The pore shape of the honeycomb paper in a paint mist filter box is a key factor influencing the interception path of paint mist particles. Optimization should focus on extending particle residence time, increasing collision probability, and reducing airflow turbulence. Traditional honeycomb paper often uses regular hexagonal pores. While this structure offers high spatial efficiency and structural stability, it has limitations in intercepting paint mist. The regular hexagonal arrangement tends to form a stable airflow path, causing some paint mist particles to pass through the pores in a straight line, reducing the chance of collision with the paper wall. This results in a particularly low interception efficiency for tiny particles (such as submicron paint mist). Furthermore, regular pores are prone to generating localized turbulence under airflow, potentially pushing particles out of the interception area and causing them to slip through the filter.
Irregular pore designs can significantly improve the interception path. Replacing the regular hexagon with an irregular polygon (such as a pentagon, heptagon, or mixed polygon) disrupts the regularity of the airflow path, forcing paint mist particles to frequently change direction as they pass through the pores. This directional variation increases the frequency of particle contact with the paper wall. For example, the sharp angles of pentagonal pores can create localized vortices, causing particles to bounce repeatedly within the pores and prolonging their residence time. The complex boundaries of heptagonal pores can expand the interception area and reduce the number of linear penetration paths. Mixed polygonal designs (such as alternating regular hexagons and pentagons) can further optimize airflow distribution. By leveraging the complementary effects of different pore shapes, they balance resistance and interception efficiency, avoiding the localized blockages or airflow short-circuits caused by a single shape.
Curvature optimization is a key approach to improving interception effectiveness. Traditional straight pore edges have a weak guiding effect on particles, while curved pores (such as wavy and spiral shapes) can enhance interception by altering particle trajectory. For example, the undulating surface of wavy pores creates continuous collision points, ensuring that particles continuously contact the paper wall as they pass, increasing the probability of adsorption or retention. Spiral pores utilize centrifugal forces to fling larger particles toward the pore edges while guiding smaller particles into the central vortex zone, achieving graded interception. This curvature design must balance process feasibility and is typically achieved through laser cutting or molding. By controlling the radius and wavelength of the curve, the pore structure maintains strength while also providing sufficient interception flexibility.
Adjusting pore connectivity can optimize particle migration paths. Traditional honeycomb paper pores are mostly independent channels. Once particles enter a specific pore, they are difficult to migrate to other areas, which can easily lead to localized blockage. Designing partially connected pores (such as creating tiny channels or gaps between adjacent pores) allows airflow between the pores, giving trapped particles an opportunity to redistribute to unblocked areas. This connectivity design requires controlled channel size: too large channels can reduce structural strength, while too small channels may not effectively guide particles. In practical applications, interconnected holes with a diameter of 10%-20% of the pore size can be placed around the edges of the main pores, creating a composite structure of "main channels + diversion channels." This ensures interception efficiency and extends the life of the paint mist filter box.
The synergistic effect of surface roughness and pore shape cannot be ignored. Even with optimized pore shape, particles can still easily slip out if the paper wall surface is too smooth. By adding micron-scale rough structures (such as concave-convex patterns and fuzzy protrusions) to the pore walls, the friction between particles and the paper wall is enhanced. Combined with the guiding effect of the pore shape, this creates a dual mechanism of "mechanical interception + adsorption and retention." For example, longitudinal patterns on the inner walls of wavy pores can further extend the particle sliding path, increasing the probability of capture. A hydrophobic coating on the inner walls of spiral pores can enhance adsorption of sticky paint mist and reduce rebound.
Multi-scale pore combinations can achieve full particle size interception. A single pore shape cannot cover the entire size range of paint mist particles. By integrating pore layers of different shapes within the same paint mist filter box (e.g., large pentagonal pores in the upper layer to intercept coarse particles, and small spiral pores in the lower layer to capture fine particles), a graded interception system can be formed. This design requires even airflow distribution between the layers to avoid excessive local pressure differences caused by sudden changes in pore shape. A gradual transition structure is typically employed, whereby the pore size and shape gradually decrease from the top layer to the bottom layer, ensuring smooth airflow while effectively intercepting particles of all sizes.
In practical applications, a balance must be struck between shape optimization and processing cost. While irregular pore shapes, curvature designs, and multi-scale combinations can improve interception efficiency, they may increase mold complexity and production costs. Therefore, optimization should be based on the particle distribution characteristics of the target scenario. For high-concentration paint mist environments, a combined design of wavy and interconnected pores is preferred, offering strong interception capabilities to offset increased costs. For low-concentration or intermittent use, a simplified solution with pentagonal pores and optimized surface roughness can be chosen to maintain basic performance while controlling costs. The ultimate goal is to achieve the synergistic effect of "low resistance, high efficiency, and long life" through shape optimization, driving the development of paint mist filter boxes towards more refined and functional designs.
