"Mineral water bottles for daily consumption, packaging for purchased electronic products, equipment labels, reusable sealed plastic bags for long-term food storage..."

If you've encountered any of these, you've likely used mylar bags.

In the food and beverage industry, packaging is no longer just a container for the product; it's a crucial component in safeguarding quality and conveying brand value. This is why companies like MTPAK, which specialize in sustainable and high-quality flexible packaging solutions, are so vital.

This article, starting with mylar bags, will introduce the basics and advantages of polyester bags to help you better understand their value and applications in packaging.

What is mylar bag?

Polyester film, made from oriented polyethylene terephthalate (PET), is also commonly referred to as biaxially oriented polyethylene terephthalate (BOPET). PET is produced industrially by evaporating aluminum in a vacuum chamber and then bonding it to a polyester sheet. "Mylar" is the trademark name for a polyester film originally developed in the 1948s by DuPont (USA), Imperial Chemical Industries (UK), and Hoechst (Germany). Today, "Mylar" is also used as a generic name for other polyester film products with similar properties.

This material possesses multiple properties: it not only maintains high mechanical strength and exceptional toughness and abrasion resistance, but also exhibits excellent barrier properties, effectively blocking oxygen and water vapor, thereby preventing oxidation and moisture from affecting the contents. It also offers excellent optical properties, with high light transmittance and gloss. It is also chemically stable, resistant to acids, alkalis, oils, and common solvents, and has a wide thermal stability range (-60°C to 120°C). In addition, as an internationally recognized food safety grade material, it is widely used in food packaging. It is safe and harmless and will not release harmful substances.

What is the principle and function of this material?

The working principle of polyester film stems from its sophisticated material science design, providing packaging protection in multiple ways. Its compact molecular chains create a tiny free volume, effectively blocking oxygen molecules from entering, significantly delaying oxidative spoilage. It also blocks moisture, preventing the clumping of contents, and effectively isolates external odors, preserving the product's original flavor. Regarding physical protection, polyester film offers high mechanical strength, puncture resistance, and abrasion resistance, resisting damage during transportation and storage. Its excellent stiffness also helps maintain the packaging's shape and facilitates stacking.

Furthermore, the material possesses excellent optical properties. Its high transparency and gloss provide a clear display window for products, enhancing visual appeal and promoting consumer decision-making. Through these comprehensive properties, mylar bags provide comprehensive protection and display of contents.

Can polyester film be composited with other materials?

Absolutely! Polyester film is a molecularly bonded material with exceptional performance, boasting not only excellent flexibility and tensile strength but also excellent adhesion properties. It can be laminated with a variety of materials to achieve functional and structural optimization. It can be laminated with a variety of substrates, including glass, plastic, wood, rubber, vinyl, silicone, carbon fiber, marble, PVC, and fiberboard. It can even achieve self-adhesion or bond to various surfaces, making it widely used in industrial and packaging applications.

A common lamination method includes dry lamination, which combines polyester film with functional materials such as PE, CPP, and aluminum foil to create high-barrier, high-strength composite structures such as PET/AL/PE. These composites are widely used in food packaging, electronic protection, and industrial materials, achieving a balance of barrier, mechanical strength, and heat-sealing properties.

Furthermore, with increasing environmental protection requirements, polyester film lamination technology continues to innovate. For example, the use of sustainable materials such as recycled polyester (rPET) for lamination not only meets environmental trends but also provides brands with sustainable packaging solutions, further expanding the application prospects of polyester film.

What are the application scenarios of mylar bags?

Mylar bags (usually in composite form, such as PET/PE) have become the first choice for many industries with extremely high requirements for freshness preservation.

-Coffee roasting industry

PET packaging is almost synonymous with specialty coffee and is often used with a one-way degassing valve. The bag's high oxygen barrier prevents oxidation, while also firmly supporting the valve, allowing internal CO₂ to escape while keeping out oxygen, creating a "breathing system" that continuously protects flavor.

-Food industry:

Snack nuts: Prevent oil oxidation and rancidity, while also protecting against moisture to maintain a crisp texture.

Powdered condiments: Prevent moisture and caking to ensure powder fluidity.

Dried specialty products: Prevent flavor loss and deterioration in mushrooms and dried fruits, extending shelf life.

Tea industry: Rely on comprehensive moisture-proofing, oxygen-blocking, light-shielding (aluminum coating or colored PET can be used), and odor-blocking capabilities to ensure the color, aroma, and flavor of tea.

- Non-food industry:

Electronics: Utilizing its strength and high transparency, it is used to protect delicate components and as retail display packaging.

Pharmaceuticals and healthcare products: Moisture- and oxygen-sensitive tablets and capsules are often protected using PET composite packaging.

Conclusion

Mylar bags are a remarkable solution for modern packaging, empowered by materials science. Their unique molecular structure effectively addresses the core needs of product preservation, protection, and display. MTPAK bridges the gap between material science and brand value. We deeply understand the essence of materials and are committed to transforming advanced flexible packaging materials into packaging tools that effectively address customer pain points and enhance market competitiveness.

Choosing MTPAK means you're getting more than just packaging; you're getting a reliable partner who's an expert in flexible packaging solutions and continuously adds value to your brand through innovative technologies.

Please contact us for more information and product quotes on Mylar bags:

Email：account@mtpak.com

Contact us：https://mtpak.com/contact-mtpak

A Guide to Application for Mylar Bag