SIG Automatic Vision Measuring Machine: Efficient Solution for Precision Measurement of White Injection Molded Parts

Introduction
White injection molded parts are widely used in medical consumables, 3C electronic housings, automotive lamp covers, clips, and connectors. However, their highly reflective nature poses a typical challenge in dimensional inspection – conventional optical equipment suffers from low imaging contrast and unstable edge detection, while manual measurement is inefficient. SIG’s automatic Vision Measuring Machine (OMM) delivers an efficient, accurate, and stable solution for full-dimension inspection of white plastic parts, thanks to its multi-angle programmable illumination system and intelligent image processing algorithms.

I. What Are the Measurement Challenges of White Plastic Parts?

White plastic parts are extremely common in manufacturing – from precision holes of disposable infusion connectors, to white plastic housings of electronic products, curved surfaces of automotive lamp covers, and various white clips, connector shells, etc. However, this “white” characteristic brings significant difficulties to optical measurement.

White plastic surfaces scatter most light. Although the reflected signal is strong, severe diffuse reflection causes insufficient edge contrast in imaging. Specifically, the challenges include:

• Low imaging contrast, unstable edge detection – Under conventional optical measurement, the grayscale difference between the white plastic surface and the background is small, leading to edge drift or instability. Even simple blind hole dimensions become difficult to measure.
• Severe interference from curved surface reflections – Smooth white plastic parts tend to generate reflective areas on curved surfaces, which can be misidentified as defects or edges by image processing, compromising measurement reliability.
• Thin-walled parts deform easily, limiting contact measurement – Most white plastic parts have thin walls. Traditional contact CMM or caliper measurements can cause part deformation, resulting in data distortion.
• Low efficiency in batch inspection – White injection molded parts are often produced in high volumes with many dimensions to check. Relying on manual calipers or projectors is time-consuming and subject to human errors like missed defects or misjudgment.

II. SIG’s Technical Advantages: Precisely Overcoming White Material Imaging Difficulties

To solve the optical measurement challenges of white plastic parts, SIG’s automatic Vision Measuring System (OMM) has been systematically optimized in three aspects: illumination configuration, optical system, and image algorithms.

① Multi-Angle Programmable Illumination System to Enhance Imaging Contrast

White plastic surfaces scatter light; a single ordinary light source cannot produce a clear edge contour. SIG’s system is equipped with a ring LED cold light source, coaxial light, and programmable contour light – all adjustable. Operators can flexibly change the intensity and angle of each light to highlight the edge features of white parts. This technique has been proven effective: by combining a high-precision upper ring light, it solves the low-contrast imaging issue, enabling precise edge detection and high repeatability.

② High-Resolution Optical System & Sub-Pixel Edge Detection for Micron-Level Accuracy

The instrument features a high-resolution color industrial CCD camera, optical zoom lens, and high-precision glass scales (resolution 0.1 μm). Together with a sub-pixel edge detection algorithm, it achieves micron-level accuracy in standard environments, with repeatability up to ±1.5 μm. This ensures that even fine features of white plastic parts are clearly captured and accurately measured.

③ Non-Contact, Non-Destructive Measurement for Thin-Walled White Plastic Parts

Given the thin-wall and deformable nature of white plastic parts, SIG’s Video Measuring System uses non-contact optical measurement. No stylus touches the part surface, and edge measurement is completed in milliseconds, avoiding deformation errors from physical contact. The system can also be optionally equipped with a line laser probe for 3D contour scanning, accurately measuring flatness, step height differences, and other geometric dimensions.

④ CNC Fully Automatic Batch Measurement for Dramatically Improved Efficiency

SIG’s fully automatic OMM (Optical Measuring Machine) features CNC capabilities. Operators simply press “Start,” and the machine automatically executes batch measurements along pre-programmed paths. Single-part inspection time is reduced to seconds. On injection molding production lines, the system supports testing speeds of dozens of parts per minute – about 20 times faster than manual inspection (based on actual production line tests), while significantly reducing missed defects and false alarms. Measurement results are automatically uploaded and generate SPC statistical analysis reports, allowing real-time monitoring of process capability and early warning of batch quality risks.

III. What Can It Measure? – Comprehensive Coverage of Key Dimensions for White Plastic Parts

SIG’s automatic Vision Measuring Machine (OMM) accurately measures the following critical parameters for various white injection molded parts:

1. Hole Accuracy & Position Tolerance

Common features such as through holes, blind holes, and clip holes in white plastic parts can be precisely measured for diameter, position, and center distance. For parts with multiple holes, array automatic inspection is supported, ensuring alignment accuracy for quick connectors, mounting bases, etc.

2. Contour Dimensions & Geometric Tolerances

One-click measurement of length, width, angle, radius, etc. Direct CAD comparison quickly verifies compliance with design drawings. The system also performs accurate GD&T evaluations including parallelism, perpendicularity, symmetry, position, and concentricity on white plastic parts.

3. Flatness & Height Difference (Optional Laser Probe)

For 3D features such as base flatness, step heights, and clip heights, the optional line laser probe enables non-contact scanning of the part’s 3D contour. Output color deviation maps visually highlight deformed areas, helping to accurately evaluate assembly flatness.

4. Complex Surfaces & Irregular Contours

Curved surfaces (e.g., automotive lamp covers) and irregular contours of white plastic parts are quickly verified using non-contact optical scanning. Widely applicable to 3C electronic housings, automotive interior/exterior trim parts, and more.

5. Special Inspection for Transparent or Translucent White Plastic Parts

For partially transparent or translucent white plastic parts, SIG’s system optimizes illumination and image processing algorithms to suppress multiple reflection interference. It accurately assesses surface smoothness and internal bubbles, meeting the high standards of medical consumables, optical instruments, and other demanding applications.

IV. What Problems Does It Solve? – Empowering Quality Improvement Across the Production Process

1. Solves the “Can’t See Clearly, Can’t Measure Accurately” Imaging Problem for White Materials

Through the synergy of multi-angle programmable lighting and sub-pixel algorithms, SIG’s system breaks the low-contrast imaging bottleneck. White workpieces now achieve clear, stable edge contours for precise measurement.

2. Eliminates Deformation Risk from Contact Measurement on Thin-Walled Parts

Non-contact optical measurement avoids stylus contact, effectively preventing deformation of thin-walled white plastic parts. Measurement results are truly reliable.

3. Significantly Improves Batch Inspection Efficiency, Enabling Full Inspection on Production Lines

Upgrading from manual single-part inspection to CNC fully automatic batch measurement reduces single-part inspection time to seconds. This helps companies move from “sampling inspection” to “100% inspection,” reducing the risk of batch defects.

4. Enables Data Traceability to Support Continuous Process Optimization

The system automatically generates illustrated inspection reports and SPC statistical analysis reports. It can be integrated with MES systems, making quality data fully traceable. This provides reliable data support for mold wear analysis and injection process parameter adjustments, shortening development cycles by more than 30%.

V. Multi-Industry Applications

SIG’s automatic Vision Measuring System (OMM) serves the precision dimensional inspection of various white injection molded parts across industries:

• Medical Consumables – Hole accuracy and surface quality inspection of white plastic parts such as disposable infusion connectors and tubing adapters, meeting high-throughput, high-standard quality control requirements.
• 3C Electronics – Contour measurement and position verification of cell phone white plastic frames, electronic connector shells, sensor holders, etc.
• Automotive Parts – Dimensional control of lamp cover curved surfaces, interior white clips, hose connectors, and other critical components.
• Automation Equipment – Batch quality inspection and full dimension measurement of pneumatic quick connectors, solenoid valve accessories, isolation pillars, and other white plastic parts.

Conclusion

Precision measurement of white plastic parts is no longer a forbidden zone for optical inspection. SIG’s automatic Geometric Dimension Measurement (GD&T) system, with its multi-angle programmable illumination, high-precision optics, and intelligent image algorithms, provides comprehensive measurement capabilities – from basic dimensions to complex GD&T – for white plastic parts. It helps manufacturers overcome measurement difficulties, improve inspection efficiency, and achieve quality upgrades.

For more information on SIG automatic vision measuring machine models, technical specifications, or application cases, please visit Sinowon’s official website: www.sinowon.com or call +86-769-23184144.