The hot rolling consolidation of fiber web is carried out by hot rolling mill. At present, most production lines that mainly produce light and thin products (6 ~ 200g / m2) adopt hot rolling consolidation process.
Under the combined action of the high temperature heat of the roll of the hot rolling mill and the high pressure generated between the two rolls, the polymer fiber web deforms, melts and adheres to each other at the knurling point, and the loose fiber web is consolidated and shaped into a nonwoven fabric with certain strength.
1、 Hot rolling mill and its main components
The hot rolling mill is mainly composed of roll, transmission system, heating system, hydraulic system, cooling system, lubrication system, frame and control system.
1. Roll
Roll is the main component of hot rolling mill. Each hot rolling mill must have at least one pair of rolls, including one engraved roll (flower roll for short) and one smooth roll (smooth roll for short), or two flower rolls and one smooth roll. The roll is made of heat-resistant alloy steel, and the commonly used materials are alloy steel of 38CrMoAl, 42CrMo, 42crmo4v, 60CrMoV, 9Cr2Mo, etc. After heat treatment, the surface hardness of flower roller can reach HRC55 ~ 58 and that of smooth roller can reach hrc58 ~ 62.
The roll is installed on the wall plate type thick steel plate (40 ~ 80mm) frame, and the wall plates on both sides are supported and connected with large cross-section square rods. For most double roll hot rolling mills, the flower roll is usually fixedly installed on the wall panel above the smooth roll, The smooth roller is generally below the flower roller
It is supported by two hydraulic cylinders. Under the control of the hydraulic cylinder, the smooth roller can be raised to press with the flower roller or from the pressure
Tight state separation. The working line pressure can be adjusted by changing the hydraulic oil pressure of the oil cylinder.
The pattern shape, size, depth, distribution density (area percentage, hot melt ratio) and other parameters of the flower roller are closely related to the application field, quantitative size and physical and mechanical properties of the product. For example, when applied in the fields of health, protection, health care, industrial cloth and so on, the commonly used carved point shapes are shown in Figure 13-1, mainly oval and square, and other flower shapes include oblong, cross, straight and so on.
