The pre-separator (1) has a base frame (4) provided with an opening (5). Swirl segments are spaced from each other and are oriented horizontally or vertically. The pre-separator is made of plastic, which possesses characteristics such that dye and color are removably and/or detachably adhered. The base frame is provided with a stop edge. The swirl segments are provided in the opening. A bonded-fiber filter (13) is provided in the opening. The swirl segments extend towards a frame part (11) that is arranged opposite to another frame part (10).
