Rolls arrangement

Figure 7.11 Some basic types of roll arrangements (a) two-high, (b) three-high, (c) four-high, (d) cluster, (e) tandem rolling with three stands, and (f) planetary milling. McGraw-Hill Encyclopedia of Science and Technology, Vol. 11, 8th ed., p. 54. Copyright 1997 by McGraw-HiU.

Different roll coating methods and roll arrangements S = steel roll, R = rubber-covered roll, E = engraved roll. (Courtesy of Faustel Corporation.)... 

As the machine speed has continuously has increased the dynamic forces to the web have increased and it has forced to support the web with felts to avoid web breaks. Before 30 s typically the web had open draw between press and wire section which was soon replaced with pick-up suction roll arrangement. In this arrangement web is picked up with a suction roll from wire and supported by press felt to the first nip. Most recent fast paper machines are using the same principle of suction roll and supporting fabric not only through press but also through dryer section. 

The Z-type roll arrangements followed developments in offset rolls. This design eliminated the floating No. 3 roll on a calender fitted with bearings. Each roll can be preloaded on to its bearings at a point that is... 

This allotrope, first described by several authors in the late nineteenth century, occurs as light-yellow, nacreous-glittering, needle-like prismatic crystals (for details see [8, 78]). There was some confusion in the literature about the crystallographic structure until Watanabe in 1974 reported a complete determination of the structure of y-Sg [8, 29]. The most recent and accurate structure data of chemically prepared y-Sg are those of Gallacher and Pinkerton in 1993 [30a] and of natural y-Sg (rosickyite) are those of Meisser et al. [30b]. The sheared penny roll arrangement of the Sg molecules in this allotrope (see Fig. 8), which has been presented earlier by De Haan [92], was... 

Different roll coating methods and roll arrangements... 

Roll arrangement Design Bearings Antifriction (ball/roller) Sleeve... 

Figure 11.11 Planar extension in four-roll arrangement...

Request good setup charts showing the final roll arrangement (after the setup test is completed). 

Z-Calender n. A calender with four rolls arranged so that, as the web of material (fabric) passes through them, the cross section of its path has a shape resembling the letter Z. 

The PVC film industry uses two dominant types of calender and roll arrangements depending on whether the material is rigid or flexible PVC. Rigid PVC manufacturers prefer the L-conflguration with four to seven roUs. The most common calender for flexible PVC is a four-roll inverted L- or F-type. This enables the plasticizer-saturated vapors to be drawn to the suction hood above the calender and be filtered and removed before reaching the atmosphere. 

In roll forming, a sheet of material is formed into some desired shape by feeding it through successive pairs of rolls, arranged normally in tandem. It is demonstrated in the chapter Roll forming of composite sheets that this process is also a very suitable method for producing, e.g. thin-walled U- or Z-profiles out of Twintex material. 

Fig. 3. Random card roll arrangements designed for (a) lightweight nonwovens and (b) highloft nonwovens.

After slitting, the partial webs have to be separated. Any overlap is unacceptable. The extent of separation is 0.2 to 0.5 mm. In order to achieve proper separation, winders are featured with a spreader device consisting, as a rule, of two spreader rolls arranged parallel to each other (Fig. 8.3). 

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