By Digital Output Staff
Part 1 of 2
If a print provider is printing to fabric and wants to keep production in house from end to end, it’s going to need to consider investing in a sewing machine or another alternative like a no-sew welder or tape to finish the ends of the fabric. A lot of options are available and it is important to conduct the appropriate research before committing to a machine.
Rick Hatton, business development manager, sign and graphics, Budnick Converting, Inc., outlines some of the main models of sewing machines. Lock or chain stitch are the two categories, a lock stitch that doesn’t run when it is pulled out and a chain stitch that can be pulled out but is preferred for long, continuous runs.
Taking it a step further, sewing machines can be specialized based on the function they perform—straight stitching, surging, hemming, or keder attachment. “Each of these tasks require special attachments and operation modes that must be designed upfront,” adds Hatton.
No-sew options include hot air and radio frequency/ultrasonic welders. Additionally, there are certain tape technologies available that can be applied without the use of any machine at all.
Deciding On the Right Device
Sewing machines are popular for fabric finishing. Key features to look for when choosing the right device for your shop depends on the business and its day-to-day and future operations.
Steven L. Kaplan, president, Kaplan Sewing Machine Co., Inc., says he is constantly surprised at how many printers and graphic companies sew with the wrong type of sewing machine. “Many shops make an initial purchase of a single-needle walking foot sewing machine and while they are great, they are not a good choice for banner and graphics finishing. The walking foot mechanism tends to introduce puckering and waviness into the sew panel.”
Automated sewing machines in general are beneficial, as this eliminates manual labor and any learning curve that may come with it. “They feature conveyors that automatically synchronize with the sewing machine. This gives you smooth material transport as you sew fabric graphics or other soft signage. Plus, you can reproduce finished graphics easily with programmable settings,” note representatives from Global Imaging and Miller Weldmaster.
Sewing machines featuring the ability to manage large and long runs are essential in a print shop environment. “They should handle the heat generated by high-speed sewing, in some cases up to a 30-foot long work piece. Other features to look for include handling medium- to extra-heavy fabrics and adjust to the variation in thickness by a push of a button. Larger bobbin capacities to reduce frequent bobbin changes are also important,” explains Dorothy Fullam, marketing manager, industrial sewing machine, JUKI.
Some popular machines for this segment are double needle, needle feed with built-in pullers, adds Kaplan. “The puller is a driven roller behind the sewing needles that allows sewing of long, straight seams, which is the most efficient way to hem a banner.”
Another important characteristic is choosing a machine that anyone in the shop can operate. “We often hear from many of our customers is that it’s very difficult to obtain an operator who knows how to run a sewing machine. There is typically a long learning curve and seamstresses are very hard to find in the labor market,” share representatives from Global Imaging and Miller Weldmaster.
At Global Imaging and Miller Weldmaster, they suggest training at least two people at time of installation. “Select a trainee with the capability to not only be the champion of the machine but is able to train other teammates.”
“Even if the system is highly automated, you need to have one person who is trained on setup and minor maintenances,” notes Hatton.
Wide format print service providers (PSPs), may not require a machine with all the bells and whistles. It is important for them to realize this during the research process. However, heavy-duty devices are helpful for heavy-duty workloads and more often than not, that is what a print shop is processing. They require industrial strength needles and threads, as well as productivity features that result in less downtime.
Fullam says any machine in the medium- and heavy-duty range is a fit for print providers in wide format. “These machines have larger bobbins for less downtime for bobbin change and higher tolerance to speed and heat created by long runs. The units are able to travel over bumps such as seam over seam and overlaps at corners. They will have less vibration, which means less wear on machine parts,” she continues.
“The sewing needles move backwards as the material is sewn, allowing much heavier material to be sewn effortlessly. These machines also allow for the use of the heavier threads often specified for sewing outdoor banners and graphics. A garment weight machine will not accommodate this type of thread, nor is it powerful enough to properly feed and stitch these materials,” admits Kaplan.
A sewing machine with the bandwidth to match the speeds of the printers and cutters in house is imperative. “If the finishing and/or sewing machines are not able to keep up with the production output of the printers, one could argue that you are negating some of the investment in a high-speed printer. An owner should make the decision of how many machines based upon projected output of the printers and what is required monthly from their customers,” say representatives from Global Imaging and Miller Weldmaster.
For example, they recommend one sewing system will keep up with two high-speed dye-sublimation printers.
Kaplan agrees that one or two sewing machines is probably the most needed by most print or graphics companies.
“If you are performing time-critical work, you need to have a backup plan for breakdowns. That could mean additional machines, spare parts, and cross trained employees. If you are doing high-volume production, you almost certainly need to have at least two machines,” recommends Hatton.
Welding machines are an alternative to sewing devices. Many print providers are already familiar with welding devices used for banner welding, so it would make sense to use a similar technology for finishing fabric edges.
Ultrasonic welding is an attractive alternative. “When it comes to ultrasonic welding, there is not a completely automated machine that will finish the final product. However, by eliminating the thread from the consumable needs of the manufacturer, and creating a welded seam—they are left with a highly durable product that is relatively simple to assemble,” explains Dan Berzack, president, Sewn Products.
Berzack notes another advantage of ultrasonic wedding is that these devices do not have to be adjusted and timed like a sewing machine. This minimal operator intervention advantage is one to consider since the number of skilled sewing machine mechanics is dwindling.
“Fabric welders are a good alternative to sewing, but not all fabrics can be welded. Banner tape, while economical, is not a long-term or permanent solution,” cautions Kaplan.
The other non-sew option is commonly used in silicone edge graphic (SEG) finishing, which is a no-sew peel-and-stick keder tape that is applied without equipment. “For many, finding a non-equipment-based finishing solution allows them to get into the textile sign SEG market immediately at a low cost with a quick and easy-to-learn method,” shares Hatton.
Sewing machines and no-sew alternatives are plentiful for the PSP looking to bring its entire fabric finishing process in house. Kaplan says many of its customers quickly find out that bringing sewing in house is very economical and most obtain better results than they had when outsourcing.
A benefit to bringing a device in house is that additional opportunities are realized. “Graphics customers find they can easily offer products such as printed awnings, pop-up canopies, and flags, once they have invested in the correct purchase,” adds Kaplan.
The next article in this two-part series gives a glimpse into some of the sewing machine and no-sew options available to PSPs.
Sep2020, Digital Output