Many European customers who deal with major national and international companies have often asked us the following questions:

What is WICKING?

What is FUNGUS or MILDEW GROWTH?

What is plasticizer MIGRATION?

What will happen if the flexible vinyl they use does not have resistance to the above?

From these enquiries we have found out that it is very important to many large users that they should be supplied with a product that is anti-wicking and resistant to fungus/mildew growth and which does not have a major plasticizer migration problem. Below we try to explain this as fully as possible according to the information we have from various manufacturers.

WICKING

Almost all flexible sign and awning membranes are reinforced internally with a fabric scrim, which gives strength to the product. It is therefore most important that the reinforcing fabric does not wick water or any other vapours when the cut edge of the membrane is exposed.

When vapours are permitted to wick into the scrim the risk of biological growth is greatly accelerated. This is very important, particularly in polluted areas. There are various methods of finding out whether the product you are using or planning to use has a wicking problem. The most common and simplest way to find out is to rub a coloured marker pen down the edge of the membrane; if the colour runs onto the scrim it means that the product is WICKING; if it does not run onto the scrim than the product is ANTI-WICKING. Some products may have wicking vertically or horizontally, but not necessarily both.

We feel that the user may be concerned about pollution and biological growth and that is why he will probably request an ANTI-WICKING product.

It should be pointed out, however, that not only is wick-resistant scrim required to prevent biological growth – the PVC must be blended with biocides and fungicides to protect the membrane satisfactorily.

FUNGUS or MILDEW GROWTH on a flexible sign or awning will cause undesirable black marks, which will be visible day or night.
To find out whether your product is blended with biocodes and fungicides you need to carry out laboratory tests for resistance to mildew growth, According to Morton Laboratories (specialists in this field in the USA), the parameters for this testing are ASTM G021-90 and you may ask the manufacturer to provide you with a test report.

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