Tag Archive: corona treating

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

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    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.

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

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    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.

  3. All Fired Up: Pad Printing Glassware

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    Most glassware has some kind of discernible shape. Logically, pad printing emerges as a natural choice in glass decorating and printing. The more complex the shape, the more suitable pad printing becomes as a decorating process.

    With the right tooling, multicolor prints, special-effects inks, and even 360 degree wrap-of-image-around-circumference are possible. Automated parts-handling options can further speed production rates.

    There are two primary inks used in pad printing glassware: frit inks and acrylic inks.

    Acrylic inks
    Acrylic inks are mixed with a catalyst hardener as well as with a solvent thinner, which allows the ‘tack-up’ and transfer from cliché to pad to part. A post-print bake is usually recommended (3-5 minutes at about 200 degrees F) to improve the durability of the print. The bi-component ink mixture typically has a ‘pot life’ of 6-8 hours, after which time the ink hardens on its own, rendering it unusable for any further printing.

    Acrylic inks are fairly durable, providing at least 50 wash cycles in your average home dishwasher.

    Frit inks
    For greater durability, a frit ink is the way to go.

    Frit inks contains:

    1. Finely ground glass particles in the ink mixture (very small, only a few microns in size)
    2. A pigment (the colorant)
    3. A binder, which is a carrier used to keep the ingredients in suspension
    4. A thinner, the solvent which facilitates the silicone pad transfer process.

    Different frit suppliers recommend different combinations of the above four components. There are no pot life issues to consider when using frit inks.

    After printing with the frit ink, the printed ware is fired in a kiln, typically at about 1100 degrees F on average for up to 30 minutes. The ground-glass particles come very close to their melt point; the organic ingredients in the print burn off, and a physical bond is created between the print and the product. Frit inks are generally considered the most durable of all glassware prints, capable of lasting a lifetime and providing tremendous abrasion resistance.

    Have you had glassware decorating challenges? Feel free to contact us for advice on the best options for all types of pad printing on glassware.

  4. Part 2: When is Automation Right for your Pad Printing Business?

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    In Part 1, I explained some of the indicators of a need to implement automation in your process, and some of the challenges you needed to anticipate and control during the implementation.

    Let Me Tell You a Story
    This is the story of a manufacturer with two endings – one happy, one sad. The company printed and labeled widgets at a rate of 100,000 per day with 15 employees on task in an environment that created an overhead of $22,000 per laborer. The supervising print manager, unable to keep up with that large a shift, threatened to quit, forcing the owner to offer him an extra week’s vacation immediately, and each year thereafter, to stay on the job.

    A year ago, the CEO/owner received an email from his engineering manager. The PPMOVT sales rep was nagging him to consider a really expensive ink jet machine. The cost was $350,000 and ran at an operating speed of 150,000 widgets per day. In his opinion, the expense and production was far more than their company needed, but he wanted to keep the owner informed of what was available.

    The owner summoned his engineering manager to his office. “How many people would it take to run this machine? What would the operating costs per widget be?” The manager had done his homework. “The ink cost per piece would be less than it’s costing now, and one unskilled person could operate the machine. But how could we afford such a big investment?”“We can’t afford to not buy it. Our total ROI would be less than 14 months!” (This didn’t even include the cost of the disgruntled print manager, who earned $56,000 per year.)

    The Happy Ending:
    The owner purchased and installed the new equipment, and was able to reduce the price of his widget by two cents apiece. Sales increased and their biggest customer dropped his Chinese supplier to give them the work.Over the next 12 months, profits increased by $300,000 and they hired 14 people to fill additional jobs created in the customer service department. Now that’s what I call ROI. They lived happily ever after.

    The Sad Ending:
    We have all personally known companies that have gone out of business because they never picked up on opportunities like this; companies that wouldn’t make the hard but necessary decisions to support growth.The alternate ending to this story? The CEO allowed himself to be convinced that the more powerful ink jet’s expense was not worth the risk, and some of their long-time employees would be out of work, too old to find new employment. They subsequently lost orders to other manufacturers who invested in new automation, which resulted in poor old ‘Jane,’ the operator who complained her replacement would be a machine, losing her job, along with the 250 other employees who went on unemployment.Then the snack bar around the corner from the formerly thriving manufacturer closed, leaving Jim the proprietor without an income and his Chef looking for a new job.Several other former vendors went out of business as well because they no longer received orders from their preferred customer. THE MANUFACTURER HAD GONE OUT OF BUSINESS.

     

    Join the conversation! How have you handled growth and change in your workplace? Are you involved in the tough growth decisions?

  5. Part 1: When is automation right for your pad printing business?

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    Engineered Printing Solutions custom solutions sometimes involve designing and engineering automation capabilities. When appropriate, we  recommend an upgrade from your existing equipment. Why would you do that? After analyzing your current process, we sit down with you and discuss where you can save time and money by investing wisely in a custom automated system.

    A successful business makes wise investments that increase in value over time. We all know time is money, but we forget that the time needed to gain a return on our investment is crucial in making decisions. A 10% return on an initial investment within one week would be classified as a huge windfall. A 10% return in 10 years, even in today’s soft market, would be a wasted effort.

    So when is the right time to consider automation?

    • It’s time to consider automation when you find your business losing time in setup, prep and assembly, especially when there aren’t enough hands to go around. It’s time when you want to grow your business but your staff can’t keep up with the orders you have.
    • It’s time if the form of automation has a reasonable ROI (return on investment) based upon industry norms. Automating can be as simple as moving a box that stores work-in-process to a more convenient location, making the job easier and quicker, saving time and therefore money. Your investment in this sample is 10 minutes of time to come up with an idea and 15 minutes implementing the idea (25 minutes total investment) which subsequently saved 5 minutes per day. ROI = 5 working days = excellent investment, when the industry standard on ROI is 16 months!
    • It’s time when the cost of labor is holding back your growth. If your company is in the business of manufacturing, in most cases your single biggest expense is labor. This is where automation can become an emotionally charged issue among employees. How many times have you heard people complain that the boss is going to replace them with a machine. Perhaps technically true; however, the bigger picture is that you must yield a few jobs to chores a machine can’t do in order to grow the company. It also provides an opportunity to retrain or release those employees who had limited or no growth potential. In order for a business to survive and thrive automation is one of the simplest tools to implement.
    • It’s time when you want to expand your business with cash and labor invested wisely, with one eye on your ROI and the other looking toward potential growth. If you had some money available and could get a 10% ROI in a month, would you do it? Would you do it if it was relatively risk free? I’ll bet you’re smiling now!

    In our next post I’ll tell the story of one CEO’s “no-brainer” decision in a tale with two endings: one happy, one sad. Until then, consider some of our custom automation solutions:

    Look at some of the videos. Can you imagine a similar step in your process?

    Join the Conversation!  How have you handled growth and change in your workplace? Are you involved in the tough growth decisions?