by Cubbison, on Mar 19, 2021 10:25:18 AM
This war against COVID-19 – and let’s not kid ourselves, it is a war – seems to have some hopeful signs. Between the delivery of vaccines and the ongoing efforts at suppression, through the use of masks and avoiding contact with possibly infected people, our efforts have us trending in the right direction.
None of those efforts, or the ongoing frontline fights to save lives in hospitals across the land once the “wounded” arrive, will work without testing. Massive, ongoing, expansive testing. The quicker the better. The more convenient the better. The cheaper the better. Let’s not forget accuracy.
Now, I don’t know about you, but the idea of having a swab jammed up my nose and then rotated is not my idea of a pleasant activity. The viral test for infection is the main one we see on TV, where the swab then goes to a specialized lab and can take a day or more to get results. It costs quite a lot to administer, collect, send to the lab, test, and then contact the subject. There must be a better way.
Turns out, there is. Clever screen printers are at it again. Antibody tests, in the form of biosensors, have led the way to cheap, fast testing. Curious readers might have clicked this link at the end of my column in the last issue.
Andy MacDougall
SPGPrints (spgprints.com) is a worldwide leader in rotary screen printing. Originally founded after WWII as an offshoot of a dairy company – and still located in Holland, with plants in manufacturing centers around the world – their screen machines are some of the fastest around. They’re well known for printing full-color fabric and wallcoverings, as well as electronic components and medical devices. SPG recently teamed up with a leading pharmaceutical manufacturer to integrate their rotary screen technology, already used to produce diabetic testing strips, into a version that would use saliva to determine infection from COVID-19.
Hank Guitjens, who first came into contact with screen printing when he went to work at SPGPrints in 2013, is their business manager. He explained that their rotary screen technology, which parent company Stork introduced in 1963 to replace their in-line textile press, is ideally suited to high-speed production of medical bio-sensors.
“The RSI-line COVID-19 speed test strips are produced on a line jointly developed with our customer. The end user is a pharmaceutical company,” says Guitjens. Due to confidentiality agreements, Guitjens didn’t name the company, but added SPGPrints has a lot of customers around the world who produce a wide variety of medical items. Non-wovens for medical clothing, blisters, and diabetic test-strips were some of the other items he mentioned.
I asked Guitjens for his best guess at the future of print, and screen printing, in this field and others. “We see a higher demand for rotary screen printing instead of flatbed screen printing, as the product volumes are getting higher and higher and flatbed has its limits in speed,” he says.
As most of us are more familiar with the concept of “flatbed” screen printing presses used in textile, graphic, and industrial printing, I tracked down Gene Hasch, director of Printing and Innovation at Cubbison Company (cubbison.com) located in Youngstown, Ohio.
I met Hasch when he worked at GM Nameplate (gmnameplate.com) in Seattle. I know he runs flatbed presses. And they haven’t slowed down. He graciously answered some questions for this article. I’m always curious as to how people get into screen printing, Hasch shared his story.
“I was unemployed, looking for a job, and my ex-father-in-law gave me an application for this company called GM Nameplate in Seattle. I had no clue what they did. So, I got the application back to them. They called for an interview, but when I went in the job had been filled,” says Hasch. “As I was talking to Mike McDaniel, department manager, his phone rang. The gentleman who was working in the dark room screen prep called and quit over the phone. Mike hired me on the spot and I never looked back.”
Hasch has now been in the industry for more than 24 years, working positions from screen making to final inspection. “I also did two years in R&D working with a chemist helping develop inks and other coatings. My passion has always been conductive inks,” he says. “During the last few years with my former employer, I was responsible for R&D of conductive inks and substrates as well as putting the products together for prototyping. I’m honored to sit on the IAPE [Industrial Applications Printed Electronics] Committee with very talented individuals and colleagues.”
I asked Hasch about some of the screen process characteristics that make screen printing – flatbed, rotary, or cylinder – suitable for use in manufacturing, and more specifically, medical or electronics manufacturing. Sometimes it’s hard to connect a T-shirt printer to a cutting-edge manufacturing technique.
“Screen printing is used because of its ability to deposit exact amounts of ink. Also, it’s the only way to get the deposition needed for printed electronics,” he says. “When you’re producing electrochemical sensors, a biosensor, like a diabetic strip or the COVID rapid tests, you need specific ink depositions for the end product to function properly.”
“Also, screen printing has the ability to run high volume jobs and keep consistent ink depositions. It’s very cost efficient and gives you the ability to control all aspects of the process. It has the ability to print fine traces; how fine depends on who you talk to,” says Hasch. “Screen printing gives us more choices of ink and substrate combinations due to the nature of the process. Ink suppliers can create inks with the correct solvents and resins to adhere to just about any substrate and not have to worry about damaging any of the components of screen printing, unlike digital.”
AM: SO, HOW DO YOU USE THE PROCESS AT CUBBISON?
GH: Screen printing is utilized in at least 80 percent of every product manufactured here at Cubbison. Our legacy side of the business is etched metal nameplates for product identification. Screen printing is used to print the resist before the etching process. Once the product is etched it can be filled with color and, yes, we use screen printing for that! Then of course we have our printed electronics that are all screen printed. We also use screen printing in conjunction with our digital printing technology.
DO ANY OF YOUR PRODUCTS HAVE A DIRECT USE IN THE GLOBAL FIGHT AGAINST COVID-19?
We produce a membrane switch and overlay for a controller that is used on a product that helps stimulate the human diaphragm after a person has been taken off a ventilator. We have seen an increase in the sales of this product after COVID-19 became apparent in the US.
WHAT ARE SOME OF THE OTHER PRODUCTS YOU MANUFACTURE USING SCREEN PRINTING THAT ARE USED IN THE MEDICAL FIELD?
We produce an overlay and membrane switch for a company that makes heart-lung machines. These units are used during open heart surgery to bypass the heart and lungs so the surgeon can perform his duties. There are up to five of these membrane switch overlays on some machines. This product includes the circuit layer, a shield layer for ESD (Electrostatic Discharge), 15 LEDs, and a gamut of other goodies in it.
ARE THERE OTHER PRINT PROCESSES YOU USE? HOW DO THEY COMPARE TO SCREEN PRINTING?
We have digital and offset printing. They play a significant role in their respective areas. Both of these print formats have their limitations. For instance, digital has a bit of an issue hitting certain colors, some grays, and some federal standard colors. Also, digital needs help from screen printing for opacity and translucent colors. Offset is great, but is limited to sheet size, inks, and substrate compatibility, whereas screen is only limited to sheet size if you don’t have a big enough press. With inks and substrate there is no limitation in screen printing – our imagination is the only limitation.
I THINK THAT’S A GREAT ATTITUDE, AND IT’S SHARED BY AN ABUNDANCE OF PEOPLE IN THIS INDUSTRY. WE’RE OBVIOUSLY INVESTED AS SCREEN PRINTERS AND CREATIVES IN SEEING WHERE OUR SQUEEGEES MAY TAKE US, IN OUR VARIOUS PRINT WORLDS. WHAT’S YOUR TAKE? WHAT DO YOU SEE HAPPENING IN THE NEAR FUTURE?
Screen printing in the industrial sector, as well as PE (Printed Electronics) and garment will be around for a long time. Screen printing as a whole grows each year. I’ve chatted with large medical corporations that are bringing screen printing in-house for large production opportunities. But they’re not the norm. The norm is to outsource to suppliers such as Cubbison. But what I find interesting is these corporations, with all their resources, are using screen printing. There are a lot of different printing formats, but screen printing seems to be the answer.
I believe that wearables and IME [In Mold Electronics] with capacity touch technology will be the future of the PE world. We’ve seen an uptick in this each year. IME is a bit slower to emerge than wearables due to the cost of tooling for IME. But with new 3D printing technology the cost of tooling has the chance to get cheaper. Additive manufacturing with 3D printing is coming to the forefront of the industry. This technology with aerosol jet has opened up a whole new realm of what we can print on. Printing on 3D images is now doable. The speed is a bit slow, but that will get better over time in my opinion. Packaging is another outlet for the PE market, as well. I’m not too versed in it, but I know I’ve seen some really cool packaging and P-O-P displays that use PE.
TEXTILE PRINTERS LISTEN UP… LAY IT ON US, GENE!
Now here is my crazy thought: that garment printers and PE printers will work together in the same spaces. With the surge of wearables that customers want, TPU [Thermoplastic Polyurethane] is only a steppingstone to printing directly on fabrics. What the PE people know is how to print the conductive inks and control them. But what we [PE Printers] lack is the knowledge of garment printing. Garment printing is a science in itself and has taken printers years to learn and perfect. But I believe that merging both of these disciplines together will produce a very big impact in our industry. There has always been a kind of a fence between the two disciplines, but with the up-tick of interest in active electronic wearables, that fence is being broken down one picket at a time. Screen printing is a passion. Keep an open mind. Learn from everyone, even a novice.
HAVE WE AROUSED YOUR SENSES YET, SCREEN PRINTERS? Next month we crack open a biosensor and find out how they are made, along with a glimpse into the future of screen printing. I interview Dr. Martin Peacock, director, co-founder, and educator at Zimmer and Peacock, and senior lecturer at Swansea University. Although he has a PhD in electrochemistry and worked for a who’s who of international pharmaceutical companies doing cutting edge research in medical sensing devices, he started out screen printing posters at age 7 in the family business. Until then, stay safe!
ROTARY SCREEN PRINTING
The screen mesh is imaged and then formed in a cylinder, with the squeegee inside, printing out. Positioned over top of a continuous roll feed of substrate, the press doesn’t stop or shuttle like a typical cylinder press – it just rolls, continuously printing on the test strip material or on the larger machines on bolts of cloth. More printheads, dryers, and other in-line finishing, including die cutting and assembly, can be added to the production line. Image size is determined by the diameter of the rotary screen and the width of the printhead.
ANDY MACDOUGALL is a screen printing trainer and consultant based on Vancouver Island in Canada, and a member of the Academy of Screen & Digital Printing Technology. If you have production problems you’d like to see him address in “Shop Talk,” email your comments and questions to andy@squeegeeville.com.
Originally posted at screenprintingmag.com