to educate our client.  We’re the “expert” and they’re depending on us to let them know what to expect – no surprises.  We’re acting in their best interest…

The problem is, even if all the claims are true (and documented), at some point, all these benefits start to stack up and it all just sounds too good to be true – and we all know what that means... 

It Happens to Us All the Time!

No place is this “Cascade Effect” more apparent than in the area of temperature control!  When you start to manage temperature, a lot of other things get affected.  Let’s take a 2-roll reverse coil coating process for example.  Now let’s hold the temperature of the incoming paint at a constant 95°F…

First off, this means that the paint will be at a constant viscosity.  And because 95°F is above normal ambient temperatures most of the year, we probably won’t have to add as much solvent to reach the desired viscosity (cost savings, anyone?).  The constant viscosity means that the applied film will be more consistent (improved quality?).  And the reduced solvent addition means a lower solvent load in the oven, which means we may be able to run at higher line speeds (increased throughput?)  But wait, we haven’t even gotten started yet…

Next, this “above-ambient-temperature” paint will start to heat the rollers, bringing them quickly to 95°F – rather than waiting for friction to do it over time.  This shortens our stabilizing time.  But then the friction generated by the rollers will start to drive that temperature above 95°F.  Now, if we can switch seamlessly from the heating mode to the cooling mode (and we can), the circulating paint will remove the energy added by friction, which then keeps the rollers cool (well, comparatively) – which controls roll swell – again, keeping the system stable and eliminating the need for the operators to intervene and make adjustments.

And it all starts to sound too good to be true…

If It Sounds Too Good To Be True…

…so it probably is!

In our temperature control example – all we have done is made temperature a tool – just like controlling pressure or motor speed – just another variable in the process that we have placed under our control.  But that comes with a cost. 

In fact, there is almost always a cascade effect – but there are trade-offs, too.  Adding temperature control means that you don’t change setups with the season.  You can no longer measure viscosity in the drum and expect it to be the same as what’s being sent to the process.  You can no longer use the drum viscosity measurement to determine how much solvent you add. 

This means new processes and new procedures.  This means updated training.  This means the familiar balance the operators have grown to know, and take for granted over the years, has changed. 

In short, there really is no “silver bullet” for any process.  It’s just like getting a new car.  The steering is more responsive.  The brakes are more sensitive.  It’s a little like learning to drive all over again.  But most of all, it’s a little uncomfortable – until you get used to it!

Did you enjoy this? Find more like it at: The Business of Viscosity Blog!