When it comes to packaging, Mylar bags are among the most popular choices for everything from food storage to cannabis packaging, and even for emergency supplies. These bags are praised for their durability, ability to preserve freshness, and overall effectiveness in protecting contents from environmental factors. But what exactly are Mylar bags made of?

Mylar bags

What is Mylar?

Mylar is actually a brand name, and the material itself is a type of metalized polyester film. Mylar bags are typically made from this polyester film, which is derived from polyethylene terephthalate (PET)—a strong, lightweight plastic. The film is then coated with a thin layer of metal (usually aluminum), giving Mylar its reflective, metallic appearance.

The process of creating Mylar involves extruding the polyester into thin sheets, followed by the application of a metal coating, usually through a method called vacuum metallization. This adds the metal layer that makes Mylar bags resistant to moisture, light, oxygen, and other factors that can degrade or spoil their contents.

What Are the Components of Mylar Bags?

  1. Polyester Film (PET)
    • The primary material in Mylar bags is polyester film, which is made from polyethylene terephthalate (PET). PET is a strong, flexible, and durable material that forms the backbone of Mylar bags. It is resistant to tearing and puncturing, making it an ideal choice for packaging fragile or perishable items.
  2. Metalized Coating (usually Aluminum)
    • One of the defining features of Mylar bags is their metalized coating, which is typically aluminum. This layer is applied to the polyester film using a vacuum metallization process. The metal layer acts as a barrier, preventing light, oxygen, and moisture from entering the bag and affecting the contents.
    • The reflective surface not only protects items from physical and environmental damage but also helps to maintain temperature and preserve freshness, which is why Mylar bags are commonly used in food packaging, cannabis storage, and other long-term storage solutions.
  3. Heat-Sealable Layers
    • Most Mylar bags are designed to be heat-sealed to create an airtight, tamper-resistant seal. This is typically done by applying heat to the edges of the bag, causing the plastic layers to bond together. This feature ensures that once the bag is sealed, the contents are fully protected from air, moisture, and contaminants.
  4. Optional Additional Layers (for Extra Protection)
    • Some Mylar bags have additional layers for enhanced strength and protection, such as a layer of nylon, polyethylene, or foil. These additional layers can make the bag even more resistant to punctures, adding extra protection for sensitive or delicate contents.
    • Desiccants or oxygen absorbers may also be included in the bag to remove excess moisture or oxygen, further improving preservation. These are commonly found in food packaging or cannabis storage bags.

Why Are Mylar Bags So Popular?

Now that we know what Mylar bags are made of, it’s important to understand why they’re such a popular choice for packaging. Here are some of the reasons why Mylar bags are so widely used:

  1. Exceptional Barrier Properties
    • The metalized coating on Mylar provides a strong barrier against light, moisture, oxygen, and other contaminants. These protective qualities make Mylar bags an excellent option for preserving the freshness of food, preventing the degradation of cannabis, or protecting important documents from environmental damage.
  2. Durability and Strength
    • Mylar bags are incredibly strong for their weight. The combination of the polyester base and the metal layer makes Mylar bags resistant to tears, punctures, and abrasions. This makes them ideal for long-term storage in a variety of industries, including food, pharmaceuticals, and cannabis.
  3. Extended Shelf Life
    • One of the main reasons people use Mylar bags for food and cannabis packaging is their ability to extend shelf life. The bag’s airtight seal and protective barrier prevent oxidation and moisture buildup, keeping contents fresh for longer periods. This is especially valuable for food storage and preserving cannabis, which can lose potency if exposed to light and air.
  4. Temperature Control
    • Mylar bags have thermal insulation properties, making them effective in maintaining the temperature of stored items. This is why they’re often used for emergency food storage, where temperature control is crucial to maintaining the quality of the food over long periods.
  5. Lightweight and Compact
    • Despite their durability and strength, Mylar bags are lightweight and compact, making them easy to store, transport, and handle. This makes them an ideal packaging solution for a variety of products, from snacks and food items to clothing and electronics.
  6. Customization and Versatility
    • Mylar bags can be customized in terms of size, shape, and even appearance. They can be printed with logos, branding, and product information, making them suitable for commercial packaging needs. Additionally, they are versatile enough to be used for different types of products, from cannabis to dry foods, medical supplies, and even electronics.

Applications of Mylar Bags

Given their protective qualities, Mylar bags are used in a wide range of applications, including:

  1. Food Storage: Mylar bags are commonly used for long-term food storage, particularly in emergency preparedness, camping, and survival situations. Their ability to protect food from air, light, and moisture makes them perfect for preserving dried foods, grains, and even freeze-dried meals.
  2. Cannabis Packaging: Mylar bags are widely used in the cannabis industry due to their ability to preserve the quality and potency of cannabis. The airtight seal and light-blocking properties protect the cannabis from exposure to light and oxygen, both of which can degrade its potency and flavor over time.
  3. Pharmaceuticals and Supplements: The pharmaceutical industry also uses Mylar bags to store medications, vitamins, and supplements. The bags help protect sensitive products from moisture and air, ensuring they remain potent for longer.
  4. Emergency and Survival Kits: Mylar bags are often included in emergency kits for food storage, blankets, and other items that need to remain uncontaminated for long periods. Their reflective nature can even help in creating emergency blankets to retain body heat.
  5. Document and Item Protection: Mylar bags are sometimes used to store important documents, photos, or even electronics. The bags can protect against water damage, dust, and light exposure, keeping valuable items in pristine condition.

Mylar bags are made from a combination of polyester film and metalized coatings that provide exceptional durability, strength, and protection against environmental factors like moisture, air, and light. Whether you’re storing food, preserving cannabis, or safeguarding important documents, Mylar bags offer an airtight, cost-effective, and highly reliable solution. Their unique combination of properties makes them a go-to choice for a wide range of industries and applications, and their versatility ensures they will continue to be a popular packaging option for years to come.