Aluminum, black steel, acid-resistant steel. Each of these metals has different properties, a degree of corrosion resistance, and therefore a price. The situation is similar with materials, and in the case of a “flexible” spill containment berm – with the coating of the technical fabric from which it is made. Knowing what the secondary berm is made of will allow you to estimate its durability and the level of safety it will provide over the next years of use.
The technical fabric is composed of the so-called “carrier”, most often made of a weave of polyester fibers, which most often has a multi-layer coating (“coating”) applied on both sides, usually consisting of the main polymer and additives.
The illustration below shows the structure of a multi-layer technical fabric:
Multi-layer elastic fabric
The three most common polymers in technical fabric coatings are:
Each polymer has its own characteristics and resistance to short and long-term contact with UV radiation, hydrocarbons, acids and bases. Based on resistance tables and materials provided by our European suppliers (reputable companies from the technical fabrics industry) and our own experience, we have created the table below.
Technical fabrics – comparison table for use with spillage tanks:
| Factor | PVC | EVA | TPU |
|---|---|---|---|
| Fabric description | $ | $$$ | $$$$$ |
| Price | +++ | ++ | ++ |
| Resistance: UV | time-limited | high | high |
| Resistance: diesel | good | high | high |
| Resistance: engine oil | non-resistant* | good – limited | high |
| Resistance: gasoline | non-resistant* | high | high |
| Resistance: glycol 100% | non-resistant* | high | good |
| Resistance: undenatured ethanol | non-resistant* | high | high |
| Resistance: formic acid 50% | non-resistant* | high | no data |
| Comments: | *the substance works destructively to the coating |
Source of data on resistance: technical data sheets and a list of certified suppliers of Exflo technical fabrics, own compilation.
PVC coating is a cheaper alternative if you do not store hazardous substances. The larger the secondary berm surface, the more you will save on purchase. However, carefully study the list of substances that, after a leak, can affect the berm covering and even destroy it (which makes the spill containment berm practically disposable, especially substances from the table with the “non-resistant” classification).
The Ethylene/Vinyl Acetate polymer used for technical fabrics has significantly greater chemical resistance than standard PVC. This allows you to create collection tanks that are resistant to a number of acids, hydrocarbons and other substances often used in industry. Additionally, it is easier to obtain surface resistance and antistatic properties, which also affects safety. As a component, it is several times more expensive than PVC fabric, which translates into the price of the final product. If in the resistance table of this coating, for the substance you are looking for, you find a resistance symbol of at least “good or limited”, it means that it is resistant to constant contact with liquid, lasting up to several months.
Highly resistant technical fabric, especially to hydrocarbons and acids. Resistance to diesel fuel and gasoline can be measured in years. However, the rare use of secondary berm is related to the price, which is several times higher than EVA
Example polyurethane structure:
In terms of materials, you need to pay attention to two aspects:
The colors of all three fabrics may even be identical, which can be confusing for the buyer at first glance (e.g. a black berm is available in both PVC and EVA). It is worth asking the seller what material the spill containment berm is made of and what the fabric weight is. Thanks to this information, you can reliably compare offers from several suppliers and choose the best option.
If you are looking for spill containment berms made of the above fabrics, you will also find them in the Exflo offer:
Find out more about spill containment berms and visit our product page.
