Unique Ink-Saver Ring

Have you ever run into the problem of producing a printed image with weak coverage on solid areas despite using the right amount of ink?  If you have then we have the solution for you.

Engineered Printing Solutions’ unique Ink-Saver Ring agitates the ink as the cup slides across the cliché, allowing the ink to evenly flow and mix over the print area. The patented Fan Blade design scoops and mixes the pigment as it passes through each chamber allowing the ink to spread evenly throughout the ink cup, providing even coverage over the entire image.

Ink Saver-Ring Figure 1 shows what normally happens to a printed image when the ink does not disperse evenly and tends to leave the sides unprinted. Solid areas can also be affected with weak print opacity.

­On the other hand, Figure 2 shows the difference when using the Ink-Saver Ring. The image prints evenly while using the same volume of ink – 25 grams in the cup.

Another issue for most decorators is the waste associated with bi-component inks.  When using the Ink-Saver Ring, less ink can be mixed and more ink can be used, resulting in less ink waste at the end of the day. Over time, this adds up to significant cost savings for any print shop.

The Ink-Saver Ring is available for all Engineered Printing Solutions’ cup sizes, as well as for other vendor’s closed cup systems.

For information about Engineered Printing Solutions’ standard pad printers, industrial ink jet, custom solutions, consumables and other auxiliary equipment, visit www.epsvt.com, email info@epsvt.com or call 1-800-272-7764.

Ink Adhesion Part 3: Ink Mixing, Contamination, Blooming and Mold Release Agents

Before printing on any parts there are several factors which are of vital importance: ink mixing, product cleanliness and substrate additives. Regardless of proper ink preparation and chemistry, surface contamination, blooming and mold release agents may all interfere with your ability to achieve satisfactory adhesion.

The two most important factors that must be addressed when dealing with ink mixing are: How are you mixing the ink? What components are you using? Inks are formulated to be mixed at specific ratios, and any deviation may result in adhesion failure. You must choose the correct ink and mix it to the exact manufacturer specifications. It is a common misconception that adding hardener over manufacturing specifications will allow for better adhesion.

Surface contamination is a huge factor in whether or not the ink will adhere to any given object. The first reason contamination may occur is because people are not handling the object correctly. Oils on the handler’s hands can be transferred onto the objects. Contamination can also occur as a result of secondary processes being performed on the parts. For instance, if you choose to wash the objects with a detergent, this may leave a residue behind on the object and the ink may not adhere properly. Here at EPS we use alcohol. This is a standard solution which readily flashes off and is used to wipe the parts of any dust, oils or any contaminants before printing. With proper handling, cleaning the parts may be unnecessary, but wiping with alcohol does assure that there will be a clean surface to print on.

Blooming is a term used in the plastic industry and it denotes a plasticizer or other additive coming to the surface of a part over time. The difficulty with this contamination is that you can wipe the surface of the part free of contaminates but over time the part will re-bloom and the contaminants will interfere with the bond between the ink and the parts.

Mold release agents (also known as de-molding agent, form oil, parting agent or release) are substances used in molding and casting that aid in the separation of a mold from the material being molded and reduce imperfections in the surface. While these additives make the plastic manufacturing process simpler, they can wreak havoc on attempts to achieve adhesion.

In the end, experience is the best weapon in attaining adhesion. If you have any questions or concerns please contact Technical Service.  For more information about Engineered Printing Solutions’ custom solutions, standard pad printers, industrial digital ink jet, consumables and other auxiliary equipment, email sales@epsvt.com or call 1-800-272-7764.

Ink Adhesion Part 2: Bi Component, Pre-Treatment and Post Cure

Have you ever looked on the back of an object and seen the recycle symbol? It tells you what material the object is made of. When it comes to plastics, Polypropylene and Polyethylene are considered the two of the most difficult materials to get ink to adhere to due to their relatively low surface energy. Polypropylene is used to make a wide variety of items and low and high density Polyethylene is commonly used in food packaging. When it comes to these difficult substrates it becomes necessary to pre-treat to affect a change in surface energy to make the surface amenable to bonding with – or cross-linking – with the ink.  This causes the substrate surface to become more receptive.

The most commonly used methods of pre-treatment are:

  • Plasma and Corona: Electricity applied to the surface.
  • Flamer: Liquid propane (LP) or natural gas. With Flamer there may be variation due to cleanliness of the burn and how the flame will pre-treat any given substrate.
  • Chemical Pre-Treatment: Usually manually applied with a liquid soaked rag.

Unfortunately on any given substrate you cannot assume that you will affect an equivalent change in the surface energy from one pre-treatment to another. Finding the correct ink pre-treatment may consist of 3 different segments: cleaning, activation and surface bonding.

Plasma surface treatment is a process that raises the surface energy of various materials in order to improve the bonding characteristics when ink is applied. Plasma is used widely in the medical industry. This is because you don’t have the bi-product of the other 2 pre-treatments such as carbon from the flaming process or residual VOC’s left behind from the from the flashing process of a chemical pre-treatment. Corona treatment is commonly used on materials such as polymers, papers, films, glass and metals.

Plasma is a good option for components that require a longer treatment hold. Some of the key advantages include: surface chemistry and 3 dimensional treatments. Corona is another form of plasma that can be used with in-line processes. When working with corona the systems are easy to maintain and user friendly.

Flame pre-treatment can also be integrated into inline processes, and require careful and sometimes precise setup in order to be safe and effective. Proper air to gas ratios, flame intensity and dwell time all play into successful pre-treating. Flame plasma systems combine compressed air and a flammable gas which is combusted to create a flame. One advantage is that the material surface only has to be exposed to the flame for a brief period of time to become polarized through oxidation. One setback is the heat level required for this treatment may cause damage to the parts.

Chemical priming is yet another way to pre-treat difficult to adhere to substrates and is generally considered a last resort due to the generally manual nature of application. Essentially primers are used to chemically modify the surface by removing contaminants, adding reactive sites for bonding and increasing surface energy. One disadvantage is that these primers often contain chlorinated solvents that are considered volatile organic contents.

Many substrates will require pre-treatment to satisfy customer’s individual requirements for print longevity. But with the correct treatment and testing, our technical service technicians will test the inks and provide samples for the individual customer’s review.

For information about Engineered Printing Solutions’  custom solutions, standard pad printers, industrial digital ink jet, consumables and other auxiliary equipment, visit Ink Adhesion Part 3: Ink Mixing, Contamination, Blooming and Mold Release Agents, email sales@epsvt.com or call
1-800-272-7764.

Ink Adhesion Part 1: General Education

Have you ever looked down at a water bottle and wondered how the logo got there? Personally I know I have. Before the colors and image can get put together on the object the first question that needs to be answered is how to choose the right ink for the job. Simply put, ink adhesion is ink that sticks to any given product to a known specification. One of the most common tasks our Technical Service team are charged with is to “find me an ink that sticks to the surface of my product.” It wouldn’t be realistic if I told you that our Technical Service team has magic powers and can automatically determine the perfect ink for the material being printed on. Even though inks are produced to stick to a particular substrate; the question is which ink is best suited to adhere to your particular substrate based on your requirements?

There are many different substrates and even more sub-sets within each . Not all polypropylene’s (PP), for example, are created equal. An ink that may exhibit flawless adhesion to one PP product may not adhere at all to another. We therefore need to match the ink series with the particular substrate being presented. However if you supply our Technical Service team with the parts you wish to print on, they will be able to begin working their “magic”. They will be able to first make an educated guess as to which ink will meet the customers’ expectations based on experience, then begin testing the inks and provide samples for the individual customer’s review.

For information about Pad Print Machinery of Vermont’s custom solutions, standard pad printers, industrial digital ink jet, consumables and other auxiliary equipment, visit Engineered Printing Solutions, email sales@www.epsvt.com or call 1-800-272-7764.

Technical Service with Remote Access

Whenever you have a technical problem wouldn’t it be nice to virtually relay the issue to the guy on the other end; without having to explain the details? There are so many times when I wish technical service could see what is on my screen rather than having to figure it out on my own. Here at Engineered Printing Solutions, our technical service representatives are able to virtually operate your machine and resolve the problems or issues you may be experiencing. This is all done by having “remote access” to the machine.

Remote access has been extremely successful with our customers. The remote access program is available with our custom machines. With this technology our technical support team can access the clients’ machine through a simple internet browser. This is a major advantage because with a complex custom machine it is challenging to describe what the customer is seeing on the screen. As soon as the customer and our technical staff are connected they are able to speak either by phone or Skype. The operator is able to see exactly what our technical support team is doing on the machine and our tech support staff can see exactly what the operator is doing on the machine. It is not just a matter of being shown how to resolve the problem; technical support can virtually operate the machine to solve the problem. For safety reasons we do want to make sure that someone is physically at the machine to ensure the safety of everyone on the plant floor and to monitor that the machine functions as expected during the operations that are being performed.

For information about Engineered Printing Solutions custom solutions, standard pad printers, industrial digital ink jet, consumables and other auxiliary equipment, visit Ink Adhesion Part 3: Ink Mixing, Contamination, Blooming and Mold Release Agents, email sales@www.epsvt.com or call
1-800-272-7764.

Ink Viscosity and Seasonal Adjustments

Pad printing is a thin film process. It starts with an etch depth in the cliché of approx. 25-75 microns and only a fraction of that ink film is picked up by the pad. Of the wet ink, 50% is a solvent that evaporates leaving only a 5 micron dry ink deposit. You can easily see why such a thin ink film is so susceptible to changing temperatures, humidity levels, static charges and even variations in airflow. Listed below are the ways you can control the ink viscosity and seasonal adjustments.

Control the rate that solvents evaporate from the ink
• Solvents evaporate too slowly
– The surface of the ink may not be tacky enough to pick up or release images from the pad
• Solvents evaporate too quickly
– Ink might not pick up from the cliché because it has dried in the etched portion of the plate, or dried on the pad in transit to it’s destination.

Same for the pad
• Solvents evaporate too slowly
– Only some of the ink will release from the pad to the substrate
• Solvents evaporate too quickly
– Ink dries and stays on pad.

Tips
• Warm environments: Add solvents every 20 – 30 minutes. Always add a measured amount, use a viscospatula and don’t guess!
• Control temperatures: Keep printer out of the sun, away from drafty entrances, exits, dryers.
Keep the temperature of the substrate to room temperature.
Don’t let printed part drop below 59°F until fully cured – 4 days or longer.
• Good housekeeping: Dust and vacuum floors instead of sweeping. Avoid cardboard boxes in production area. Wipe down all surfaces using a damp cloth.
Static electricity feathers the print. Slow the down stroke and pickup.
• Too hot: Solvents in the ink will evaporate very quickly. Solvents are attracted to water vapor molecules in the air.
– Speed up the forward travel of the pad stroke.
– Thinner / retarder mix (75% Thinner to 25% Retarder)
• Too cold: Solvents won’t evaporate quickly enough. Ink won’t be tacky enough between pickup and and lay down to transfer completely to the substrate.
– Slow down the forward travel of the pad stroke
– Select a faster drying thinner
– Use a hair dryer pointed at the pad as it travels forward after ink pickup to speed up the evaporation of the solvent
– Raise ambient temperature.