Know-how

We understand the subject of “moisture prevention in sea containers” like no other and are happy to take care of your concerns, nevertheless we can imagine that you are curious about the facts or have specific questions. On this page we try to answer your most commonly asked questions, along with links to key topics or products. If you are unable to find the answer to your question(s) here, simply contact us utilizing our online contact for additional assistance or give us a call, our team will be happy to assist you.

Frequently Asked Questions

How do container desiccants help to solve moisture problems?

A container desiccant contains Calcium Chloride that very aggressively grab and absorb moisture from the air. The container desiccants dry the air. When the air is dry, there are no moisture problems.

Can container desiccants solve all moisture problems?

Well, not all. Some cargoes may be so wet that any reasonable number of desiccants to be used get overwhelmed. But container desiccants can reliable protect even very difficult cargoes that may contain tons of moisture, such as coffee- and cocoa beans, wood products or paper.

I load my container under dry conditions, and it is very tightly sealed. How come I still experience moisture problems?

Your cargo or the packaging, including the wooden container floors, pallets and crates, contain moisture that is evaporated into the air during transport. Wet packaging material is the most common cause of unexpected moisture problems.

I have shipped the same cargo for years with RJB Drybags without any trouble, but now I have a lot of damage. Have you changed the desiccants?

Check your container and your packaging material. Did you just start to store your pallets outdoors? Does your forklift drive into the container with water or snow on the wheels? Did you just change supplier of crates? You can’t tell by looking whether wood or carton is dry. The moisture properties of wood and cartons have an exponential character. It makes a huge difference if your pallets moisture content should be 17% instead of 20%, say. RJB Drybags™ never reduces the capacity of the desiccants we only improve the performance for realizing a higher absorption capacity.

I ship consumer goods in tubes/cans/jars etc. that contain no moisture, yet I still have problems.

Consumer goods are often shipped with a lot of cardboard packaging. Even if the boxes seem dry, they could literally hold tons of water.

Each container of my cargo of peanuts/coffee/cocoa contains tons of moisture. What difference does it make that RJB Drybag absorb a few liters during a voyage?

All the important things that happen have an exponential character. That means that a small change in circumstances can have a huge effect on the outcome. RJB Drybags create circumstances that allow almost all of the moisture to remain in the cargo even while the level of humidity in the air is lowered by a crucial amount, sufficient to prevent damage. It is a question of ‘leverage’.

Does it make a lot of difference that my cocoa beans have a moisture content of 8% instead of 7%?

Yes, such a difference could be all the difference between no damage and disaster. The moisture behavior of most agricultural products have a strong exponential character.

My cargo of peanuts had suffered damage in the center even though the outside of the cargo looked fine and there was prolonged no sign of condensation?

Lots, if not most, damage to cargoes is caused by prolonged periods of elevated humidity without any condensation (Container rain, Container sweat, Super Saturation Event). It is common that cargoes loaded at cool temperature and then moved into warm condition suffer damage in the center of the cargo as a result of a difference in temperature between the outside and the center of the cargo. Warm air from the outside of the cargo becomes humid as it moves into the cooler center. RJB Drybags protect against this effect even though the bags are mounted on the container walls.

I had damage to my cargo even though I used lots of silica gel and/or clay based dessicants and there was no condensation. Would it help to switch to RJB Drybags™?

Calcium chloride absorbs moisture even when the humidity is not very high. This protects the cargo against damage caused by prolonged periods of elevated humidity. Some kinds of steel start to corrode at 70% relative humidity, moulds can grow at 80% relative humidity and at near 90% relative humidity lots of things go wrong. Yet, RJB Drybags™ are also at their most efficient protecting against condensation. Most other products, such as silica gels, are really effective only in very humid conditions and in protecting the cargo against condensation damage. The only big disadvantage of Silica gel and Clay related products are that they cannot keep large quantities in the bag and they will start to leak and damage quickly.

What is so great about container desiccants from RJB anyway?

Well, they will not fall off the wall, get punctured during loading and unloading, leave a wet puddle on the cargo or run out after half the voyage. They are installed in seconds without ladders and take up no cargo space. The capacity of each desiccant bag is big, so fewer is required. The cost of an installation is very competitive, even against much inferior alternatives. Besides the high absorption capacity, the bags are have extra safety skills by the gel transformation and double bag materials against leaking, sweating and damaging. In addition, you will receive thorough and substantiated advice based on years of experience with container transports and packaging of goods worldwide.

How many container desiccants do I need?

The number of container desiccants required to protect the cargo depends on the cargo, the temperature conditions during the voyage, the length of the voyage ‘ and just how safe you want to be. For some really dry cargoes e.g. steel coils or household removals, 2 – 3 desiccant bags are enough, although we also see situations where 10 desiccant bags are used. For a lot of ‘normal’ goods 4 – 6 desiccants are about right. Some cargoes with very difficult moisture properties on long voyages may require up to 16 desiccant bags. For each cargo type we advise a different type of Drybag, please ask our specialist for the right one!

Do I need to line my container with “corrugated” Kraft paper?

Lots of containers are lined with “corrugated” Kraft paper primarily for reasons of hygiene or to simply isolate the cargo from direct contact with the container walls. The liner will act as a kind of sponge, catching and absorbing any droplets of water and they re-evaporate the moisture into the air. If a liner is used without desiccant bags it could contribute to a kind of pumping effect, drawing moisture out of the cargo. When used together with desiccant bags the liner will act as a buffer in extreme conditions and will prevent any container rain from reaching the cargo. Much the same can be said for so called dew cloths.

My container is absolutely filled with cargo. Will the RJB Drybags™ still work?

Moisture diffuses very effectively, even through a seemingly compact cargo. Experience shows that our desiccant bags will make a difference even to mould growth inside cartons in the cargo. It is, however, necessary that some free space is left in front of the grille of each desiccant bag. If some desiccant bags have collected less water than others inside a container, there may be a problem with air access to those bags.

I have problems with mould growth inside my shrink-wrapped pallets. Will RJB Drybags™ help?

Yes, so long that there is some access of air through the top and bottom of the pallets. If this is not possible, a spiked roller may be used to tear holes in the shrink wrap.

My shipments of steel/galvanized components/aluminum/ machinery etc. arrives corroded, stained or miss colored despite heavy packaging. Will container desiccants help?

You can forget about your tectyl, coatings, oil-paper and plastic wraps that are expensive both to apply and remove. Your container can probably be equipped with a sufficient number of desiccant bags to protect against any damage at less cost than your present packaging.

I got some brine on my hands while removing used desiccant bag. Is it dangerous?

No, it isn’t. Our Calcium Chloride is non-toxic and environmentally safe tested by the laboratories of Silliker Europe a high-end food testing laboratory and part of Mérieux NutriSciences. It is the second biggest constituent of sea-salt and is liberally sprinkled over icy roads in cold countries. The brine is somewhat similar to very salty seawater and may cause irritation and rashes if left to dry on the skin. We recommend that you wear gloves and goggles when handling used desiccant bags in general, but should you get splashed by brine just wash off immediately with lots of fresh water.

Can I re-cycle my used bags?

The desiccant bags are made by PP/PE plastic, similar to what is used to make drink bottles, and is readily recyclable. Each part of the desiccant bag is appropriately marked for optimum recycling. Any remaining calcium chloride is easily removed by soaking the bags in fresh water.