Weather Guard Lightning Tech

Sunrez Prepreg Cuts Blade Repairs to Minutes

Bret Tollgaard from Sunrez joins to discuss UV-curing prepreg that cuts blade repair time by up to 90% and has recently received OEM approval.

Sign up now for Uptime Tech News, our weekly newsletter on all things wind technology. This episode is sponsored by Weather Guard Lightning Tech. Learn more about Weather Guard’s StrikeTape Wind Turbine LPS retrofit. Follow the show on YouTube, Linkedin and visit Weather Guard on the web. And subscribe to Rosemary’s “Engineering with Rosie” YouTube channel here. Have a question we can answer on the show? Email us!

Allen Hall: Brett, welcome back to the program.

Bret Tollgaard: Thanks for having me again.

Allen Hall: So a lot’s happening at sunrise at the moment. Uh, there’s, uh, activity with sunrise materials on a lot of blades this year.

Over the last couple of years actually, ISPs, operators, OEMs, are realizing that UV curing is a huge advantage.

Bret Tollgaard: Turns out there’s a lot of value added, uh, to the entire process when utilizing UV cure, uh, pre-req.

Allen Hall: So the, the pre pres are, have been available for a couple of years. The qualification though was always the concern.

Has the OEM qualified this material? Are they gonna give you the blessing? Does this show up in the manual? If I call the OEM, are they gonna say they have talked to you guys? A lot of those hurdles have been cleared at this point.

Bret Tollgaard: Yeah, great question. And we are happy to announce that we have finally been approved by a large OEM for use on the epoxy blade for now all general kind of repairs.

We have several more OEMs that have already passed their phase one mechanical testing, and we’re iterating through now [00:01:00] their, uh, secondary and tertiary kind of tests. And so we do expect to be fully qualified by several OEMs before the end of the year, which should make the ISPs integration and utilization of our materials much, much easier.

Allen Hall: So the, the, the problem you’re solving is repairs in the field for the most part, or sometimes in the factory. Mm-hmm. But a lot of times in the field that those repairs. It happened quite a bit. They’re the same repair, the same area, the same kind of thing over and over and over again. And wetting out fabric on site takes time.

Particularly if you’re using standard materials, you have to bag it. You have to apply heat in some cases to get it to kick, and then you have to wait several hours for it to cure. So in the repair cycle time, most of your time is waiting.

Bret Tollgaard: It sure is. Uh, and on top of all that, we all know that there aren’t enough technicians in this industry to even do all the repairs, uh, that would like to be done.

Yeah. And so to really kind of streamline all of that, [00:02:00] uh, we’ve rolled out a couple of new things and we’ve had a lot more interest in some pre consolidated preki patches for customers. Uh, if a particular blade model has an issue that is a standardized kind of repair. We’re actually now building custom prepregs, or we will build the appropriate width length, stack it, consolidate it, uh, wrap it between our films.

So then all the customer has to do when they get on site is, uh, you know, do do the appropriate surface prep. Scarfing, apply a little bit of our UV surface primer to the backside of that patch. But now they can go up tower, single peel, stick, roll out, and then they’re cured.

Allen Hall: And that’s a. How many hours of saving is that?

It’s gotta be like six, 12 hours of saving, of, of

Bret Tollgaard: labor. It’s upwards of 80 to 90% of the labor that’s gonna actually need to be done to apply that. Otherwise, and then same thing too. We’ve had a couple instances where we took a several day repair down to one, to two to three hours. And these are multi-meter long repairs that were fast tracked because we pre consolidated preki [00:03:00] everything.

Some were in flat sheet forms, some were much longer on rolls, where you’re actually then rolling out with a team. Um, and so we’ve been able to demonstrate several times, uh, over the last 12 months, uh, the, the value that a UV cure preprint.

Allen Hall: Well, sure, because that, that would make sense. The issue about wetting out fabric in the field you just done in the back of a trailer or something, somewhere like that.

Usually it is, it’s that you’re never really sure that you got the fabric wetted out. The experienced technicians always feel like, have done it enough that they get very consistent results. But as you mentioned, getting technicians is hard and, and there’s so many repairs to do. So you’re doing those wetting out composite things takes practice and skill.

Just buying it, preki it, where you have control over it. And you guys sell to the military all the time. So that, and you’re, are you ass 91 qualified yet? You’re in the midst of that?

Bret Tollgaard: So we, I mean, a, we just got ISO certified, uh, at the end of last year in December. So our [00:04:00] QMS system and everything like that’s up to date, that’s huge.

Another big qualification for the OEMs that want to see, you know, true quality and output.

Allen Hall: That’s it. I, if I’m gonna buy a preki patch, so, uh, uh, that would make sense to me, knowing that. There’s a lot of rigor as a quality system. So when I get out the the site and I open that package, I know what’s inside of it every single time.

Bret Tollgaard: Well, and that’s just it. And like we got qualified based on the materials that we can provide and the testing that’s being done in real world situations when you’re wetting out by hand and you’re vacuum backing and you’re trying to cure. It is a little bit of an art form when you’re doing that. It is, and you might think you have a great laminate, you got void content, or you haven’t properly went out that glass ’cause humidity or the way the glass was stored or it was exposed.

The sizing and the resin don’t really bite. Well. You might think you have a great repair, but you might be prematurely failing as well after X cycles and fatigue. Uh, simply because it’s not as easy to, to truly do. Right? And so having the [00:05:00] pre-wet, uh, pre impregnated glass really goes a long way for the quality, uh, and the consistency from repair to repair.

Allen Hall: Well, even just the length of the season to do repairs is a huge issue. I, I know I’ve had some discussions this week about opening the season up a little bit, and some of the ISPs have said, Hey, we we’re pretty much working year round at this point. We’re, we’ll go to California. We’ll go to Southern Texas.

We’ll work those situations. ’cause the weather’s decent, but with the sunrise material, the temperature doesn’t matter.

Bret Tollgaard: Correct. And I was actually just speaking to someone maybe half hour ago who came by and was talking about repairs that they had to do in Vermont, uh, in December. They could only do two layers of an epoxy repair at a time because of the amount of the temperature.

Allen Hall: Yeah.

Bret Tollgaard: Whereas you could go through, apply a six or an eight layer pre-reg cure it in 20 minutes. Uh, you know, throughout that entire length that he had and you would’ve been done. That’s, and so it took several days to do a single repair that could have been done in sub one hour with our material.

Allen Hall: I know where those wind turbines are.

[00:06:00] They weren’t very far from, we used to live, so I understand that temperature, once you hit about November up in Vermont, it’s over for a lot of, uh, standard epoxy materials and cures, it is just not warm enoug...