| 摘要 |
To solve the problem of damage resulting from the presence of fibrils or lint in a membrane which uses multifilaments that arise in the prior art, the present invention comprises: a further improved membrane, in which an open-weave knitwork is spirally manufactured using a monofilament, and then the spirally manufactured open-weave knitwork is embedded into a polymer resin. The open-weave knitwork is characterized in that it is woven at a certain angle by each monofilament so as to form either a rhomboid shape or a diamond shape. The monofilament is woven on a plasticized PVA cable so as to form a knitwork, and a polymer dope for a membrane is coated on the knitwork, thereby embedding the knitwork into the polymer. The dope is then coagulated. Here, the plasticized PVA cable determines the inner diameter of the membrane. The membrane, into which the open knitwork formed as described above is embedded, is expandable (extendable) in the lengthwise direction thereof, and is expandable in the radial direction thereof, such that the membrane is biaxially expandable (extendable). That is, the membrane is flexible in the radial direction thereof and in the lengthwise direction thereof. The radial flexibility of the membrane enables the latter to be backwashed at a greater pressure than can a membrane using a multifilament in which radial expansion is nearly impossible, so as to improve backwashing efficiency. |
