Choosing the Right Desiccant Saves you Time and Money!

An efficient active packaging solution is quintessential for extending a product's lifetime for every manufacturer and distributor. Desiccants are compounds that are used in facilitating low humidity environments. By reducing moisture-induced degradation, desiccants play a key role in enhancing product shelf-life without compromising safety and efficacy. Hence, it is vital to select the right desiccant. Desiccants are often used to develop, transport, maintain, or store various materials and products.

The cheapest or the most convenient option doesn't lead you to the most valuable solution. The poor quality and wrong quantity of desiccant can result in over or under-desiccation, which can impact your product's life span and efficacy. This could be detrimental to both the company and the end-users. Hence, investing the time in selecting the right quality and quantity of desiccants in the development and packaging of your product will not only increase the chances of the product's success in the market and ensure the product's efficacy for end-users.

 What do You Need to Know Before Selecting the Desiccant?

When deciding on the proper desiccant, you must examine various parameters, such as LOD (loss on drying), and MAC (Moisture Adsorption Capacity) at low relative humidity and high temperatures. The container in which the product will be packaged, shipped, stored, and packaging headspace is also vital in determining how much of a particular desiccant you need and in what packaging form.

 It would be best if you also considered the temperature and relative humidity to which the product will be exposed.

Each issue is best dealt with by a specific type or combination of different desiccants. An effective desiccant will absorb the water vapor in the air, lowering the relative humidity to the point where water cannot condense, i.e., the dew point.

Use a desiccant tailored to your requirements.

At Silica Gel Desiccant, we understand just how important choosing the right desiccant is!

For this reason, we offer a diverse array of desiccants that can be customized to fit a variety of design and manufacturing parameters. 

The key to ensuring product stability and integrity is the incorporation of a structural desiccant during the initial design and storage phase. By comparing the properties and capabilities of each desiccation product, you can identify the suitable desiccant for your needs and make a clear choice. Some of these desiccants are as follows.

Types of Desiccants

1)Silica Gel

Silica gel is a popular desiccant choice in the food and drug (pharmaceutical and nutraceutical) industry due to its inert, non-toxic, and highly stable properties. Silica gel is a partially dehydrated form of polymeric colloidal silicic acid. Silica gel has an amorphous micro-porous structure. Its interconnected pore opening sizes of roughly 3-60 angstroms form a vast surface area that attracts and retains water by adsorption and capillary condensation, allowing silica gel to adsorb up to 40% of its weight in water. Silica gel is the most suitable desiccant for products with stable storage temperatures and high relative humidity. It is seen that silica gel is highly efficient at a temperature below 25°C (77°F) at a relative humidity of 40% (Fig. 1 & 2). However, caution must be exercised; as the temperature rises, the desiccant will desorb water or lose a part of its adsorption capacity like clay (Fig. 3). 

Figure 1: Adsorption Rate (H?O) of Various Adsorbents

Figure 2: Equilibrium Capacity (H?O) of Various Adsorbents

2) Molecular Sieve

Molecular sieves (also known as Synthetic Zeolite or aluminosilicates) adsorb moisture more strongly and rapidly than silica gel or clay (Fig. 2), making them ideal for products requiring instant protection from moisture degradation. 

Molecular sieves have a distinctive feature in the uniformity of the pore size openings in their crystal lattice structure. Due to this uniformity, molecular sieves have a high adsorption capacity even at low relative humidity, making them an economical choice of desiccants. This uniform structure of the molecular sieve does not allow it to desorb moisture into the package as readily as silica gel or clay would as temperature increases (Fig. 3). This is particularly important for packaged products that can experience a wide range of environmental conditions. However, caution should be exercised when selecting the proper dosage for products with specific RH requirements.Choosing the right specific desiccant within the desiccant range is as important as selecting the right type of desiccant. Molecular sieves come in various styles, such as, type 3A, 4A, 5A, 13X, carbon molecular sieve, and molecular sieve powder. Similarly, there are different varieties of silica gels. Silica gel blue, silica gel white and silica gel orange. Each of these types has specific properties for specific uses per your products' requirements. 

Both desiccants, i.e., silica gel and molecular sieve, are used to protect drugs, active pharmaceutical ingredients (APIs), diagnostic kits, and medical devices from the harmful effects of hydrolytic degradation triggered by unbound water in packaging headspace.

Figure 3: Equilibrium H?O Capacity in reference with temperature

3) Montmorillonite Clay

Montmorillonite Clay is a naturally occurring, porous adsorbent that is mined and then dried for use as a desiccant. One of the biggest advantages of the clay is that the clay can be successfully regenerated for repeated use at very low temperatures without substantial deterioration or swelling. However, this also causes the clay to desorb moisture into the container as temperatures rise. Clay is an inexpensive and an effective desiccant within the normal temperature and relative humidity ranges (Table 1).

                                                                         Table 1: Properties of Adsorbents

Property	SILICA GEL	CaO	CLAY	MOLECULAR SIEVE
Adsorptive Capacity at low H?0 Concentrations	Poor	Excellent	Fair	Excellent
Rate of Adsorption	Good	Poor	Good	Excellent
Capacity for H?0 at 77° F (25°C), 40% RH	High	High	Medium	High
Separation by Molecular Sizes	No	No	No	Yes
Adsorptive Capacity at Elevated Temperatures	Poor	Good	Poor	Excellent

 

 4) Calcium Oxide (CaO)

Calcium oxide (CaO) is a cost-effective desiccant that you should use if your product is stored or transported in areas with high temperatures. The substance, also known as quick lime, is distinguished by its ability to absorb much greater water at low relative humidity than other materials (Fig. 2). Calcium oxide is used mainly in packaging dehydrated foods where a low critical relative humidity is necessary.

Users can select the right desiccants based on the abovementioned factors and requirements. 

Looking to buy high-grade desiccants? Silica Gel Desiccant is your place to go. Remember, help is just an email away! For more information on the best desiccants suitable for your products, our technical sales representative would be more than happy to help you.