Desiccant bags refer to substance that can remove moisture from moist substances. It is often divided into two categories: chemical desiccants, such as calcium sulfate and calcium chloride, which combine with water to form hydrate for drying; physical desiccants, such as silica gel and active Alumina, etc., dry things by physically adsorbing water.
Moisture is closely related to the product quality. As far as food is concerned, with proper temperature and humidity, bacteria and molds in food will multiply at an alarming rate, causing damage and discoloration to food. Electronic products can oxidize due to excessive humidity, resulting in defective products. The desiccant bags are used to prevent excess water from causing defective products. A well-known international brand selling desiccant is Damprid.
Type A: Potassium A (3A), Sodium A (4A), Calcium A (5A), Type X: Calcium X (10X), Sodium X (13X) Type Y: Sodium Y, Calcium Y
2. Silica gel desiccant
Type A: Small size, low humidity and high adsorption Type B: The average concentration is 40-70AO, the pore volume is 0.6-0.75ml/g. Type C: coarse-pored silica gel, it is milky white and translucent ground glassy.
Main desiccant bags types
1. Calcium Chloride Desiccant
2. Silica gel desiccant
3. Montmorillonite desiccant
4. Molecular sieve desiccant
5. Active mineral desiccant
6. Fiber desiccant
Desiccant bags Application
Desiccant is mainly used in seven areas: food, medicine, sea transportation, electronics, clothing, leather goods, hardware.
How do desiccant bags work?
According to its drying principle, desiccants can be divided into chemical desiccants and physical desiccants.
1. Chemical desiccant
Chemical desiccants are substances that can absorb moisture accompanied by chemical reactions. The vapor pressure of a chemical desiccant is lower than that of water vapor. As a result, the water vapor in the air or in the moist material continuously condenses into the desiccant and generates crystal hydrates or corresponding acids or alkalis.
Soda lime is another kind of chemical desiccant, which easily absorbs water and carbon dioxide, and can be used as both a desiccant and an absorbent of carbon dioxide.
The principle of using chemical desiccant packs is that the desiccant used to dry the gas cannot react with it. Generally speaking, acidic gas can be dried with acidic or neutral desiccant, but not alkaline desiccant; alkaline gas can be dried with alkaline or neutral desiccant, but not acidic desiccant.
2. Physical desiccant
A desiccant that can absorb moisture without chemical reaction is called a physical desiccant. The most common physical desiccant is silica gel. Silica gel is also called oxidized silica gel. It is a colorless, transparent or milky white granule, with generally about 3% to 7% of water content, and up to 40% moisture absorption.
Desiccant packs contain CoCl2, which is called discoloration silica gel, are often seen on the market. Its color change in water absorption and dehydration can indicate the degree of moisture absorption of silica gel.
Silica gel’s drying principle is to rely on adsorption to remove water molecules in moist substances. Most of these materials have many pores and a huge surface area.
Physical desiccants that have adsorption effect and can be used as desiccants, in addition to silica gel, there are activated carbon, activated alumina, etc.
How long do desiccant bags last?
The effective time of the desiccant is determined by factors such as packaging size, air humidity, and food (environment) moisture content. The expiration date of different types of desiccant varies, so you need to ask the supplier for details.
If the desiccant is silica gel, the silica gel blue dry particles inside indicate that they can continue to absorb moisture, and the red particles indicate unavailability.
If the desiccant is quicklime, from lumpy to powdery, the moisture absorption capacity reduces and it is not able to reuse.
Can desiccant bags be reused?
1. Quicklime desiccant
Put the used quicklime desiccant into water. If there is no air bubbles or heat generated, the desiccant has expired.
2. Montmorillonite/Mineral Desiccant
It cannot be judged intuitively. It can be compared by weighing test. It can absorb a certain weight of impurities, but the reused effect is too poor to reach the standard adsorption.
3. Silica gel desiccant
In theory, the silica gel desiccant can be reused after being baked at high temperature. It should be baked at 80-120 degrees Celsius to use again, but it is not recommended.
Because the inner layer of the packaging bag is made of heat-sealed glue with 80-120degrees temperature resistance, so the packaging bag needs to be torn off when baked. Therefore, in terms of the manpower, material cost and operability of baking, it is not recommended to reuse them.
How to buy Desiccant Bags?
If you have a demand for aluminum desiccant bags, please contact BALLYA's sales staff via email: email@example.com or fill out the below contact form, we will respond within 24 hours.