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Companies that manufacture products with hermetically sealed volumes, such as refrigerators, safes, electronic equipment, tanks, air conditioning systems, etc., are often faced with the need to protect these products from the formation of internal mould or corrosion that can form especially during storage or during use.

Many of our customers have approached us to solve this particular problem of moisture in sealed interior cubicles.

In this article we will discuss how the introduction of dehydrating sachets, made of silicagel or clay, can be an important choice to preserve the integrity of these products and guarantee end customer satisfaction.

What situations lead to condensation?

By its very nature, an enclosed and sealed space does not give rise to the possibility of mould or corrosion, since external moisture cannot enter. In fact, the problem is not directly generated by external conditions, but rather by the presence of water vapour trapped inside the volumes prior to closure.

For example, a cellular refrigeration system that is perfectly sealed to the outside may exhibit mould and odour once it arrives at its destination.

In cases such as this, it is very likely that cold rooms have been closed and sealed in waterproof packaging without assessing the presence of air inside the room.

protect sealed cold room spaces from moisture during storage with silica gel

A change in external temperature, as often happens during shipping or storage of goods, triggers a change in the internal conditions of the trapped air: in the event of a drop in temperature, the trapped air will compress, releasing the water vapour it contains, which will condense into droplets, covering the surfaces of the space it is in, both outside and inside the products and goods.

protect refrigerator cells from humidity and condensation during storage

This condensation process, which is absolutely natural, can however compromise the preservation of goods in storage or in particular working conditions if it is not intercepted and managed, generating significant intervention or replacement costs.

Identifying the weak point in the process

When does the problem of trapped moisture in closed volumes arise?

In most cases the weakness can be identified at two different times during the product manufacturing process:

1. due to water vapour remaining trapped at the end of particular production systems, internal to the production cycle;

2. in the air that remains inside the product at the moment of final packaging and closure.

Identifying when the problem arises is an important first step, because it allows us to understand when to intervene to limit the problem, i.e. whether to act during the production cycle or at the end of packaging in the packaging.

How to use dehydrating pouches

Once the cause has been identified, various actions can be implemented with the aim of containing or eliminating the moisture problem. One of these actions can be the insertion of dehydrating sachets during the production process or in the preparation phase of the final packaging.

To arrive at the best dehydrating solution, it is good to evaluate some additional elements:

  • SIZE: know the size of the volume to be protected;
  • CONDITION: have a fairly precise idea of the conditions in which the product will find itself during handling or storage, e.g. shipping in containers, stationary in warehouses, etc;
  • TIME: what will be an average time in transport or storage situations.
the factors to analyze to choose the appropriate desiccant: size, conditions, time

Once this information has been acquired, it will be possible to determine the optimal number of dehydrating bags and the most suitable weight to effectively manage the problem of condensation, thus avoiding the appearance of bad odours, mould, corrosion and oxidation.

Disidry silicagel range of dehydrating sachets

Dehydrating sachets are available in different sizes, starting from as little as 1 gram up to more generous sizes such as 1 kg.

This range allows you to select the most suitable size for the product that needs to stay dry, taking into account the environmental conditions it will be exposed to over time.

Which dehydrator to choose?

The choice of the type of desiccant contained in the sachets is an important aspect to consider.
In such situations, sachets containing activated clay (montmorillonite) are an excellent solution.

These desiccants boast excellent absorbency, comparable to that of silica gel sachets, but at a significantly lower cost.

This is attributable to the clay production process, which, starting from a natural raw material, is significantly less expensive than the creation of synthetic products such as silica gel.

montmorillonite activated clay to protect sealed products from internal humidity

Another aspect to take into consideration is the total naturalness of montmorillonite clay, which can be disposed of more easily than other synthetic dehydrators and with less complexity in the bureaucratic handling of customs permits when shipping goods to particular countries.

Standard silica gel sachets are just as functionally efficient. Although they are less cost-effective than clay bags, there are situations where they are explicitly requested by customers or specified in the specifications and are therefore the best solution.

If you are facing problems with internal moisture in your products and would like an effective solution, please do not hesitate to contact us. We are here to help you find the best solution for your needs.


We have analysed and identified some important steps to address and manage problems related to condensation and humidity inside products that have sealed compartments such as refrigerators, cold rooms, machinery, safes, closed systems, etc..

The good news is that these problems can be solved and kept under control. If you would like additional information or have a similar problem please contact us at info@silica-gel.it

You can see or buy all our dehydrating products directly in the shop www.silica-gel.it