April 2009

President’s Message

I hope this letter finds all of you well. This month I wanted to write about something that is timely and relevant to all of our membership as we put the first quarter of 2009 in the record books. The South Texas section of the Society of Plastics Engineers is a very large and diverse group of plastics professionals. Our section membership represents a majority of the special interest groups in the SPE. The communities in which we live and work, as well as the relationships we share, have never been more important than today.

While I don’t wish to dwell upon the negative economic news of the times, I would like to take this opportunity to focus on the positive and build on the strengths that we have as a community of plastics professionals. The knowledge and information we each hold, such as market trends and opportunities, available personnel and services, are powerful tools for growing revenues, reducing costs and improving margins. Our individual strengths and business acumen are enhanced when we invest the time to escape from our offices and exchange knowledge and build relationships with other plastics professionals.

On a monthly basis, our section provides many opportunities for our members to participate in professional fellowship. We hold a breakfast meeting the first Tuesday of every month at the I-HOP at I-10 and Washington. A lunch meeting is held the third Friday of every month at the Steel City Pizzeria in The Woodlands. In April we will be hosting a golf tournament on the south side of town at the Timber Creek golf club in Friendswood. There are a host of other committee meetings and informal opportunities to get together. Check out the website www.spe-stx.org or call any of the officers listed on the website for directions and a friendly face to welcome you and help make introductions.

Today we have many tools available to exchange information and help each other. We may use the networking services of Facebook or LinkedIn to communicate to groups of people and share ideas. I would encourage you to contact me with ideas you may have as section members and industry professionals for collaboration, idea sharing or provide networking opportunities for those seeking employment. As long as we are operating within the guidelines of our Anti-trust policy all ideas are welcome.

I would ask that you make a commitment to go to at least one event in April. Stop by the breakfast or lunch meetings, and I look forward to seeing everyone at the Timber Creek Golf club on April 20, 2009. Register now at http://www.spe-stx.org/GolfOuting.cfm

http://www.timbercreekgolfclub.com/golf/proto/timbercreekgc/course/course.htm

Wishing you the best,

Jeff Applegate
SPE South Texas President 2008-2009

http://www.facebook.com/group.php?gid=35280334773&ref=ts

Join the South Texas Section of the Society of Plastics Engineers on Facebook. Click on the above link and you will be directed to our group page. We hope that this will serve as another communication tool for our Professional Section and be a familiar platform to welcome and inform the Student Sections. It is easy and free, so join in.

Plastics Hall of Fame Taps New Member

By Bill Bregar | PLASTICS NEWS STAFF

CHICAGO (March 6, 4:45 p.m. ET) -- The Plastics Hall of Fame’s class of 2009 covers a global spectrum of leaders in materials, machinery, screws and packaging.

Donald Witenhafer

Witenhafer pioneered technical achievements at B.F. Goodrich Co. that helped save the PVC industry after it was discovered that vinyl chloride monomer causes cancer.

In 1969, Goodrich’s plant physician at its Louisville, Ky., plant called a news conference to announce that several workers had acquired a rare form of liver cancer. These were workers who entred the PVC suspension polymerization reactors after each batch and scraped polymer buildup off the walls. The doctor announced the VCM was a likely human carcinogen.

Goodrich’s board of directors created an emergency project to solve the problem. The team included Witenhafer, a scientist in the PVC polymerization research and development group.

The team thoroughly studied PVC production, looking at ways to eliminate emissions and reduce the residual, un-reacted VCM to very low concentrations before it left the plant.

Witenhafer made the key innovations to solve both of those problems.

He worked for Goodrich for 20 years and SC Johnson & Son Inc. as manager of polymer research for five years before starting a consulting business in 1992.

Bulletin Board

Plastics Information: Check it Out

The Houston Public Library on McKinney has resources on plastics and polymers. Check out their catalog at www.hpl.lib.tx.us. If you are not near the McKinney location, you can arrange to pick up your books at your local branch.

The Fondren Library at Rice University has the most complete collection of books on plastics and polymers. This is also a prime resource for patent and trademark information, as well as other US Government documents. You cannot check out books there unless you join Fondren Library [$50], but you can arrange for books to be sent to your library by inter-library loan. Use their catalog at http://library.rice.edu/.

The next best place to browse is at the MD Anderson Library at the University of Houston central campus. South Texas Section has donated many plastics books to this library. If you plan ahead, you can get a TexShare library card from a library where you are a member, which will allow you to check out books from any U of H library. Their catalog is at www.library.uh.edu/.

Book Bag

	Scientific Molding Package - 8 Online Courses SPE | A. Routsis Associates, Inc. Online Training Courses - One Year Unlimited Access $797.00 All injection molders can benefit from Decoupled MoldingSM techniques. Starting from the basics and extending into advanced concepts of Decoupled Molding, this package provides and excellent way to advance the knowledge any processor in your facility. Our Scientific Molding package is also a great way to prepare your employees for MasterMolderSM training. This pacakge includes the following: Injection Molding Basics Understanding Plastics Decoupled MoldingSM
	Fuel Cells Durability: Stationary, Automotive, Portable Knowledge Press Proceedings, 2005, 450 pages $175.00 A compilation of presentations from an interdisciplinary forum for industry leaders, decision makers, and leading scientists from academia working in the fields of system design, fabrication, and fuel testing of fuel cells. Includes the following areas of fuel cells R & D industry: • Durability issues in polymer electrolytes and membranes • Electrocatalysts durability and its effect on the system interface • State of the art in novel diagnostic and testing methods • System level prospective of fuel cells durability
	Handbook of Analytical Instruments R.S. Khandpur, 2007, 770 pages $102.00 Offers scientists and engineers a complete guide to the principles and building blocks of today's high-tech instruments, so that they can select the right analytical tools to optimize their projects and research. This expert resource covers instrumentation basics and recent advances, such as biosensors, gamma spectrometers, and visualization methods for electrophoresis. The book takes readers through flame photometers, radiochemical instruments, automated chemical analysis systems, blood gas analyzers, digital circuits, and more. Contents include: Fundamentals of Analytical Instruments, Colorimeters and Spectrophotometers (Visible-ultraviolet), Infrared spectrophotometers, Flame Photometers, Atomic Absorption Spectrophotometers, Fluorimeters and Phosphorimeters, Raman Spectrometer, Photoacoustic and Photothermal Spectrometers, Mass Spectrometer, Nuclear Magnetic Resonance Spectrometer, Electron Spin Resonance Spectrometers , Electron and Ion Spectrometers, Radiochemical Instruments, X-Ray Spectrometers

2009 Wonders of Plastics Essay Contest Winners

Thank You from Lamar

Texas A&M Polymer Specialty Certificate Program

Since the Polymer Specialty Certificate Program was approved in Fall of 2006 and students began taking advantage of the Program in Spring of 2007, PTC is pleased to announce the following:

• Six students have received the Polymer Specialty Certificate to date
• Three students will be receiving certificate in May ‘09
• One student has just enrolled

PTC is working hard in keeping students aware of the Polymer Specialty Certificate Program. We are hoping that more students will take advantage of this program.

BENEFITS

The Polymer Specialty Certificate is designed to provide a strong interdisciplinary educational program for undergraduate engineering and suitably prepared science students interested in pursuing a polymer career. The certificate will also reduce training time required to turn Texas A&M students into productive members of the industrial workforce. This program is the first of its kind offered in the State of Texas. No schools in the State of Texas offer a formal polymer curriculum, despite the significant role the polymer industry plays in the state’s economy.

REQUIREMENTS

1. Be in good academic standing within major department
2. Obtain a “C” or better in each course taken towards certificate program
3. Achieve an overall GPR of 3.0 in approved certificate program coursework.
4. Submit completed Certificate worksheet to the Engineering Student Services and Academic Programs office upon registering for final course(s) to complete certificate requirements.

Required Courses: (2 of 3)
• CHEN 451 Intro to Polymer Engineering
• CHEM 466 Polymer Chemistry
• MEEN 458 Processing & Characterization of Polymers

Electives:
• AERO 406 Polymer Nanocomposites and their Application
• AERO 485 Individual Research
• BMEN 482 Polymeric Biomaterials
• CHEM 485 Individual Research
• CHEN 485 Individual Research
• CHEN 642 Colloidal & Interfacial
• MEEN 451 Viscoelastic Solids
• MEEN 455 Engineering with Plastics
• MEEN 471 Elements of Composite Materials
• MEEN 485 Individual Research

Poster Awards

Po-Han Lin
Poster Title:”Properties of Crosslinked Epoxy/POSS Nanocomposites”
School: Texas Tech University, Dept. of Chemical Engineering
Award: First Place, $1000

Mary Jane L. Felipe
Poster Title:”Synthesis & Characterization of Linear Dendron Molecules:: Non-protein Fouling Surfaces”
School: University of Houston, Dept. of Chemistry & Cemical Engineering
Award: Second Place, $750

Mai LP Ha
Poster Title: “Rheological Properties of PS-PMMA and Layered Silicate Composites”
School: Unversity of Houston, Dept. of Chemical & Biological Engineering
Award: Third Place, $500

Koffi L. Dagnon
Poster Title: “Synthetic Surface Active Clays for Enhanced PHBV Crystallization”
School: University of North Texas, Dept. of Materials Science & Engineering
Award: Honorable Mention, $125
Note: Honorable Mention Award was provided by a special grant from Mr. Gerry Wissler of 21st Century Polymers

View of student dinner Sunday evening.

SPE-STX Board Meeting

Location: Kililon Labs / Jorgensen Machinery (Houston, TX)
Date: January 13, 2009

Process Considerations for UV Curing of 3D Decorated Plastic Parts

Kevin H. Joesel, Fusion UV Systems, Inc.

Abstract

The use of UV coatings, inks, and adhesives on thermoset and thermoplastic substrates continues to grow at a rapid rate. UV and electron beam curing has moved from primarily curing of inks to functional and decorative coatings. One of the areas with the highest growth rate is the use of industrial coatings on 3D parts. Processing of 3D part presents a number of challenges – the critical process challenge is that UV curing requires line-of-sight to achieve activation and cure.

Introduction

The total market for plastic coatings is very large and encompasses a wide variety of applications. The single largest market is for automotive exterior coatings, followed closely by automotive interior coatings. The automotive market accounts for approximately 50% of the total market. Flooring, stamping foils, business equipment, DVD/CDs are also significant markets. (See Graphic 1)

The coatings technologies used in these applications vary significantly from solvent-borne 2K polyurethanes, solvent-borne and water borne acrylic and other technologies. However, actinic radiation cured coatings (including UV) currently accounts for over 1/5 of the market.¹

The advantages of UV curing technology are relatively well known. They include the ability for curing at ambient temperature, very fast curing, requiring a small process footprint, and providing coatings with improved performance characteristics. These attributes lead to the fact that the UV curing process is usually done at a greatly reduced costs. In a recent article, a case study was conducted that demonstrated the cost advantages of UV cured hardcoats for polycarbonate lenses compared to a thermal alternative. The case study documents cycle time reduction from an average of 49 minutes to 7.6 minutes, labor costs and cycle time were reduced by 85%, the burden rate was reduced by 54% and the coating cost was reduced by 33%.²

UV technology is used extensively for CD/DVD manufacturing including the bonding adhesives, memory medium, and decorative graphics. Other applications include coatings and adhesives used in the manufacture of personal electronic devices, medical devices, ophthalmiclenses, pen bodies, and golf balls just to name a few.

In the automotive applications, UV technology is used almost exclusively in the manufacturing of headlamp lenses and reflectors. Other applications include primers on Class A SMC body panels, clearcoat over decorated plastics, UV ink-jet of wiring harnesses, and silk screened instrument panels and labels. New applications continue to emerge such as a UV curable basecoat/clearcoat for automotive components³ and a coating for BMC that mimics the look of stainless steel.⁴

Further driving interest in UV technology is the continuing trend price increases in natural gas. Natural gas prices have had significant increases – over 100% -since 2000. Based on forecasts provided by the Department of Energy, the price if natural gas will not be falling under 2000 prices.⁵

A quick word about chemistry – most UV cured formulations used in these markets utilize “free-radical” curing mechanism. This is the most widely used UV chemisty class, but there are others that are being used such as cationic systems. Of course, new chemistries are always under development and new advances such as products utilizing photo-latent bases for polyurethane catalysis is just an example.⁶

From a process perspective, the type of chemistry is important, but this is usually translated to key process parameters that are the primary concern of the UV process designer.

UV 3D Process Challenges

There are three key UV process parameters :
1) UV Irradiance – Maximum and Minimum (mW/cm²)
2) UV Energy – Maximum and Minimum (mJ/cm²)
3) Heat or IR requirements – Maximum

It is very important that the formulator provides the UV radiometer used to set the process specification (i.e. EIT Powerpuck, 5W unit), the type of bulb used (i.e. H, D, or V) and the UV band ( i.e. UVA, UVB, UVC, or UVV)⁵

The formulator takes the performance property requirements from the end-user to develop the formulation that meets their needs. However, with a UV cured coating, a new set of parameters becomes a concern – spectral absorption, both by the photoactive constituents such as the photoinitiator and UV absorbers and other components such as pigments and dyes. The spectral response is determined to provide the process parameters mentioned in the previous paragraph. (See Graphic 2)

Once this information is known, then the various UV process solutions are explored.

UV Curing ProcessChallenges/Considerations

There are many factors that need to be taken into account when designing the UV curing process and how it will be integrated into the finishing line. The four primary considerations that should always start the analysis are:^3,4

• UV energy curing requirement of the coating
• Productivity
• Part size, geometry, and orientation
• Critical performance surfaces of the part

The following challenges are the primary concern of the UV lamp solution provider:^5,6

• Uniform irradiation of the UV-curable coating on the substrate.
• Minimization of shadow areas.
• Uniform and stable UV spectral energy at wavelengths consistent with the coating formulation.

There are also a wide variety of other considerations that may have been defined that could have an impact on the UV curing installation.^3,4

• New installation of retrofit on an existing line
• Physical Constriants –How much room is reserved for the UV section?
• Conveyor Type Options – Continuous chain, indexing, power & free, etc.?
• Part Arrangement – How will the parts be oriented? What are the limitations?
• Part movement – will the part have the ability to be moved during the curing process?

It should be clear that these factors are interdependent. To determine the most cost-effective solution, it is critical that the formulator, lamp supplier, finishing line integrator, and end-user should be brought together to discuss these factors as early as possible.

There are typically three distinct type of projects; a new manufacturing facility, a new or rebuilt finishing line, and fitting UV curing into an existing finishing line. As we move from a new facility toward a retrofit installation, the number of constraints increases and decreases the options available for the UV curing installation. (Graphic 3)

When creating the UV curing process design, the primary concern is how the optics of the lamp relates to the geometry of the part to provide the UV energy required by the curing process window. Though this may be a complex problem, there are a number of standard solutions that are utilized. They can be broken down into the following groups:

• Single lamp or one array of multiple lamps – this solution is used for simple shapes or for one or two-dimensional substrates.
• Multiple arrays of UV lamps – This is the most common and most flexible solution. You usually design the lamp array to provide UV energy to a defined part window.
• Automation of the lamp(s) – this can be as simple as a lamp, or an array of lamps, rotating about an axis or moving in a single plane. It can also be as complex as a UV lamp mounted on a robot.
• Movement of the part – Again
• Hybrid Systems – This is using a combination of fixed lamps with lamps that have some movement.

It should be said that coatings on convex surfaces are easier to cure than coatings on concave surfaces. However, concave parts such as headlamp reflectors exclusively utilize UV coatings. So, the most cost-effective UV curing process solution can almost always be determined through careful analysis of the various factors such as the coating’s UV energy requirement, productivity requirement of the finishing process, geometry and orientation of the part, and the optical properties of the lamp.

When considering the UV curing process for 3D parts, the part and the lamps can have one of three motions -static, linear motion, or complex motion. If we look at the options from the perspective of the part, we can analyze the various solutions and provide examples where they are used in industry. (Graphic 4)

I) Part: Static – Lamp: Static
The industry typically defines this as “static” cure system. It is not generally used in a manufacturing environment, but it is used in testing and in applications where productivity is not a key requirement. A primary example of this is in the automotive collision industry where use of low intensity UV lamps to cure spot primers has been used for several years.

II) Part: Linear Movement – Lamp: Static Single Row
This is by far the most common arrangement utilized. It is mostly characterized by movement of a part(s) on a conveyor moving through a UV curing zone. It can be as simple as a single lamp, or a single row of lamps, over a conveyor. This is common for parts with a low vertical profile. Examples of this arrangement are thermoformed plastic panels. (Graphic 5)

This is a common example where there is a defined part window. The advantage is process simplicity and robustness. The disadvantage is the number of lamps is determined by the critical surface that receives the least amount of energy.

A common arrangement is lamps oriented to cure parts racked in a vertical position where by four vertical arrays of lamps angled to irradiate the leading and trailing edges of the part.

III) Part: Linear Motion – Lamps: Linear Movement
The movement of lamps is a more complex situation. In the simplest terms, the trade-off is that automation minimizes the number of UV lamps but adds the cost of automation and adds complexity to the process. The responsiveness to the coating under the curing conditions under consideration must also be understood. Partial curing or pre-initiation of the coating may create defects or inferior performance of the coatings. Once again, the optics of the lamps, geometry of the part, and responsivity of the coating to UV energy must be considered.

Automating the previous concept of fixed arrays to illuminate the leading and trailing edges is a primary example. In this specific case, two of the vertical array ofl amps is mechanized to rotate about the vertical axis as the part(s) pass through the lamps.⁷ (Graphic 6)

IV) Part: Static or Linear Movement – Lamp: Complex Movement
The most common example of this situation is a UV lamp mounted on a robot. This concept has been in service for a number of years in different applications. Special concern must be given to pre-initiation of the coating on parts that are larger than the aperture of the lamp. A careful evaluation of the UV coating to this type of exposure is required to eliminate any potential for coating defects. (Graphic 7)

V) Hybrid Systems Part: Linear Movement – Lamp: Static & Movement
Hybrid solutions that utilize both fixed lamps in combination with automated lamps. An example of this type of solution is the current concept to cure UV clearcoat on car bodies. The fixed lamps cure the vertical surfaces of the vehicle, while the horizontal lamps are mounted in a roof-beam that follows the profile of the vehicle as it moves under the lamps by moving in the vertical plane. The lamps also have the ability to rotate about the horizontal axis allowing the lamps to illuminate the leading and trailing surfaces as the vehicle passes by the roof beam. (Graphic 8)

Another example is where static lamps are used in conjunction with robot-mounted lamps. This solution utilizes the robot to illuminate areas that are very difficult with static lamps. An example would be to use a robot mounted lamps to irradiate concave surfaces in large parts such as a fascia.

VI) Part: Complex Movement – Lamp: Static
There are examples where the part is moving on a continuous conveyor and rotates before fixed lamps. This solution is used frequently by the personal electronics industry. The advantage is it presents the part, to illuminate leading and trailing edges, dynamically to the lamps. There are two common types of solutions; the parts are moving linearly and rotating or the parts are brought to the lamps on a power-and-free conveyor and rotated before the fixed lamps for predefined period of time. Special attention must be paid to the relationship between the line speed, rotation frequency (rpm), and the position of the lamps to ensure consistent exposure.

Conclusion

UV curing of coatings, inks, and adhesives on plastic substrates continues to grow from a relatively large base. The recent need to decrease energy costs due to the rise in natural gas prices has increased interest in alternative curing technologies including UV curing. Though UV requires line-of-sight curing for most formulations, there are a multitude of potential solutions for curing of 3D parts. There is not a standard solution that fits all the needs, but there always is a best solution. The best solution is derived by a thorough analysis of the critical UV process factors -the UV energy process window of the coating, the geometry and surface area of the part, and productivity requirements for the finishing line -weighed against the constraints of the specific UV installation.

References

1. The ChemQuest Group, “Proprietary Study for RadTech Int’l.”
2. Stansfield, J., L’Abbe, P, Joesel, K., “UV Coatings for Plastics – The Profitable Choice” RadTech Report September/October 2005
3. Cannon, K., “High-Solids UV-Curable Basecoat and Clearcoat for Flexible Plastic Auto Components” RadTech Report September/October 2005
4. Tanner T.J., “Innovative Applications with UV-Curable Technology” RadTech Report November/December 2005
5. http://www.eia.doe.gov/oiaf/aeo/pdf/trend_4.pdf
6. Dietliker, K. et al., “Novel Chemistry for UV Coatings: Photolatent base system optimizes performance for refinish clearcoats” European Coatings Journal, 2005, no10, pp. 20-24
7. Stowe, R.W.; US Patent 6,566,660 “UV Dryer for Curing Multiple Surfaces of a Product.”