Wide-format Graphics: An overview of digital finishing

by all | 18 July 2016 8:45 am

By Steve Urmano
With the availability of ‘soft signage’ substrates, rigid boards and polypropylene (PP) alternatives to polyvinyl chloride (PVC), today’s sign shops have more choices than ever when it comes to printing materials. 
The installed base of both roll-to-roll (RTR) and flatbed printers has increased steadily.

Given this growth, post-print finishing has also become more important, as so many of these graphic materials need to be framed, laminated, mounted, contour-cut and/or routed. Often, the value of finishing provides a higher return on investment (ROI) than printing. Traditional manual methods of finishing, however, are becoming woefully inadequate at meeting today’s deadlines and cost requirements.

High-speed printing platforms are driving huge volumes of graphics. When a shop is printing two rigid 1.5 x 3-m (5 x 10-ft) boards per minute, similar cutting throughput is required. Keeping up is particularly difficult with high-speed textile printers, as fabric graphics are more likely to need trimming, hemming, sewing and grommeting.

Indeed, without continuous, significant increases in the automation of material handling and in cutting capacity and speed, sign shops’ investments in faster and wider printers may prove fruitless, to the point of eroding their growth and profits. It is important to prevent finishing processes from becoming major bottlenecks that could delay delivery and invoicing. For digital printing to continue its march forward, digital finishing is not merely an option, but a must.

Much like the diverse range of digital printing equipment, however, there are many choices to make among cutting and finishing devices. Signmakers need to consider not only what types of products they are planning to finish, but also how those products will be physically handled and processed through an automated production workflow.

Avoiding bottlenecks
Sales of wide-format ultraviolet-curing (UV-curing) hybrid and flatbed printers, along with durable aqueous ‘latex’ inkjet printers, have increased substantially in recent years. Market research firm InfoTrends’ latest report shows installations of wide-format UV printers have grown by nearly 20 per cent, while HP reports placements of its latex printers increased by 35 per cent between 2013 and 2014.

Print service providers (PSPs) that invest in wide-format digital presses typically do so to become more competitive in their market in terms of running costs and versatility of applications. The same is true with automated finishing equipment, which requires less operator intervention, achieves greater productivity and reduces waste.

With complex contours and shapes, finishing time can exceed printing time, especially for point-of-purchase (POP) graphics and thicker materials. Printing is a ‘scanning’ process, whereby the addition of more printheads and nozzles will increase a machine’s speed. Cutting, on the other hand, is a ‘narrow path’ process, where speed is directly related to the complexity of the cutting path and the thickness of the substrate, not simply to one true cutting speed of the machine. For this reason, in many shops, the finishing department needs to be larger than the printing department if bottlenecks are to be avoided.

Application trends
As mentioned, the rise of diverse substrates is driving the evolution of trends in finishing. Textile printing, for example, has grown considerably, including the use of transfer-based and direct dye sublimation, flexible UV-curable and latex inks. Contour cutting has helped turn printed textiles into finished signage, exhibits and apparel. Some businesses discover they need to add sewing capabilities, as well.

At the same time, UV-curing flatbed printers have boosted rigid graphic material volumes over the past few years. These materials are nearly impossible to cut efficiently by hand without significant damage to the print. The only practical method for cutting and finishing them is a flatbed router/cutter.

Today’s choices for sign media are more diverse than ever. Frontlit and backlit signs can be printed on polyester or vinyl-based materials with outdoor durability. Latex, UV-curable and solvent-based inks offer a wide range of effects.

Thermoformed signs printed with UV inks can stretch by up to 200 per cent and require a heat moulding process to give ‘relief’ to an image. Signs printed on paper are laminated to foam-core boards for rigidity. Soft and UV-susceptible inks and materials are also laminated to make their graphics more resistant to harsh outdoor conditions. Vehicle graphics, in particular, require lamination before they can withstand the rigours of a car wash.

Polyester-based textiles have also become a large part of the sign and graphics market, thanks especially to the flags, fabric banners, table drapes and tensioned signs that have largely replaced rigid trade show displays. Not long ago, businesses commissioned expensive, single-use displays for trade shows, but in today’s age of shrinking marketing budgets, many booths are instead made of extruded aluminum channels with silicone-edge fabric graphics that can be used again and again. The same materials are also being used in retail environments. As mentioned, printed textiles often require precision cutting and sewing during the finishing process.

Hardware options
Finishing options go beyond cutting. Signs also need to be mounted, pole pockets need to be sewn, banner grommets need to be installed and backlit and frontlit displays need to be framed.

Flatbed cutting tables are versatile in terms of tool options and roll adapters that enable the use of both rigid and RTR media. The size of the table will depend on the shop’s throughput requirements, but there are also double-sided beds that allow an operator to cut on one side of the table while loading the next substrate on the other side, for non-stop productivity.

With the rise of dye sublimation, cutters with special handling capabilities are now 
in demand. Laser cutting heads are needed 
to properly finish polyester-based media, by simultaneously cutting the material and sealing its edges to prevent fraying. Other cutters 
for aluminum, steel and polycarbonates are required to answer growing demand from industrial printing applications.

That said, lower-end RTR contour cutters account for the largest segment of the market, by far. And while the demand for specialized tools has increased, the trend begs the question: do all such needs justify their own type of cutter or would a multi-purpose machine that can handle many types of materials be a better fit?

InfoTrends’ studies show the market penetration of vinyl cutters and printers with built-in cutters reached nearly 85 per cent in 2014, while high-end flatbed cutters comprised roughly 15 per cent. As such, there are still significant opportunities for both (a) dealers selling specialized equipment and (b) PSPs offering cutting and finishing services to their fellow PSPs.

There is now a trend of sign shops replacing many smaller printers with fewer bigger ones, so as to achieve higher volumes of throughput. In response, some midsized shops are expanding their facilities and exploring options to improve their workflow.

Finishing also needs to be highly flexible to accommodate the necessary workflow changes. Wider materials, especially, have driven the addition of automated cutting, due to their size and throughput requirements. Factors like accuracy and cleanliness also come into play.

RTR cutters
In today’s market, many RTR cutters are available that are competitive in terms of price and features. They are best used to cut and score paper, canvas, polystyrene (PS), films, foils, polycarbonates, magnetic media, PVC and other vinyls. Lower-end models have been introduced for lighter-duty requirements.

Features may include self-sharpening blades, a front roll shaft to help ensure even widths, automatic-lowering pressure bars to hold materials in place during cutting, automatic optical registration crop mark sensors for additional precision and ‘half-cuts’ to leave a backing sheet that can be easily detached when necessary, e.g. for decals and stickers.

Cutting tables
Having expanded from the early days of woodworking sign shops, today’s computer numerical control (CNC) routers and cutting tables are equipped with easily changeable cutting heads and tools, including options for kiss-cutting, through-cutting, oscillation-cutting, V-notching, creasing and scoring. Various models can finish printed graphics, wood, metal and packaging materials.

Digital cutting technology has both increased throughput for full-time operations and made short-run prototypes and samples economically viable for wide-format and industrial printing environments. Many tables are equipped with vacuum ‘hold-down’ beds to keep substrates firmly in place after they are conveyed by belts, some of which can move materials on and off the bed automatically, to maximize productivity.

Indeed, automation is being applied to cutting just as it has to printing. Wide-format inkjet printers using raster image processor (RIP) software can be ‘cut-enabled,’ whereby they both output a cutting file and print cutting marks on the material that are then detected by machine vision registration technology, for co-ordinated print-to-cut functionality. Workflow software is also being deployed across printers and cutters to assist with pre-press requirements, job management and cost tracking.

Multi-functional tables are synchronizing cutting, perforating, marking and routing to support variable-production workflows, based on the optimal configuration for each job. Moreover, automation means loading, unloading and processing can all occur at the same time.

Some of these tables combine knife cutting with automated laser cutting, which is better-suited for fabrics and some non-PVC plastics. With this combination, virtually any material that can be inkjet-printed on a wide- to grand-format press can then be digitally cut on a table. One of the keys with regard to automation is to integrate both (a) a motorized roll unwinder to place fabrics on the table without stretching or wrinkling and (b) a board system for loading rigid sheet materials from a pallet.

Sewing systems
Sewing has become more important as some PSPs expand their focus beyond display graphics to encompass interior décor and apparel applications, which can be printed using dye sublimation inks onto paper, transferred onto polyester-based fabrics and cut on a flatbed table before they are sewn. Compared to the traditional, non-digital production of such applications, wide-format inkjet printing offers the benefits of ‘just-in-time’ production, customization and versioning. Manufacturing cycles have been shortened from weeks to days.

As such, InfoTrends anticipates major advances in the automation of sewing for everything from pillows to soft signage to activewear. There are models geared specifically for sewing, seaming and heat welding, including some that sew edge gasket beads for signs and sew and hem pole pockets and ropes for banners. A cooling system may be needed, for example, to prevent the sewing needle from getting too hot and deforming the latex bead common to channel-based graphic frames. Otherwise, operators need to stop at given intervals to cool the needle, rather than work continuously.

Laminators
Available since the early days of wide-format inkjet printing, lamination is one of the oldest and most widely accepted finishing processes in the sign industry. The earliest aqueous inks could not withstand the rigours of outdoor use, so the technology quickly evolved to meet the industry’s needs.

Today, despite the introduction of more durable inks and substrates, lamination remains a necessary step 
to ensure the graphics can hold up to the demands of outdoor installations. It is certainly a basic requirement for vehicle wraps and decals. Roll-based substrates are often laminated before they are cut. There are hot and cold laminators, as well as liquid laminators for use with UV-curable and latex inks.

A growing need
Finishing has always been an integral part of the overall manufacturing process for wide-format graphics. As sign shops, PSPs and other digital printing companies have continued to market more specialized products, however, the choice of the right finishing equipment has become even more important. And with today’s wider array of printable materials, the growth of digital fabric printing and increased press speeds, the need for digital, automated finishing equipment has become clearer in hard economic terms. Sewing, in particular, is seeing a resurgence 
in demand as it transitions from a labour-heavy process to a more fully automated one.

Today’s sign shops can select from a wide range of RTR cutters, flatbed cutting tables, routers, laminators, sewing machines and welders, among other systems, depending on the nature of the products they need 
to finish. Each machine must be considered as part of an overall workflow, which will change over time.

With this in mind, vendors and resellers bear some new responsibility for training highly skilled operators of their finishing equipment. And as the installed base of such equipment continues to grow, programs will also need to be introduced at vocational schools and colleges, to ensure the sign industry has access to a new generation of workers who are properly trained to optimize digital technology.

Steve Urmano is director of InfoTrends’ wide-format printing consulting service and develops annual global market forecasts for hardware and supplies used in the wide-format graphics market. This article is based on a white paper he prepared for the International Sign Association (ISA). For more information, contact him via e-mail at steve.urmano@infotrends.com[1] and visit www.signs.org/research[2].

Source URL: https://www.signmedia.ca/wide-format-graphics-an-overview-of-digital-finishing/

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