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How to Evaluate LED Items – Glues for Driver

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During last time’s evaluation for the water proof driver for LED flood light. We (FCS. 3rd party testing & inspection) found there are different kind of glue has been injected into the driver. Do not neglect these glues, it’s important for the performance of heat conduction for components as well as the performance of water proof. Glues might affect lamp’s life, reliability.

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▲Glue Burning

But why some of them is flammable, will burn only by small fire. And some of them is inflammable we can only see glue’s sparkle under flaming.
Some glues are pure glue but some of them looks like there are powders has been mixed.
Today, we will analyze these questions with glue’s expert.

1. Glue’s Material is Different
There are two kinds of materials for the majority glues has been injected into the driver: Silica Gel & PU.

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▲Silica Gel VS PU

As per above data, by the advantage of silica gel on anti-flaming and temperature resistance, compare with PU, silica gel will be much more suitable as injecting glue for drivers.
Then how about the truth in the market? Let’s continue the test.

2. How to separate Silica Gel and PU
Let’s study with our expert.

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Yes, the smell of silica gel and PU is different and easy to be separated. If your experience is more enough XDDDD.
Then how to separate them if as a beginner. A soldering iron is required.

▲Separating PU

▲Separating Silica Gel

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▲Left: PU after scalding / Right: Silica Gel after scalding

Difference after scalding:
PU: glue melt, with oils around
Silica Gel: without obvious change


We can also separate the silica gel and PU by flaming:


Silica Gel

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▲Left: Silica Gel after flaming (white) / Right: PU after flaming (black)

Difference after flaming:
Silica Gel: inflammable, glue become white
PU: flammable, glue become black

3. Evaluating – Extra Chapter
Well, with these new skills, let’s check which kind of glues has been used on the driver evaluated in last weeks.

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Hmmm, there is sand inside the glue?
Exactly, it’s confirmed there is sand inside the glue by double check with different experts, engineers. But it’s not real sands from beach. It’s some kind of powder, some people said it will be useful for heat conduction, and some said it’s just for reducing cost.
We will continue analyzing the sand. See you again soon.

We are 3rd party testing & inspection.
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E-mail: info@skdindustry.com

The measured data of the following products has been approved by the supplier, and will be uploaded and released by Back Morning independently!

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