How to Protect Rubber Products Against UV Degradation

Manufacturer:  We observe that our products deteriorate and discolour when exposed to both diffused sun light and fluorescent light. Any chance of overcoming or minimizing this problem? Our customers insist that the products must be packed in transparent plastic films.


John Woon (Senior Latex Consultant): Rubber products (natural or synthetic) tend to undergo a deterioration and degradation process when exposed to weathering and sunlight. The deterioration rate is increased in the presence of UV light.

There are a few things you can do. If possible, make the products black or if they have to be white, increase the level of TiO2 as the pigment would adsorb the UV light. Adding a blend of UV absorbers  to cover the high and low UV light frequencies would definitely help.

However it could be expensive if your products are thick as most of the UV absorber is "trapped" in the interior of the rubber matrix instead of the rubber surfaces where the absorption of UV light takes place.

Another cost effective but innovative method  is to select transparent plastic packaging material which has already been incorporated with UV absorbers. One good example of UV absorber is Benzophenone.

It allows manufacturers to package their products in clear and transparent plastic. Without it, opaque (with TiO2) or dark (with carbon black) packaging materials would be required.

Primary Backing of Tufted Carpets

Manufacturer: We intend to make our own primary backing compound for our tufted carpet.
Please tell us what properties of the end products we should expect and some advice on the compounding formulation.



John Woon (Senior Latex Consultant): As requested, my detailed report has been sent to you separately. I would therefore give a brief explanation here.

A properly designed primary backing compound should give you the following properties to your tufted carpets:

1) Firm handle or feel
2) Dimensionally stable
3) Excellent light and heat ageing resistance
4) Low discolouration
5) High tuft bond
6) Edge-fray resistance
7) minimal or no flex cracking

Latex choice could be either natural rubber or SBR.

Filler such as calcium carbonate can be added at 400 to 700 phr depending on your requirement on cost verses performance. Primary backing is usually visible and hence it is advisable to add TiO2 to increase the whiteness.

Small amount of wetting agent can be included to aid in spreading and coverage while anti-foaming agent can control foaming tendency in the lick-roll tank/bath.

Try to aim at getting a coating weight of 600 to 1000 gm/m2.