Ultrasonic welding success cannot be judged by a single indicator. It requires multi-faceted testing through appearance, dimensional measurements, mechanical strength, and functionality tests to ensure that the welding quality is stable and meets design requirements.

1. Visual Inspection

The most basic and quickest way to make an initial judgment.
Key inspection points include:

• Welding line: Should be continuous, uniform, and complete.

• Flash (excess material): Check for excessive flash or uneven melting.

• Surface issues: Look for burnt, whitened, or deformed areas on the housing.

• Symmetry: The welded area should be symmetric without any noticeable displacement.

👉 Judgment Principle: High consistency in appearance typically indicates stable welding energy and structural design.

2. Dimensional Measurement

Use measurements of the post-welding dimensions to confirm process repeatability.
Common tests include:

• Post-welding height: Should match the design value.

• Collapse distance: Must be consistent.

• Welding depth: Check if it remains stable.

👉 Judgment Principle: Minimal dimensional variation indicates a controlled welding process. Large differences may point to unstable energy or fixture issues.

3. Mechanical Strength Test

Verifies if the welding joint meets the required strength.
Common tests include:

• Tensile test: Measures the pulling strength.

• Shear test: Assesses resistance to shear forces.

• Bending or twisting tests: As required by the product.

👉 Judgment Principle: The welding strength should meet design specifications, and the failure mode should match the intended performance.

4. Sealing Test

Applicable for products requiring airtight or watertight seals.
Common methods include:

• Leak test: Checks for any leakage.

• Pressure hold test: Verifies if pressure remains stable over time.

• Water immersion test: For waterproofing applications, depending on the design.

👉 Judgment Principle: No pressure decay or leakage within the specified time indicates a well-formed welding interface.

5. Destructive Test

This is the final test for confirming welding quality (typically performed on samples).
Key check points include:

• Failure location: The failure should occur in the base material, not at the welding interface.

• Weld quality: Ensure sufficient melting and bonding at the weld zone.

• Problems like unmelting, delamination, or brittleness: Should not be present.

👉 Judgment Principle: The ideal failure mode should be "base material failure," which means the welding strength is equal to or better than the base material.

6. Process Data Monitoring (Advanced Quality Control)

In mass production or high-spec products, equipment data monitoring is commonly used to determine success.
Items to monitor include:

• Actual input energy: Ensures correct energy input during welding.

• Welding time and displacement curves: Monitors the timing and movement during welding.

• Amplitude and power variations: Ensures consistent energy delivery.

👉 With a Closed-Loop ultrasonic welding system (T-sonic iS Series, iX Series), suspicious defective products can be detected in real time, improving process monitoring and traceability.

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📌 Comprehensive Criteria for Judging Welding Success:

A successful ultrasonic weld should meet the following criteria:

• Consistent appearance.

• Stable dimensions.

• Strength that meets or exceeds specifications.

• Functional performance is within acceptable limits.

• Failure mode is reasonable (base material failure).