1. Material Differences: Traditional backpacks are made of breathable or even meshy materials, partly coated to protect against rain, but still have a useful life.
Waterproof backpacks, however, are made of impermeable or impermeable materials, with thicker coatings and even a film on the other side that can withstand more than one atmospheric pressure.
If thicker, such as TPU film, the 0.12 pressure compound membrane can withstand the pressure of 2 atmospheres.
Waterproof materials mainly include: TPU laminated cloth, this is an environmental protection material, temperature resistance is more broad-spectrum; another is PVC net, this widely used, low cost, but the temperature range is not large.
2. Processing technology difference: Traditional knapsack material joining can be achieved only by traditional seam-based technology.
The material of waterproof backpack needs to be opened, and high frequency and high frequency machine welding is needed.
Make a waterproof backpack, no amount is difficult to open the mold, high cycle machine also depends on the different power corresponding to different mold size, if the mold is larger, the higher the power required, the more expensive the machine.
The difference between 3. knapsack bags:
The traditional knapsack is basically zippered, and the zipper is also breathable.
There are several ways to open the mouth of a waterproof backpack: generally, the opening is rolled, that is, the mouth of the bag is folded together and fixed with a plug or other parts, so as to achieve sealing effect.
The other is a jammed sealed bag mouth, which is used for small waterproof bags more, large waterproof bags unrealistic. Another kind is the air-tight zipper opening, air-tight zipper is a waterproof high-level zipper, this kind of high-cost zipper, generally used in advanced waterproof backpack opening, outdoor ice bag, waterproof waistbag.
