Why SAN YOUNG uses PC lens on LED Light Bars and LED Work Lights?
Why SAN YOUNG uses a PC lens on LED Light Bars and LED Work Lights?
Now nearly no manufacturers are using tempered glass as an LED Light Bar lens because of it’s fragility, big density, and also the risk of material storage and transferring.
If someone is still using tempered glass on LED Light Bar, the only explanation is because of its cheap cost!
Manufacturers are mostly using PMMA (polymethyl methacrylate Acid ) and PC (Polycarbonate) as the lens of LED Light Bar or LED Work Lights. Although they are the best option in plastic category for LED Light Bar lens, San Young Lights still insists to stick with PC Lens for its best performance.
Firstly let’s see the comparison of PC again PMMA.
Material
|
Density
|
Temperature Resistance
|
Scratch resistance
|
Impact Resistance
| |
Glass
|
2.5
|
75%
|
600 °C
|
Good
|
Fragile
|
PMMA
|
1.19
|
93%
|
70 °C
|
Normal
|
Flexible
|
PC
|
1.2
|
89%
|
120°C
|
Good
|
Up to 50 times of PMMA. Bulletproof Glass always has 3mm thickness of PC on the top
|
Now, let’s compare the characters one by one
1, The Density.
PC and PMMA make no obvious difference in weight. But Glass lens on LED Light Bars makes it heavier which makes air freight cost higher.
2, Light Transmittance.
PC and PMMA make no obvious difference in Light Transmittance but Glass loses 25% of the light.
3, Temperature Resistance
PMMA ‘s Temperature Resistance is only 70 degrees. As we know LED chips create a lot of heat making LED Light Bar body up to 60 degrees or even more. So its obviously PMMA lens gets deformed and water goes inside LED Light Bars from the deformed places. That’s why some LED Light Bars are no longer waterproof after a few times.
(More factors causing Water instrument please refer to SanYoung 's another topic “ Why Moisture in LED Light Bars “ )
4, Scratch resistance
PMMA is the worse one. Actually, a lens with some small scratch does not affect the performance, but it affects the selling price.
5, Impact Resistance
Definitely, PC is much better than PMMA and Glass. In our test, testers can not break the PC even with a hammer. PC material is also used on the top of Bulletproof Glass to stop the spall.
So how important the Impact Resistance is for an LED Light Bar?
There is always a gap left in the LED Light Bar for the lens. Manufacturers normally use numbers of screws to fix the lens in LED Light Bars for waterproof purposes. Image that can a flexible PMMA lens be still waterproof when it rebounds after a brief spell?
Once a client in South Africa showed San Young lights a photo of LED Light Bar from his previous supplier like the photo below that PMMA lens got cracked easily because of summer heat.
 |
| Deformed Lens on LED Light Bar |
So It’s Very Important to select the right lens for your LED Light Bars!
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