Polyester heaters also referred to as Polyester film heaters or Polyester foil heaters consist of an electrically conductive ink between two insulating respectively carrier layers of polyester. With a maximum size of 600 x 1000 mm, their average height is only 0.2 mm. As the picture examples show, practically any shape and type of cut-out is possible.
Polyester foil heaters are resistant to permanent temperatures of up to 90°C (max. 100°C for short periods). It is generally not possible to predict which temperature a Polyester heating element will reach in the application, as there are extremely many influencing factors. These include not only the power, but also the mass and type of goods to be heated, the ambient temperature, air currents, the type of mounting and, of course, the control technology.
As a rule of thumb: the lower the surface load on the Polyester foil heater, the longer the lifetime. We recommend a maximum surface load of 0.2 W/cm2 for polyester heaters.
Of course, safety and control elements such as temperature fuses, temperature limiters, thermocouples and resistance sensors can also be integrated into the design.
Due to their full-surface heating ink, Polyester heating foils are clearly superior to heating mats with wire wound or printed heating conductor tracks in terms of temperature profile, electromagnetic compatibility and immunity to interruptions. Also, minor damage to the ink does not automatically lead to failure of Polyester heating elements.
A further advantage of the heating ink is the easy realisation of power distributions across the heating surface: for this purpose, either the composition of the ink is varied or omissions are provided (see also the Polyester foil heater in the picture, with the dotted foil edges).
With the ink it is possible to install very low power on small areas even at 230 V. Here competing designs with resistance wire or etch foil quickly reach physical limits.
The flexible Polyester heater can be pressed on or fixed with a self-adhesive foil. Wrapped in PVC, it can also be used in liquids (IP67).
Typical applications for Polyester heaters are e.g. cup warmers in fully automatic coffee machines, mirror heaters, plate heat exchangers, flat applications with a target temperature below 90°C. Standards can be used for aquarium and terrarium heaters.
Technical data for Polyester Heaters vs. Silicone Heaters and Kapton Polyimide Heaters
(up to 200°C)
|Flat Heating Elements
|Wire Wound||Etched Foil|
|* higher surface loads can be achieved, depending on the application, with very good heat consumption and fast control
(No warranty claims can be derived from this table)
|Continuous temperature resistance||-60 °C - 200 °C||-60 °C - 200 °C||-269 °C - 200 °C||-30 °C - 90 °C||350 °C||450 °C|
|Continuous temperature resistance with self adhesive foil||-60 °C - 180 °C||-60 °C - 180 °C||-60 °C - 180 °C||-30 °C - 90 °C||-||-|
|Short term temperature resistance||250 °C||200 °C||200 °C||100 °C||700 °C||900 °C|
|Recommended max. watt density*||0,8 W/cm²||0,8 W/cm²||0,8 W/cm²||0,2 W/cm²||4,0 W/cm²||5,0 W/cm²|
|Power tolerance||+5 / -10%||+5 / -10%||+5 / -10%||+/-10%||+5 / -10%||+5 / -10%|
|max. dimension||940 x 3000 mm||595 x 2500 mm||285 x 550 mm||1000 x 600 mm||2000 x 1000 mm||2000 x 1000 mm|
|min. dimension||30 x 30 mm||20 x 20 mm||25 x 25 mm||25 x 25 mm||30 x 30 mm||30 x 30 mm|
|min. height||1,1 - 3,0 mm||0,8 - 1,5 mm||0,2 mm||0,2 mm||2,0 mm
|Dimension tolerance||+/- 1 mm||+/- 1 mm||+/- 1 mm||+/- 1 mm||+/- 1 mm||+/- 1 mm|
|Quantities||from 1 piece||from 1 piece||from 1 piece||from 25 pieces||from 1 piece||from 1 piece|
|min. bend radius||5 mm||5 mm||2 mm||5 mm||-||-|
|Adhesive foil possible||yes||yes||yes||yes||no||no|
Geometry of Polyester Heaters
For production reasons, the size of our flexible Polyester heaters is limited to a minimum of 25 x 25 mm and a maximum of 600 x 1000 mm. The minimum height is 0.2 mm. Within these dimensions, practically any shape and contour is possible, round, angular, with cut-outs and holes. Bending radii of min. 10 mm are possible with flexible Polyester film heaters.
Manufacturing Process of Flexible Polyester Heaters
Polyester heaters are manufactured using the screen printing technology, whereby first silver-based conductor tracks are applied for contacting and then a layer of conductive resp. heating ink is applied. The large variety of different heating inks and the continuous search for new recipes allows the production and the development of new products to be adapted very flexibly to customer requirements.
This technology, which is unique in its kind, often makes it possible to achieve required performance adjustments (+/- 20%) simply by varying the heating ink, and thus to avoid tooling costs completely.
Due to their full-surface heating ink, Polyester film heaters are clearly superior to heating mats with wire winding or printed heating conductor tracks in terms of temperature profile, electromagnetic compatibility and immunity to interruptions.
A further advantage of the heating ink is the simple realisation of power distributions across the heating area: for this purpose, either the composition of the ink is varied or omissions are provided (see also the picture showing the Polyester film heater with the dotted foil edges).
As tooling costs are incurred for each Polyester heater design, they are usually used for quantities of 25 pieces and more. Due to automated production, Polyester heating elements are particularly suitable for the serial production of larger quantities (from 100 pieces on).
If they are to be used in liquids, the Polyester heating elements can also be welded into PVC. Thus a classification of IP 67 can be achieved.
Mounting Options for Polyester Heaters
The flexible Polyester heater can be pressed on or bonded with self-adhesive foil. Once the heater is fixed with self-adhesive foil, it is not possible to remove it without destroying the heater.
- self-adhesive foil
- not removable
- good heat transfer
- suitable for any shape and size
- download bonding instructions for flexible heaters here
Limiter, Thermocouple, Fuse, NTC,...
As with silicone heaters it is basically possible to attach limiters, thermocouples, fuses, etc. to the Polyester heater pad.
In order to achieve an even more homogenous heat distribution, an aluminium foil can be laminated on one or both sides of the Polyester heater.
Termination below silicone patch
Termination below plastic housing
Termination with plug according to customer request
Power Leads for Polyester Heaters
Type, length and position of the leads can be freely selected. Please note that the connection area always has a slightly stronger build-up than the rest of the Polyester film heater. Silicone leads are most commonly used for Polyester heaters because they are light and flexible. PTFE, PVC and glass fibre leads are also possible. Often the contact is made on a tab outside the heating surface.
The length and type of the connecting leads can easily be changed for subsequent orders of an existing heater design. For a change of the connection position on the heater, however, a new tool must be created.
In principle, it is possible to provide the connecting leads with a protection sleeve. However, fixing the sleeve results in a significantly thicker connection area.
Thermal protection also plays only a minor role due to the comparatively low operating temperatures of Polyester heaters. For mechanical protection, however, there are numerous alternatives from glass fibre sleeves to silicone sleeves to shrink sleeves.
Conformities & standards
Our Polyester heating elements are manufactured according to the strictest test criteria and meet all relevant standard and safety requirements as far as these are applicable due to the nature of the product. You will find general organisation or product group related certificates of conformity in our download centre under Service > Quality. Product-specific confirmations are available on request.
- UL (Optional with surcharge, only possible with UL-CSA approved accessories)
- VDE (Optional with surcharge, only possible with VDE approved accessories)
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