Conference Program

TUESDAY, MARCH 19, 2019

Break + Exhibits

10:00 AM – 10:30 AM

Lunch + Exhibits

12:30 PM – 2:00 PM

Reception + Exhibits

4:00 PM – 5:00 PM

P: (240) 497-1242
uveb@radtech.org

RadTech International North America
The Association for Ultraviolet and Electron Beam Technologies
6935 Wisconsin Ave, Suite 207
Chevy Chase, MD 20815

UV Curable Elastomer Development for High Performance Dynamic Applications

Kyle Baldwin, MacDermid

While many UV curable polymers exist for demanding applications requiring a balance of strength, curing capability and appropriate viscosity ranges, such polymers do not perform as well in situations requiring high elastic response. Print environments, for example, often require a very soft elastomer with rapid elastic response time, high resilience and tensile strength properties, all while being cured appropriately in thicknesses as high as ¼”. Combining these properties into the world of 3D printing is a complex challenge given the demands of viscosity and cure speed that exist today. This presentation will introduce some of the concepts and challenges we work with in developing polymers for dynamic printing environments, and how these polymers may ultimately be applied to the 3D Printing world in the future.

Photopolymerization of Thiol-yne Polymers for Use in Additive Manufacturing

Darryl Boyd, US Naval Research Lab

Thiol-yne chemistry is a branch of the thiol ‘click’/coupling family of reactions that has grown in popularity amongst polymer researchers in recent years. Major advantages of polymers made using thiol-yne chemistry include that they can be made via photopolymerization, tend to have high refractive indices, can have high glass transition temperatures, and the thiol-yne polymerization process is generally not inhibited by oxygen. Despite these valuable and advantageous qualities, modifying thiol-yne chemistry to be compatible with Additive Manufacturing technology has been a challenge. We present our nascent efforts to print thiol-yne polymers using Additive Manufacturing, including luminescent thiol-yne polymers containing quantum dots.

Characterizing 3D printing voxel-voxel interactions in real time

Callie Higgins, NIST

Layered fabrication techniques harnessed by additive manufacturing (AM) such as stereolithography introduce microscale anisotropic heterogeneities in chemical, thermal, and mechanical properties such that the performance of parts depends strongly and often unpredictably on printing conditions. Specifically, the interactions between voxels during printing govern the final part properties, but standard characterization techniques are unable to adequately capture this dynamic environment. Sample-coupled-resonance photorheology (SCRPR) is a new atomic force microscopy technique developed to study this dynamic environment that captures fast, voxel-scale rheological and mechanical property changes in three dimensional (3D) printing resin throughout polymerization. Here, we present the first demonstration of the ability to image the 3D mechanical and rheological properties formed between adjacent AM voxels in the native printing environment with unprecedented temporal and spatial resolution using SCRPR. Our findings indicate that the in situ mechanical properties vary significantly as a function of voxel separation distance and highlight the importance of optimized resin formulation for a given illumination intensity and desired final part.

Formulating for UV Cure in Additive Manufacturing

Jo Ann Arceneaux, allnex USA, Inc.
Additive manufacturing, or 3D printing, has evolved from use in prototyping to use in manufacturing finished parts. The performance properties for finished parts are very different from those for prototypes. Thermoplastic type properties are desired, with ABS (acrylonitrile-butadiene-styrene) and PP (polypropylene) type properties the most popular. Very flexible formulations are also advantageous. This paper will evaluate the properties of various oligomers and monomers. The properties of 3D printed formulations based on these materials will then be determined and compared to ABS and PP.

Validating use of UVC LED for enhancement of leafy green safety and spoilage avoidance

Tatiana Koutchma, Agriculture and Agri-Food Canada

Fresh produce is among top risk foods that caused numerous food-borne outbreaks that resulted in lost revenue and thousands of hospitalizations. Current post-harvest practices of washing and sanitizing using chlorine prove ineffective at reducing contamination with a greater likelihood of disseminating pathogens than removing them.

It has been shown that UVC exposure has potential to increase microbiological safety of fresh produce and reducing instances of cross-contamination. Among advantages of UV disinfection is the lack of by-products (e.g. chloramines); and the non-thermal, non-ionizing, non-chemical organic nature of light, which reduces the risk of changing the sensory and nutritional properties of produce. It is however, limited in its efficacy by shading caused by irregular surfaces and its inability to penetrate below the surface of most materials. Multiple wavelengths nature of UV LEDs and their other advantages has been explored for pathogens and spoilage organisms inactivation in the model saline solution and on the surface of apples and romaine lettuce.

Germicidal efficacies of a low pressure mercury (LPM) lamp at 253.7 nm and UV LEDs in 257 – 365 nm range were compared against pathogenic Escherichia coli, Listeria, and Salmonella. UVC LEDs emitting at 259 and 268 nm were the most effective in pathogen inactivation in model solution. Combining 259 and 289 nm LEDs wavelengths at an equivalent UV dose had a synergistic effect on reduction of E. coli and Listeria, yielding a 1.2 and 0.6 log higher effect, respectively, than the expected additive effect. 277 nm UV-LEDs custom unit was tested for pathogens and spoilage organisms inactivation inoculated on the surface of fresh produce. UV-LEDs were more effective against L. monocytogenes on apple skin, however, LPM lamps were more effective against E. coli on lettuce leaves. Therefore, the most effective treatment relies somewhat on the medium being treated as well as the organisms being targeted. Also, the efficacy of LEDs for treatments in the refrigerated environment will be discussed along with UV dose effects on quality parameters and shelf-life extension.

Why Romaine Lettuce is so susceptible to E. Coli contamination and UVC means to control it

Keith Warriner, University of Guelph

Within a 12-month period, there were three outbreaks of Escherichia coli O157:H7 infection linked to contaminated romaine lettuce with over 200 cases being reported between the US and Canada. The outbreaks were all linked to contaminated irrigation water with the pathogen was recovered from river sediments. The underlying reasons for leafy greens being susceptible to contamination by E. coli O157:H7 remains largely unknown although is partly attributed to growing regions (California and Arizona) and large volumes of irrigation water required for cultivation. The preferential growth of E. coli O157:H7 on damage lettuce tissue is an additional factor. The open nature of farming makes control of contamination at the farm level challenge although UV treatment of irrigation water is a potential intervention. UV can also find utility by reducing the microbial counts and chlorine demand in post-harvest wash tanks. In more recent work, an alternative to post-harvest washing has been devised based in using a combination of UV, ozone and hydrogen peroxide through an Advanced Oxidative Process (AOP). Through laboratory based studies it has been demonstrated that an optimized AOP treatment can support a 5 log cfu reduction of E. coli O157:H7 on the surface and cut edges. The AOP process has been commercialized and offers an additional tool for enhancing the food safety of leafy greens.

Use of UV LED as a supplement during growth for higher yield and better quality

Yan Ren-Butcher, Illumitex

This session will review published scientific reports of the effects of UVA and UVB radiations on plant growth and development, quality improvement and disease controls. The possibility of introducing UV spectra to increase THC and other cannabinoids, as well as is becoming widely talked about amongst cannabis growers. From our research collaborations with growers, we found that UVA light increased yield and reduced Powdery Mildew infection by 100%. Beyond cannabis, the effect of UV radiation has been studied on several other crops including red-leaf lettuce, tomatoes, basil, wheat, and rice. The observations have shown both positive and negative results regarding crop quality and yield. This presentation will also provide some suggestion on how to apply UV light to your plants.

Opportunities for Application of UVB and UVC Devices in Cannabis Grow Facilities

Tim Leach, HyGriene IEQ

It is well understood that microorganisms such as mold and bacteria can infect and in many cases decimate agricultural crops. These microorganisms cause more crop loss than all other biotic stresses combined. Cannabis crops are also highly susceptible to damage caused by microorganisms, the two most problematic species being Botrytis cinerea or “Gray Mold” and Sphaerotheca macularis or “Powdery Mildew”. Chemical biocides such as DeMethlation Inhibitors (DMI) and Sterolbiosynthesis Inhibiting (SI) have been commonly used to combat these microbes. Combining these facts with the movement from toxic chemical pest control to more environmentally friendly and sustainable methods accord manufacturers of UV germicidal devices significant opportunities. This presentation will share data and explore systemic opportunities for the application of UVC and UVB devices in cannabis grow facilities. Applications presented and discussed will include grow rooms, facility ventilation systems, drying and storage rooms.

Accelerating Material Development with Artificial Intelligence

Will Tashman, Uncountable

Uncountable is a machine learning company that helps R&D teams reduce the cost of development by increasing the speed of innovation. We build custom machine learning models that understand ingredient interactions within a formulation space, and how those interactions impact critical performance properties. These models are used to suggest new formulations for testing, enabling a substantial acceleration in the development process over traditional DOE methods. Uncountable's customers include large polymer, coating, foam, adhesive and rubber manufacturers, like Cooper Standard. Working with Uncountable, R&D teams have seen a 2-3x decrease in the number of experiments and time that it takes to develop new formulations that meet their end-customer's requirements. This presentation will detail how Uncountable's technology differs from traditional DOEs, and adapts to the difficulties that scientists face when trying to develop innovative new chemistries.

Alkyl Tin Keggin Clusters as EUV Photoresist Technology

Rebecca Stern, Lawrence Berkeley National Laboratory

With integrated circuit manufactures reaching sub-10nm feature sizes, EUV lithography is the next developing technology for the job. The challenges with using polymer-based photoresists and EUV lithography can be eliminated by using oxohydroxo metal nanoparticle photoresists instead. Oxohydroxo metal clusters have the potential to provide faster writing speeds, higher resolutions, and better etch resistance than chemically amplified polymer resists. The Persson Group at UC Berkeley, in collaboration with Oregon State University and the Center for Sustainable Materials Chemistry (CSMC), is conducting research on the stability of organotin Keggin clusters for use as sensitive high-resolution photolithographic resists. The tin clusters we were able to synthesize and computationally model, crystallized readily without counterions which increases the simplicity of the synthesis as well as improves the yield, purity, and reproducibility. Its neutral charge makes it a valuable model system for understanding the fundamental patterning mechanisms at play. This presentation will also touch on how the Materials Project, an open-source international materials database, can provide chemists a high-throughput method to determine some properties for polymers to design new oligomers, monomers, and photoinitiators.

Advancements in Formulating for Additive Manufacturing

Neil Cramer, Colorado Photopolymer Solutions

3D printing/additive manufacturing continues to be one of the fastest growing and exciting technologies in the UV curing market. UV Curable (SLA and DLP) printing is considered the high-end technology choice for additive manufacturing because of its high resolution, strength in the Z-axis, and the ability to customize resins among other positive features. This presentation will focus on development of novel formulations to achieve improved attributes required for the next generation of additive manufacturing materials. Through innovative formulation strategy advancements in printed materials properties such as strength and toughness are achieved. Different chemistries are also utilized to improved cure speed and dimensional stability as well as other unique properties.

Light-Enabled Materials for Regenerative Engineering

Ali Khademhosseini, UCLA

Stimuli-responsive biomaterials, particularly those activated with light have enabled emerging micro- and nanoscale technologies as powerful tools for controlling the interactions between cells and their surroundings for biological studies, tissue engineering, and cell-based screening. Among these biomaterials, photocrosslinkable hydrogels have increasingly been used in various tissue engineering applications since they provide cells with a hydrated 3D microenvironment that mimics the native extracellular matrix. In our lab, we have developed various (UV and visible) light-mediated approaches to merge microscale techniques with hydrogel biomaterials for directing stem cell differentiation and generating complex 3D tissues. In this talk, I will outline our work in controlling the cell-microenvironment interactions by using light-activated patterned hydrogels to direct the differentiation of stem cells. In addition, I will describe the fabrication and use of photocrosslinkable microscale hydrogels for tissue engineering by using `bottom-up' and `top-down' approaches. Top-down approaches for fabricating complex engineered tissues involve the use of miniaturization techniques to control cell-cell interactions or to recreate biomimetic microvascular networks within mesoscale hydrogels. Our group has also pioneered bottom-up approaches to generate tissues by the assembly of light-mediated shape-controlled cell-laden microgels (i.e. tissue building blocks), that resemble functional tissue units. In this approach, microgels were fabricated via photocrosslinking and seeded with different cell types and induced to self assemble and generate 3D tissue structures with controlled microarchitecture and cell-cell interactions.

Advanced Prototyping and Direct Manufacturing

Maximilian Zieringer, Formlabs

Over the past years, 3D printing has become increasingly popular for rapid prototyping. Stereolithography has demonstrated its full potential as a powerful tool to take away on designs quickly and generate looks-like, feels-like parts. More recently, based on advances in 3D printers and material properties, stereolithography demonstrated its capabilities in direct manufacturing of end use parts. In manufacturing, 3D printing unlocks new design opportunities that cannot be achieved with traditional manufacturing techniques, allows for shorter product cycles, and has the potential to decrease warehouse and shipping costs. Formlabs has developed a variety of valuable solutions to address the demand in directly manufacturing dental products, footwear, and consumer goods. This presentation will cover some of these examples as well as a general overview of current trends, future directions and challenges in material development for stereolithography.

Driving Additive Manufacturing Towards Production of End-Use Parts

Ellen Lee, Ford Motor Company

This presentation will cover an overview of the use of additive manufacturing in the automotive industry both over the past 30 years and future trends. Automotive industry needs differ significantly from those of aerospace, medical, and consumer industries in terms of performance and durability, as well as cycle time and annual volumes. Material developments and new additive manufacturing processes focus on bridging these gaps. Current case studies that highlight functional applications will be discussed.

Use of UVC equipment for Processing Yogurt

Neil Cikurel, RND Arastirma Gelistirme Tasarim

Coming Soon.

Reductions of Listeria monocytogenes on cold-smoked and raw salmon fillets by UV-C and pulsed UV light

Askild L. Holck, Nofima

Salmon is the food most frequently reported in the RASFF (Rapid Alert System for Food and Feed) database in conjunction with Listeria monocytogenes, and consumption of cold-smoked salmon has led to severe outbreaks of listeriosis infections. UV-C and pulsed UV light were investigated for their ability to reduce L. monocytogenes on salmon. Cold-smoked and raw salmon were spiked with a mix of ten L. monocytogenes strains and subsequently exposed to UV-C light (0.0075 - 0.6 J/cm2) or high intensity pulsed UV light (1.3 – 10.8 J/cm2). Reductions of L. monocytogenes on smoked salmon were 0.7 - 1.3 log, depending on the fluence. Corresponding reductions for raw salmon muscle side and skin side were 0.2-0.9 log and 0.4 -1.1 log, respectively. No sensory changes were detected in UV-C treated (0.05 J/cm2) smoked salmon. Due to the lack of critical control points in salmon production, it is not possible to ensure that products are consistently free from L. monocytogenes in the absence of mitigation strategies. UV treatments should be considered important tools for the industry to contribute to lower prevalence and levels of Listeria. This will contribute to enhanced food safety, reduction of costly recalls and longer shelf-life.

Opportunities for UVC equipment for Air Treatment in Food Processing Facilities

Jim Beavers HyGriene IEQ

A growing body of research has shown that a building’s HVAC system can become a reservoir of problematic microorganisms containing mold and bacteria which can significantly impact the hygiene of a building’s indoor environment. Many facility managers underestimate the problems resulting from microbial biofilms. Biofilms cause HVAC systems to become less efficient, consume more energy and negatively impact a facility’s indoor environmental quality (IEQ). Poor IEQ can impact product quality, as well as, employees’ health and productivity. This presentation will share industry data and explore systemic solutions utilizing UV to reduce the impact of HVAC biofilms on a building’s IEQ.

Applications of UVC LED for treating water before and after lettuce processing

Jim Cosman, Aquisense Technologies

Foodborne illness is a serious public health problem around the globe. Foodborne illness is an infection or irritation of the gastrointestinal (GI) tract caused by food or beverages that contain harmful bacteria, parasites, viruses, or chemicals. Researchers have identified more than 250 foodborne diseases. CDC estimates that each year 48 million people get sick from a foodborne illness, 128,000 are hospitalized, and 3,000 die. The U.S. Department of Agriculture (USDA) estimates that foodborne illnesses cost more than $15.6 billion each year.

UV technologies have been used for food manufacturing applications for more than 50 years. UV-C is very effective at inactivating foodborne pathogens such as Salmonella, Listeria, and E coli. In addition to improving food safety, UV technologies also play a key role in extending the shelf life of many food and beverage products. Within the food production chain, UV technologies are used for the treatment of air, water, surfaces, and packaging. The introduction of new innovations such as UV-C LED based systems is expected to accelerate the adoption of UV technologies for food protection.

This paper will examine key applications where UV technologies are currently being evaluated and implemented for food protection applications. Key suppliers and sub-applications will be briefly reviewed along with any appropriate certification or compliance requirements. The examination will also include a brief review of newer UV-C LED technologies that will lead to additional innovative solutions for the prevention of foodborne illness.

Production Redefined: Carbon's Novel Digital Light Synthesis Platform for Manufacturing Next Generation of High-Performance Polymeric Products

Jason Rolland, Carbon, Inc.

This presentation will provide an overview of Carbon’s Digital Light Synthesis (DLS) platform. We will discuss how DLS provides the key elements - speed, materials, and software - to enable true digital manufacturing at scale. Carbon’s dual-cure materials platform enables a broad portfolio of high performance resins for a variety of production applications. By combining light-curable chemistry with thermally-curable chemistry, high resolution parts with outstanding mechanical and thermal performance are now possible. Finally, we will present a variety of production applications enabled by DLS across a range of industries including footwear, protective cushioning, automotive, consumer products, dental, and medical.

Digital Manufacturing to enable automation, speed to market and mass customization thereby revolutionizing footwear manufacturing

Avin Dhoble, Voxel8, Inc.

Voxel8 has developed a digital manufacturing core technology platform with an immediate focus on Athletic Footwear Uppers. The footwear industry has a relatively antiquated supply chain. In recent years, the industry has been aggressively moving to establish an automated digital supply chain to address the issues with current processes and reduce time to market. Voxel8’s ActiveMix® and ActiveImage® technologies enable digital printing with elastomers and on-the-fly zonal tuning of the material properties with embedded high-resolution full color images. These enable footwear brands to manufacture uppers with customization of both mechanics and aesthetics, while eliminating the need for tooling and labor.

Integrated Digital Deposition System with both inkjet and aerosol deposition of functional inks using integrated multi curing UV LED, NiR and Photonic curing solutions for thin-film coating, fine conductive lines and high resolution patterns in 2D or 3D

Tim Luong, CERADROP, a MGI Group company

This talk will focus on solutions for requirements of digital jetting precision functional materials and processing using aerosol stream or small drops of 1pL volume up to 80pL volume from single or multiples 16 nozzles low cost disposable inkjet cartridges to multiples 2,048 nozzles count scaled for industrial piezo ink jetting throughput. Additionally, we have fully integrated multi in-line major third parties pre and post processing solutions such as inspection, sintering and curing solutions.

UV Cured Thin Films of Novel Fluorine-containing Polymers Exhibit Remarkable Hardness and Dramatically Increased Modulus.

Kelly Bonetti, SUNY Albany

Hard, photochemically cured coatings may find utility protecting sensor windows, optical fibers, composite material surfaces, electronic devices and other surfaces where scratch resistance, chemical stability and hydrophobicity may be important. Our visible light catalyzed polymerization produces photoreactive polymers containing hypervalent fluorinated sulfur in the backbone. Post UV exposure, thin polymer films have hardness and modulus values that perform beyond what is expected for most polymer films. Young’s modulus of 145 nm thick cured films exceeded 44 GPa, greater than even plasma deposited organosilcones. Measured hardnesses, up to 1.57 GPa, were nearly ten times higher than similar PMMA films. These novel, photosensitive polymers are easily deposited and readily prepared in larger quantities.

The Third Age of Fashion

Julia Daviy, Designer

Coming Soon.

Advances in Impact Modification of Photocured (Meth)acrylic Systems

Manjuli Gupta, Sartomer

Photocurable (meth)acrylic resins are important materials in additive manufacturing and are the subject of significant research and material innovation to bring improvements to the physical properties of final printed parts. Historically (meth)acrylic systems create rigid parts with strong mechanical properties including high modulus and strength, however this tends to equate to brittle, non-impact resistant materials. Incorporation of toughening agents used in thermoplastic applications has been tried with acrylate systems, unfortunately with limited success. Recent developments in impact modification utilizing novel chemistry have resulted in cured materials demonstrating elevated mechanical properties. Additionally, these new materials feature increased dispersion quality, stability and mechanical properties against traditional impact modifiers in (meth)acrylic systems.

Accelerating Open Additive Production through Partnership

Stephanie Benight, Origin

Coming Soon.

Using Additive Manufacturing for Advanced and Agile Development

Charlie Wood, Fast Radius

Coming soon.

Evaluation of Approaches for Formulation of UV LED

Paul Snowwhite, 7D Innovators

LEDs for UV curing are currently available 4 wavelengths – 365, 385, 395 and 405 nm. With all of the LED’s being in the UVA range and monochromatic this creates challenges to the UV formulator to overcome surface cure and achieve desired physical properties. The presentation will review novel formulation and curing approaches to solve surface curing issues and explore interactions with the various wave lengths.

Photoinitiator Choices with 365 nm UV LED Cure Formulations

Jo Ann Arceneaux, allnex USA, Inc.

Coming soon.

When it comes to UV LED, most overlook the Big Ideas…

Jennifer Heathcote

In order to increase the rate of technology adoption and gain market share over competitors, companies mistakenly market anecdotal concepts as universal facts with the expectation that targeted users will simply accept what is promoted and blindly invest in the technology. Unfortunately, the unintended consequences of this approach are that a true understanding of the technology’s potential is inhibited by the noise of disconnected and otherwise meaningless, misleading, and confusing facts and the powerful Big Ideas that ultimately drive wide scale adoption fail to properly register within the industry. At their core, Big Ideas provide strategic frameworks that activate thought, foster challenges, push boundaries, and spearhead testing of inferences that ultimately help users validate Big Ideas for their own unique set of application conditions. This paper will identify Big Ideas for UV LED curing and provide insight into how these Big Ideas should be employed to drive faster and more successful application development, adoption, and market penetration over the coming years.

Opportunities for New Applications with the Advancements in Technology of Short Wavelength UV LEDs

Mike Kay, Excelitas Technologies Corp.

Hard, photochemically cured coatings may find utility protecting sensor windows, optical fibers, composite material surfaces, electronic devices and other surfaces where scratch resistance, chemical stability and hydrophobicity may be important. Our visible light catalyzed polymerization produces photoreactive polymers containing hypervalent fluorinated sulfur in the backbone. Post UV exposure, thin polymer films have hardness and modulus values that perform beyond what is expected for most polymer films. Young’s modulus of 145 nm thick cured films exceeded 44 GPa, greater than even plasma deposited organosilcones. Measured hardnesses, up to 1.57 GPa, were nearly ten times higher than similar PMMA films. These novel, photosensitive polymers are easily deposited and readily prepared in larger quantities.