Glucose Meter LSR Micro-Pore Molding Technology

Precision Micro-Pore Molding Technology for Blood Glucose Meter LSR Silicone Seals

Blood glucose meters are essential daily self-monitoring tools for diabetic patients, where measurement accuracy and reliability directly affect treatment outcomes. At the test strip interface, LSR silicone seals guide blood samples, isolate the environment, and ensure measurement accuracy. Precision micro-pore molding is the core technical challenge in the manufacturing process.

I. Functions and Structure of Blood Glucose Meter Seals

1. Core Functions

• Guide blood sample precisely into test strip reaction zone
• Prevent external air and moisture from interfering with electrochemical reaction
• Isolate test strip internal electrodes from external environment
• Ensure measurement repeatability and consistency

2. Structural Features

• Overall dimensions: approximately 8mm × 5mm × 1mm
• Micro-pore diameter: 0.3-0.8mm (varies by test strip type)
• Micro-pore positional accuracy: ±0.03mm
• Pore wall surface roughness: Ra ≤ 0.5μm
• Typical structure contains 2-4 precision micro-pores aligned with test strip electrode layout

II. Technical Challenges in Micro-Pore Molding

1. Extremely Small Pore Diameter

A 0.3mm micro-pore means the mold core diameter is only 0.3mm, which is prone to bending deformation under 170°C mold temperature and vulcanization pressure.

2. High Positional Accuracy

Relative position deviation between multiple micro-pores affects blood channel alignment after test strip insertion, requiring control within ±0.03mm.

3. Demolding Difficulty

High friction between micro-pore core and vulcanized LSR; demolding easily damages pore walls or breaks cores.

4. Flash Control

Micro-pore edge flash (>0.05mm) affects blood capillary action, causing measurement deviation.

5. Consistency Requirements

In 32-cavity or 48-cavity molds, every seal micro-pore must be identical in size and position.

III. LSR Precision Micro-Pore Molding Process

1. Mold Design

• Micro-pore cores using tungsten steel or ceramic, hardness HRC 90+
• Core root thickened to 0.8mm, gradual transition to 0.3mm working section
• Core surface DLC (Diamond-Like Carbon) coating, reducing friction coefficient for easier demolding
• Cavity venting: micro-vent grooves (0.005mm depth), preventing air trapping in pores
• Zoned mold temperature control: micro-pore area ±0.5°C

2. Injection Parameter Optimization

• Injection speed: slow injection (5-15 mm/s), avoiding high-speed erosion causing core deflection
• Injection pressure: 60-100 bar, lower pressure reduces core stress
• Mold temperature: 155-165°C, temperature uniformity ±1°C
• Cure time: 25-35 seconds
• Vacuum assist: cavity evacuated to -0.09 MPa before mold closure, eliminating micro-pore bubbles

3. Demolding Technology

• Compressed air-assisted demolding, 0.3-0.5 MPa air pressure
• Ejector pins avoiding micro-pore area, preventing core damage
• Robot pick-and-place, ensuring uniform demolding force

IV. Quality Inspection and Control

1. Micro-Pore Dimensional Inspection

• Optical microscope measurement, accuracy 0.001mm
• First and last article per batch 100% inspected, intermediate sampling
• Pore diameter tolerance: nominal ±0.02mm

2. Positional Accuracy Inspection

• Vision measuring instrument for micro-pore relative positions
• Tolerance: nominal position ±0.03mm

3. Flash Inspection

• 50× magnification visual inspection
• No visible flash or flash allowed

4. Seal Performance Testing

• Air tightness test: 0.1 bar pressure for 30 seconds, leak rate ≤ 0.5 mL/min
• Blood sample simulation test: standard blood solution verifying capillary filling effect

5. Biocompatibility

• ISO 10993-5 cytotoxicity, ISO 10993-10 skin sensitization testing

Precision micro-pore molding technology for blood glucose meter LSR silicone seals represents the perfect combination of micro-molding process and medical precision requirements, where every micron of control relates to patient health and safety.