You all hear the words like waterproof, water repellent and water resistant but you may not know about their difference and the uses. All the types are meant for water protection and are very much essential for bags and luggage.
There are bags available with all the three types of water protection.
Water Resistant Bags: They are made with specialised processed material and are tightly woven in order to withstand water. But since the zippers here are composed of standard ones instead of waterproof zippers, water can enter into the bag after its exposure to water at certain level. These standard zippers with holes in between their teeth, use traditional sewing method. This indeed does not cover the holes placed in the zip, allowing water to penetrate within. Such kinds of bags will soak completely at the time of heavy rain or water drowning.
Water Repellent Bags: They are also prepared with superior fabrics and are coated with better finish to prevent water from penetrating inside. When the water hits, small beads are formed on the surface of the fabric. Thus, water repellent bags provide better water protection than that of water resistant bags. Although, standard zips are still used in such bags instead of waterproof ones leaking the water through its holes.
Waterproof Bags: There is a use of Thermoplastic Polytherane (TPU) or PVC plastic that coats the fabric of the waterproof bags. Thereby providing the complete protection from water. These bags are prepared with seams that are ultrasonically welded before the installation of waterproof zippers. There are no holes and needles found in the waterproof zippers, thus, water cannot leak through them. Moreover, there is a roll-top closure being used with more than two folds over the opening of the bag. This leads the bag to become completely airtight and waterproof.
The major differences found between all the above water protected bags are:
A specialised fabric is used in water resistant bags, which is tightly woven without specific coating, whereas various types of plastic coatings are used in water repellent and waterproof bags in order to protect water from penetrating within the bag.
Waterproof bags are welded ultrasonically to resist water while water resistant and water repellent bags have needle hole allowing the entrance to water.
Waterproof bags also have roll top closure system, which is an add-on protection to water. However, this extra feature is not a part of water repellent and water resistant bags.
Thus, it can be observed that waterproof bags use waterproof zippers instead of the standard zippers used in water resistant and water repellent bags.
SBS provides waterproof zippers with various materials to make the bag more repellent. There is a thin layer of TPU film attached over the tape of the rubberizing plastic and coil zippers for water repellence. Such zippers are also available in shiny, matte and half-matte surface in accordance to the customers' requirements. Beside these types, there is also a water-tight or the air-tight zipper, known as sealed airtight waterproof metal zipper. They are formed of two fabric tapes and sealed with chloroprene rubber at both ends and the inner teeth fixed with the outer one by a fabric tape. This provides protection against water, air, dust, sunshine even though exposed to pressure and bending.