Natural and Safe Dehydrating Solution

The Moisture Grabber is a dehydrating bag specifically designed for the leather goods market to eliminate quality issues associated with excess moisture in packaging. Preventing mold growth ensures that product quality remains intact even during long-term storage or sea transport in containers. The Moisture Grabber is manufactured in Italy, contains no fungicides, and does not emit any chemical substances.

Disidratante Naturale

Natural Activated Clay The dehydrating clay is a calcium bentonite that naturally adsorbs and traps moisture, removing it from the environment in which it is placed. The clay used in the Moisture Grabber complies with technical standards DIN 55473, MIL 3464E, NFH00320.

The dehydrating clay is identified by CAS number 1302-78-29. The dehydrating clay in the Moisture Grabber is a natural mineral quarry product, thus exempt from REACH registration obligations under Article 2, paragraph 7, letter (b). Besides being exempt from registration, the clay is a non-hazardous substance, free of SVHC substances, or any with PBT or vPvB classification, so there’s no need for exposure assessments or use communications along the supply chain.

Printing is done with inks suitable for food packaging, using typographic technology to ensure maximum readability, making the Moisture Grabber suitable for high-end products. The information on the bag is printed in Italian, English, Japanese, French, German, and Spanish.

The packaging allows a view of the natural desiccant inside the bag without releasing dust from the desiccant. The selected non-woven fabric is food-safe and classified as Type B (low dust release) according to DIN 55473 technical standards.

The number of dehydrating bags to use should be determined based on the product to be protected, the volume and type of chosen packaging, and the desired shelf life. Pay particular attention to the water vapor permeability of the packaging to be used.

Dehydrating Bags – “Salts”

Dehydrating bags (commonly also referred to as “salts”) are used to remove moisture from within a package to preserve the quality of the products inside.

Although often called “dehydrating salts,” none of the desiccants used for packaging protection are actually salts. In fact, the DIN 55473 industry standard specifies that dehydrating bags must not contain any trace of salt (chlorides) to prevent oxidation when in direct contact with metal surfaces. Over the years, desiccants have been likened to salt, likely because silica gel resembles coarse kitchen salt and because salt itself has hygroscopic properties. However, salt is not technically a dehydrating agent, as it adsorbs moisture but does not retain it as effectively as clay or silica gel.

Why Are Salts Not Used in Packaging?

Firstly, dehydrating bags are placed inside packaging in direct contact with goods that need protection, so they must not cause any type of oxidation.

Secondly, silica gel and dehydrating clay have characteristics that common salts do not possess.

Desiccants Are Highly Efficient Materials:

  • They can reduce relative humidity to levels below 4%.
  • They do not easily release adsorbed moisture.

The primary desiccants used for packaging protection are:

  • Calcium Bentonie (also known as Montmorillonite, Salt, Expanded Clay, Active Clay, Desiccant, Bentonite, Dried Clay)
  • Silica Gel (often also called Salt, Silica Gel, Silica, Silicon, Drying Gel)

Are Salts Used in Protective Packaging?

The distinction between desiccants (silica gel and clay) and salts is important to avoid misunderstandings in certain situations.

Calcium chloride (which is indeed a salt) finds its natural application in dehydrating bags used to protect containers from the “rain effect.”

In this context, it’s necessary to absorb large amounts of moisture without needing to reach low relative humidity levels (typically aiming to maintain relative humidity around 50% within the container). Thus, the characteristics of calcium chloride make it the ideal desiccant for this purpose.

It is a hygroscopic salt characterized by a high capacity (the amount of water vapor it can remove from the environment) and limited efficiency (the dryness level it creates around itself is about 40% relative humidity).

Desiccant Selection

Protection within packaging

  • Dehydrating Clay: General industrial use.
  • Silica Gel: Pharmaceutical industry.

Transport Protection via Container

  • Calcium Chloride: Levodry Gel, Container Bag.

How to Prevent Mold on Shoes

The Source of the Problem

The moisture naturally present in leather, combined with that from the manufacturing process (e.g., water-based adhesives), can cause excess moisture to accumulate inside the packaging, creating an environment conducive to mold growth.

Excess moisture may also cause a loss of leather sheen, forming a dull layer over the shoe’s surface. Finally, mold growth is almost always accompanied by a bad odor that permeates the shoes.

Products most prone to these issues are:

  • Shoes;
  • Leather goods;
  • Leather bags;
  • Hygroscopic materials.

Mold can also develop on entirely synthetic materials when favorable conditions (humid heat) are present.

The Solution

Anti-mold clay bags absorb moisture from their surroundings, removing the key factor that allows fungal spores to thrive.

This solution is simple, easy to implement, and, most importantly, safe for end users and operators.

These dehydrating bags do not release any chemicals into the packaging. Being a natural, non-labeled desiccant compliant with all safety regulations, they can be safely used even in packaging that will eventually reach consumers.

Removing moisture completely eliminates the conditions that cause mold growth, regardless of the strain. Commercial anti-fungal cards, which use synthetic products, may not offer complete action and allow mold to grow due to unremoved moisture in the packaging.

Advantages of a Natural Solution

The desiccant does not release chemicals and does not alter the leather’s scent. No chemicals are released that could affect the leather’s sheen, and there are no potentially hazardous chemicals. Mold growth is inhibited by removing excess moisture, not by using chemical fungicides.

Precautions Regarding Hygroscopic Materials

An essential aspect when addressing mold issues in leather goods packaging is to ensure that all hygroscopic elements (such as paper and cardboard) are dry and stored in conditions that prevent excess moisture accumulation. Most moisture inside packaging usually originates from the cardboard box. Properly stored packaging elements greatly reduce the amount of desiccant needed.

Dehydrating Unit

The Problem

Dehydrating bags are generally made using Silica Gel and Dehydrating Clay.

  • Silica Gel is a synthetic desiccant obtained by acidifying sodium silicate, followed by washing and drying.
  • Dehydrating Clay is a naturally sourced bentonite that is quarried, sieved, and dried.

When produced, stored, and processed correctly, Silica Gel performs consistently (no variations across different batches), with an efficiency of 20% of its weight in grams of adsorbed water vapor (96g) under DIN test conditions of 23°C and 40% RH. For this reason, silica gel bags have always been sold and purchased by weight; two 480g silica gel dehydrating bags, regardless of the manufacturer, will have identical performance, provided both manufacturers use quality silica gel and process and package the product according to industry standardsDehydrating clay, on the other hand, is a natural product, so its performance is not always consistent. Moreover, not all clays meet the requirements for dehydration us.

Dehydrating clay, on the other hand, is a natural product, so its performance is not always consistent. Moreover, not all clays meet the requirements for dehydration use.

A 480g clay dehydrating bag may have variable performance, ranging from 18% to 19.5%, adsorbing between 86.4g and 93.6g of water vapor or, in the worst case, if it is made using unsuitable clay, it may have no effect or even release moisture within the packaging.

o determine the performance of clay dehydrating bags, the user should conduct an absorption test and, each time, request the performance details of the clay used for subsequent supplies.

Obviously, at an industrial level, this process would be impractical, so international production standards have been developed to classify and regulate the production of clay dehydrating bags.

Among the various standards, the concept of the Dehydrating Unit was introduced.

The dehydrating unit is the amount of desiccant needed to adsorb XX grams of water vapor in a climate chamber under 23°C and 40% RH conditions.

DIN MIL NHF

The main standards are:

  • NFH 0321: One dehydrating unit equals the amount of desiccant needed to adsorb 100g of water vapor.
  • DIN 55473: One dehydrating unit equals the amount of desiccant needed to adsorb 6g of water vapor.
  • MIL 3464: One dehydrating unit equals the amount of desiccant needed to adsorb 6g of water vapor.

In other words:

  • 1 NFH Unit = 16 DIN Units = 16 MIL Units
  • 1/16 NFH Unit = 1 DIN Unit = 1 MIL Unit

Why Introduce the Dehydrating Unit Concept?

When buying or selling a dehydrating bag, it’s always helpful to refer to the dehydrating unit because the aim is to buy or sell not the weight in grams of clay but the weight in grams of water vapor the bag will remove. The bag’s weight may vary (within certain limits), but performance remains consistent.

The Key Takeaway:

When buying a clay dehydrating bag, you are purchasing its final performance (for which the manufacturer is responsible), not its weight in grams.

Levosil tests the performance of each batch (1,000 kg) of raw materials in a climate chamber to ensure that all produced dehydrating bags meet standards.

Climate chamber samples of various batches for dehydrating performance testing

The “French” NFH standard = Grams of water vapor adsorbed under 23°C / 40% RH conditions = MIL/DIN standard

  • 1 NFH Unit = 100g of adsorbed water vapor = 16 MIL/DIN Units
  • 1/2 NFH Unit = 50g of adsorbed water vapor = 8 MIL/DIN Units
  • 1/4 NFH Unit = 25g of adsorbed water vapor = 4 MIL/DIN Units
  • 1/8 NFH Unit = 12.5g of adsorbed water vapor = 2 MIL/DIN Units
  • 1/16 NFH Unit = 6.25g of adsorbed water vapor = 1 MIL/DIN Unit
  • 1/32 NFH Unit = 3.12g of adsorbed water vapor = 1/2 MIL/DIN Unit
  • 1/50 NFH Unit = 2g of adsorbed water vapor = 1/3 MIL/DIN Unit
  • 1/100 NFH Unit = 1g of adsorbed water vapor = 1/6 MIL/DIN Unit