Structural design of handle
The handle structure of the Paper Shopping Bag has a key impact on its mechanical properties. Common handle structures include flat, round rope, and combination of flat and round rope. Flat handles are usually made of multiple layers of paper pasted or pressed, and their width and thickness need to be carefully considered. A wider handle can disperse the force and reduce local pressure, but too wide a handle may affect the appearance and ease of use. The round rope handle relies on the flexibility and tensile strength of the rope to carry the weight. Its diameter determines the tensile force it can bear. Generally speaking, the larger the diameter, the greater the tensile force it can bear. For example, for shopping bags with heavier items, using thicker round rope handles or appropriately widened and thickened flat handles can effectively increase the carrying capacity and prevent the handles from breaking.
Material selection and combination
The material selection of the handle is an important step in optimizing mechanical properties. In addition to ordinary paper, some high-strength fiber paper or composite paper can be used for handle production. High-strength fiber paper such as carbon fiber paper has extremely high tensile strength and toughness and can significantly improve the mechanical properties of the handle, but the cost is relatively high. In practical applications, a combination of paper and other materials is often used. For example, reinforcing materials such as plastic or twine are embedded inside the paper handle. The plastic can provide a certain degree of flexibility and tensile resistance, while the twine can increase friction and overall strength. This combined design not only takes advantage of the processability and environmental protection of paper, but also makes up for the lack of mechanical properties of paper itself with the help of other materials.
Connection methods and reinforcement processing
The way the handle is connected to the main body of the shopping bag also affects the overall mechanical properties. The strong connection ensures that the handle will not easily detach when bearing heavy objects. Common connection methods include glue, sutures, and rivets. For glue pasting, you should choose a glue with strong viscosity and high strength after drying, and the pasting area should be large enough to ensure the reliability of the connection. Sutures are used to tightly connect the handle to the bag body through needle threads. The material and stitch density of the stitches will affect the connection strength. Generally, high-strength sewing threads are used and an appropriate stitch density is maintained. For some large or heavy shopping bags, rivets can also be used to reinforce the connection parts to further improve the stability of the connection between the handle and the bag body, so that the shopping bag can better withstand weight and tension during use.
Mechanical property testing and optimization adjustment
To ensure the effectiveness of the handle design, mechanical performance testing is required. By simulating the loading of items of different weights on the shopping bag, the tensile strength, deformation degree of the handle and the stress on the connection part with the bag body are tested. Optimize and adjust the handle design based on the test results. If it is found that the handle is excessively deformed when bearing a certain weight, it may be necessary to increase the thickness of the handle or replace it with a stronger material; if the connection part is prone to cracking, the connection method needs to be improved or reinforcement measures need to be added. After repeated testing and optimization, the handle of the Paper Shopping Bag can not only meet the mechanical performance requirements, but also take into account factors such as cost, aesthetics and ease of use, thereby improving the overall quality and practicality of the shopping bag.
