Welding vinyl for banners and signs has several advantages over sewing for the same applications.
Heat welding produces a stronger bond than sewing. With the correct application of heat and pressure welds are as strong as the material itself. Conversely, the holes made by the sewing needle weaken the fabric and provide the most likely point of breakage in a final product.
Many sewing threads are not suited for use outside as they deteriorate quickly under the strain of the elements. UV-treated threads tend to be thick and more difficult to work with. Welded seams hold up as well as the rest of the banner or sign.
Sewn seams are more visible than welds, particularly from the front of material. Welds are near invisible improving the finished product’s appearance.
With heat welding, joining two fabric rolls can be done in a single pass instead of multiple sewing passes required to achieve the same joint.
Ease of use
Large projects are much more suited to heat welding than sewing. Large pieces of material are heavy and awkward to pick up and move through a sewing machine. Automatic welding machines allow material to remain stationary while the machine itself moves.
Some operator training is required to produce precise and neat welds but equipment operation is simple. Once the correct parameters are found, welding is largely done automatically by the machine.
Not sure which joining method is best for your application? Contact your Technical Sales Representative for help.
Our previous article covered Finding the Right Welding Parameters for your Industrial Fabric. In brief, the differences between brands, coatings, composition, textures, and environmental factors mean that each material and environment require a different combination of speed, temperature, and air flow to achieve a good weld. When welding a new material, we recommended consulting with the fabric manufacturer to obtain a product data brief. The information in the brief can help minimize the number of test welds needed to find the appropriate welding parameters.
As with all materials, make sure to have numerous, clean samples on hand before beginning testing. Properly fasten each to the table or floor with tape or weights. A consistent plant environment (temperature, humidity, air movement) will produce better results. Make sure that the operator is trained on how to use the welding machine. If you’re using a Leister UNIPLAN, see our article Welding Industrial Fabrics with the UNIPLAN E.
Learn how to install a piping kit, hem kit, guide bar and other accessories on the Leister UNIPLAN.
While Laser IR Thermometers are an extremely common tool, they are entirely ineffective for measuring the outlet temperature of an air heater. To understand why, we must first understand how this tool works. Laser IR Thermometers measure the surface temperature of an object by measuring the thermal energy emitted by the target. Knowing the amount of thermal energy discharged and the emissivity of an object’s surface, the object's temperature can be determined by the device.
When measuring a heater’s output air temperature, the largest issue with these tools is that they measure surface temperatures. As the heated air is transparent, the measurement will always be the surface temperature of a nozzle or a component of the heater housing; and frequently it will be an exterior surface. These items will always be cooler than the heated air, often by a significantly larger margin than the user would expect. To accurately measure the output temperature of an air heater you must measure air temperature and laser IR thermometers are incapable of doing so.
Large format printing of banners can produce a stunning final product. Very large banners require the joining of two or more pieces of material by welding, stitching, or gluing. When welding two banner pieces together the type of ink used becomes an important consideration.
Solvent-based inks cannot be welded. The ink interrupts the bonding process. Instead, leave a margin unprinted on the banner the width of the required weld. Be sure to carefully align the pieces of material to make sure the final product is perfect.
Water-based inks can be welded without issue, no margin need be left when printing.
Have questions about your material? Give us a call.
The new HEMTEK stationary welder from Leister is easy to use, see how in this video:
Have questions? Give your Technical Sales Representative a call for help!
We often get asked by customers what welding speed and temperature they should use for their material. The simplest answer is we don’t know. Each material and environment require a different combination of speed, temperature, and air flow to achieve a good weld.
Let’s examine each parameter and how they affect the welding process.
Materials often have a range of acceptable welding temperatures, speak with the manufacturer of your material to see if they have recommendations for your specific fabric. Use these recommendations as a starting point.
The ideal temperature depends not only on the material but also the environment. Welding outdoors, in a cold environment, or in the direct sun can all affect the required temperature. Make sure to take into account if conditions change during the course of the project and conduct test welds periodically.
Why is using the correct tool for the job important? Results.
Using a tool that is undersized for the job will give you unsatisfactory welding results. There are two factors at play: power and weight.
An under-powered tool will have trouble heating the material sufficiently to achieve a good weld. Sometimes a lack of power can be compensated for by decreasing the speed of the machine but often the result is still an incomplete weld.
The thicker the fabric the more weight is required to ensure a good weld. Although supplementary weights can be added to machines, adding weight beyond what is recommended by the manufacturer will cause the machine to work harder and break down more often.
Another consideration when selecting the correct tool is speed. If your application requires long, straight welds a machine that is capable of greater speeds is an asset. However, if you are welding short lengths, speed may be less important allowing you to purchase a less expensive machine or if you are welding curved seams a slower machine that allows you to fine-tune as you weld may be more suitable.
For help selecting the correct tool for your material contact your Technical Sales Representative.