拉鍊的微粒穿透特性

Abstract

微粒防護衣可以保護使用者避免危害物質與皮膚接觸，有研究指出微粒防護衣在衣材結合處有洩漏的情形，在所有連結衣物的配件中，拉鍊佔了80%以上，但在氣膠微粒穿透率上卻尚未有詳細的規範，因此，本研究目的為探討拉鍊的微粒穿透特性。 現今常用的拉鍊鍊齒材質主要分為金屬、尼龍和塑鋼三種，從氣膠微粒穿透的觀點而言，依鍊齒嵌合結構可大致分為單純鍊齒嵌合(金屬和塑鋼)及鍊齒加上縫線與布帶組成(尼龍)兩種進行實驗探討，另外本研究又依尼龍拉鍊布帶是否完全覆蓋鍊齒分為Tape A與Tape B兩種。拉鍊鍊齒的嵌合無法完全互補，因而造成鍊齒之間有孔洞，且孔洞的大小與形狀隨著鍊齒結構不同而改變，本研究統一以等效直徑(De)呈現孔洞的大小。測試拉鍊穿透率表現的方法為主動式採樣法、內循環採樣法及螢光微粒測試方法。 研究結果發現，孔洞De越大，氣膠微粒穿透率也越高，反之亦然，但與鍊齒型號大小無關。孔洞De很接近的情況之下，金屬拉鍊與塑鋼拉鍊穿透率表現會與上述趨勢相反，因為氣流流經拉鍊的路徑也會造成影響。尼龍拉鍊Tape A的微粒穿透率較Tape B低，而Tape A背面(布帶面朝前)的穿透率又低於正面(鍊齒面朝前)。微粒防護衣若使用尼龍拉鍊，建議使用背面將有更佳的防護效果。本研究中穿透率最低的拉鍊為型號#5的塑鋼拉鍊，但是依照搭配的防護衣阻抗不同選擇不同拉鍊搭配才能有最佳的使用效果。

Particulate protective clothing (PPC) is designed to protect workers’ skin from making contact with hazardous substances. It has been shown that PPC provided less protection when the junctions became part of the ensemble. Among the junctions, zippers account for about 80% of all the junction accessories. Therefore, this study aimed to investigate the characteristics of aerosol penetration through zippers. Zippers are commonly categorized into metal, nylon and plastic, based on the materials they are made of. In the present study, metal and plastic zippers were designated as one group for the same appearance and design principle. Nylon zippers were classified as another group according to the structure of zipper chains. The nylon zippers were further divided into two types by whether the chain can be fully covered by the tape (type A) or not (type B). Effective diameter was used to characterize the leak size between teeth of metal and plastic zippers, when the zippers were chained. Active sampling, closed-returned sampling, and fluorescent aerosol methods, developed in previous studies, were employed to measure the aerosol penetration through zippers. The results showed that aerosol penetration through zippers increased with increasing effective diameter for both metal and plastic zippers, but not the size of the zipper teeth. Aerosol penetration through type-A nylon zipper was lower than that in type B because of better tape design. Moreover, aerosol penetration through the back of type-A nylon zipper was lower than that through the front, indicating that the current design of nylon zipper was solely aesthetic thinking. The zippers should be turned around to provide better protection against airborne particles. Extra attention should be paid to the quality control of the zipper manufacturing, since zippers might become the major route of entry of hazardous substances.