Page 19 - Solutions for Plastic Evaluation

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Surface Structure Product Evaluation

FTIR

Analysis of Film Surface by FTIR-ATR Method
The ATR (attenuated total reflection) method obtains information about a sample surface held closely against a prism. Therefore, it
can be used to obtain information about coating materials, adhesives, or precipitates from within a sample on the sample surfaces, Plastic Materials Evaluation of
without requiring any sampling or other pretreatment processes. The figures below show the results (black) from measuring a
commercial film and ATR spectrum (red) of typical polyethylene sample. This shows that the commercial film product is made of
polyethylene, but it also shows peaks that are not observed in the standard polyethylene. Raw Materials Evaluation of

ATR Measurement Optics with Sample Held Tightly Against Prism Product Evaluation

ATR Spectrum of Commercial Film Product (Black) and ATR
Spectrum of Polyethylene (Red) Product Information
The figure on the right was obtained by removing the commercial film from the prism and measuring only what remained on the
prism. Since the ATR method involves pressing the sample against the prism, substances from the sample surface, precipitates from
within, or other substances can be transferred to the prism. In such cases, information from only the transferred substance can be
obtained by removing the sample and measuring again.
In this case, it was determined that the transferred substance was
a fatty acid amide, such as stearic acid amide. Fatty acid amides
are commonly used as polyethylene smoothing agents, releasing
agents, printing ink additives, or pigment dispersing agents.

ATR Optics for Measuring Transferred Substances ATR Spectrum of Transferred Substances (Black) and ATR Spectrum
of Stearic Acid Amide (Red)

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