Every industry has its own product names and many times those brand names become synonomous with the actual product. Like Hoover, Sharpie, Tupperware and Velcro, Correx is another one of those trade marks that became the generic term.
Correx, or to give the product its Sunday name – fluted polypropylene – is a twinwall corrugated plastic designed for strength and used primarily in the graphics and print market. That’s the reason we’re delving in to today for a once over what it does, what’s good about it and why we use it for certain jobs.
Fluted polypropylene doesn’t exactly trip off the tongue when you’re ordering a pack of 8×4 sheets so you can see why in the UK, Correx has become the go-to name for describing the product. Other brands of fluted polypropylene available are Twinplast, Corriflute, and in the USA, Coroplast. From researching this article, it seems that Coroplast has the same level of brand recognition in the US as Correx has over here.
Uses of Correx
Correx has always been used for estate agent boards. It’s waterproof, lightweight yet resilient so even though it bears the brunt of the traffic, wind and the weather outside homes for sale, it usually keeps up and stays in place. Another popular use is for all the election signage. Next time you’re driving along the road and being told to Vote For…., you can be fairly sure the candidate chose Correx to help get their party’s message across.
Its also a real mainstay for anything cable tied to a lamp-post or railing. Along with vinyl banner, it’s the Village Fete sign substrate of choice!
When you look at it’s profile, all the flutes are in line and like little girders. These flutes help with strength just like girders and also keep it cost effective compared to a solid sheet. I don’t see rigid polypropylene in much thicker gauges than 1200mic (1.2mm) so with Correx being usually around 4 to 6mm you can quickly see why its much more economical to produce with much less material needed to manufacture. It’s a trade off between overall toughness and suitability against cost per sheet for its intended purpose.
For economical and short to medium term signage which needs to be on a rigid substrate instead of something like a vinyl banner, Correx is certainly up for the job.
Now, being polypropylene, the face of Correx has a low surface energy that in laymans terms means it can be an issue getting stuff to stick to it. Originally screen printing the image was the way as those solvent inks would chew their way in. Once digital rollfed inkjet became more prevalent then printing onto self adhesive vinyl and applying was the next option – there were issues though with different vinyls not adhering quite as well as necessary but for short term applications it usually worked. With UV curable inkjet its pretty much now back to the ink adhesion of screenprint but with the option of full colour graphics to boot. Correx printed signs go upmarket!
Like Mr. Sellotape, it must be great to own the trademark! Most people specify or ask us for Correx even though as I said, its really a fluted or twinwall polyproplylene. The brand name of Correx is held by DS Smith who manufacture in the UK and manufacture other similar products such as Akyprint or bubble board along with a solid polyprop sheet. Like Correx, Akyprint is a twinwall product with a face and back sheet. The difference though is that instead of flutes running along the length or width of the board, dots or bubbles are inbetween the two panels. This creates a strong sheet that also doesn’t have the lines that can sometimes be visible on the face of a standard fluted polypropylene.
At this point I feel like passing the This Is Your Life red book over to Correx and watch the title credits roll.
As the theme tune starts, let’s give a quick recap:
It’s a cost effective, waterproof rigid substrate that is still lightweight and durable. Available in a wide number of sizes maxing out usually at 1.5 x 3m along with flutes running parallel to either width or sheet length. Correx lends itself to economical short to mid term outdoor signage and, useful when printing directly onto, its also available in a range of colours. Mentioning printing, Correx can be printed effectively using screenprint or digital UV inks. It can also have vinyl applies to it but give it a quick test first as not everything likes to stick to it.
So there you go, a brief 101 into Correx and how it fits in with modern print, signage and display.