層壓 (台灣稱作護貝，香港稱作過膠) 是指人們將多層不同的材料通過熱能、壓力、焊接、黏合劑、壓力機等手段拼合在一起的過程，目的是改善物體的強度、隔音性、外觀或其他性能[1]。而在紙上表面包上一塊薄塑膠（或者其他物質）膜的過程，則叫塑封或覆膜。它可以起到保護紙張的作用。
參考文獻
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