Verifying Inorganic Filler Concentrations in Foreign Masterbatches Crossing Trade Borders
Verify masterbatch ash content via ISO 3451 calcination at 600°C to protect duty lines, catch mineral substitution, and prevent process failures.
ATR Mode
Meaning
Surface reflectance sampling captures infrared spectra directly from solid polymer parts without requiring solvent dissolution or thin film pressing. Analysis executed in atr mode relies on an internal reflection element pressing against the sample surface to generate evanescent waves. The method applies to molded parts, elastomer seals and multilayer films, stopping where bulk internal composition rather than surface chemistry must be measured.
Crystal Contact
High refractive index crystals made of diamond, germanium or zinc selenide transmit infrared radiation while maintaining contact with the polymer specimen. Operating in atr mode demands physical force to ensure intimate optical contact across rigid plastic surfaces. Insufficient pressure introduces air gaps that distort spectral peak intensity and baseline stability.
Depth Penetration
Infrared beam penetration reaches depths between zero point five and two microns into the polymer matrix. Sampling through atr mode isolates skin layer orientation and surface additive blooming from bulk resin chemistry. Shallow penetration prevents heavy filler particles embedded deep in the core from overwhelming surface spectra.
Surface Degradation
Chemical modifications resulting from ultraviolet exposure or thermal oxidation show up clearly during reflection measurements. Utilizing atr mode allows quality control technicians to inspect degraded part surfaces for carbonyl formation and crosslinking. Identifying localized degradation assists in diagnosing part failure during outdoor exposure testing.