Mylar® A polyester film

Supplier to the Queen - the Queen of England also relies on tailor-made seals from Dr. Dietrich Mueller GmbH.
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Mylar® A polyester film

Everything you need to know about Mylar A polyester film

As an extremely popular PET film brand, Mylar A is a material that we can easily recognize in our daily life. From food storage bags to other storage supplies, the material has made a name for itself.

Mylar A is a registered trademark of the DuPont company, which manufactures and sells BOPET films. BOPET essentially stands for biaxially oriented polyethylene terephthalate. It is a polyester film obtained from the stretched form of polyethylene terephthalate. The material is known for its high tensile strength and offers a wide range of chemical and physical properties.

In this blog, we will dive deep into the topic. We will also understand different aspects of Mylar A as a material and why it matters so much.


What are Mylar polyester films?

Mylar A, derived primarily from ethylene glycol and dimethyl terephthalate, is a common ingredient in a variety of applications. Since it first appeared in the early 1950s, the material has been used in hundreds of segments to add value to products.

It has been over 40 years since the material was introduced, but the needs it has met are valuable. Mylar A is one of the most promising materials we have today. This is due to the bundle of physical, chemical, thermal and optical properties it possesses. It has come a long way from an excellent balance of features to a great range of performance capabilities. 

Mylar A is an ideal material when a wide variety of applications are required in various industries such as imaging, electronics, packaging and construction. Therefore, it is also of great importance from the point of view of the versatility expected from a material. Therefore, there is no closer substitute that can surpass its qualities and excellent performance.

The polyester film Mylar® A is tensile and tear-resistant and has excellent electrical properties. This material has good resistance to heat, cold and common solvents.

Mylar® A is UL certified (UL file E93687). Since the Dr. D. Mueller GmbH is a UL-recognized repacker, the materials do not lose their UL certification during processing.

What material is Mylar Polyester made from?

Another question that might come to mind is the base material of Mylar A. Well, these polyester films are basically made of polyethylene terephthalate. Although technically the process that follows the production and manufacture of this strain is not very difficult to understand.

Let's take a look at how the whole process works. The first steps involve the extrusion of polyethylene terephthalate on a cold-rolled drum to produce the base film. This material is then machine stretched and then adjusted in the cross direction. The film for Mylar A is then fed over the rollers at exponentially increased speed to direct it into a burning flame where it is squared.

In the next step, the starting material is stretched and the entire material slot is rearranged into a processed and ordered structure. The remaining materials and scraps are then used to improve the mechanical properties of the polyester film before it is processed into the final material. Once this process is complete, the film is stabilized by heat to ensure it does not shrink again before finally being exposed to the outside environment.

What are the most important properties?

Because Mylar A is an ideal material used in various applications, it is important to know its main components and properties. Physical properties include various parameters such as tensile strength, elongation, surface roughness, density, modulus and total yield strength.

The other properties of Mylar A differ significantly from the physical properties as they serve the electrical components. These include the dielectric strength, the volume resistivity, the dissipation factor and the dielectric constant. These parameters are defined in terms of their ethical value units and the test methods used to test them. Therefore, the applicability of grades such as Mylar A and their use depends on the electrical and physical property requirements of each.

Apart from that, the polyester film also possesses several thermal properties which are defined in terms of their typical values, units and test methods. These properties include melting point, dimensional stability, and temperature requirements when converting to other materials. This also includes the requirements for the specific heat temperature, the flame class and the thermal expansion.

Balanced properties

One of the most appealing aspects of Mylar A polyester film is the perfect balance of its physical, chemical and optical properties. Here are some unique property combinations that give it an edge over other materials:

  • It has remarkable strength, toughness, brilliance and clarity.
  • Easy conversion to other materials. It can be easily printed, die-cut, molded, laminated or colored.
  • The material is extremely easy to handle when it needs to be stored alongside high-speed equipment.
  • It possesses remarkable mechanical properties such as optical clarity, strength, toughness and the ability to adapt to a wide range of temperatures.
  • It offers excellent resistance to extreme temperatures and humidity.
  • Mylar A combines easily with other materials and offers high puncture resistance and initiation.
  • The material is also characterized by its chemical resistance for the respective application.

Mylar A products:

What is Mylar polyester film used for?

As a material that is transparent by nature, Mylar A finds its application in many different industries and segments than the usual areas. But have you ever wondered what other industries make extensive use of Mylar A?

The exponential growth of its use in recent decades depends heavily on its natural properties. In addition to being transparent, the material is an excellent electrical insulator, making it a far better material than the available substitutes. Because Mylar A possesses these qualities along with the versatility required, there is no shortage of applications it can be used for!

Here are some common uses of Mylar A polyester film:

emergency blankets – The most important application of Mylar A is in rescue blankets due to its insulating properties. It is a commonly used body temperature stabilization material in areas where no other measures are available. The material is also used in outdoor survival kits, where the requirements are usually higher than usual.

In recent years, however, there has been a clear trend towards the use of rescue blankets. As such, the steady and unexpected increase in Mylar A use over the last several years is no longer a surprise.

labeling and packaging – The labeling and packaging industries use Mylar A to meet their packaging needs as it is less gas permeable than other plastic materials. In addition to many other common applications in the field of food labeling and packaging, it is also used as a foil pouch. This is due to its ability to form a flexible film that offers better barrier properties and greater resilience.

These properties help food stay fresh and therefore have a longer shelf life. Mylar A is also used for storage of pharmaceutical products and related categories that are sensitive to moisture.

Hydroponic Gardening – Another very common application of Mylar A is in hydroponic gardening. A key differentiator in this application category is that hydroponic growers use this material alongside the garden system to reflect additional light onto the plants. Mylar A is instrumental in increasing the growth rate of plants and improving the efficiency of indoor greenery. Therefore, it is a common substitute material for cultivating plants that do not grow in soil.

insulation – Mylar A is also used in applications that involve insulation. This is due to its construction as a reflective and metalized metal foil on the surface. This Mylar variant reflects large amounts of light and is comparatively less gas permeable. This is the main reason it is used for electrical insulation. On the other hand, if kept in a cold environment with lower temperatures, the material can also be used as a structure that reflects its shiny surface with a warm interior.

electrical insulation – Mylar is used in applications where electrical insulation is important. Due to the very good dielectric strength, the material is used as a cover slide and slot insulation in electric motors and generators.

Is Mylar polyester film the same as polyester?

When you hear the term polyester film, what is the first thought or image that comes to mind?

The most common answer to this question is probably plastic wrap. It's a common misconception that Mylar A and polyester are the same material. In reality, however, Mylar is a brand name registered as a trademark for a specific family of products. These products are made from the resin polyethylene terephthalate, better known as PET.

Additionally, the Mylar A grade refers to another category of material used as a general purpose film and is comparatively more translucent. This material has a comparatively higher tensile strength, giving it better resistance to moisture. This is a much better value than most other chemicals that cannot withstand the extreme temperatures of up to 150°C.

This is also the reason why this material is preferred over other available substitutes. Due to its chemical and physical properties, Mylar A offers a number of advantages over traditional materials. Therefore, it is understandable why it is much more preferred, even though it differs from raw polyester.

What are the handling requirements?

First and foremost, the environmental conditions must be taken into account. Often Mylar A is coated or similarly treated on one or both sides to enhance its various properties. This can either be an improvement in the adhesive properties or the conductivity. This treatment offers various properties that cannot be achieved with the usual pre-treatment methods. However, most people are unaware of the costs that come with this convenience.

The high performance properties of Mylar A may or may not apply to these processes and treatments. Because of this, there can be a significant reduction in potency when exposed to extremes of temperature/humidity.

While it is necessary to take the necessary precautions for handling and storage, it is also important to understand the underlying issues. Mylar A's blocking systems can become apparent when it loses its ability to separate the layers of its film without tearing them. This stage usually occurs when the moisture content within the film layer increases during processing or shipping. Temperature fluctuations can also cause this situation. However, if a roll of Mylar A is stored at a lower temperature and then placed in the opposite state, the likelihood of blocking due to condensation increases significantly. On the other hand, if the material is stored in a high humidity environment, the results may differ from the previous case.

What are the storage requirements?

As for the other aspects of Mylar A, it is equally important to know the ideal storage conditions for the material. To avoid possible processing or blocking problems, keep the following points in mind:

Keep the material at room temperature between 0°C and 30°C.

Protect the material with a polyethylene film or other material that is moisture resistant. You can also avoid storing or transporting the material in a place with high humidity.

Always try to process Mylar A in a controlled environment and under controlled conditions. Relative agitation and humidity should not exceed 60%. Because too much dryness can also make the material overly static or cause it to shrink.

Condition the material for at least two days before removing the moisture-resistant residue from the packaging.

In summary, Mylar A is an outstanding product of modern science that has revolutionized countless use cases in the world today. The material has not only made our everyday life easier, but also helped several industries to overcome their existing and potential challenges. Because of the range of physical and chemical properties it possesses, it becomes even easier to experiment and see beyond the benefits it currently offers.

Inquiries from everyone else about countries:
Tel: 49 4435 971010
Fax: +49 4435 971011

Let us know what product you are search and we will give you the Address of the right sales partner.

Direct request:
Inquiries from Great Britain:
dr Dietrich Mueller UK Limited
Tel: 44 20 80894197
Fax: + 44 20 80894198


Get your parts into production today.