Dehumidification without hermetic sealing

Unlike by sea, where the position of the container determines how exposed the cargo is to the elements, by rail the conditions are the same for all containers. The New Silk Road runs for a good 10,000 km not only across national borders, but also through different climate zones. Extreme temperature fluctuations and thus equally strong ups and downs in relative humidity favour the formation of condensation - and thus increase the risk of moisture damage.

Finding a solution together

After analysing the requirements, the ThoMar product manager in charge recommended the use of 20 SeaDry Hook 600 g desiccant chains. These should always be distributed as evenly as possible in the container and can be attached to the lashing rings by means of a sturdy hook. The amount of desiccant required was determined on the one hand by the expected day and night temperatures typical for the time of year (May / June) in the areas passed through. On the other hand, a safety buffer was necessary concerning the absorption capacity, as the transfer on the Silk Road can be considerably prolonged by the rerouting to other gauges as well as by waiting times in the customs area. It had to be ensured that the desiccants could keep the relative humidity at a non-critical level during the entire transport period.

SeaDry keeps your cargo dry

Thanks to the data logger used, the temperature and relative humidity could be precisely tracked. The progressions confirmed the precautionary measure of using desiccants during transport. The mould limit of 75% RH was not exceeded at any time, and on average the relative humidity was at an optimal 44.1%. The desiccant chains absorbed a total of 7.7 litres of water, about 60% of their own weight. Since the absorption capacity of SeaDry is at least 200%, there would have been sufficient reserves to ensure a longer transport time if necessary.

Reaching a solution together

Several pieces of the container desiccant SeaDry Pole H were suspended from the container's lashing eyes, and the compact SeaDry Single desiccant bags found their place in the shipping boxes. These measures were successful: the use of desiccants prevented the moisture level from exceeding the critical mould threshold during transport. There were hardly any dark spots left on the wood.

On the basis of our advice, the company optimised further steps of its shipping preparations. They use kiln-dried timber now. This step ultimately resolved the remaining mold issue. Our aim is to collaborate on equal terms with our clients, and to help them accomplish the best possible result while managing costs efficently at the same time.

Reaching a solution together

Our container desiccant SeaDry, on the other hand, consists of a salt binder mixture. Besides calcium chloride, starch is added to the desiccant bags to bind the water. The salt absorbs moisture from the ambient air and the starch ensures that the resulting liquid is bound to form a gel. This prevents water from leaking and the saturated desiccants can be easily disposed of.

For a test, our customer received precise instructions on how to proceed with the tested desiccants and data loggers after arrival at the destination. The relative water absorption capacity of our SeaDry products (over 200 % of their own weight) was much higher than that of the pure draining systems (approx. 125 %). This makes them cheaper to use than competing products. In addition, SeaDry offers greater safety by binding the absorbed water to form a gel. This means our customer benefits twice over.

The evaluations showed that during transport up to 80% relative humidity was reached in the vehicle interior. This led to odor development. In addition, the corrosion threshold was also regularly exceeded outside the vehicle in the container, which encouraged formation of rust. After our customer applied the desiccant SeaDry Strip ADH and the compact desiccant bag SeaDry Single , there were no further complaints from the recipient.

Reaching a solution together

After a close coordination process between the customer and the ThoMar consultant in charge, the goods were packed in a customised aluminium composite bonnet, together with desiccant bags according to DIN 55473, and sealed airtight. In addition, desiccant blankets - SeaDry Blanket - were used to prevent possible mould growth on the wooden export crate used. For this purpose, the SeaDry Blankets were placed on the aluminium composite foil. ThoMar delivered the film cover as well as the required desiccants to the customer just in time. Thus protected, the goods arrived at their destination in perfect condition.

The use of the desiccants SeaDry Blanket and SeaDry Single proved to effectively prevent corrosion. In order to enable an economically optimized use of desiccants, a weather-protected storage of the pallets as well as a weather-protected loading of the general cargo was organized. Subsequently, the use of SeaDry Single desiccant bags was no longer necessary.

An analysis of the logistics process by our consultant showed that the stowage plan and sequence of container loading in this individual case required the placement of a desiccant directly on the bagged goods. Here our customer decided on the desiccant SeaDry Blanket. To further reduce the risk of damage, the company now dispenses with the cover film on the pallets to allow air circulation in the pallet packaging. In addition, before stretching, the small SeaDry Single desiccant bags are placed in empty spaces in the packed pallets.

Reaching a solution together

Together with the company, we worked out a procedure with the aim of using desiccants in a more effective way. In principle, the temperature fluctuations between day and night can already be sufficient for the humidity in a freight container to repeatedly exceed a critical level. In addition, the analysis of the ThoMar consultant in charge revealed that the individual course of the packaging process in the specific case further favoured the formation of condensation in the packed sales containers.

To prevent moisture damage to the contents and packaging of the container cargo, our SeaDry container desiccant is a solution that is as simple as it is safe. In the case described, the choice fell on the variants "Blanket" (desiccant blanket, e.g. for placement on stretched pallets) and "Single" (compact desiccant bags for flexible positioning). The adaptation of the packing scheme on the pallets by the customer enabled a particularly effective application in terms of both effectiveness and economy.

The measures have absolutely paid off. The container was exposed to direct sunlight during the day. The data logger recordings showed strong temperature fluctuations between -2.2° C and +43.9° C - this means a maximum risk of condensation! Nevertheless, the corrosion threshold in the container was not exceeded during the storage period: The average value was 37.3% relative humidity. For ThoMar, this result is proof that the SeaDry container desiccants, originally developed for the purpose of securing cargo during sea transport, are also highly effective in the area of storage.

An equally simple and effective solution to this problem is the use of container desiccants, such as SeaDry from ThoMar's range. With the coordinated mix of calcium chloride and starch, SeaDry desiccants draw moisture from the air like a sponge and store it safely inside the desiccant bags. SeaDry comes in various shapes and sizes, as well as with different attachment options - sure to suit your needs.