I've seen a video on TV about all the big piles of clothes which were over produced by companies, then thrown into incinerators to be burned.
この場合、次のような言い方ができますよ。
ーI've seen a video on TV about all the big piles of clothes which were over produced by companies, then thrown into incinerators to be burned.
「過剰生産された洋服の大きな山が焼却炉に投げ入れられ燃やされる映像をテレビで見たことがある」
clothes which were over produced「過剰生産された洋服」
incinerators「焼却炉」
ご参考まで！
カナダ 
