A UV hyperspectral camera (covering a wavelength range of 250–490 nm) was used to collect hyperspectral data of plastic film samples.

The collected data underwent preprocessing procedures — including noise reduction and reflectance calculation — using hyperspectral data processing and analysis software.

高光谱数据：

The area within the red frame is the UV adhesive layer region. Based on the observation of original hyperspectral data:

Other materials (non-UV adhesive areas) exhibit ultraviolet (UV) light reflection at the 280 nm band.

The UV adhesive region absorbs UV light (no obvious UV reflection observed at the 280 nm band).

Threshold Segmentation

Threshold Segmentation

The threshold segmentation method was adopted: by distinguishing the acquisition intensity at the 280 nm band, the difference between UV adhesive and other materials can be clearly identified.

However, misidentification of non-UV adhesive materials occurred, which was attributed to three factors:

The camera did not collect integrating sphere data;

Uniformity correction was not performed;

The UV lamp had uneven illumination and insufficient intensity.

Conclusions

From the original spectral curves, it is possible to clearly distinguish whether a sample has been coated with UV adhesive.

The threshold segmentation algorithm enables relatively intuitive identification of UV adhesive.

Key Issues Identified

The UV light source has a limited spectral band range and a small illumination area.

Uniformity correction was not conducted before data collection.

The feasibility of identifying other types of adhesives (beyond UV adhesive) remains untested.

The impact of UV adhesive coating thickness on its light absorption performance is unclear.

Next Steps

Optimize the data collection environment: adopt a multi-band UV light source and expand the illumination area.

Perform uniformity correction prior to data collection.

Conduct identification tests using other types of adhesives to verify the method’s applicability.

Validate the impact of different coating thicknesses on absorption by testing samples with varying UV adhesive thicknesses.

Key Translation Notes