These are characterized as having the best cake release, the highest flow rates, less likely to blind, and by comparison would have the poorest retention (filter efficiency). The yarns are measured in terms of mil diameter, for example, 6 mil diameter yarns, 8 mil diameter, 12 mil diameter, 15 mil diameter, etc. The larger the mil number, the larger the diameter of the yarn. We might also assure that the smaller the yarn size, the higher the number the threads per inch; therefore, the better the retention and the lower the flow rate probably. The higher the mil diameter, the higher the flow rate, and the poorer the retention.
Monofilament fabrics are woven in satin weaves, twill weaves (2 x2 / 2 x1), and plain weaves.
Monofilament fabrics are finished generally by calendering. Calendering adjusts the permeability as well as setting the weave and implanting stability into the fabric. Calendering can best be described as passing the fabric between two hard rolls and literally squeezing them as in the old style wringer washing machine. In addition to calendering, on of the rolls or both of the rolls may be hot; this tends to soften the yarns somewhat so that it will calender easier with somewhat less stress. Woven monofilament fabrics may initially start at 500 to 600 CFM and may be calendered to as low as 30 and 40 CFM. The high count fabrics, such as, 6 mil yarns may be calendered down to as low as 2 to 3 CFM.
Monofilament fabrics can be found on all major forms of filtration equipment: such as, rotary vacuum drum filters, plate and frame, pan filters, vertical disc filters horizontal vacuum filter belts, etc.
Generally, when we think of monofilament fabrics, we think polypropylene. The vast majority of the fabrics supplied by Menardi are monofilament. However, there are a few polyester and some polyethylene.