The manner which produces the filter, and the filter which are produced the even expanded metal which possesses variable pitch, the production manner, making use of the expanded metal

摘要

Nesting in a metal filter is reduced by using a variable opening pitch expanded metal sheet having different spacings between adjacent rows of openings. Such a filter is made by varying the rate at which the sheet is fed through the equipment, the rate of punching, the amount of stretching, and/or the amount by which the sheet is optionally flattened. The expanded metal sheet is useful in making filters for automobile airbag inflators. Nesting can also be reduced by transversely indexing the punch, using different punch sizes on multiple punches, or combinations of these techniques. The filter can be wire wrapped to enhance its strength.