In today's competitive sign and graphics industry, production efficiency matters just as much as print quality. As banner orders grow larger and turnaround times continue to shrink, many shops discover that printing isn't the bottleneck—finishing is.
One of the most time-consuming finishing processes is hemming. Traditionally, operators weld one edge of a banner, reposition the material, and repeat the process on the opposite side. While effective for lower production volumes, this extra handling quickly adds unnecessary labor and slows throughput.
Double hem banner welding eliminates that inefficiency by allowing both long edges of a banner to be welded simultaneously. The result is stronger finished products, fewer handling steps, and significantly higher productivity.
This guide explains what double hem banner welding is, how it works, the materials it supports, and why the Miller Weldmaster DH7600 has become an ideal solution for high-volume banner production.
A banner hem is the folded edge around the perimeter of a finished banner that provides additional strength for mounting hardware such as grommets, rope, or pole pockets.
Instead of finishing each edge individually, double hem welding produces both long hems simultaneously during a single pass through the machine. This creates consistent, reinforced edges while dramatically reducing production time.
The additional layer created by the folded hem distributes stress more evenly throughout the banner, helping prevent edge failure caused by wind, tension, or repeated installation.
For outdoor graphics, construction signage, event banners, and large-format advertising, proper edge finishing is one of the biggest factors affecting product longevity.
Many banner failures don't occur in the printed image—they begin at the edges.
Weak edge construction can lead to:
Choosing the appropriate finishing method for each application ensures banners perform as expected while helping reduce costly remakes.
| Finish Method | Strength | Waterproof | Best Applications |
|---|---|---|---|
| Heat-Welded Hem | Excellent | Yes | Outdoor signage, high-volume production |
| Tape Hem | Moderate | No | Indoor and temporary graphics |
| Sewn Hem | High | No | Fabric and mesh materials |
| Flush Cut | Low | N/A | Framed displays or temporary use |
Double hem welding uses a banner welding machine that applies heat and pressure to permanently fuse thermoplastic materials together.
Depending on the material, manufacturers commonly use one of two heating methods, and weld width is one of the setup variables that must match seam requirements and banner finishing needs:
A heated metal wedge, one of the heated elements that transfers energy into the material during welding, is positioned between the folded material layers. As the material moves through the machine, the welding surfaces reach the proper temperature before compression rollers permanently fuse the seam. Hot wedge systems can also produce pole pockets in addition to hems and overlaps.
Instead of a heated wedge, controlled hot air softens the material immediately before pressure is applied. This process provides excellent flexibility across many banner materials and thicknesses.
Both methods produce waterproof molecular bonds that outperform adhesives in demanding outdoor environments.
The greatest advantage of double hem welding isn't necessarily faster welding speeds—it's reducing material handling.
With traditional finishing:
Every repositioning step requires additional labor while increasing the opportunity for alignment inconsistencies.
The DH7600 removes this entire process by welding both edges simultaneously.
For shops producing hundreds of banners every shift, those saved minutes quickly become hours of recovered production time, and that workflow gain matters even more on large banners, where each repositioning step takes more labor.
Double hem welding is designed for thermoplastic banner materials that soften under heat and permanently fuse together, so it is not ideal for fabric banners that cannot be heat welded.
Common compatible materials include:
As more environmentally conscious materials enter the market, testing new substrates before full production remains a best practice to ensure optimal weld quality, especially with pvc free banner material where weldability can vary.
The DH7600 Double Hemmer was engineered specifically for manufacturers who require fast, repeatable, and consistent edge finishing.
By welding both outside edges simultaneously, this banner welder dramatically increases production capacity while reducing operator handling.
Its dual heating system combines both hot air and hot wedge technologies, giving manufacturers flexibility across numerous material types and production requirements.
Before installation, shops should confirm the machine’s power requirements, including appropriate electrical service and any compressed-air needs.
With welding speeds reaching approximately 60 feet per minute (18 m/min), the DH7600 is built to support continuous, high-volume production environments.
Although designed with banner manufacturers in mind, the DH7600 is equally valuable for producing other flat thermoplastic products requiring simultaneous edge finishing, and the same approach is useful for vinyl banners and building wraps that need strong seams at scale.
Applications include:
This versatility allows manufacturers to maximize equipment utilization across multiple product lines.
Not every shop requires a dedicated dual-edge finishing system, and for lighter output it may not always makes sense.
However, as production volumes increase, the savings become substantial.
Tape-based options can be more cost effective for low volume work, but automated welding becomes more cost effective as volume rises and labor cost accumulates.
A dual-edge machine is an excellent investment if your operation:
For shops where finishing limits overall throughput, increasing banner output often begins by removing unnecessary handling—not simply increasing weld speed.
If your production line is spending valuable time repositioning banners for a second pass, the DH7600 Double Hemmer can help streamline your workflow while producing consistent, high-quality results.
Contact the Miller Weldmaster team today to discuss your materials, production goals, and finishing requirements to determine whether the DH7600 is the right solution for your operation.
Banner finishing plays a critical role in both product durability and production efficiency.
Double hem banner welding allows manufacturers to produce stronger finished products while significantly reducing labor and material handling. By eliminating the need to reposition banners between welds, manufacturers can streamline production, improve consistency, and increase daily output.
The Miller Weldmaster DH7600 delivers these advantages through simultaneous dual-edge welding, versatile heating technologies, and operator-friendly controls designed for demanding production environments.
If your finishing department has become the slowest part of your workflow, it may be time to evaluate whether a dual-edge hemming solution can help increase productivity and support future growth.