The leap from materials to a sterile barrier
I. Core Processes for Blood Bag Heat Sealing Production
1. Material Selection
- Primary material: Multi-layer composite films (e.g., PET/AL/PE, PVC/PE) with barrier properties, flexibility, and heat-sealing compatibility.
- Components: Blood collection tubes (PVC, TPU) and ports (rigid plastic).
2. Heat Sealing Process Classification
| Process Type | Principle | Application Scenarios | Advantages/Disadvantages |
|---|---|---|---|
| High-Frequency (HF) Sealing | Molecular friction heating via high-frequency electromagnetic fields | Tube-to-bag connections, port sealing | High efficiency, superior sealing; costly equipment |
| Hot Plate Sealing | Direct heating via electric heating plates | Main bag welding, large-area sealing | Low cost; prone to flash formation |
| Ultrasonic Sealing | Heat generation via ultrasonic vibration friction | Small-area sealing, tube connections | Suitable for thin materials; lower efficiency |
II. High-Frequency Sealing Process (Mainstream Technology)
1. Working Principle
- High-frequency oscillator: Generates 27.12 MHz electromagnetic field to induce molecular friction and heat.
- Pressure system: Applies pressure (0.2–0.8 MPa) during heating for tight material bonding.
- Cooling system: Rapid solidification of seams for high-strength sealing.
2. Process Flow
- Pre-treatment:
- Clean surfaces to remove contaminants (oil, dust).
- Precision cutting of films and tubes.
- Positioning & Clamping:
- Secure components in molds via mechanical/pneumatic systems.
- HF Heating:
- Material heated to melting point within 0.5–2 seconds.
- Pressure Welding:
- Apply 0.2–0.8 MPa pressure for material fusion.
- Cooling & Solidification:
- Seams solidify in 0.5–1 second after heating stops.
- Testing & Packaging:
- Pass leakage tests (e.g., pressure retention) and visual inspection; sterile packaging.
III. Key Process Parameter Controls
| Parameter | Function | Typical Value | Control Considerations |
|---|---|---|---|
| Frequency | Heating depth/efficiency | 27.12 MHz (fixed) | No adjustment needed |
| Power | Temperature regulation | 5–15 kW | Adjust based on material thickness |
| Pressure | Ensures material contact | 0.3–0.6 MPa | Low pressure → delamination; excess → damage |
| Sealing Time | Controls melt depth | 1–3 seconds | Overheating degrades materials |
| Mold Temp. | Prevents cold sealing | 80–120°C | Adjust per ambient conditions |
IV. Production Equipment & Automation
1. HF Sealing Machine
- Structure: Oscillator, pressure system, molds, cooling unit.
- Automation:
- Auto-feeding, positioning, welding, and inspection.
- Integrated vision systems for real-time seam monitoring.
2. Automated Production Line
- Workflow:
Film unwinding → Cutting → Tube insertion → HF sealing → Testing → Packaging. - Benefits:
- 50%+ efficiency gain, reduced labor costs.
- Minimized human error, improved consistency.
V. Quality Control & Testing
1. Seam Quality Tests
- Leakage Test: Inflate to 0.1–0.3 MPa; ≤5% pressure drop over 30 seconds.
- Peel Test: Seam strength ≥70% of base material.
- Visual Inspection: Smooth seams, no flash/bubbles.
2. Biocompatibility Testing
- Extractables Testing: Ensure no harmful substance release from seams.
