细孔

Plastic material is extruded through very small holes to form fibres.

塑料挤压出来形成纤维。

Pinhole. A short unwelded area in the weld line extending through the entire pipe so that fluid will leak out through the area very slowly.

针。指焊缝线上位焊接的、贯穿管子整个壁厚的，可导致流该缓慢漏出。