Waterproof structure of bags

Description

BACKGROUND OF THE INVENTION

It is known that bags like school, travel or sporting bags are often made by sewing. However, the sewing region of a bag is easy for the drench of water to its interior. In rainy days, water from the sewing line may soak books, files, papers, clothes, and other objects inside the bag. In order to prevent from infiltration, many students simply cover their school bags with a plastic membrane to prevent said problem. But it is troublesome and not effective enough. Once the plastic membrane is discarded, the environment pollution caused by said membrane will certainly be anther problem. Though the sewing line can be adhered by a plastic membrane for the water-resistant, its appearance will be bad and not attractive, and will lose competitivvity in the market.

SUMMARY OF THE INVENTION

It is an objective of the present invention to overcome or substantially ameliorate at least one of the above disadvantages and/or more generally to provide an improved waterproof bag and its structure. The waterproof structure of the bag comprising:a cloth surface (1) attached by plastic inner layer (2), plastic sidewall (3) and cloth sidewall (4), characterized in that the plastic sidewall (3) embraces both sides, of the plastic inner layer (2), which are welded together by ultrasonic wave. The cloth sidewall (4) embraces the cloth surface (1) and the plastic inner layer (2) which is welded with the plastic sidewall (3), and both cloth surface(1), plastic inner layer (2) and cloth sidewall (4) are sewed up all together.

It is therefore an objective of the present invention, generally stated, to provide a bag having improved waterproof quality, and having an eye-appealing sewing line better than the traditional bags.

BRIEF DESCRIPTION OF THE DRAWINGS

A preferred form of the present invention will now be described by way of example with reference to the accompanying drawings, wherein:

FIG. 1 is a perspective view of a bag, constructed in accordance with the present invention.

FIG. 2 is a schematic cross-sectional elevation of the waterproof portion of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT

In the accompanying drawings there is schematically depicted an item of bag. The waterproof structure of the bag comprising: a cloth surface (1), attached by plastic inner layer (2), plastic sidewall (3) and cloth sidewall (4), characterized in that the plastic sidewall(3) embraces both sides, of the plastic inner layer (2), which are welded together by ultrasonic wave. The cloth sidewall (4) embraces the cloth surface (1) and the plastic inner layer (2) which is welded with the plastic sidewall (3), both cloth surface(1), plastic inner layer (2) and cloth sidewall (4) are sewed up all together.

As it can be seen, if a bag is left exposed to the rain for example, water on the surface or sewing line of the bag will not enter the bag compartment because of the presence of impermeable barriers, that is, the plastic inner layer (2) welded with the plastic sidewall (3) and sewed up tighter with cloth sidewall (4) provides the bag having improved waterproof quality, and having an attractive sewing line better than the traditional bags.

It should be appreciated that immaterial modifications and variations which are obvious to those persons skilled in the art are within the scope of the present invention.