UV Protection

Hello again my friend.

I have some "exposure" to UV rpotection of plastics from automotive manufacture and also a little experience with corflute used for signs and placcards.

A protective film MIGHT provide some improvement or might actually make it worse. The corflute could become heat stressed by trapped heat and warp/deform from that impact.

The reason that PP is used (available) is demand driven. It's cheap and usually used for temporary items like political campaign signs or real estate markers.

I also suspect that attempting to draw thin sections in PVC would not provide the quality of finish or yield the manufactureres would expect.

From experience here, the corflute failure is typically due to physical failure (bent by wind, torn by debris impact, overgrown with grass, or support structure fails).

For your own peace of mind, ask to see photographs of the UV samples they base their "2 year" claim upon. You might get a pleasant surprise. They may consider a "fail" condition because of surface craze or minor chalking that is not critical to your application.

In some testing that I was involved in the fail criteria was well before the point where a typical discerning customer would even notice the degradation.

Thanks Mate

I like the pleasant surprise bit. I have been prototyping with Core Flute for a while now and in extreme conditions. No fail conditions in sight. I have seen very old signs that were close to turning into powder though.

This material is very suitable for my application but what would an insurance company think about it? My pleasant surprise might turn into frustration and they will want to see what ever "standards apply".

The problem of avoiding extreme heat (Above 60C) has been solved in my case so only the UV resistance http://www.polisilk.com/resi.html has to be improved. This is only one of many links. The real question is:

"Is the additional cost of using PVC (including other process changes) cheaper than laminating a UV stabilized film to the Core Flute"? Will it extend the life span and make it more feasible to use?

I regret living so remote because I could just walk into the factory and ask questions there and then, have a discussion about the difficulties involved in the process and hear it from the horses mouth.

Foreign companies (you know who) promise all kinds of things but could be using peanut butter as a UV stabilizer, for all I know. Quality control is not to be compromised, if at all possible.

You know, I have the feeling that there is a bit of trade secrets involved. No, not conspiracy, just some insider knowledge which is not readily available, or so it seems.

Thanks for your instant reply

Have one on me, Ky.

Hey ky,

Here's a link to the US manufacturer. http://www.coroplast.com/

I've got a running experiment going on this material. It will be two years in August that it's been outside..............it seems fine.

Now the print on this material is another story. Standard printing methods will be toast in two years, but I think the corrugated PVC should still be fine.

This has been a running project for me. I'm looking into solvent printing at the moment..............or maybe silk screen printing, but rather than using ink, using the paint that is designed to burn into the plastic, much like the primer for PVC tubing softens the PVC substrate prior to gluing.

I found this in their catalog.

http://catalog.coroplast.com/plasticor-whitecap/

It would be very suitable. Again, they are very silent on the life span. Maybe I have to look a bit harder but I have been doing that over the last few days. Only so many hours in a day to do this stuff.

The print matter is not relevant so much but what I have read is possible in most cases. The pigment fading will never be completely resolved. That shiny thing up there has a lot of power and not only the UV spectrum does damage. Good luck with your project.

Maybe the Australian company is a sister of these guys and one could exchange ideas. Yeah, I know, not very likely during these cut throat times.

Thanks, Ky.

G'day Mark, in my experience it's nearly imposible to glue to PP so i am totally amazed that they can print onto plastic bags. I suggest you try and find out what sort of ink they use for that.

regards'

Jim

http://internationalcoatings.wordpress.com/2009/12/15/printing-on-non-woven-poly-bags/

The other alternative might be to use a clear UV spray coating. The specialist paint companies doe have these and your substrate will be reliably consistent for their formulation.

We used "LS1" for vehicle lenses. This was a clear coat material that was spray gun applied and touch dry in minutes. It was formulated for the specific substrate we were using (PC) and would not be suitable for PP. You definately need to use an "etching" type of coating and you might like to research "UV resistant laquer" instead of paint.

If you are after "heaps" of the stuff, the 'flute supplier might perfrom the coating process for you.

Rub aloe vera SPF30 on it?

Just got back Mate

I worked it out. If what I am planning comes to fruition I will need, just for Australia, 36.000 workers applying "it" day in day out. Good thought though. At the going rate I could cover the stuff with gold instead and never have to go to Maggie's farm no more.

I have the stuff growing in my garden! Maybe a plantation?

Is that twisted enough?

This is interesting. Apparently there is similar material that is made specifically to withstand the sun.

http://www.greenhouses-etc.net/glazing/

Here's some with a ten year warranty, but they don't say what the treatment is.

http://www.matraplast.com/twinwall/hicore_xl.html

Thanks Mark

I'll be out all day and have a closer look when I get back. It looks like some have made it possible. Once I see the price I'll know why. No free lunch I suppose.

I'll let you know, Ky.

Though PVC holds up well to UV the pigments used to color it do not. Most fade with in a year. Most PVC window extrusions are white. If to be colored they are laminated with a color bound foil or spray coated with a colored coating that will handle the UV better.

You are correct about coatings and PVC windows. We coated PVC windows for several manufactures for awhile. Designed and tested many application systems and the materials to do same. Came across several paint suppliers who said they had materials that would block UV and meet the industries standards "AAMA" . But only two out there that really did (with water born materials). Have to be careful on PP materials though I only have found one company (and it is 2k oil) that works with this product and is UV blocking. Have run test to see how it weathers and waiting on results (sorry can't give more then that).

You might check with Ferro Pigment and see if they have a company they are working with on bases packages.

You can buy Coroplast with extra UV inhibitors on special order, but the coating is even better if you don't mind. Polypropylene foam with a metallized surface is now popular for grilles and other brightwork on cars. It lasts as long as the skin.

Hi Edubya

I have found by now is that it will always be a compromise.

UV inhibitors have an influence on other properties.

Laminating does not stop other weathering effects.

Any second handling will bring the price up considerably.

I had hoped to find some comments on the use of PVC or why it is not used in the first place. Even if it would be, say 30% dearer and have a guarantied life span of say 15 years, then why not go for the quality?

If I want no rust I choose 316. I pay but I can be safe and never worry about it again. I am aware that they could formulate what I want but like I said better not compromise when it is not absolutely necessary.

The guys I am dealing with here in Australia know what they are doing and I want to avoid misunderstandings when it comes to the extrusion process itself. Maybe the extrusion of PVC is more acidic than PP? Which again would require higher grade steel for the extrusion line?

I have something to search for now.

I'm on the case.

Thanks, Ky.

PVC sheet will last longer. If you're going to be printing on it, of course the print will have a limited lifespan.

A few other things that may or may not be a disadvantage:

It's way more expensive

It's heavier

It's harder, (more time consuming), to cut.

Maybe look into what, if anything, they use on roadsigns to make them last so long.

It just occurred to me, there's another type of plastic, and I don't know if it's PVC, that seemingly lasts forever outdoors.

I don't know if it comes in other colors but gray, but I'm talking about the stuff they make exterior electrical conduit, telephone boxes, cable boxes, etc. out of.

That stuff is impervious to the sun.

G'day Ky, there is a product that looks like core flute but is made from polycarbonate. it is now U.V. protected on both sides and is available in a range of colours. As it is polycarb it has good impact resistance and is much stronger than core flute.

For some &^%#*(y reason i can't paste a link here.

Google Laserlite Australia and search for Multiwall.

Regards from the ( dry ) West.

Jim

Interesting link Jim

I have worked with the Macralon material. It is indestructible but huge in price. A compromise has to be reached and because I am the only one who knows all about the application it is a bit difficult to communicate.

There is the alternative to use billboard style vinyl but the detailing can be a big hassle if you don't have a huge workshop and very expensive welding equipment. The convenience of this Core Flute is that it can be easily manipulated in a few ways with out the need for special tools and large setups.

In any case, my request will require some alterations to the standard processes. The more I know about the possibilities the better my ability to agree to a reasonable and justified price. The good news is that if and when it is manufactured it will put a head on the snake, Industrial symbiosis so to say.

I'll get there and will let you guys know how I ended up. Ah, I forgot to mention the final product has to be recyclable. Any more wishes?.

OT:

Yeah Mate, you guys have it dry since some time now. I have a second hand well for sale if you want. It collapsed on itself after all the rain we had. Simply under washed. It was built at a time when getting materials to the Island was a slog. Lucky nobody was hurt when it caved in. It took 18m³ to fill her in.

It all looks a bit worse for wear but that is what the cyclone left us with.

It will rain soon and a piece of string is exactly 348mm long, if anyone asks.

Good luck, Ky.