Miller Time: More on Angel Hair


Rob Miller

Further to Dr Henwood’s comments on Angel Hair, I would like to add the following…

Dr Henwood is correct that it is typically formed due to high temperatures in the conveying line.

I would comment that a good conveying system design utilizing good conveying parameters can be employed to eliminate the creation of angel hair, therefore eliminating the need for any kind of angel hair trap. Traps can be helpful in collecting the angel hair that is created, but why not investigate and potentially eliminate the basis for the angel hair creation?

Most conveying in the plastics industry is known as “Dilute Phase conveying”. This typically represents that the conveying line is approximately 10-15% material concentration at any given moment.

In the designing of a conveying system, there are limited factors that can contribute to a safe or unsafe conveying situation.

Velocity is everything in conveying. Continue reading

Ask Dr. Nick: Avoiding “Angel Hairs”


Nick Henwood

On ARM’s most recent What’s Your Problem? teleconference, there was a question asked about powder piping systems, especially about avoiding and dealing with “angel hairs”. I provided some follow up to the molder after the call, which we’re happy to share here for everyone’s use.

My first recommendation was to contact ARM’s mainstream pulverizer supplier members, who should be able to offer good advice. They are the real experts in this area.

In the meantime, I also recommended installing simple traps for angel hair in your lines.  Pulverizer systems have these in place.  The grid has something like ½ inch gaps and the sideplate can be opened for manual removal of accumulated debris.  The pulverizer folks will have proper drawings of this; please excuse my rudimentary draftsmanship!

trap for angel hair

As far as I’m concerned, angel hair production gets bad when ambient heat is sufficient to start to soften powder particles.  A particle momentarily trapped on an obstruction will then get stretched and elongated by fast air flow around it and a hair gets formed.  So keeping temperatures down (say below 100°F), or not generating elevated temperatures in the first place (correct pipe sizing and avoidance of sharp bends), should help a lot.

Note from staff: ARM offers What’s Your Problem? teleconferences — an audio version of our popular troubleshooting workshop — to our members every six weeks as a free benefit of membership.

Dr Nick Henwood serves as the Technical Director for the Association of Rotational Molders. He has 25 years-plus experience in rotomolding, specializing in the fields of materials development and process control. He operates as a consultant, researcher and educator through his own company, Rotomotive Limited, based in UK.

Executive Forum in Napa: Speakers

Join your rotomolding colleagues March 25-27 at the Archer Hotel in Napa, California for the ARM Executive Forum. Below we’re highlighting a few of the event speakers.

Dr. Christopher Kuehl, Armada Corporate Intelligence , is one of our highest rated speakers and we’re glad to welcome him back after speaking at the Executive Forum in 2015. He has been Armada’s economic analyst and has worked with a wide variety of private clients and professional associations. He is the chief editor for the Business Intelligence Briefs, distributed all over the world by business organizations and he is one of the primary writers (with Keith Prather) for the Executive Intelligence Briefs.


Chris Kuehl

Seeing the Dark Cloud Behind the Silver Lining – Five Things to Worry You in 2019

There is no doubt that 2018 was a good economic year – low unemployment, solid growth, a robust (if volatile) stock market. But trouble is never very far away and 2019 is likely to be a lot less encouraging. The five most worrisome aspects of the coming year will include the return of inflation, negative reactions to the trade wars, truly bitter partisanship in government, mounting debt levels for the government, corporate community and the consumer and drastic changes in leadership for countries that matter to the US (Mexico, Brazil, UK, Israel, Germany and others).
There will be some bright spots as well – nobody wants to be utterly depressed so early in the year. The real question will be whether the bad stuff can be managed and dealt with soon enough to avoid a recession at the end of the year or early 2020.

Ben Varquez is a partner at Whistle Work, an employer and industry branding, recruiting and retention solution. He’s also the managing director of Youth Marketing Connection, the largest student-focused marketing agency in the United States. Throughout his career, he has worked closely with industry leaders such as Google, Capital One and Spotify and leading trade and professional associations such as the American Institute of CPAs and the Center for Audit Quality. Varquez is a graduate of The George Washington University’s School of Business, an outdoor enthusiast and a lifelong learner. He enjoys cooking, building furniture and playing ultimate frisbee.



Ben Varquez

Attract and Retain the Next Generation Workforce

Many plastics processors  struggle to find candidates to fill their job openings. Low unemployment, while a great sign for the economy, compounds this issue. In this session, you will take an all-encompassing look at developing, recruiting and retaining your future workforce. You’ll learn best practices by reviewing multiple research studies, engaging with experts and analyzing real-life examples of what Millennials and Gen-Z are looking for in a career and employer.


John Mackay

John MacKay, Chairman of the Mackay Research Group, served as Vice President of the Profit Planning Group, a research and executive education firm headquartered in Boulder, Colorado. He joined the Profit Planning Group in 1982 to head up its profitability survey activities. Over his 20 year tenure, John helped build PPG’s client roster from 1 to 80 associations, most of which were distributor-member based. In 2001, PPG began to expand its client base to include more trade associations with manufacturer members. In the process, it became clear that many of the tools PPG had developed for distributor clients did not quite fit for manufacturers and that some changes would be required. To respond to this growing need, in 2003 Mackay spun-off a segment of the company so he could work with manufacturer clients in a more targeted manner. John is a frequent seminar and convention speaker on topics such as Improving the Bottom Line, Getting Serious About Profit, and Doing More with Less. John received his undergraduate degree from The Ohio State University and his MBA from the University of Colorado.

Insights from the ARM Wage and Benefits Survey

John Mackay and Taylor Mackay will present on the compensation they conducted of ARM members. They will present key insights to the entire meeting, and conduct an additional discussion with those companies that submitted data.

Jon Ratzlaff, Chevron Phillips Chemical Company, is the Technical Service Manager (for Rotational and Injection Molding Polyethylene) responsible for business development and support through design, processing, and polymers (technical services).  Jon has been involved in the plastics industry for 30 years. He holds experience in rotational molding, injection molding, compounding, extrusion, film, sheet and thermoforming. He is a graduate of Oklahoma State University in Chemical Engineering. He has time well spent in management, manufacturing, quality, research and development, and technical service which includes his favorite: product/application & business development.  He was on the Executive Board of the Society of Plastics Engineers for 7 years including the President in 2013-2014.


Jon Ratzlaff

Exciting Growth in Plastics Require Sustainable Solutions

Today  is an exciting time to be in plastics industry.  With an ample supply of low cost feedstock, North America has seen unprecedented increases in plastics production.  Polyethylene in particular has seen the highest production growth in the history of North America.  But in spite of high growth coupled with strong worldwide consumer demand, plastics have come under fire in the public’s eye with increased attention being placed on mishandled plastics entering our waterways and oceans.  Some have proposed plastics bans,  but the truth is these materials are needed by a growing middle class to meet basic human needs for safe food, safe water and energy efficient homes and transportation.  In response, a range of programs are under development to address post consumer plastics mismanagement around the world while continuing to meet the needs of a growing middle class. This presentation will highlight drivers behind this unprecedented industry growth, the challenges faced by our industry and the illustrate examples of programs under development to deliver sustainable solutions globally.

Panels and additional speakers will be announced as well. For more information and to register visit: 

The State of ARM: Scholarships for High School Seniors

The Roy Crawford Education and Development Foundation has just announced that it will award three scholarships to graduating seniors this coming spring.

Employees of ARM member companies and their children are eligible to apply by completing these forms by March 18, 2019. The Foundation will award at least three scholarships of $2,000 each.

This scholarship is a new benefit that ARM member companies can offer employees! Please spread the word among your company.

We are also announcing multiple ways to support the Foundation. Make a general donation to support all of the Foundation’s projects (including rotomolding R&D and education), help build our scholarship fund for future years, or make donations that will be used in their entirety to increase the total scholarship amounts awarded in 2019.

The State of ARM: New Website

ARM’s new website is now live. The redesign subtly improves the visuals on the site but the big changes are behind the scenes.

Members will find that the user experience is significantly improved. For example, once signed in, you will be able to register multiple people instead of being required to log out and back in.

We have focused on making sure that our online benefits are accessible and improved on the new site. We have converted our webinar library so that everything will be accessible on iOS devices.

Screen Shot 2018-12-02 at 1.49.30 PM

We’re ending the year by sharing updates with our members on The State of ARM.

Ask Dr. Nick: What’s an Acceptable Scrap Rate in Rotomolding?


Dr. Nick Henwood

Recently an ARM member from Latin America phoned in with a technical question and we got into a conversation about the vexed subject of scrap.  I appreciate that it’s a bit of a prickly issue and probably not something individual rotomolders would be keen to discuss openly.

Not being a molder, I was probably more comfortable than most to tell our colleague what I had observed myself, having worked with hundreds of rotomolding companies over my 30 years in this business.

I thought that my observations might be useful, if only to reinforce how important this issue can be commercially.  We have to live in the real world, so some scrap is almost inevitable. Rotomolding is simultaneously fascinating and frustrating, because there are so many variables at play and not all the variables are easy to control (eg the weather / ambient conditions).

It seems to me that the main trick is to stay vigilant and bear down on scrap and the reasons why we may make scrap.

Anyway, here are some of my thoughts.  If any of you molders out there would comment, that would be fantastic!  If you think I’m talking nonsense, feel free to “roast” me! Continue reading

The State of ARM: Roy Crawford Rotomolding Education and Development Foundation


Professor Roy Crawford

In June 2018, the Rotomolding Education and Development Foundation’s Board of Governors voted to change the organization’s name to the Roy Crawford Rotomolding Education and Development Foundation. This change is an opportunity for the Board to proudly pay tribute to a true pioneer and giant in the rotomolding process, Dr. Roy Crawford.

This year the Foundation has been able to take significant steps in achieving its mission by moving forward with two projects identified early on as primary goals: making rotomolding training more accessible and funding research projects that support our industry as a whole.

The first of the Foundation’s 2018 milestones is the completion of a rotomolding curriculum, which the Board of Governors has been developing since the Foundation’s earliest days. The curriculum has been made accessible to rotomolders by ARM in the form of the Operator Training Program, a series of webinars discussed above.

The Foundation’s second major milestone of 2018 is the collection of proposals to fund rotomolding research projects and the awarding of $10,000 in grants this year. The funded projects will be presented at future rotomolding conferences for the advancement of our industry.

The Foundation is currently announcing the funding of a research project on the Effect of Pigment Addition Rate on Impact Strength for Dry Blends to be conducted by Dr. Nick Henwood.

The Foundation also plans to announce funding for a second project once a schedule for the research has been finalized.

We’re ending the year by sharing updates with our members on The State of ARM.