Customs Act Article 56

I. Raw materials imported for use in manufacturing articles intended for export may be exempt from duty if they are re-exported within one year following the date of release for entry, and are approved by the MOF within one year following the day on which the raw materials were released for entry.II.The application for exemption for the re-exported raw materials referred to in the preceding paragraph shall be submitted within six months following the date of exportation.
中文原文 關稅法第56條
進口供加工外銷之原料,於該原料進口放行之翌日起一年內,經財政部核准復運出口者,免稅。
前項復運出口之原料,其免稅手續應在出口日之翌日起六個月內申請辦理。

English translation for reference only; the Chinese text prevails. Not legal advice.