The high-frequency heat sealing machine meets the precise heat sealing requirements of disposable medical supplies bags

1. Principle of precise heat sealing
Mechanism of high-frequency electromagnetic field
The high-frequency heat sealing machine generates a high-frequency electromagnetic field (usually 27.12MHz or 40.68MHz) through a self-excited oscillator of an electron tube. When plastic materials containing polar molecules such as PVC and TPU enter the electric field, the positive and negative charges inside the molecules undergo rapid polarization movement under the action of the high-frequency electric field.
The intense friction between molecules generates heat, causing the surface of the material to melt rapidly, and the molecular level is fused under the pressure of the mold to form a firm sealing layer.
Heat sealing precision control
Time control: The heat sealing time (usually 0.5-3 seconds) is accurately set through the PLC control system to ensure uniform melting depth.
Pressure control: Using a pneumatic or hydraulic system, the pressure fluctuation range is controlled within ±0.1MPa to avoid differences in heat sealing strength due to uneven pressure.
Temperature control: Through the cooperation of high-frequency power regulation and cooling system, the temperature of the heat sealing area is controlled within the range of ±5℃ of the melting point of the material to prevent overheating and degradation of the material.
2. Technical advantages of high-frequency heat sealer
Heat seal quality stability
Molecular-level fusion: The thickness of the heat seal layer is uniform (usually 0.1-0.3mm), and the peel strength can reach 15-25N/15mm (much higher than the industry standard ≥10N/15mm), effectively preventing leakage and air leakage.
No burnt edge phenomenon: High-frequency heating only acts on the surface of the material, avoiding the carbonization of the material that may be caused by traditional hot pressing sealing, and ensuring that the heat seal area is transparent and free of impurities.
Improved production efficiency
High-speed heat sealing: A single heat sealing cycle is ≤2 seconds. With the automatic feeding system, the production speed can reach 30-50 pieces/minute (taking 500ml infusion bags as an example).
Low energy consumption: The high-frequency heating efficiency is as high as 85%, which saves 30%-50% energy compared to traditional hot air sealing.
Aseptic environment guarantee
Non-contact heating: The high-frequency electric field only acts on the surface of the material, without direct contact with the heat source, reducing the risk of microbial contamination.
Clean production: The equipment can be equipped with a laminar flow purification system, and the heat-sealed area meets ISO Class 5 (Class 100) cleanliness requirements.
3. Application cases and data verification
Infusion bag heat-sealing test
The heat-sealing strength test of 500ml PVC infusion bag shows the following results:

Test item Test value Standard requirement
Peel strength (N/15mm) 22.3±1.2 ≥10
Seal integrity 100% no leakage ≥99%
Transparency of heat-sealed area 92% Transmittance ≥90%
Tracheal tube joint sealing
The tracheal tube joint made of TPU is heat-sealed, and the leakage rate is ≤0.01mL/min (industry standard ≤0.1mL/min), which meets ISO 80369-7 standard.
IV. Comparison with traditional heat sealing technology

Comparison items High frequency heat sealer Traditional heat press sealing
Heat sealing accuracy ±0.05mm ±0.2mm
Production efficiency 30-50 pieces/minute 15-20 pieces/minute
Energy consumption 0.8-1.2kW·h/thousand pieces 1.5-2.0kW·h/thousand pieces
Aseptic adaptability High (non-contact heating) Medium (heat source contact risk)
Equipment footprint Small (compact design) Large (need to match hot air system)
Conclusion
The high frequency heat sealer achieves molecular-level heat sealing through high-frequency electromagnetic fields. It has the advantages of high heat sealing accuracy, high production efficiency, low energy consumption, and strong aseptic adaptability. It fully meets the needs of disposable medical supplies bags for precise heat sealing and aseptic environment. Its technical indicators and actual application data are superior to traditional heat sealing technology, and it is an ideal choice in the field of medical device packaging.