In food processing sites, especially clean workshops like those for baking, dairy, and meat products, V-shaped pleated high-efficiency air filters serve as the main terminal filtration equipment. These filters are vital parts of air purification systems. Their effect directly determines the cleanliness of the production environment. In turn, this influences the safety and quality of food. The following analysis covers four aspects: core role, dimensions of effect verification, advantages and limitations, and key factors that influence the effect. I. The Core Function of V-shaped Pleated High-Efficiency Filters
The core function of the V-type high-efficiency filter is to capture tiny airborne particles: microorganisms, dust, and other impurities. By forcing air through the filter material, the filter achieves deep air purification. It ultimately provides a clean air environment that meets national food processing standards, such as GB 14881 ‘General Hygienic Specifications for Food Production’ and GB 50073 ‘Code for Design of Clean Rooms’.
Its filtering objects mainly include: Microorganisms like bacteria, mold spores, and yeast are major sources of food spoilage and cross-contamination. Abiotic particles such as dust, fibers, pollen, and metal debris affect the appearance, taste, and stability of food. Ii. Core Verification Dimensions of Actual Effects
The effectiveness of V-type high-efficiency filters needs to be verified through four key indicators: “filtration efficiency, air flow resistance, dust holding capacity, and service life”, and a comprehensive judgment should be made in combination with the special requirements of food processing sites (such as anti-cross-contamination and easy cleaning).
1. Filtration efficiency: A core indicator meeting the cleanliness level of food
Filtration efficiency is the core criterion for measuring its effectiveness. It is usually based on the retention rate of particles with a diameter of 0.3μm (in accordance with GB/T 13554-2020 “High Efficiency Air Filters”) and is classified into the following grades:
| Filtration grade (GB/T 13554) | Efficiency for 0.3μm particles | Applicable to food processing scenarios |
| H13 | ≥99.97% | Aseptic filling (such as liquid milk, fruit juice), health food (such as probiotics), and food for medical devices |
| H14 | ≥99.99% | High-cleanliness aseptic workshops (such as freeze-dried food, bioactive food) |
| U15/U16 | ≥99.995%/≥99.999% | Ultra-clean scenarios (such as food-grade biological preparations) |
The actual effect is reflected Under the premise of compliant installation, the H13 grade V-type filter can reduce the concentration of 0.3μm particles entering the clean area to less than 0.3 per liter. Combined with the pre-filter (primary filter + medium filter), it can stably maintain the workshop cleanliness to reach Class 100, Class 1,000 or Class 10,000 (in accordance with GB 50073) Class 100 refers to the situation where the number of particles ≥0.5μm per cubic meter is ≤ 3,500, effectively cutting off airborne microbial contamination from the source.
2. Airflow resistance: Balancing purification efficiency and energy consumption
Airflow resistance is the pressure loss when air flows through a filter, which directly affects the energy consumption of the air conditioning system and the stability of the air supply volume.
Advantages of V-shaped structure: By using “pleated + V-shaped arrangement”, the filter material area is increased (3-5 times larger than that of traditional flat high-efficiency filters). Under the same air volume, the resistance is 20%-30% lower than that of the flat type (the initial resistance is usually 150-200Pa, much lower than the 250-300Pa of the flat type).
Actual effect: Reduce the load of the air conditioning fan and lower energy consumption; At the same time, it is crucial to avoid insufficient air supply due to excessive resistance and ensure the stability of the “positive pressure” in the clean area (preventing the infiltration of external contaminated air), which is essential for preventing mold contamination in baking and dairy workshops.
3. Dust holding capacity and service life: Compatible with the production cycle of food processing
The dust holding capacity is the maximum total amount of particles that a filter can retain, which directly determines its service life.
The filter material area of the V-type filter is large, and its dust holding capacity is usually 200-400g/m² (much higher than the 100-150g/m² of the flat type). In food processing sites (with complete pre-filtration), its service life can reach 6-12 months, which is suitable for the production batch cycle of most foods (such as the quarterly cleaning cycle of dairy products).
Actual effect: Reduce the downtime caused by frequent filter replacement and lower maintenance costs; At the same time, avoid a sudden drop in efficiency caused by the “saturation” of the filter (for example, when the resistance exceeds 450Pa, the efficiency may drop by 10%-20%), and prevent the risk of contamination from rebounding.
4. Safety and Compliance: Meet the hygiene requirements for food processing
Food processing sites have special requirements for the “hygiene and safety” of filters. V-type high-efficiency filters need to meet:
No filter material shedding: Hot melt adhesive is used for sealing (instead of traditional glue, avoiding VOC release and chemical pollution), and there is no fiber shedding at the edge of the filter material (preventing food from being mixed in).
Cleanliness resistance: The frames are mostly made of aluminum alloy or stainless steel (rust-proof and easy to disinfect), and can be used in conjunction with the CIP (in-situ cleaning) or disinfection processes in the workshop (such as ultraviolet light, hydrogen peroxide fumigation).
Compliance certification: It is necessary to pass food-grade relevant certifications (such as FDA-certified filter materials) to ensure no migration of harmful substances.
Actual effect: It avoids the filter itself becoming a “pollution source”, complies with the requirements of GB 14881 for “Hygiene of production environment and equipment”, and reduces the risk of food compliance.
Iii. Advantages and Limitations of V-type High-Efficiency Filters
Advantage: Adapted to the core pain points of food processing
Purification efficiency and energy consumption balance: The V-shaped structure ensures high-efficiency filtration while reducing resistance, solving the problem of “high energy consumption and low air volume” of traditional high-efficiency filters.
Save installation space: Under the same air volume, the volume of V-type filters is 30%-50% smaller than that of flat plate filters, making them suitable for compact Spaces in food processing workshops (especially in the renovation of old factories).
Convenient maintenance: It mostly adopts “drawer type” installation. When replacing, there is no need to disassemble the air duct, reducing secondary pollution to the clean area.
Limitation: It needs to rely on system coordination
The effect of the V-type high-efficiency filter is not “independently achieved”, but depends on the pre-filtration system and workshop design:
If the pre-filtration (primary filtration for large particles and medium filtration for 1-5μm particles) is not perfect, the V-type filter will quickly become saturated, and its service life will be shortened by more than 50%.
If the supply and return air layout in the workshop is unreasonable (such as dead corners of air flow), even if the filter efficiency meets the standard, the cleanliness in some areas may still not meet the standard (for example, the cooling area in the meat products workshop is prone to bacterial growth due to stagnant air flow).
Iv. Key Factors Affecting Actual Effects
To ensure that V-type high-efficiency filters perform at their best in food processing sites, the following four key links need to be controlled:
The compatibility of the pre-filtering system
The three-level filtration process of “primary efficiency → medium efficiency → high efficiency” must be followed:
Primary filter (G4 grade) : Retains particles ≥5μm (such as dust and hair), protecting the medium filter.
Medium-efficiency filter (F8 grade) : Retains particles ≥1μm (such as pollen, some mold spores) to prevent premature clogging of V-type high-efficiency filters.
Negative case: If the medium-efficiency filter is omitted, the service life of the V-type filter may be shortened from 10 months to 3 months, and frequent replacement can easily lead to shutdown and contamination in the clean area.
2. Tightness of installation and sealing
The sealing between the filter and the frame is the key to “preventing leakage” : if the seal is not tight (such as aging of the sealing strip, installation gap > 0.1mm), unfiltered air will seep in through the gap, causing the particle concentration in the clean area to exceed the standard (possibly dropping from Class 10,000 to Class 100,000).
It is recommended to adopt “liquid tank sealing” (silicone liquid tank + filter edge insertion), which can control the leakage rate below 0.1%, far lower than the 1% of the traditional “gasket sealing”.
3. Regular inspection and replacement
The replacement timing needs to be determined through a particle counter (for real-time monitoring of particle concentration in the clean area) and a differential pressure gauge (for monitoring filter resistance)
When the resistance reaches twice the initial resistance (or ≥450Pa), or the particle concentration in the clean area continuously exceeds the standard (for example, in a 10,000-level workshop, the number of ≥0.5μm particles exceeds 35,000 per m³), immediate replacement is necessary.
When replacing, the “Clean Area Operating Procedures” (such as wearing sterile clothing and using sterile tools) must be followed to avoid introducing contamination during disassembly and assembly.
4. Workshop air flow organization design
The supply air volume of the V-type filter should match the volume of the workshop (for example, the supply air volume of a Class 100 workshop should be ≥20 times per hour), and the airflow should be “unidirectional flow” (from the high-cleanliness area to the low-cleanliness area) to avoid cross-contamination.
For example, in the aseptic filling workshop of dairy products, V-type filters need to be installed inside the ceiling “laminar flow hood” to ensure that the airflow blows vertically downward, covering the filling port and preventing external air from mixing in.
V. Summary: The core conclusion of the actual effect
In food processing sites, the actual effect of V-shaped pleated high-efficiency filters is “system-dependent” :
If equipped with “primary + medium” pre-filters, installed in compliance with regulations and maintained regularly, it can stably achieve H13/H14 filtration efficiency, meet the cleanliness requirements of 100 to 10,000 grades, effectively cut off airborne microbial contamination, and ensure food safety.
If the system coordination is ignored (such as the absence of a pre-filter or installation leakage), its effect will be greatly reduced, and it may even become an “ineffective filter”.
Therefore, when food enterprises make a selection, they need to comprehensively plan based on their own cleanliness requirements (such as sterile vs. non-sterile), production cycle, and workshop layout, rather than simply relying on the “grade label” of the filter.
2. Airflow resistance: Balancing purification efficiency and energy consumption
Airflow resistance is the pressure loss when air flows through a filter, which directly affects the energy consumption of the air conditioning system and the stability of the air supply volume.
Advantages of V-shaped structure: By using “pleated + V-shaped arrangement”, the filter material area is increased (3-5 times larger than that of traditional flat high-efficiency filters). Under the same air volume, the resistance is 20%-30% lower than that of the flat type (the initial resistance is usually 150-200Pa, much lower than the 250-300Pa of the flat type).
Actual effect: Reduce the load of the air conditioning fan and lower energy consumption; At the same time, it is crucial to avoid insufficient air supply due to excessive resistance and ensure the stability of the “positive pressure” in the clean area (preventing the infiltration of external contaminated air), which is essential for preventing mold contamination in baking and dairy workshops.
3. Dust holding capacity and service life: Compatible with the production cycle of food processing
The dust holding capacity is the maximum total amount of particles that a filter can retain, which directly determines its service life.
The filter material area of the V-type filter is large, and its dust holding capacity is usually 200-400g/m² (much higher than the 100-150g/m² of the flat type). In food processing sites (with complete pre-filtration), its service life can reach 6-12 months, which is suitable for the production batch cycle of most foods (such as the quarterly cleaning cycle of dairy products).
Actual effect: Reduce the downtime caused by frequent filter replacement and lower maintenance costs; At the same time, avoid a sudden drop in efficiency caused by the “saturation” of the filter (for example, when the resistance exceeds 450Pa, the efficiency may drop by 10%-20%), and prevent the risk of contamination from rebounding.
4. Safety and Compliance: Meet the hygiene requirements for food processing
Food processing sites have special requirements for the “hygiene and safety” of filters. V-type high-efficiency filters need to meet:
No filter material shedding: Hot melt adhesive is used for sealing (instead of traditional glue, avoiding VOC release and chemical pollution), and there is no fiber shedding at the edge of the filter material (preventing food from being mixed in).
Cleanliness resistance: The frames are mostly made of aluminum alloy or stainless steel (rust-proof and easy to disinfect), and can be used in conjunction with the CIP (in-situ cleaning) or disinfection processes in the workshop (such as ultraviolet light, hydrogen peroxide fumigation).
Compliance certification: It is necessary to pass food-grade relevant certifications (such as FDA-certified filter materials) to ensure no migration of harmful substances.
Actual effect: It avoids the filter itself becoming a “pollution source”, complies with the requirements of GB 14881 for “Hygiene of production environment and equipment”, and reduces the risk of food compliance.
Iii. Advantages and Limitations of V-type High-Efficiency Filters
Advantage: Adapted to the core pain points of food processing
Purification efficiency and energy consumption balance: The V-shaped structure ensures high-efficiency filtration while reducing resistance, solving the problem of “high energy consumption and low air volume” of traditional high-efficiency filters.
Save installation space: Under the same air volume, the volume of V-type filters is 30%-50% smaller than that of flat plate filters, making them suitable for compact Spaces in food processing workshops (especially in the renovation of old factories).
Convenient maintenance: It mostly adopts “drawer type” installation. When replacing, there is no need to disassemble the air duct, reducing secondary pollution to the clean area.
Limitation: It needs to rely on system coordination
The effect of the V-type high-efficiency filter is not “independently achieved”, but depends on the pre-filtration system and workshop design:
If the pre-filtration (primary filtration for large particles and medium filtration for 1-5μm particles) is not perfect, the V-type filter will quickly become saturated, and its service life will be shortened by more than 50%.
If the supply and return air layout in the workshop is unreasonable (such as dead corners of air flow), even if the filter efficiency meets the standard, the cleanliness in some areas may still not meet the standard (for example, the cooling area in the meat products workshop is prone to bacterial growth due to stagnant air flow).
Iv. Key Factors Affecting Actual Effects
To ensure that V-type high-efficiency filters perform at their best in food processing sites, the following four key links need to be controlled:
The compatibility of the pre-filtering system
The three-level filtration process of “primary efficiency → medium efficiency → high efficiency” must be followed:
Primary filter (G4 grade) : Retains particles ≥5μm (such as dust and hair), protecting the medium filter.
Medium-efficiency filter (F8 grade) : Retains particles ≥1μm (such as pollen, some mold spores) to prevent premature clogging of V-type high-efficiency filters.
Negative case: If the medium-efficiency filter is omitted, the service life of the V-type filter may be shortened from 10 months to 3 months, and frequent replacement can easily lead to shutdown and contamination in the clean area.
2. Tightness of installation and sealing
The sealing between the filter and the frame is the key to “preventing leakage” : if the seal is not tight (such as aging of the sealing strip, installation gap > 0.1mm), unfiltered air will seep in through the gap, causing the particle concentration in the clean area to exceed the standard (possibly dropping from Class 10,000 to Class 100,000).
It is recommended to adopt “liquid tank sealing” (silicone liquid tank + filter edge insertion), which can control the leakage rate below 0.1%, far lower than the 1% of the traditional “gasket sealing”.
3. Regular inspection and replacement
The replacement timing needs to be determined through a particle counter (for real-time monitoring of particle concentration in the clean area) and a differential pressure gauge (for monitoring filter resistance)
When the resistance reaches twice the initial resistance (or ≥450Pa), or the particle concentration in the clean area continuously exceeds the standard (for example, in a 10,000-level workshop, the number of ≥0.5μm particles exceeds 35,000 per m³), immediate replacement is necessary.
When replacing, the “Clean Area Operating Procedures” (such as wearing sterile clothing and using sterile tools) must be followed to avoid introducing contamination during disassembly and assembly.
4. Workshop air flow organization design
The supply air volume of the V-type filter should match the volume of the workshop (for example, the supply air volume of a Class 100 workshop should be ≥20 times per hour), and the airflow should be “unidirectional flow” (from the high-cleanliness area to the low-cleanliness area) to avoid cross-contamination.
For example, in the aseptic filling workshop of dairy products, V-type filters need to be installed inside the ceiling “laminar flow hood” to ensure that the airflow blows vertically downward, covering the filling port and preventing external air from mixing in.
V. Summary: The core conclusion of the actual effect
In food processing sites, the actual effect of V-shaped pleated high-efficiency filters is “system-dependent” :
If equipped with “primary + medium” pre-filters, installed in compliance with regulations and maintained regularly, it can stably achieve H13/H14 filtration efficiency, meet the cleanliness requirements of 100 to 10,000 grades, effectively cut off airborne microbial contamination, and ensure food safety.
If the system coordination is ignored (such as the absence of a pre-filter or installation leakage), its effect will be greatly reduced, and it may even become an “ineffective filter”.
Therefore, when food enterprises make a selection, they need to comprehensively plan based on their own cleanliness requirements (such as sterile vs. non-sterile), production cycle, and workshop layout, rather than simply relying on the “grade label” of the filter.
