Desiccants, or as sometimes referred to moisture scavengers, are materials that will attract and chemically bind moisture. Desiccants can offer a simple and economical way to eliminate moisture problems in plastics processing that can otherwise cause unattractive surface defects such as lensing, voiding, and splash marks in the finished product.
Desiccant masterbatch can reduced the need for pre-drying of materials, allow processors to use recyclate with high moisture content and extend the control of processing moisture sensitive polymers.
A desiccant is a hygroscopic substance that is used to induce or sustain a state of dryness (desiccation) in its vicinity, it is the opposite of a humectant. Commonly encountered pre-packaged desiccants are solids that absorb water. Desiccants for specialized purposes may be in forms other than solid, and may work through other principles, such as chemical bonding of water molecules. They are commonly encountered in foods to retain crispness. Industrially, desiccants are widely used to control the level of water in gas streams.
With this feature, desiccant is used popularly in plastic industries which concentrates bind moisture during the processing of plastic materials. The active ingredient in these masterbatches reacts chemically with water molecules and effectively removes them from system.
Desiccant masterbatch is a new type of functional masterbatch developed to eliminate the moisture of recycled PE and recycled PP. Besides, it also solves moisture problem when filler masterbatch (plastic additives is added in production to reduce cost) is applied much more than it’s usage limitation. Desiccant may be effective for products produced with hygroscopic materials where lensing (fish eyes) can be a problem. Moisture absorbing masterbatches are useful to reduce lensing after storage of raw materials in high humidity areas.
For example, in blown film manufacturing, maximum usage of one filler masterbatch grade is 15-20 % mixed, 85-80% remain is resin plastic and additives, if using it more than 20%, it will appear melt fracture or fish eyes at the ending products. US MASTERBATCH desiccant masterbatch helps remove moisture and cuts out oxidizing effect that occurs during recycling of the polymer. It is known as defoaming masterbatch.
Desiccant is an additive having a moisture adsorptive capacity of not less than 28.5% by weight. The remarkable feature of Desiccant is that it will absorb a much greater amount of water vapor at a very low relative humidity than other materials. Desiccant is most effective where a low critical relative humidity is necessary, and where there is a high concentration of water vapor present.
Desiccant masterbatch is non – toxic, non contamination and no influence to property for plastic products. It offers a simple and cost effective solution to solve moisture problems
Desiccant masterbatch can counter problems which develop during the processing of plastics due to the presence of moisture. Moisture can be present in raw materials such as hygroscopic polymers, fillers and pigments. Reclaim and recycled polymer can also have high moisture content. When processing polymer with high moisture content the polymer can become porous and show voids in molded articles or extruded sheet. In film applications the high moisture content can lead to Lansing and film bubble breakage. Desiccant masterbatch chemically binds moisture during processing and allows higher levels of reclaim or recycled polymer to be used; addition of higher filler levels; and can reduce the need for pre-drying in many applications. In the process of molding, desiccant masterbatches can strongly absord the moisture in the plastic raw materials or other related plastic materials additives. It can increase product quality and the rate of finished products, improve obviously productivity and reduce energy consumption.
There are different colors of desiccant masterbatch, common colors are grey and milk white as picture 1 and picture 2.
Elimination of moisture problems in related polymers products manufacturing
At US MASTERBATCH, Desiccant Masterbatch products consist of UD 03, UD 04 and UD 05. They are some popular grades of our clients which is manufactured by twin crew extruder machine and the most modern technology represent in Vietnam. These products contains: CaO, resin and some additives. It’s suitable for extrusion, blowing film, threading yarn, injection molding, etc. They have dispersion very fine, free of agglomeration and remove humidity of resin, recycle resin, filler
Technical information of UD 05 as below
Appearance (Surface color) : Milk White Pellet (Picture 1)
Additives : Dispersion agent, processing aid
Processing temperature : 140 – 280oC
Usage rate : 1-10 %
Pellet Size : 3×3 (±0.3) mm
Carrier resin : LLDPE, LDPE
Compatibility : LLDPE, LDPE
Packing : 5 kgs per bag. 25 kgs/carton box
Storage and Handling: