Need Help Pole Banners Ripping

[Thompson Design]

Hello everyone, in November we were contracted to do 70 pole banners for our township. We did our research and ordered in 2 rolls of Ultraflex Pole Banner Pro 18oz for the job. We printed 2 sided on the Roland, contracted a seamstress to hem and sew, she used a military grade thread. She returned them and we grommeted the banners and delivered.

Township contracted another guy to install them. Now they have ripped away from the poles where the grommets were. Almost all of them are either flapping in the wind or tangled up around the hydro wires, or completely fallen off. Some of them are cracked as well. :-(

Notes about the job: They only had the bar across the top to secure the poles, we put two grommets below the pocket for the bar to be secured and one grommet in one bottom corner. We reinforced the grommets by adding a couple of pieces of vinyl to each side. He attached the banners to the poles with Zip ties.

They came back and ordered 10 more to replace the ones that got ripped the worst. We made them and instead of grommeting the bottom, we used a mesh seatbelt material and added a D-Ring sticking out the side, and now those have failed.

We are north of Toronto, have had up to 91km/hr winds in the area, but to be honest the banners were ripping before then. I spoke with supplier I purchased the Pole Banner Pro from, and they are saying that it is because there were no wind slits in them. I did suggest wind slits when quoting the job, but the client was adamant that he did not want them, as he saw them as a weak spot and figured they would start ripping there.

Being a fairly new company to town, I want to make it right, and provide a solution for the town, but honestly I don't know if the wind slits would help or not? Is the problem that they need the bottom bar? Did I use the correct material?

Customer service-wise, I want to provide the township with something (either reprint or offer a credit or something...) so they will continue to work with me in the future, we are putting roots down in this town and every time I drive through the main st. I have a sick feeling looking at them all. What would YOU do?

Opinions? Thanks everyone.

 

[Billct2]

First, banner fail in high winds, especially solid banners. You could try mesh, but personally I don't like the way they look, especially double sided.
They need horizontal poles top & bottom. Then the banner should be secured to the vertical pole/or pole bracket top & bottom
Also put a piece of webbing across the width of the banner at the pole pocket hems and have the grommets in that.

 

[bannertime]

I thought wind slits had been debunked and that you'd need to make a cut that's like 70%-80% of the banner? +1 on the grommets in the webbing and adding a bottom pole. It's common knowledge that unsecured edges will fray and rip.

 

[printhog]

Wind slits are a myth. The structural defect from the un hemmed slit is far worse that the minimal decrease in wind load.

Without seeing an up close shot of the failure is difficult for any of us to come to a solution. Are the grommets failing, if so that may be from improper setting. If the hem's are failing it's likely they may have been sewn to tightly.

I'd recommend you find an awning shop with a RF bar welder to weld hem them. Or buy a banner welder like a leister, with a hem foot. Both machines literally fuse the banner coatings so that they are as strong as they can be.

You can also try using hh16 vinyl solvent cement to patch if you need to. it acts like the RF or heat welding, but on smaller scales.

Ive welded thousands of billboards using these means.

HH-66 Vinyl Cement, 1 Pint, 16 Ounce Can - Shipped from The USA!: Amazon.com: Industrial & Scientific

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[printhog]

US Stock-AC110V High Speed Hot Air Banner Welder with 30mm Welding Width | eBay

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[netsol]

wind slits

just to be clear, i have never done this...
that being said, would it be possible to stitch at the end of the slits, so the slit will not tear?

i am thinking what a machinist does when repairing a crack in cast iron (which cracks like glass). you drill a small hole just past the end of the crack. when the crack spreads to the hole, the stress is relieved and the crack doesn't spread.

i as planning on trying this on an upcoming banner order (yes, an untested theory)
we could stitch with a similar color thread, possibly all around the slit

Wind slits are a myth. The structural defect from the un hemmed slit is far worse that the minimal decrease in wind load.

Without seeing an up close shot of the failure is difficult for any of us to come to a solution. Are the grommets failing, if so that may be from improper setting. If the hem's are failing it's likely they may have been sewn to tightly.

I'd recommend you find an awning shop with a RF bar welder to weld hem them. Or buy a banner welder like a leister, with a hem foot. Both machines literally fuse the banner coatings so that they are as strong as they can be.

You can also try using hh16 vinyl solvent cement to patch if you need to. it acts like the RF or heat welding, but on smaller scales.

Ive welded thousands of billboards using these means.

HH-66 Vinyl Cement, 1 Pint, 16 Ounce Can - Shipped from The USA!: Amazon.com: Industrial & Scientific

Sent from my SM-G900T using Tapatalk

 

[GAC05]

You might be fighting a loosing battle, I imagine the temperature is low enough now to stiffen up any material to the point of it being brittle enough to fail.
Defiantly need the lower pole bracket to spread the wind stress over more of the banner. Wind slits reinforced or not are a bad idea.
I think a combo of stitching (with the widest stitch length they can do) and HH66 will give you the most strength.
Good luck.

wayne k
guam usa

Why do you guys up north have your power poles running horizontal instead of vertical, is it a metric thing?

 

[TimToad]

Without a really good look at a banner its hard to tell if its a fabrication flaw or not. Those don't look like they were installed well at all, but it could be the weather you took the photos in.

I try to suggest clients seeking street pole banners to order the brackets that have the spring feature that allows the whole pole armature to flex in the wind instead of the banner itself. They cost more, but they save in the long run.

Depending on the client's expectations of durability, we will sometimes print the two banners on one long piece with the images opposite of each other and butting up to each other at the top. This creates a seamless top pole pocket and double thick banner itself. Then we apply full coverage laminate adhesive and stick the two sides together, then have them hemmed.

 

[printhog]

Netsol.. the idea of wind slits was to reduce the load, but the math doesn't support this. You have to cut so much out that it isn't feasible. The scrim in the banner is rip stop nylon. When you cut it or perforate it you are decreasing it's integrity. Sewing is like making a perforated border around it. Like a coupon on a brochure. Tears easier.

Grommets do the same.

The whole concept of hemming goes back to the days before vinyl coated scrim. The old cotton sign cloth we used in the 70s tore easily, so we hemmed the frail fabric.

The rip stop scrim and vinyl coating is so freaking durable I've seen festival tents get wind loaded and toss a full size Chevy pickup thru the air without the tent ever ripping. The truck was being used as an anchor for the tent.

That kind of fabric strength means the only reason for hemming is appearance and miseducation.

You could use wind slits but in the cold the decreased structural integrity and the flapping action could be the demise of your banner.

I'd look into a low temperature banner stock. Cooley would likely have one. Needs to have a lot of plasticisers in it. You may need different fabric for different seasons.

You cold opt to print on Sunbrella brand. That's what those Street banners are usually made from. Google it.

For this issue I'd get the hot welder, and some hh66 glue. Bring the bad ones in to the shop. Patch them with the glue. Fix the damaged hemmed areas by welding or gluing an overlay. On future work hot weld the hems.

Benefit from this.. you learn to fix them and they'll be loyal to that. And the banner welder and glue allows you to make almost seamless looking giant banners.

That is how the trade makes building wraps and 14'x48' billboards... All day everyday.

Right tool .. right process



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[NateF]

I'm sure this isn't the only way to do it, but here's what has worked for us on similar jobs. The only failures we've had are from trucks hitting them:

Airow banner rods from Kalamazoo Banner will flex, allowing the banner to spill some of the wind load in high winds.

HH-66 is awesome stuff for welding light pole banners. The banner media itself will tear apart before the glue will fail. But note that the glue will not work well on top of ecosol inks; you'll need to leave white stripes in your design for gluing. Latex inks may be a different story... We use masking tape when applying the glue to keep the finished product nice and neat.

We add grommets at each end of the hems as an added "rip-stop" measure.

I've never been a fan of sewn banners - its seems like the holes from the stitching create a weak point that ends up tearing more easily than the rest of the banner.

 

[signed off]

Order them from Printmate Graphics, you won't be sorry, we tried making our own a couple of years back and had the same issues. The next order we went to printmate and on the small ones 40" tall we have only one arm ( no wind slits) and used heavy duty zip ties ( purchased at Westburn electrical ) for the larger ones it has to have top and bottom arms and again no wind slits. Not sure what size you are doing but hope that helps