The TPU inflatable inner capsule of the massager is heat-sealed
Technical Solutions for Thermal Sealing Process of Massager TPU Inflatable Bladders
Combining medical-grade material properties with industrial application experience, the following key solutions are proposed:
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I. Material Selection & Pre-treatment
Medical-grade TPU Film
• Recommend medical TPU with Shore hardness 85A-95A, tensile strength ≥40MPa, and elongation at break ≥500% to ensure structural integrity during inflation/deflation cycles.
Surface Treatment
• Clean TPU film with isopropyl alcohol before welding to remove mold release residues.
• Optional plasma treatment (300W power, 30-second exposure) to enhance surface energy.
II. Thermal Sealing Parameters
High-Frequency (HF) Welding
• 27.12MHz HF equipment with 0.3-0.5MPa electrode pressure and 3-5 second welding time for bubble-free continuous seams.
Ultrasonic Welding
• 20kHz ultrasonic welding with 50-70μm amplitude and 2-3 second holding time, suitable for 0.2-0.5mm TPU films.
III. Quality Control Standards
Airtightness Testing
• Pass 0.5MPa pressure retention test (≥30 seconds) with leakage rate <5ml/min.
Peel Strength
• Seam peel strength ≥8N/cm per ASTM D1876 testing standard.
IV. Process Optimization Recommendations
Mold Design
• Use split mold structures with 0.02-0.05mm clearance between moving cores and fixed cavities to prevent material extrusion.
Temperature Control
• Maintain mold temperature at 80-100°C during HF welding to avoid TPU thermal degradation.
Note: Conduct Design of Experiments (DOE) to optimize parameter combinations, balancing welding strength and airtightness.
