Desiccant;drying agent

Drying agents (also called desiccants) come in various forms and have found widespread use in the food, pharmaceuticals, packing, electronics and many manufacturing industries A desiccant is a hygroscopic substance that induces or sustains a state of dryness in its vicinity. Ideally, it is chemically stable and chemically inert (i.e., silica).


Moisture damage may be costing your business millions every year. Whether it’s reducing the risk of corrosion, contamination, rotted cargo, or unpleasant odors; creating a dry environment is essential to minimize moisture damage

Desiccant Applications

Electronics,The focus of the Dri-Box Moisture Control System.

Food,Everyone needs it, and needs it to stay clean and dry when stored.

Shipping,Keep that cargo safe!

Sailing,Those ocean breezes may be invigorating, skipper... but they're corrosive as well.

Tools ,Keep their metal rust-free and their wood strong!

Travel & Relocation,Rain or shine, you'll come through fine.



Electronic devices depend on complex electrical interactions in their circuitry in order to function. Furthermore, most of these devices are not made to be waterproof, allowing moisture or water vapor to seep in through the cracks and contact the internal workings.Functionality of the device thus becomes impaired in subtle ways.Compared to the cost of replacing these items, desiccants are a convenient and cheap alternative.


Let's face it: everyone has to eat.  Many do, and many more should. The staples of food most suited to long-term storage are dried ones... grains, legumes, and dehydrated meats, fruits and vegetables. Not to mention seeds for the planting or replanting of crops.the very gas that gives us life, oxygen, is another threat to the longevity of stored foods! desiccants are very important on our food storage solutions;


For hundreds of years sailing vessels have been a principal source of trade in the world,   Massive amounts of cargo move between ports, jostled and thumped in largely wooden crates and spending days or even months on the high seas, possibly facing one or more storms along the way. Does it even need to be pointed out what a damp environment this is?Anyone shipping their products overseas or even on lakes should be taking a long, hard look at desiccants if they are not being included already. If a portion of your cargo is being lost to ruin caused by damp conditions, desiccants can only save you money!


In much the same way as cargo shipments, recreational sailors would do well to have desiccants on board. Salt water is about as corrosive as you can get, and most skippers today make use of very sensitive instruments including the all important Global Positioning System receivers! The last thing you need is your navigation fritzing out on you at a bad time due to dampness.

In fact, just about anything you store aboard your boat, electronics or not, should be kept as dry as possible. Many pleasure boats stay docked a good deal of time, making it a relatively easy proposition to pack things up with some adsorbent to keep away the salt air.


Whether the latest powered drill or a simple wood and metal hammer, tools are another item that often spends long periods in storage and are often stored in a less than secure space such as a garage or shed. Besides the already covered effects on electrical tools, moisture more simply just rusts metal and rots wood.To extend the useful life of your tools, get some enclosed storage for them, and get some desiccant to keep them dry!

Travel & Relocation

You're moving the household to another state, or maybe you're just a businessperson taking your laptop with you to Taiwan. Whenever travel is involved you have two possible danger areas, the transit itself and your eventual destination.

Are you moving to or through a damper environment than usual? Desiccants are in high demand by people like wildlife photographers who have to tote their high tech cameras through jungles and forests... they know very well what that humid air might do to their livelihood. If you're actually relocating desiccants can become even more crucial, with the likelihood of irreplaceable heirlooms, documents and photographs being present, some of them already old and fragile.Why take the chance of moisture damage? Stick in some desiccant and good barrier materials, and buy some peace of mind.


Other Applications

Only a fraction of the many applications for desiccant use are covered on this page. A short list of other items desiccants benefit are:

     Laboratory equipment and hygroscopic chemicals

     Shoes and other leather articles

     Books and rare manuscripts

     Photo slides and film

     Hearing aids

     Guns, gun accessories, and fishing tackle

     Stamps

     Surgical and dental instruments

     Pharmaceuticals

     Clothing and fabrics

     Scientific instruments

     Museum and historical artifacts

     Paintings and valuable art objects

     Athletic equipment



Hoo chemtec specializes in desiccants that provide humidity control for protecting machinery, products, and industrial processes from moisture. We can provide you with a desiccant solution that will minimize moisture and maximize the lifespan of your products and equipment; moisture protection is profit protection;

At present, the widely used absorbents for dry and moisture resistance mainly include:


*silica gel - beaded or granular grades

*molecular sieve - type 3a, 4a, 5a, 13x and others

*indicating silica gel (with and without cobalt chloride)

*potassium permanganate (ethylene gas adsorption)

*activated carbon - coal and coconut grades

*activated alumina - 1/8, 1/4 and 3/16 inch pellets

*specialty blends - silica gel/carbon, etc

*corrosion inhibitors (zerust)

*calcium chloride pearls

*organoclay ,bentonite,montmorillonite


Hoo chemtec service specilist-customized desiccants,we can also provide you with a completely customized bulk desiccant to meet your specific needs. Our expert staff will work with you to identify and then create the best desiccant solution that will protect your products from corrosion, contamination or any other moisture damage.


How effective are different desiccants?

Different desiccants are based on different substances with different capabilities to absorb moisture.when choosing your desiccants it is important to know that different substances have different characteristics.

One important factor is the ability to absorb moisture in relation to its own weight , other factors are absorption rate at different levels of relative humidity and the risk for re-evaporation.


Silica Gel, characteristics


1.Silica gel Brief introduction:

 the main component of silica gel is an amorphous silica, transparent or milky irregular particle or spherical solid. It features open-type porous structure and can absorb many substances due to its strong adsorbability. It is a high-performance active adsorbent in numerous mesh sizes designed for many uses in industry.

2. Silica gel Characteristics:

a. Free of toxicity and odor, stable chemical property. Can not react with any other substances except strong alkali and hydrofluoric acid.It is adsorption material for desiccant accepted by FDA can directly contact with drug and food. It is safety and reliable.

b. The silica gel has strong adsorption capacity under various conditions. Under optimal conditions silica gel will adsorb up to 40% of its own weight,but under practical conditions usually much less.The absorption ability falls at temperatures above 30 to 40°C.

3.Silica gel Advantages of Silica Gel

*Silica gel has an almost indefinite shelf life if stored in airtight conditions.

*Silica gel can be regenerated and reused if required. Gently heating silica gel will drive off the adsorbed moisture and leave it ready for reuse.

*Silica gel is a very inert material, it will not normally attack or corrode other materials and with the exception of strong alkalis and hydrofluoric acid is itself resistant to attack. and Silica gel is non-toxic and non-flammable.

*Silica gel also works well as an adsorbent for sulfur and nitrogen compounds, CO2, C12, HC1, gasoline-range hydrocarbons, aromatics, and many other compounds. Bulk gels can adsorb many of these substances in large quantities. It is used widely for a broad range of industrial applications requiring a selective adsorbent or a high-capacity desiccant.

*Self-indicating silica gels have a moisture sensitive additive added to the basic silica gel. This indicator changes colour as moisture is adsorbed thus giving a visual indication as to the activity level of the silica gel.There are a number of different self-indicating silica gels: Orange To Dark Green;Orange to Colourless;Blue to Pink;


*Standard white silica gel is referred to as being non-indicating. As it adsorbs moisture it remains physically unchanged. Non-indicating silica gel is both cheap and effective, available loose in bulk packs or packed in sachets.

Advantages of silica gel as a desiccant, It is most frequently and conveniently used packed in a breathable sachet or bag. These are available in a wide range of sizes suitable for use with a wide range of applications.


What  types of products Silica Gel can protect?

Silica gel can be used to protect a variety of items from moisture ,such as ,

Tool boxes, Storage containers, Computer, Metal and machine parts, Industrial equipment,       Pharmaceuticals and vitamins, Electronics, Military instruments, Circuit Boards, Documents,Instruments,Photographic equipment and film, Foodstuffs,Batteries,  Medical equipment, Textiles etc.



1. Brief introduction: it is a crystalline aluminosilicate compound which contains neat and uniform pore channel in the crystal structure. The hole diameter is molecular level, which only allow the molecule smaller than this hole diameter to enter; therefore, the molecules in mixture shall be sieved as per diameter, which is consequently named as molecular sieve.  It is these diameters (measured in Ångstroms) that classify molecular sieves - 3Å, 4Å, 5Å, and 10Å (also known as 13X).

2. Characteristics:

(1) When the humidity is extremely low, the water vapor in environment can still be absorbed greatly and the environmental humidity can be effectively controlled. They will reduce water vapour to much lower levels  than silica gel, making their use essential when a very dry product or atmosphere is required.

(2) The moisture adsorption speed is extremely fast, large quantity of water vapor can be absorbed within extremely short time. They adsorb water vapour more rapidly than silica gel.

(3) They perform more effectively as moisture adsorbers at higher temperatures (greater than 25°C) than silica gel does.




1. Brief introduction: the active mineral desiccant is formed through the activation treatment of attapulgite and has better moisture adsorption ability than montmorillonite.  It has the appearance of white chalky beads.Standard stock sizes have 2 - 5 mm or 5 - 8 mm beads.1.2 - 2.4 mm beads are also sometimes available.


2. Characteristics:

*Desiccant grade activated alumina is a highly porous form of aluminium oxide,The moisture adsorption capacity under high humidity is good.

*Due to the chloride ion content, it can not directly contact with food, drug, metal, etc.




Calcium chloride, characteristics

Calcium chloride, CaCl2, is a common salt and the compound of calcium and chlorine. It behaves as a typical ionic halide, and is solid at room temperature. It has several common applications such as brine for refrigeration plants, for use in concrete, as well as for ice and dust control on roads. The anhydrous salt is also widely used as a desiccant, where it will adsorb so much water that it will eventually dissolve in its own crystal lattice water. It can be produced directly from limestone, but large amounts are also produced as a by-product of the Solvay process. Because of its hygroscopic nature, the anhydrous form must be kept in tightly-sealed containers.

Calcium chloride aggressively absorbs moisture from the air, first causing a swelling of the crystals. If the air is humid enough and the temperature is high enough, the crystals melt and liquid saline solution brine is formed.

Calcium chloride desiccants work well over a temperature range from freezing up to 80°C or more. At low temperature the salt does not absorb moisture under dry conditions. In practical terms calcium chloride desiccants are effective at relative humidity above 30%, while being more effective under moist conditions.



1. Brief introduction: Montmorillonite is also named as microcrystalline kaolinite, which is the desired mineral of bentonite mine. Due to different causes of formation, metallogenic environment, origins, montmorillonites in the world appear different colors such as white, light gray, pink, light green, etc. and the forms are irregular, which can be processed into spherical state. Due to its crystal structure and molecular composition, it is free of toxicity and harm and can be naturally degraded. In addition, it has strong adsorbability and cation exchange performance, enabling it to be widely used in the absorbent

2. Characteristics:

a. It is manufactured through the drying, breaking and sieving of natural bentonite and can be naturally degraded. It is a natural environmental friendly product and free of toxicity and harm.

b. When the relative humidity is below 20%, the moisture absorption is superior to silica gel and the cost is lower.




Desiccant activated clay sachets are still used in many industries and regions in preference to silica gel  sachets. The adsorption capacity of clay is lower than silica gel so more is needed to do the same job,but the lower cost of clay though does mean that overall costs can be similar between both products.



A granular coconut shell carbon suitable for various air and water treatments (including diving equipment applications) is available from stock - packed in 2.5kg, 7.5kg and 15kg containers.