The surface roughness of paper corner protectors plays a key role in the friction process between them and packaging materials, and profoundly affects the magnitude and characteristics of the friction between the two.
First, the surface roughness affects the actual contact area. When the surface of paper corner protectors is relatively rough, the bumps on the microscopic level contact the surface of the packaging material more and more densely. According to the theory of friction, the friction is proportional to the actual contact area. For example, when the rough surface of paper corner protectors contacts the smooth plastic packaging film, the numerous tiny bumps sink into the depressions on the surface of the plastic film, making the contact between the two closer, thereby increasing the friction. This increased friction can effectively prevent the relative sliding between the paper corner protectors and the packaging material during packaging stacking, and improve the stability of the packaging.
Second, the surface roughness changes the friction coefficient. The rough surface of paper corner protectors will increase the friction coefficient. This is because during the contact process, the unevenness of the surface will hinder relative movement and need to overcome more resistance. When paper corner protectors with different roughness rub against the same packaging material (such as corrugated cardboard), paper corner protectors with high roughness will produce greater friction resistance. During logistics transportation, the bumps and vibrations of the vehicle will cause the items in the package to have a tendency to move. At this time, a larger friction coefficient can ensure that the paper corner protectors can better fix the packaging materials and reduce the risk of damage to the items.
Furthermore, surface roughness and environmental factors such as humidity work together on friction. In a humid environment, the rough surface of paper corner protectors may absorb moisture and form a layer of water film. This layer of water film will change the nature of friction and may reduce friction to a certain extent. Because water plays a lubricating role, it reduces the direct friction between the paper corner protectors and the convexities and concavities of the packaging material. However, if the humidity increases further, the moisture may soften the packaging material or expand the fibers on the surface of the paper corner protectors, which will change the contact state and change the friction again.
The surface roughness of paper corner protectors has a multi-faceted impact on the friction between them and the packaging material by affecting the actual contact area, friction coefficient, and interaction with environmental factors. A deep understanding of this mechanism of action will help to reasonably select the surface treatment process of paper corner protectors according to different packaging requirements and environmental conditions in packaging design and application to optimize friction, ensure the safety and stability of packaging, and improve the overall performance of packaging.
