What is Bentonite Activated Clay Desiccant?

What is Bentonite Activated Clay Desiccant?
Published On:January 17, 2020 Revised On:December 13, 2023

Moisture damage presents a risk to diverse products and industries, emphasising the critical importance of implementing effective moisture control solutions. Among these solutions, clay desiccants stand out as a highly effective option.

Derived from natural clay minerals, this eco-friendly moisture absorber offers numerous benefits. This article will explore its characteristics, applications, and why it stands out as an environmentally responsible choice for moisture control.

What is Bentonite/Activated Clay?

Clay desiccant is a highly absorbent substance made from natural montmorillonite clay, a phyllosilicate mineral. Its unique structure and chemical properties make it an exceptional moisture absorber. As humidity levels rise, the clay desiccant attracts and adsorbs moisture, effectively reducing the moisture content in the surrounding environment.

The desiccant is manufactured through an eco-friendly process. The production involves mining, processing, and packaging the natural montmorillonite clay into the final desiccant form. Here’s a general overview of the manufacturing process:

  1. Mining: The first step is to extract montmorillonite clay from natural deposits or mines. Montmorillonite is a type of phyllosilicate mineral known for its high moisture-absorbing properties. These mines are usually situated in clay-rich regions.
  2. Purification: Once the clay is extracted, it is purified to remove impurities, rocks, and other materials. The goal is to obtain pure montmorillonite clay with high moisture-absorbing capabilities.
  3. Drying: After purification, the clay is dried to reduce its moisture content and ensure consistent performance as a desiccant. Drying can be achieved through various methods, such as natural sun-drying or industrial dryers.
  4. Activation: Activation is crucial in enhancing the clay’s adsorption capacity. It involves subjecting the dried clay to a controlled heating process, typically between 400 to 900 degrees Celsius. This process alters the clay’s structure, creating tiny pores and increasing its surface area, which enhances its moisture-absorbing ability.
  5. Particle Size Control: The activated clay is then crushed or milled to achieve the desired particle size. Controlling the particle size ensures uniformity and makes it suitable for different packaging applications.

Characteristics and Advantages

The absorption capacity of activated clay desiccant varies depending on the specific grade and formulation. However, activated clay desiccants generally have a higher moisture adsorption capacity than regular non-activated clay. They can typically absorb between 15% to 25% (or even more) of their weight in moisture.

The activation process significantly increases the clay’s surface area and porosity, allowing it to effectively trap and retain more water molecules.  Unlike many synthetic desiccants that contribute to landfill waste, clay desiccant is an eco-friendly option. It is derived from natural minerals and is biodegradable, making it a sustainable choice for businesses and consumers looking to reduce their environmental impact.

Clay desiccant is non-toxic and poses no harm to humans or the environment. This safety aspect is crucial, particularly for applications where the desiccant may contact food, pharmaceuticals, or other sensitive materials. With its high moisture absorption capabilities and long shelf life, clay desiccant provides a cost-effective solution for preserving the quality and integrity of products during storage and transportation.


Clay desiccants can be used across a wide range of applications and industries, including electronics, textiles, leather goods, and pharmaceuticals, from moisture damage during transit and storage. Furthermore, for the long-term preservation of important documents, heirlooms, or sensitive equipment, clay desiccants play a vital role in maintaining optimal conditions and preventing deterioration caused by moisture.

Moreover, clay desiccants are also used in container desiccants for shipping containers to protect goods from the harmful effects of humidity and condensation during international transportation. Their moisture-absorbing capabilities help ensure that the goods arrive in pristine condition. Additionally, in environments like museums and libraries, clay desiccants are instrumental in preserving historical artefacts, books, and artworks by preventing moisture-related deterioration and the growth of harmful moulds.

Using Clay Desiccant Effectively

Clay desiccants are easy to use and offer effective moisture control for a wide range of applications. Users can maximise their efficiency and ensure optimal product protection by following simple guidelines. Here’s a step-by-step guide on how to use clay desiccants effectively:

  1. Select the Right Size and Quantity: Determine the appropriate size and quantity of clay desiccants based on the enclosed space and the level of moisture control required. Manufacturers typically provide guidelines and recommendations to help users choose the right amount for their application.
  2. Choose Proper Packaging: Place the clay desiccant inside moisture-resistant packaging, such as Tyvek pouches, cloth bags, or paper envelopes. Ensure the packaging is tightly sealed to prevent the desiccant from absorbing moisture before use.
  3. Insert in the Packaging: Insert the clay desiccant inside the packaging and the product needing moisture protection. Consider placing multiple desiccant packets evenly throughout the space for larger containers to ensure uniform moisture control.
  4. Monitor Moisture Levels: Periodically check the moisture levels inside the packaging or container. Users can use moisture indicators or humidity meters to assess the effectiveness of the clay desiccant. This step is particularly crucial for the long-term storage or transportation of sensitive items.
  5. Replace When Needed: The clay desiccant will reach its moisture absorption capacity over time. When users notice the desiccant becoming saturated or reaching its limit, they should replace it with fresh packets to maintain consistent moisture control.
  6. Proper Disposal: When disposing of used clay desiccants, follow proper waste management guidelines. Since clay desiccants are biodegradable, they can be disposed of with regular household waste, or users can recycle them as soil conditioners or natural amendments.

By adhering to these best practices, make the most of clay desiccants’ moisture-absorbing capabilities and effectively protect their products from the harmful effects of humidity and moisture damage during storage, shipping, or long-term preservation. Proper usage and disposal contribute to a sustainable and environmentally friendly moisture control solution.

Determining the Quantity of Clay Desiccants

Determining the required amount of clay desiccants for packaging depends on several factors, including the size of the packaging, the nature of the product being protected, and the desired moisture control level. Here are some essential considerations when determining the number of clay desiccants required:

  • Packaging Size: The packaging size plays a significant role in determining the desiccant needed. Larger packages or containers require more desiccant to achieve uniform moisture control throughout the enclosed space. Conversely, smaller packages may need only a few packets of desiccant.
  • Product Sensitivity: The product’s packaging nature is crucial in determining the moisture control requirements. For highly sensitive products, such as electronics, pharmaceuticals, or precision instruments, using enough desiccant to maintain extremely low humidity levels and prevent moisture-related damage is essential.
  • Packaging Material: Different packaging materials have varying permeability to moisture. Packaging with lower moisture barrier properties may require more desiccant to compensate for moisture ingress. High-quality moisture-resistant packaging, such as foil-lined or barrier-coated materials, can reduce the desiccant needed.
  • Environmental Conditions: The environmental conditions during packaging and storage are also important factors. If the packaging area or destination has high humidity levels, a higher quantity of desiccant may be necessary to counteract the moisture present in the surrounding environment.
  • Moisture Control Level: The desired level of moisture control is subjective and can vary based on the specific application. Some products require extremely low humidity levels, while others only need moderate moisture control.

It’s essential to strike the right balance when using clay desiccants. Using too little may not provide adequate moisture control while using too much can be wasteful and increase packaging costs unnecessarily.


Bentonite Activated Clay Desiccant is a highly effective and versatile moisture-absorbing agent that has found wide applications across various industries. With its natural and eco-friendly properties, this desiccant offers a safe and sustainable solution for controlling humidity and moisture in various products and environments. Its ability to absorb moisture while maintaining a dry and stable state makes it valuable in preserving sensitive goods’ quality, integrity, and shelf life.

At Stream Peak, we take pride in providing quality clay desiccants, which undergo rigorous daily in-house quality checks in our dedicated QA lab. As a trusted desiccant manufacturer, we offer a wide range of clay desiccant bags, ensuring reliable moisture control for various applications. Our commitment to excellence is further demonstrated by our adherence to ISO 19001 and 14001 certifications, ensuring supplying products that meet international quality and environmental management standards.