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Jul 19,2019

Bag Knowledge+: Waterproof & Water Repellent

They are different!?

★Waterproof
If you have ever joined the annual swimming gala across the Sun Moon Lake in Taiwan, you will see many people swimming with the floating board while eating cookies, bread, and make the selfie. Why do these people swim with these things without getting them wet? Because they are taking "waterproof bags."

How can a bag be waterproof?
1. The fabric is waterproof.
2. The zipper is waterproof or has no zipper at all, but the bag is closed by other structures.
At present, there are 100% waterproof zippers with some branded zipper manufacturers, but the price is quite high, so most of the waterproof bag openings on the market are still closed by the rolling design.
3. Use high temperature to replace sewing or to seal the needle hole: High Frequency Welding and Seam Sealing.
"High Frequency Welding" is a kind of using high temperature to melt the coating to stick the fabrics. The whole bag does not need to sew, there is no needle holes and the water will not get in.

"Seam Sealing" is used to seal the needle hole from the back side of the fabric with Seam Sealing Tape to avoid water get in the bag through the needle holes.

★Water Repellent
Imagine if you just finished your graduation thesis and bound it into a book, going home with these in your backpack, and being excited to plan your graduation trip. At this point, the sky starts to rain and you don't have an umbrella. You rush home to open the backpack and check if the thesis got wet?
If the bag you use is not with Water Repellent, please go back to reprint the papers.
If the bag you use is with Water Repellent, then you can go to dinner with peace of mind!

Water Repellent is not 100% waterproof, but Water Repellent can still cope with the general rain! The most important thing is the difference in the fabric: To add "Water Repellent" layer after the fabric dyeing process is completed, which will create an invisible protective layer around the fibers of the fabric. With this protective layer, the fabric can "temporarily" block the rainwater. When it rains, the water droplets will slide directly over the surface of the fabric instead of directly penetrating into the fiber. You can shake off the rain easily. But after all, the effect of Water Repellent is NOT waterproof, and the rain might still penetrate the fabric after time passing and pressure.

Therefore, the effect of Water Repellent and Waterproof should not be confused!