Emery Cloth: Graded Grit Between a Make Coat and a Size Coat

Emery cloth is a coated abrasive: grains of emery, a natural abrasive used for polishing metal, glued to one face of a cloth backing. Cloth is chosen over paper where durability matters. The grit is graded to one size, glued down with a make coat, and locked in with a second size coat. Hide glue is the traditional adhesive; it does not stand the heat of machine sanding and is not waterproof, so resin is used where that matters. Closed-coat cloth has 90–95% of its face covered with grain, open-coat 50–70%, which clogs less on soft materials.

متوسط

Factory process

التعليمات

Crush and grade the grit

Crush the emery, then sort it to one size: pass coarse grit through successively finer sieves, separate medium grit by air classification, and the finest by water classification, letting particles settle in a tank by how fast they sink.

المواد لهذه الخطوة:

صخر السنباذج1 as required

الأدوات المطلوبة:

كسّارة صخور

طقم مناخل (فتحات متدرّجة)

مصنِّف هوائي

خزّان الترسيب

Make coat

Run the long ribbon of cloth backing through the coating line and coat one face with adhesive, the make coat that will bind the grit to the cloth.

المواد لهذه الخطوة:

قماش قطني1 as required

غراء الجلد الحيواني1 as required

الأدوات المطلوبة:

خط طلاء المواد الكاشطة

Coat with grit

Drop the graded grit on to the wet make coat (gravity coating), or pass backing and grit through an electric field so the charged grit is drawn on to the backing (electrostatic coating), which holds it more strongly. Cover 90–95% of the surface for closed coat or 50–70% for open coat.

الأدوات المطلوبة:

خط طلاء المواد الكاشطة