Quality Management

Desiccants to protect goods against humidity

Desiccants to protect goods against humidity by the Quality Control Blog

Desiccants are made to protect goods against humidity while stored and transported. They can be placed in the product’s individual packaging or in the container in which the goods are being transported. There is a wide range of desiccants available in the market, which ones are they? What are the differences?

Products concerned by desiccants

The humidity affects a very wide range of consumer products and it also affects food:

  • Agriculture products: spices, coffee, tea, tobacco, pepper, ginger, cloves, cashew, rice, wheat, corn products etc
  • Wooden products: Furniture, paper products etc.
  • Electronic products: electronic appliances, cables, toys etc.
  • Leather products: footwear, garments and sofa furniture etc.
  • Metal products: sheets, coils, machinery, auto/spare parts, aluminum billets, copper products etc.
  • Textiles: garments, batik, fabrics etc.
  • Household products: glass ware, melamine, handicraft etc.
  • Pharmaceuticals

Desiccants to protect goods against humidity

Each desiccant caters to specific needs of specific products. There are experts in this field who are able to advise and perform some tests in controlled conditions to identify the most suitable one. However, it should be noted that most common desiccants used by importers are silica gel and clay even if their absorption capacities are limited. Here are the various options available:

Calcium chloride

Made of CaCl2. it is non toxic and odorless. It protects the goods following a chemical reaction. When pure, it ensures up to 700% (of its net weight) moisture absorption under cold and hot temperatures, from -5ºC to 90ºC. However calcium chloride based desiccants need other ingredients to help to turn the absorbed moisture into a gel, hence, depending on the mixture, these desiccant can absorb up to 200% in a normal condition.

Silica gel

Its main ingredient is the SiO2 (silicon dioxide). They are transparent or semitransparent solid granules packed in a bag. It allows a physical absorption with mild reactions: its absorption capacity is limited (10%-27%) as well as its efficiency, which is optimum under reasonable conditions, below 35ºC.

Clay

Also called montmorillonite desiccant, it is a natural product and the cheapest per grams. It comes in the form of powder or small balls. It is additive-free, non-toxic and environmentally friendly. Its absorption capacity is very limited, from 15-25% and efficient under temperatures below 50ºC. Its main weakness is that when used at high temperatures it tends to reject humidity which increases the risks of mold.

Molecular sieve

The molecular sieve is a recyclable, non-toxic, non-corrosive, chemically stable product. Its strong advantage involves its ability to resist extremely high temperatures (230ºC) however, its capacity to absorb humidity remains quite low: 10-25%.

And you: which desiccants do you use to protect goods against humidity?

Thank you to superdry.com for sharing useful information in order to write this article!

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