CHOOSING YOUR DESSICANTS

USING ABSORPTION MATERIALS

There are three different main types of Absorbers.

• Silica Gel
• Clay or mineral absorbers
• Calcium Chloride based absorbers

They each have their different properties which make them suitable for different purposes.

Silica Gels are good absorbers at room temperature, but tend to catastrophically give up the absorbed water if the temperature gets near 40C. In our opinion they are unsuitable for use in containers where such temperatures are not uncommon.

Clay absorbers are cheap, but also have a low absorption. In moderate conditions they are an alternative, but they cannot handle more challenging circumstances.

Calcium Chloride is the most aggressive absorber. As the salt absorbs moisture from the air a saline solution - a brine - is formed. This brine needs to be handled with care. It is strongly corrosive on metals. If left exposed to the air, the brine will under some circumstances give up the moisture it as absorbed in a way that can cause great damage, in some cases even leaving a briny pool.

The World Drybag products are all based on the use of high grade Calcium Chloride to aggressively remove moisture from the air. The moisture is transformed into a hard gel in the bag its elves where it is safely sequestered from further contact with the air. This simple principle is the bass of superior functional properties of these products:

• A high absorption capacity. - Exactly how much moisture the salt will absorb depend on the temperature and humidity, but is often more than 100%.
• A high absorption rate. - When the temperature changes quickly, a lot of moisture needs to be absorbed in short time to prevent condensation from dripping onto the cargo. The rate depends on the temperature and humidity, but may reach 10g/hour or more.
• Self-limiting at extreme events - It is good to have a high rate of absorption, but not if it means exhausting the absorber at a single extreme event. Especially not, if all that's achieved is to draw more moisture out of the cargo. The absorber needs to last the entire voyage. The geometric shape of the container and other design details makes the World Drybags self-limiting in such cases. It lasts the voyage.
• The gel process is safely sequestered. It will not leak out and it will not re-evaporate
• Calcium Chloride is completely nontoxic and can safely be used in food shipments. The World Drybags are made of environmentally safe PE/PP plastics or "non" Woven fabrics that can be easily re-cycled.
• The World Drybags are easily mounted in the wall corrugation of secure hooks. They do not fall down or break.
• World Drybags have proved successful with every type of cargo. For protective installations with the same level of protection, World Drybags are usually cheaper than the alternatives and bring additional advantages, besides. (see list above).

Safe to use and Environmentally friendly!

As the main function of a desiccant is absorbing allot of moisture out of the air we constantly try to improve the function of our products to assure high-end and safe products based on the latest standards.

To create a desiccants several different chemicals are being used, the mixture of these chemicals creates the absorption function and the gel transformation to assure against leaking, sweating and harm the cargo. The strength of absorbing and the speed of transforming into a hard gel depends on the mixture composition and the way the product is packed.

RJB has an in house Research and Development team and we constantly are testing our products, new mixtures and of course competitors' products. We test and try to understand new mixtures, after external consultations and in case of improving results we will implement these in our products as long as they are safe for the environment!

Unfortunately not all competitive desiccants are safe to use as they pretend to be, they might contain "natural" chemicals which are difficult to control on negative additives which can cause risks for human and animals health, even when it seems like they are directly from out of the earth like vermiculite and potassium.

We regret to say these materials are not communicated 'clearly' to the end-user or their customers as it's not part of the sales strategy, we advise to pay good attention when deciding to purchase desiccants.

RJB Drybags are only developed with pure natural products which are safe to use, we work with reliable suppliers and we pay huge attention on our quality control!

How to use World Drybags?

How many weight of World Drybags are required depends on the kind of cargo and the length and conditions of the voyage. We have a lot of experience from different cargos, and are able to make a first estimate from comparison with similar shipments. But there may turn out to be significant differences that prove the first estimate wrong.

We usually recommend that you start with some extra weight/Drybags beyond what you think you need, so as not to risk your cargo on experimentation. The number can then be reduced once you have gathered some data on the voyages from feedback on damages, the amount of moisture collected in the Drybags and perhaps from sensors and electronic loggers.

The best way to get a recommendation on the number of World Drybags you need is to one of our experts. Usually you can have an answer within a day or two.

However, some general figures can of course be given. Under moderate conditions (not a very long voyage, not crossing the equator etc) a 20 ft container should have.

• Dry Cargo 3-6 World Drybags
• Moisture containing cargo (wood, paper, lots of packaging) 4-8 World Drybags

Under more difficult conditions (long voyages, crossing the equator, long inland transports, very moist cargo etc.), the above figures need to be increased by 50% or more.

A 40ft container generally requires a little less than twice a 20 ft container.

The only way to really decide what is the most economical and effective number for your cargo is to collect real data on your shipments. That you should do not only as a test, but systematically.