What is a moisture barrier?
There are three types of barriers: vapour, water and moisture barriers.
A vapour barrier blocks to gas, a water barrier blocks liquid, and a moisture barrier blocks moisture, a combination of water and vapour.
A moisture barrier packaging protects foods, nutrients, drinks, medications, and cosmetics against physical, chemical, and microbiological deterioration. They have minimal gas and water permeability, which protects the contents from external influences while preserving the flavour and nature of the packaged product.
Why is protecting products against moisture important?
Moisture can cause corrosion, damage electrical components, discolouration, and undermine the structural integrity of the goods due to constant expansion and contraction in transit. It can also cause mould and mildew to grow on the product.
When shipping products over long distances, the goods are often exposed to various weather conditions, temperatures and humidity levels; this raises the possibility of moisture coming into contact with the products.
An example would be container rain which occurs when moisture in the air condenses within a shipping container. Without specific moisture-control measures, the container rain can result in the loss of entire shipments, leading to unsatisfied customers and loss of profit.
In addition, no crate or box can completely keep moisture out. Even if they are strong and well-constructed, wooden crates and corrugated boxes cannot provide a solid moisture barrier. Moisture can quickly penetrate the wood and corrugated boxes. Timber and corrugated boxes contain significant amounts of moisture and can add to the problem. Thus, moisture barrier packaging is vital for preventing this damage.
Types of moisture barrier packaging
Moisture barrier bag
Moisture Barrier Bags (MBB) works by enclosing a device with a metal or plastic shield that prevents moisture vapour from entering the bag. Specialised film layers regulate the Moisture Vapour Transfer Rate (MVTR). The pack also provides static shielding protection.
They are one of the most effective packaging options available today for preventing corrosive damage from humidity, moisture, oxygen, odours, grease, and other airborne pollutants. These materials are a low-waste alternative to other rigid packaging options meaning less material ends up in a landfill.
Moisture Barrier Bags have an 80-times lower transfer rate than a regular polyethene liner. That implies the packaging is also 80 times better at keeping moisture out. It also works the other way around that a Moisture Barrier Bag will keep goods from drying out if it retains certain moisture content.
They are not only known to keep products dry but also for corrosion prevention. A sealed Moisture Barrier Bag containing a precisely calculated amount of desiccant will keep relative humidity well below the 40% level required for metal corrosion. Moisture Barrier Bags can also include a humidity indicator inside the bags.
Moisture absorption film (MAF)
Moisture absorption film (MAF) is a high-function film which integrates a film and a desiccant. Because of the integrated desiccants, MAF has moisture absorption capability, ensuring that the inner contents of the pouch are kept at low humidity. Low humidity prevents product quality from deteriorating during storage and shipment. There are various kinds available, ranging from bone-dry type to humidification. It can also be utilised in a variety of pouch applications and forms.
Since the film absorbs moisture, it addresses desiccant risks for businesses by preventing consumers from accidentally ingesting or misusing desiccants. The MAF enables organisations that do not have a desiccant packaging process to put a moisture absorption function on their packaging lines. It also allows for a humidity control function and moisture absorption effect in compact packing bags and pouches with limited space, which standard desiccant sachets and backpacks may not fit.
The MAF absorbs water vapour from the content within, unlike the moisture barrier bag, which prevents water vapour from entering the bag. As a result, they are not required to be utilised with desiccants and humidity indicator cards (HIC).
How to create a dry packaging
To create a safe and dry packaging that protects goods from ElectroStatic Discharge and moisture:
- Place the desiccant and HIC on a tray stack where the products are stored. Take note to keep desiccants in an airtight container until they are needed.
- Insert the tray stack with desiccant and HIC into the moisture barrier bag.
- Using a vacuum sealer, remove a small amount of air from the packaging and seal the bag closed.
Moisture prevention tips
1. Using Corrosion Resistant Packaging
Corrosion-resistant packaging and materials, such as volatile corrosion inhibiting (VCI) products, desiccants, and humidity indicator devices, aid in keeping the contents clean, dry, and corrosion-free during transportation and storage. In addition, most of these items are non-toxic, affordable, and simple to use.
2. Using Transparent Packaging
Transparent moisture barrier bag packaging allows products to be inspected without exposure to chemicals and conditions that cause corrosion, such as acids, moisture, salts, water, sulphur gases, acid vapour, and ammonia gas.
3. Considering the Mode of Transport
The type of transportation by air, land, sea, or a combination of these modes, will be required to determine how much protection is needed. Goods travelling by sea, for example, may be exposed to significantly more moisture than shipments travelling by air or freight train.
4. Considering the destination and receiving facility
Shipments may stay outside for several hours on a dock or other places before being relocated to storage or prepped for the final part of the journey. At this point, the climate outside may be extremely humid, and the environment inside may be dry. Knowing these conditions can help decide the amount of protection and the materials needed.
5. Consider Customisation
Moisture barrier packaging either come ready-made or can be customised to fit specific sizes. Customisation allows selecting various protective materials and thicknesses rather than using the same material and consistency for all components.
Moisture barrier packaging can help extend the shelf life of products and deliver optimal, long-lasting quality to the users. Moisture barrier packaging can be custom-made with protective layers and materials to prevent unwanted moisture from entering the pouch or bag, making them useful for dry ingredient products like powdered soup mixes, nutritional supplements, and non-food items like household chemicals and nutraceutical products.