Dandy roll is intended for an installation in PM wire parts. It is designed for improvement of the surface quality especially of printing papers. Usually, it is installed between suction boxes. The dandy roll location depends on a required type of produced paper.
Pneumatic guides PR are designed for paper machines wires and felts run regulation or for a contingent regulation of other endless belts. The regulation itself consists of a pneumatically controlled sensor with a vane and of a pneumatic circuit.
Shaker is used for better felting of paper and for reaching of higher paper strength. Fibres coming on the wire from headbox are formed in longitudinal machine axis direction. This fact could cause very low cross strength of the paper.
Low-pressure shower NOT is used for wires and felts cleaning and conditioning. They influence considerably the felt and screen life time, PM productivity, the quality of paper produced and the energy consumption.
Suction box is a weldment made of stainless steel. It is fixed to the beams with stands which enable a height adjustment of the box with respect to a possible wearing of the lining. The cover can be made of polyethylene or ceramics and its height ranges from 30 to 40 mm.
Suction tube is used for a mechanical or chemical cleaning of PM wires and felts. By means of an underpressure, it sucks out the given cleaning medium (water, chemicals) that is consequently led through suction piping outside the paper machine.
Threading and trimming water jet is designed for trimming of paper web edges in the PM wire part and for making a tail for its threading in a PM press and drying parts. It is also used for fast paper web cutting in case of a web break. A standard design consists of one threading water jet (in case of the web break) and two trimming water jets. Trimming water jets are intended for a paper web trimming to a required size.
Two - wire formers are used for more intensive stock dewatering and improving of paper parameters. Top former with endless wire is used to be installed above the bottom wire board with the endless wire. Top former is installed on new and reconstructed paper machines as well.
Vibrating screen VP is designed for screening in lines for processing of chemical pulp, ground wood and waste paper where it is used mainly as an end part for final sorting of the reject from screening stages. An advantage of this screen is its open design; the stock can be seen while being screened.
An optimal wire tension is one of basic prerequisites for an efficient PM wire part operation. An insufficiently stretched wire may bring a driving roll slippage followed by an abnormal wearing both of the wire and of the driving roll and possibly of the suction couch roll.
The wire part of the PM serves for stock dewatering and consequently it transforms the stock into the “paper sheet“. The stock goes out of the headbox on a longitudinal endless wire where the paper stock is dewatered so that the fibres settles down on the wire surface.