By Cassandra Balentine
Folding and gluing is essential to completing packaging applications. As runs get shorter and designs become more complex, these finishing functions must be re-evaluated to ensure efficiency and productivity in an evolving market. Digital printing and finishing technologies are well suited to serve this demand, bringing many benefits as well as concerns for those accustom to analog production.
Along with shorter runs, driven by product SKU diversity and new products; and more complex designs, Chris Raney, VP of postpress, Heidelberg USA Inc., says additional trends in folding and gluing include window patching and quality control.
“Sometimes a window is required to show the product off and then it needs to be held in a specific orientation in the carton,” he offers.
Further, quality control is becoming critical. “With different SKUs in production, customers want to eliminate the risk of mixing cartons of the same shape but different content. This can be achieved by using quality control equipment, reading bar codes in real-time and ejecting non-conforming cartons. Depending on the product, the level of quality control can be further increased to validate glue application, readability of quick response codes, etc.,” he explains.
Digital Finishing Challenge
Specific to folding and gluing for packaging, several considerations reduce the chance for complications down the line.
One point is to either varnish the digitally printed piece or make sure that the inks are rub resistant enough to endure the production process. “On a folder gluer, the printed surfaces will rub on belts, etc., so it is important to ensure the printed surfaces are correctly protected to avoid marking—a good varnish is the best way to ensure this,” recommends Raney.
Mallet points out that paper stock selection is important if you want to reduce bubbling after gluing. “Very dry paper can be problematic. A minimum five percent water content is recommended. For best results coated one side is recommended,” he suggests.
For reliable feeding in the folder gluer, the cartons have to be completely dry to eliminate sticking. The friction between them also needs to be low enough to ensure they can slide one by one from the friction feeder,” offers Raney.
Shorter turnaround times are a challenge across the board in today’s print environments. When it comes to digital printing and finishing, customers expect it fast. Solutions that improve turnaround times on shorter run work is in demand.
Having a streamlined workflow is critical, this includes getting artwork prepared and approved efficiently, points out Raney.
“Equipment ease of use is a must. Problems with gluing machinery can become a bottleneck. Keep it simple,” stresses Lester Mallet, president, Gluefast.
Skilled/well-trained staff are also a must. “Having a skilled operator will always ensure an efficient makeready,” comments Raney.
Mallet agrees, noting that proper employee education about the process and good equipment maintenance are essential to reducing turnaround times.
Some machines offer makeready time saving features that allow key settings like carrier positions to be pre-set and then stored for when the job is re-run.
The area around the machine should be well organized with all attachments from the gluer stored on a rack so they are easily available and in good condition.
Further, having structural design capability in house is essential to improve productivity. This allows new structures to be be cut and tested in house for approval by the end user and discussed with the production so that it can be manufactured efficiency. “Keeping this process in house will streamline the process,” states Raney
From there, when getting a new job on folder gluer for a first time, having prior involvement upfront means no surprises when the die cut job gets to the folder glue.
There are several points where automation and features aim to reduce labor and manual processes throughout the folding and gluing processes.
“The machine can be equipped with a certain level of automation, which usually focuses on the position of the main carriers of the folder gluer. However, the nature of every folder gluer is that many of the settings and folding tools required need to be positioned manually based on the job being run and experience,” says Raney.
He adds that moving equipment into the gluer is hard manual work and is more difficult when the run lengths are longer or the running speeds are high. “At the feeder of the machine there are automatic feeding options that ensure greater consistency of feeding while allowing a larger reserve of cartons to be built up in the feeding unit. This reduces the stress on the feeder/operator and ensures the machine runs more consistently,” he continues.
At the end of the machine there are several different solutions for automation. “If the run lengths are long enough, unlikely in a hybrid digital environment, an automatic packer could be appropriate where the cartons are packed directly into a corrugated case. However, this is really only a solution for the longest runs. There are intermediate solutions on the market that provide an assist to the operator. These collate the cartons into a stream to make the collection and packing much easier and faster, this results in directly increasing the machine running speeds since the hand packing is less of a bottleneck,” adds Raney.
Moving to shorter runs is a challenge for traditional package converters. It is important to find a folder gluer that can improve turnaround and reduce manual processes in hybrid digital/analog print environments.
“We offer simple roll coaters to glue paper to various board stock, along with suitable water-based adhesives,” says Mallet.
When it comes to duplexing, he says Gluefast offers a complete system for short runs with an affordable price tag. This includes the gluing machine, adhesive, alignment board for lining up duplexed materials, a rotary press to smooth the duplexed materials, and a weighted board to hold down the glued materials to eliminate warping.
Heidelberg offers a variety of solutions that are very suitable for hybrid/digital markets including the Diana GO 88 and Diana Easy 85/115.
The Diana GO 85 is a machine with a small footprint of 32 feet in length, excellent design features, and highbuild quality. The Diana GO 85 has a belt speed of up to 1,000 feet per minute. It can produce straight lines and lock bottom cartons. “A range of specialty devices can be added to allow the production of pocket folder, envelope, and more. A bump and turn unit is also available to further extend the range of special designs that can be produced,” offers Raney.
The Diana Easy 85/115 is a much longer machine at 58 feet. This also means that it has a much wider range of capabilities. In addition to the products that can be produced on the Diana Go, the Diana Easy can also be equipped with rear folding technology. This allows the folding of rear panels so that four and six corner cartons can be produced as well. Raney says the extra length makes it more suitable for complex cartons with internal fitments.
“Both of these machines can be equipped with an extrusion glue system that can have quality control functions. Tipping and taping units can also be added to further enhance the capabilities,” he explains.
To help automate the packing, the MK Easypacker is available. This is a semi-automatic packing solution that will help increase machine speeds by simplifying the job of the packers at the end of the machine.
Moving on Down
As shorter runs become increasingly in demand, packaging providers look to add automation to improve turnaround times, reduce labor, and enhance efficiency. Folder gluers well suited for hybrid/digital print environments address these evolving needs.
Nov2021, DPS Magazine