Volume 5  Number 1                            Dennis R. Dinger                                1 November 2006

Updates

The E-zine

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"... for Ceramists" Series Books

The paperback version of Characterization Techniques for Ceramists is available on the Books and Downloads page at the web site!    Retail price is $29.95 plus shipping and handling. The book has 256 pages and it covers 34 different characterization techniques that are commonly used by ceramists.  Order your copy NOW!

The book sets on the web site have also been revised to include this new book.  A 3-book set of paperbacks, including one each of Particle Calculations for Ceramists, Rheology for Ceramists, and Characterization Techniques for Ceramists, is now available for $64.85 plus shipping and handling.  This is a $10 saving off the total retail price of the 3 paperback books.  A 3-book set of downloads is also available for $52.85.  This, too, represents a $10 saving off the total retail price of the 3 downloadable books.  

The E-Book version of Characterization Techniques for Ceramists is available for downloading at the Books and Downloads page of the website for $24.95.  The download is a 2.889 Mb self-extracting Zip® file for the Windows® environment which unzips to the 2.998 Mb book in PDF file format.  Those of you who order the downloadable book will want to know that the PDF book is formatted to print on 5.5" X 8.5" paper (i.e., 8.5" X 11" sheets cut in half.)

The other two books, Rheology for Ceramists and Particle Calculations for Ceramists, continue to be available for purchase as downloadable E-books and as paperback books at the Books and Downloads page of the web site.

Chemical Details and Documentation Considerations 

Introduction

There are lots of different types of chemical additives that are used with ceramic processes.  Frequently, ceramists are not chemical experts, so they don't pay close attention to the compatibility of their additive chemicals or to the details provided by MSDS sheets for each chemical.  Regardless of your level of expertise in chemistry, it is necessary --- absolutely necessary --- that you pay attention to the details of each chemical's properties and that you question and/or test the compatibility of chemicals with each other.  Strange things can happen when such issues are not considered.  

Another question we might ask is WHY? ---- Why did the designers of a process made the decisions they did.  When was(were) the decision(s) made and are they well-documented?  With engineers changing jobs frequently between companies or within companies, to lateral or advanced positions, adequate documentation is a necessity to address such questions.  Are your processes documented adequately?

Some of these problems may stem from an average engineer's dislike for reading and/or writing.  Some of these problems may stem from a company's lack of documentation requirements in the form of reports, publications, and lab notebooks.  Many such problems occur years after a process has been developed and placed in operation.  Where are the designers of those projects and processes today?  Where is the documentation the designers produced to explain the process or operation?  Did the designers produce documentation for a process or operation?

We will consider several examples of these types of problems in this article.

Additive Chemistry Example One

The first incident that comes to mind is a company which came to us to determine the problem with their production body.  It contained several different chemical species, but more importantly, it gelled (or curdled) after sitting on the shelf for a few weeks.  Why did it do this?

Upon contacting suppliers of ingredient chemicals, we learned that it was recommended that one additive be used only at pH values greater than 9.  The recommendation on another additive was that it be used only at pH values less than 7.  A note about shelf-life was contained on a third additive --- it would gel (or appear to curdle) after several weeks.  The other additives all had similar warnings and recommendations.

It was interesting that the very problem to be identified for this body appeared as a warning on one of its ingredients.  It was curious, also, that the two other additives were used -- even though one was supposed to be used only at pH values less than 7 and the other only at pH values greater than 9.  Last I checked, those two conditions were mutually exclusive.  Did the designers know this, and use the two chemicals anyway?  We don't know!  Apparently, this process was not well documented.

This particular problem was solved rather quickly -- but it left many unanswered questions --- both to us, and to the process engineers.

Who Actually Designed the Body?  .... and Why?

Do we engineers and scientists keep good records and write good reports to explain what we did, and why?  Consider the following case:

An engineer came to us for help on his process.  That process was designed in the late 1950s or early 1960s.  It was revised several years later (apparently by the original designers.)  The process then ran for years ( twenty-five or more????) without alteration.  At that point (during the 1990s), this engineer inherited responsibility for this process.  He tried to learn the details of the process, but there were no records to explain how and/or why any parts of this process were designed as they were.  None of the original designers worked for the company any more.  They either had changed jobs, retired, died, or combinations of the three applied.  In any case, they were not available, nor were any records or reports.   

So what's my point?  No one at that company had any idea why the designers set up the process as they had.  Was it because they had particular raw materials that only worked in the process as they designed it?  Did they have several choices of process design and they decided to select this one?   Did they choose this one from several equally-good alternatives?  Were there critical points in this process that this particular method skirted?  In all of these cases, no one knew any answers.

This leads to another question:

How Good Are Your Records?

Some companies don't keep great records because (they say) they are afraid someone will steal their documents and learn their secrets.  Many engineers simply don't like to write.  (In college, we always used to joke that we were engineers --- you know --- we had low verbals [i.e., low verbal scores on SAT exams]).  I have taught a lot of engineering students since then who were poor writers.  When I was in college, I certainly was a poor writer.  I once actually saw Jim Funk's recommendation for me to graduate school.  He recommended they accept me -- but he told them I was a lousy writer.  So here I am today, writer of e-zines, co-author of a 700 page textbook with Jim Funk, and author of several other books.

How did I learn to write?  By writing and writing and writing.  I learned by doing.

It may seem that we are far afield from the original question, but not really.  In addition to being a poor writer, I did not really like to read.  I read a lot these days, considering that I was and still am a slow reader.  I have one speed --- slow.  Most of my family can read a Louis L'Amour western in a few hours.  It takes me several evenings to finish the same book.  The slow reading is the main reason why I still claim I do not like to read.  I believe this dislike for reading also deserves credit for my inability to writer well.  

If I read and write fairly well today, it is only because I have practiced, practiced, practiced.  

Over the years, I have taught many engineers who also fit into this same category.  They don't read any more than necessary --- and they don't write any more than necessary either. 

If you don't like to read, are you going to slug your way through the fine print on the bottle's label, or on the bag, or on the sales literature, or on the MSDS sheets?  I think in many cases the answer is, "No."  We make assumptions, without bothering to read the details that are actually provided.

Don't most engineers follow the motto, "When all else fails, read the directions!"?  Many people are surprised that I actually read directions --- not all the time, of course, but more often than not.  My wife is constantly amazed that I actually read directions.  When directions are not available, however, I simply dive right in.

And if you don't like to write --- but you must --- are you going to write excellent, high quality reports that others can follow?  In labs, we teach that data and procedures, etc., must be entered into lab notebooks so you and others (engineers, managers, etc.) can precisely read, understand, and repeat the experiment exactly at a later time and/or place --- and exactly reproduce the results.  Do we write this level of details into our lab notebooks and in our reports?

Do we explain (as if we are writing into a diary) why we chose a particular process or why we added a particular feature, etc., to our processes?  Do we enter our reasoning into our notebooks, or do we reserve it only for tables of numbers and data?  I think in many cases, we reserve our notebooks only for tables of numbers and data.  Numbers are insufficient.  Reasoning and decisions should also be recorded.   

Do we produce laboratory notebooks that are neat enough for others to read and learn how and why we did things?  I think not.

"Why Don't You Write Down What You Know?"

This is a question that I posed to a senior engineer in my first industrial job.  I was a new college graduate who was learning the business and the details of our particular products.  He seemed to know everything about everything.  Having been in that job and company for most of his career, he had an absolute wealth of information in his head.  So I suggested he write it down so we all could benefit from his experience.

His answer:  "That's too great a task -- I wouldn't know where to begin."  So he didn't begin.  When he retired a few years later, he took his vast knowledge and experience with him.  That company lost a great resource, and after his retirement, their engineers could no longer benefit from his knowledge and experience.  Frequently, therefore, they were forced to reinvent wheels.

The PPC textbook that Jim Funk and I wrote is the result of this same question.  In addition to being co-author and technical editor of that book, I am most pleased that I was able to facilitate the recording (in a form that is available for all to see) of much of Jim's vast ceramic technical knowledge and experience.  I didn't ask him this specific question.  We simply set out to develop a processing short course for practicing ceramic engineers -- a course that would use an easily readable handout.  The handbook continued to get bigger and bigger.  Then one day a representative of a publishing company walked into my office looking for technical ceramic books that his company could publish.  I told him we had this huge document we were using for our courses.  So our short course handout became a textbook.  (The book is now out of print, but I still have the original handbook that I've been copying and making available in lieu of the textbook.)  Jim died several years ago, but we still have some of his knowledge and experience recorded in this book.

This question should be applied to all of the senior engineers in your companies.  Is this a priority within your company?  Are your young engineers encouraged to write excellent notes and detailed reports?   Are your senior engineers encouraged to write textbooks or large reports that organize and preserve what they know for future engineers?

If we don't do this, we end up reinventing wheels.  We force new process managers to perform research just to figure out how they should be controlling their new processes.  And we force all other engineers to reinvent wheels that many older engineers already know and/or understand.

Many subscribers to this e-zine are in the age group who should consider organizing and writing down all that you know.  Many of you younger readers should be encouraging senior engineers to do this.  Yes, it can be a formidable task.  But it is a worthwhile formidable task.  Start now!

Additive Chemistry Example Two

Another company was using an anionic polyelectrolyte as a dispersant along with a PVA binder to improve green strength.  They weren't achieving their desired green strengths, so they added more binder.  That caused body viscosities to increase, so they added more deflocculant.  Their next bodies still didn't have enough green strength, so they added more binder and then they added more deflocculant.  This two-stage adjustment process (more binder, more deflocculant) was repeated several more times --- with rapidly diminishing returns.

Their original composition should have had more than enough binder to achieve their desired green strength.  After their first adjusting increase of binder, their body should have been plenty hard -- but it wasn't.  They continued to increase both binder and deflocculant several more times without achieving desired strengths.  It was clear that they weren't achieving the full binding power of the binder, but the reason "Why?" was not clear.  

It turns out that no one had ever tested the compatibility of the binder with the dispersant.  When they mixed pure binder with pure dispersant, they ended up with a beaker of dispersant with what Jim called a "hockey puck" of binder floating in the middle of it.  This same phenomenon was apparently also happening in their body.  When they added more and more binder and deflocculant, the binder was apparently forming little droplets (micelles) which floated in the interparticle fluid/dispersant mixture.  Droplets of binder in the interparticle fluid will not perform the binding function as will binder that is spread out on particle surfaces as expected.  Since binder molecules were not coating particles, green strengths weren't increasing and the benefits of the binder additions weren't being effected.

The test for compatibility of the deflocculant and the binder was performed as an afterthought -- only after there was so much binder in the body that the wares should have been rock hard (but they weren't.)

Summary

It is necessary that ceramists carefully read the fine print on MSDS sheets for their raw materials and chemical additives, and that they compare and consider whether all of their chemical additives are compatible.

It is necessary that ceramists also pay attention to other issues, such as shelf life of all additives going into their production bodies.  Some new additives are biodegradable which can possibly be controlled by co-additions of preservative chemicals.  Are we noticing these kinds of details?  Are we considering the specific properties of our chemical additives and combinations of chemical additives?  Are we using this kind of information to help us make process decisions?  WE MUST!

It is absolutely necessary that ceramists produce excellent documentation for their research and production processes.  We write reports and papers to tell others exactly what we did.  In many cases, we are the very ones who need these papers, reports, and notebooks, to help us to remember exactly what we did (and why we did it) a long time ago.

For example, do you remember why, after you ran a rheogram of your slip production body back on 17 August 1981, you decided to change both the deflocculant type and concentration?  ... and why you decided to use those particular values?  Do you remember the specific reasoning and logic which led to that decision on that particular occasion?  Does the engineer that is now responsible for that particular body and that particular process have access to your notes, reports, publications, and reasoning on that particular occasion?

This is exactly why we write reports and keep documentation on everything we do.    Do we do this?