NKY Firm Joins Global Effort to Create Disposable Face Shields

Hebron-based Zumbiel Packaging is joining more than forty other firms from twenty different countries to create an organization called “Fiber Shield” to create single-use, disposable face shields in response to COVID-19 and the global shortage of Personal Protective Equipment (PPE) for medical professionals.

Packaging producers and supply chain partners from around the world pooled their collective resources and expertise to develop, in record time, face shield designs that could be produced on existing packaging equipment with readily available materials.

Two packaging companies, Pawi from Switzerland and Zumbiel Packaging, launched this initiative in March and, to date, have already been joined by over forty packaging firms from twenty countries who have committed to produce protective paperboard face shields.

Every participating company is committing to donate at least 100,000 shields to start.

Pawi, Zumbiel Packaging and Pulver Packaging (Chicago) have already committed to donating over 700,000 shields to medical providers in Europe and North America who are at the epicenter of the pandemic. The group is confident that they can produce and distribute over 10 million face shields in the next several weeks.

“Our industry wanted to do something to support the fight against COVID-19,” said Ed Zumbiel, from Zumbiel Packaging, “so when we realized that face shields were in short supply, and that we could in fact manufacture them with our existing production assets, we turned our organizations loose.”

According to Zumbiel, “virtually everyone in the packaging ecosystem has jumped in to offer raw materials, production assistance, and logistics support to the companies who are producing the shields.”

Today, over 1 million face shields have been donated but Fiber Shield members guarantee that there are many more to come, according to a news release.

– Article by RCN: https://www.rcnky.com/articles/2020/04/13/nky-firm-joins-global-effort-create-disposable-face-shields

Flexography or Flexo Printing

Flexography, or flexo for short, is a form of printing that is common in packaging. The printing plate is the heart of the process and is essentially a high-tech flexible rubber stamp made of a plastic material. The image area (the area that will print the image) is raised up so that ink can be applied to it without the non-image recessed area (the area that will not print) receiving ink.

Take a look at the “FLEXO” rubber stamp and the image it produced. The word “FLEXO” is raised to receive ink from the ink pad and to transfer the image to the paper.

 

 

Now look at the nutrition facts panels on the green flexo plate images above. The raised image area accepts ink and then transfers that ink to the paperboard. The non-image recessed area does not receive ink and does not contact the paperboard. Note that the image is reversed on the stamp and plate so that they print positive on the paper.

 

The printed nutrition facts panel is above.

 

The flexo plate gets wrapped around the plate cylinder before going into the press.

An inking cylinder called the anilox contacts and transfers ink to the plate. The inked plate contacts the paperboard and transfers the image to the sheet much the same way the rubber stamp makes contact with, and transfers its image, to the paper.

 

The image above shows the anilox in the foreground, the plate wrapped around the plate cylinder in the middle and the image printed on the substrate in the background.

 

Flexo plates are made of a special material called photopolymer. That material allows the plate to carry images with very small dots so that it can print process work (see our four-color process printing blog). See the dots that make up the words “Est. 1905” in the image above.

The photopolymer plates are so advanced that they can print images that are at least 133 line screen. That means that in one linear inch the plate can hold 133 dots and each of those dots can be one or two percent of that. They can be as small as .0002” inches.

4-Color Process Printing

4-color process printing is the method used to print full-color images such as photographs.

The concept behind the process is that the primary colors we all learned about in the first grade can theoretically combine to make up virtually any color. Recall that the primary colors were blue, red and yellow. The 4 process colors are the same with the addition of black – Cyan, Magenta, Yellow, and BlackTogether they are known as CMYK.

When applied consecutively on a printing press and in the proper color separations and ink densities, they make up all the colors in an image. Take a look at the image below and then take a look at the color separations. Each color is printed one at a time and on top of each other. The order they print is black first followed by cyan, magenta and finally yellow.

 

 

If you take a look at a printed image of a photograph under magnification you will see the dots of each color making up the image. Some phones have strong enough zooms in camera mode to let you see them.

 

 

 

More About Paperboard

This blog is a follow-up to the “6 Steps to Making Paperboard” blog.  We will briefly discuss the types of wood used to make virgin paperboard, the most important characteristics of paperboard, and the properties of the various grades of paperboard.

 

Wood

Virgin paperboard can be made from two types of wood – softwood from pine trees and hardwood from deciduous trees (lose their leaves every year). Each has different characteristics that lend themselves to different applications.  The primary difference is that softwood has longer fibers than hardwood does.  Those long fibers lend themselves to better tear resistance and better stiffness since the longer fibers have more surface area to bond together.

 

 

However, hardwood’s short fibers lend themselves to a smoother surface because, if on occasion fibers do not lay completely flat on one another, they stick up slightly toward the surface of the sheet.  Short fibers stick up less than long fibers do, resulting in a smoother sheet.  All coated paperboard is smooth because of the coating applied to the top of the sheet, but paperboard from short fibers is smoother.

 

The eight most important characteristics of paperboard:

1. Machine direction (MD)– the direction in which the fibers naturally line up in the paperboard making process, effects stiffness and tear strength.

2. Cross direction (CD)– perpendicular to the machine direction, also impacting stiffness and tear strength.

3. Smoothness– how smooth the sheet is, affecting its printability.

4. Tear strength– long fibers “grab” each other better than short fibers. For example, beverage can cartons need strong handles that won’t tear easily.  Tear strength is greater in the cross direction (across the fibers) than in the machine direction (parallel to the fibers).

5. Stiffness– long fibers provide more stiffness, again because of the greater surface area. Stiffness is important in gluing cartons and in high-speed filling because those operations stress the cartons.  Stiffness is greater in the cross direction (across the fibers) than in the machine direction (parallel to the fibers).

6. Basis weight– the weight of 1,000 square feet of paperboard.

7. Caliper– the thickness of paperboard in thousandths of an inch. Typically paperboard for folding cartons ranges from .0014” to .026”.

8. Brightness– how white and bright the sheet is.

 

Six Steps to Making Paperboard

Step 1 – Pulping

Pulping is the process of reducing wood or old paper and paperboard down to the fiber level.  Think of fibers as small splinters.

For virgin paperboard (paperboard that is made from wood), pulping is accomplished by “chipping” logs down to wood chips and then pressure cooking those chips in a solution that breaks down the wood’s natural glue (called lignin).

Once the chips are reduced to the fiber level they become pulp.

The pulp is washed to remove impurities and, depending on the type of paperboard being made (white or natural brown), it may be bleached.  For environmental reasons the bleach is made from oxygen and hydrogen peroxide, not chlorine.

For recycled paperboard the source of fibers is old paper, corrugated boxes and paperboard.  The old materials are mixed with water in a pulper (a machine that looks like a very large blender).

The blades in the pulper beat on the material until it is reduced to fibers. The recycled pulp gets washed to remove impurities like staples, wires, tape and paperclips.  The larger impurities are removed mechanically from the solution that resembles oatmeal.  To clean the smaller ones out, the solution passes through a series of screens.  At this point, when fibers have been cleaned, they are called pulp.

 

 

Step 2 – Forming

It can be helpful to think of paperboard manufacturing as reducing the wood or recycled material down to the fiber level, then reassembling those fibers again.

Regardless of whether the pulp solution is made of recycled or virgin fibers it is pumped into the headbox at the front of the machine.  The headbox is a container the width of the machine that collects the pulp solution and then pumps it out evenly through a long orifice onto a moving piece of fabric, similar to a conveyor belt, traveling at 1,000 feet per minute or more.  The amount of pulp solution that is pumped out of the headbox determines the paperboard’s weight and is one of the determinants of the paperboard’s caliper or thickness.

The pulp solution is between 98 – 99.5% water as it leaves the headbox.  In essence, the paperboard machine’s primary purpose is to remove water from the pulp solution as the fibers travel down the machine.  Water falls through the fabric as the solution travels down the fabric conveyor. More water can be removed by vacuum boxes located underneath the fabric, so that by the end of the forming section the material is down to 75% – 90% water and is able to support itself.  It is now referred to as a web.

 

Step 3 – Pressing

The web now leaves the fabric and transfers to the press section of the machine. The press section is a series of top and bottom cylinders the width of the machine.  As the web travels through this section more water is squeezed out so that by the end of the section it is down to approximately 65% water.

 

Step 4 – Drying

The drying section is the longest part of a machine that can easily be 100 yards or more from beginning to end.  It is a series of many (over 100) steam heated cylinders over and under which the web passes.  Each cylinder removes a little more moisture so that by the end of the drying section the web’s moisture content is down to only 6% or 7%.

 

Step 5 – Coating

A clay coating (essentially latex house paint) is applied to the web to smooth out the surface, provide whiteness, and to ensure that ink stays on the surface of the sheet during printing.  A coating roller the width of the machine dips into a vat of coating and then contacts and transfers that coating to the top side of the web.  A smooth rod also the width of the machine wipes away the excess coating and leaves what had been a somewhat rough paperboard surface, smooth.

After a quick pass through an infrared dryer another roller applies a second coat of the coating.  The second coat provides more whiteness.  This time instead of a rod wiping away the excess, an air knife blows it off.

 

Step 6 –Finishing

The last steps are to wind the web onto a large reel and then slit the reel down to the desired roll widths.  Some machines are more than 200 inches wide, so the reel can weigh in at 25 tons and yield several rolls almost 7 feet tall.

 

For more information…

https://www.youtube.com/watch?v=QDNJRfgGNsA

https://www.youtube.com/watch?v=E4C3X26dxbM