When it comes to flexible product packaging, there can be no debate on print quality – it has to be perfect every time. When you’re aggressively fighting for consumer product market share, your brand is everything. What’s on the bag is just as important as what is in it.
Making the most of your shelf space at the grocery store requires vibrant, 360-degree package branding. That’s why companies spend small fortunes fine-tuning their brand images, following the advice of marketers and psychologists alike. There’s an expectation that printing will be crisp, clear and on point. The wrong color on a logo will stand out like a spelling mistake. It just won’t do.
Ink companies have responded by developing formulations that bond well and dry quickly on a range of challenging flexible package substrates like coated paper and plastic films. Getting the pigments, extenders and vehicles put together properly requires an efficient dispensing system.
Whether you’re installing a new printing line or modernizing an existing operation, an automated dispenser is the critical piece of equipment that will bridge the gap between your complex ink inventory and your precision printing press. In particular, the complexities of flexible packaging ink demand state- of-the-art solutions for dispense valves, control systems and automated cleaning features. It’s worth understanding how the right dispenser can help you get the most out of your ink.
Consider the case of end users who print on a BOPP substrate, popular for food packaging. One of their smaller batches would be 10 pounds, a fairly typical request for short runs or press top-ups. If the smallest component within the batch is 1 percent of the total, then they need 0.1 pounds of that ingredient, or about 45 grams. They strive to hit the ideal ±1 percent precision on each component, so they need an absolute precision of about ±0.001 pounds or ±0.5 grams. That’s only one-tenth of a teaspoon!
If you have a parcel scale with a stated precision of ±2 or ±5 grams, try as you might, you cannot precisely dispense small ingredients. For some additives and catalysts, it just doesn’t matter. But for intense pigments, like black or purple, a few extra drops can mean the difference between a perfect draw down and a pail of scrap ink. It is critical that the dispenser has a weigh station that can measure the desired precision of your smallest ingredient.
Automated ink dispenser valves must have a high turn-down ratio. That means the valve can pass a lot of ink in a short period of time, but also modulate the flow down to a very precise stream or pulse. Standard, single-stage process valves cannot accomplish this, so ink dispensing valves are highly customized creatures. In a properly balanced system, the valve should be capable of finely dispensing small increments equal to or less than the smallest scale division of the weigh station.
To balance speed and precision, dispense valves need to be on a dedicated control loop. The old method of using desktop computers with consumer-grade operating systems introduced too much process lag and unpredictability. Industrial, solid-state, real-time control systems now exist and they’re the right choice for an industrial ink dispenser.
Machine hygiene is just as important as performance. Flexible packaging inks are fast drying, which is great for the printer, but it can make a mess that’s difficult to clean up. These inks don’t respond well to old-style soaker pans, and manual valve cleaning is ineffective because people forget or are simply too busy. When ink dries on dispense valves they plug, they spray and they don’t perform properly. Worse still, valves can damage themselves when dried ink is pulled through delicate seals.
The best time to clean a valve is immediately after it cycles when the ink is still wet, and it can be accomplished by using an automated valve cleaner. Systems are now available on the market that can offer vacuum-induced, enclosed spraying with drip-free operation and 100 percent recycling of cleaning fluid. These automated valve cleaners will leave your valves clean and dry after each dispense and require minimal maintenance over the life of the equipment.
Once you’re confident that your ink dispenser has all the right hardware, the human-machine interface deserves just as much attention. Your automated dispenser should offer an intuitive interface with organized menus and options without feeling buried in a background operating system. With minimal training, operators must be able to quickly and easily execute standard and modified batches. Issues such as over-dispensing and empty source containers must be simple to correct without any risk to the batch.
Ink room managers and production leaders need to be able to easily set up projects, manage inventory, run reports and customize machine operation as required. A remote, web-based connection should be offered for factory-level support for technical training and troubleshooting to keep the machine running efficiently around the clock. All together, these features make the machine more accessible and inviting, and help to improve the productivity and morale of your team.
Though it represents a small part of the overall investment for a printing operation, the right automated dispenser can deliver a substantial return on investment through reduced operating costs, reduced waste, improved product quality and reduced process downtime.
Consider how precision, performance and hygiene will impact your overall printing operation. Research the available options and ask questions. Your efforts up front will help you to commission the best dispensing solution to get the most out of your ink.