Tek Tip - UL Flame Ratings for Polycarbonate Films
What do the Underwriters Laboratory flame ratings really mean for polycarbonate films?
Polycarbonate films can be used in a large variety of applications some of which have more stringent specifications than others. A common specification requirement is that the polycarbonate film be UL rated, meaning that it has been tested and assigned a rating by the Underwriters Laboratory. According to the UL website, the Underwriters Laboratory provides inspection, advisory services, education, training, testing, auditing, analytics, certification software solutions, and marketing claim verification in regards to various types of technologies.
In regards to the polycarbonate film industry, the Underwriters Laboratory evaluates a material's ignition, burning, electrical, physical, and mechanical characteristics. Once these tests have been completed the results are recorded on a UL Yellow Card for that specific material. There are several different ratings that the Underwriters Laboratory can assign to a material.
UL Yellow Card Flame Rating System
- UL 94-5VA Surface Burn; Burning stops within 60 seconds, test specimens MAY NOT have a burn through (no hole). This is the highest (most flame retardant) UL 94 rating.
- UL 94-5VB Surface Burn; Burning stops within 60 seconds, test specimens MAY HAVE a burn through (a hole may be present).
- UL 94 V-0 Vertical Burn; Burning stops within 10 seconds, NO flaming drips are allowed.
- UL 94 V-1 Vertical Burn; Burning stops within 60 seconds, NO flaming drips are allowed.
- UL 94 V-2 Vertical Burn; Burning stops within 60 seconds, flaming drips ARE allowed.
- UL 94 H-B Horizontal Burn; Slow horizontal burn test (H-B) are considered "self-extinguishing". This is the lowest (least flame retardant) UL 94 rating.
Many polycarbonate films tested are given the V-2 designation which is the second lowest flame retardant rating. Typical applications for polycarbonate films such as appliance overlays and in-mold decoration do not require the material to withstand flammable environments. It is only required that the material extinguishes within 60 seconds, thus the V-2 rating for standard polycarbonate is sufficient. However, there are applications within the electronic market where the material may see high heat or flammable environments in which case a flame retardant polycarbonate would be used.
SABIC Innovative Plastics uses the 'V' designation for their products that are UL rated. For example, the 8010V product is UL rated at all thicknesses. However, they do have several products that are UL rated even though they do not have the 'V' designation. The products SABIC has had tested by the Underwriters Laboratory and have a V-2 rating are listed below:
- LEXAN™ .030 8010
- LEXAN™ .007 8A35
- LEXAN™ .020 8A35
- LEXAN™ .020 8A13F
- LEXAN™ .007 8B35
- LEXAN™ .015 8B35
- LEXAN™ .020 8B35
- LEXAN™ .015 8B35F
- LEXAN™ .020 8B35F
- LEXAN™ .030 8B35F
If you have any further questions regarding the UL rating system or if you need a UL rated material for your application please contact Tekra at 1-800-448-3572 for more information!