Combination metallic and nonmetallic cloths consist of metallic wires and weak cloth or asbestos threads. There are some difficulties in weaving when attempting to maintain uniformity between wires and the cloth, and considerable dissatisfaction has been experienced with such construction. While cotton weaves well with the asbestos, the cotton fibers destroy the fabric's resistance to heat and corrosion. Its use is, therefore, quite limited, despite its resistance to high temperatures, acids and mildew.
Cotton cloths are sometimes treated with metallic salts (copper sulfate) to improve their corrosion-resistant qualities. Such cloths are in the usual cotton filter cloth grades, and while they are not equivalent to metallic cloths, the treatment does materially prolong the life of the cotton fiber. When dealing with metallic cloths, the following terms are important:
Mesh - Number of openings per lineal inch. Measured from the center of wires. The number of openings precedes the word "mesh".
Wire - The diameter of wire used in weaving cloth measured by gauge or decimal inch.
Opening - The size of clear opening between parallel wires. For a given mesh, the space is determined by the diameter of wire used.
Woven wire cloth is available in a broad range of alloys with mesh counts as coarse as 1" in most alloys and as fine as 635 in some alloys. The following is a list of alloys normally used:
Stainless Steel Type 304 Aluminum
Galvanized Steel Plain Steel Brass Copper
Galvanized Steel Monel 400 Plain Steel
Stainless Steel Type 304 Stainless Steel Type 321 Stainless Steel Type 347 Stainless Steel Type 430
High Temperature Alloys
Precious Metals Stainless Steel Type 316 Stainless Steel Type 330 Stainless Steel Type 410
Was this article helpful?