Method for recycling release sheet

A release liner recycling method, comprising:

• supplying a resin sheet laminate to a user company, the resin sheet laminate comprising:
• an adhesive sheet having an adhesive layer;
• and a release liner adhering to the adhesive sheet, the release liner having a first surface on which a release layer is formed and a second surface opposite to the first surface and having a base made of a resin material;
• collecting a used release liner peeled from the resin sheet laminate from the user company in any form selected from a rolled sheet or a cut sheet using a collection bin;
• determining, as a determination step, whether a contained item in the collection bin collected from the user company is the used release liner by conducting a sorting inspection of the contained item;
• removing foreign matter determined not to be the used release liner in the determination step from the contained item in the collection bin;
• and
• recycling the used release liner into a resin raw material,
• the determination step including an analysis test of determining whether the contained item is the used release liner by utilizing visible light, infrared light, or ultrasonic waves, using an analysis system equipped with a storage unit, an irradiation unit, a detection unit, and a determination unit,
• the analysis test including:
• a sub-step of detecting, by the detection unit, the visible light, the infrared light, or the ultrasonic waves emitted from the irradiation unit to the contained item and reflected from the contained item or transmitted through the contained item;
• and
• a sub-step of determining whether the contained item is the used release liner by checking in the determination unit whether a detection result by the detection unit matches a composition of the release liner stored in the storage unit in advance.