It’s hard to know which to choose between polyimide and polyester films. This is primarily because both of these materials have some similar qualities, such as their durability, reliability, chemical resistance, and heat resistance
Due to these similar properties, it is easy to confuse the two as the same. However, they are used for different purposes.
Here we will provide a comprehensive guide to polyimide and polyester films. You will understand the difference between the films, how and where these films are used, and the manufacturing process. Let’s go!
A Guide to Polyimide Films
What is Polyimide Film?
Films made from polyimide are used in a wide range of applications, especially where there is a need to withstand harsh temperatures. This makes polyimide remarkably reliable and durable.
Polyimide is not used by common industries or in standard applications. It is a high-quality HN grade insulation film developed by Dupont in the 1960s. They make polyimide sheets with Kapton as their brand name, which is recognized worldwide.
It is usually ordered by and manufactured to cater to the needs of large companies in the government and private sector.
Polyimide Film Properties
Polyimide Film performs well at extreme temperatures and other harsh conditions due to the following properties:
· The product performs well in a wide range of temperatures due to its good temperature resistance.
· –269 °C to +400 °C for a short period
· –60 °C to +250 °C for a long period
· Polyimide film has good chemical stability
· It is lightweight, durable, and flexible
· Polyimide can be combined with many other materials that may further enhance its properties
· It is an insulation material with good thermal, chemical, and electrical properties
Polyimide Film Dimensions
The dimension varies depending on the type of film used. The polyimide films technical data sheet or specification sheet will serve as a good guide on the thickness, width, and weight.
3 Types of Polyimide Films
There are 3 types of polyimide films
HN - This is the standard film type
VN - It contains all of the HN film type properties plus superior dimensional stability
FN - The HN is coated with tephylon on one or both sides, which greatly increases its heat and chemical resistant properties.
Industry Usage
A variety of industries commonly use polyimide film. The common usage of polyimide films includes and is not limited to:
· Labelling
· Electronics
· For multilayer insulation purposes
· Tapes
· Other high heat resistance applications such as coils of transformers, cables, motors, wiring, etc.
How Is A Polyimide Film Made?
The first step is to create a stock solution. Mix polyethylene oxide and water to prepare the stock solution. It may take hours to a couple of days for the solution to fully dissolve.
Once the solution is ready, it will be mixed with a dye soft solution. Once done, it will be placed on a hot plate. On the hot plate there should be a circular dish, and inside it, a premium cover glass on which the prepared solution will sit. It will take approximately 45 minutes for the polyimide thin film to prepare. It will then be stored and used in the complete manufacturing process.
A Guide to Polyester Films
What is Polyester Film?
Polyester film, also known as PET film, is widely used in many applications. Among polyester products, PET is the first to be industrially produced and is widely used throughout the world.
The material is also the world's most consumed, most used, and most produced polymer synthetic material. The film has a relatively comprehensive performance as a packaging material. Furthermore, its excellent performance makes it an increasingly popular choice among consumers.
Polyester Film Properties
Here is a list of some of the properties of the polyester film:
· It has a good chemical resistance
· It is tough and durable
· The film can withstand high temperatures; heat, and cold resistant
· UV Resistant
· Excellent for high-quality printing and lamination
· Airtight making it moisture resistant
Polyester Film Dimensions
Polyester films don't come in specific dimensions. These films are manufactured according to the customer demand and their specific requirements.
Types of Polyester Films
Polyester films are produced in a wide variety. It is best to contact the manufacturing company or look at the datasheet to get a better idea of the type of polyester films available.
The data will provide detailed tabular information about the film such as thickness, durability, strength, stretch resistance, testing data, and so on.
Some of the common brand names are:
· Skyrol
· Mylar
· Melinex
· Hostaphan
Industry Usage
Other polymer products cannot compare with polyester film in terms of advantages. Due to Polyester films being strong, transparent, and dimensionally stable, as well as chemically resistant, they are used in a variety of applications such as:
· Medical packaging
· Printing and Labelling
· Electronic appliances
· Plastic cards and wrapping
· Electrical insulation
How Is Polyester Film Made?
The manufacturing process is quite technical, involving the use of chemicals and heavy machinery.
Two chemical substances are used in the making of polyester films terephthalic acid and ethylene glycol. The first process is drawing the film in the machine using heated rollers. Each direction typically has a draw ratio of three to four.
The second phase begins after the completion of the drawing process. In this phase, a temperature between 200 and 250°C is used for crystallising the film. The heating process is essential to lock the film in its place, preventing it from shrinking to its original non-stretch form.
Final Thoughts
Hopefully by now you have a clear idea of what these two films are used for and which one is the right choice for you. They are both ideal for a wide range of different applications due to their impressive qualities. All that’s left for you to do is choose the right one for you and your project.