Reel-slitting

The paper has by now been dried down to 3 4% water content. It is then conditioned to 7-10% water so that the paper is no longer brittle, prior to reeling. The reels are stored on end on skillets under covered conditions, until needed for reel slitting and/or sheeting. 

The objective of reel-slitting is to convert the large parent reels (machine reels, jumbo reels) from the paper machine into suitable size rolls which can be either sent directly to the end-user, e. g. a printer, or receive further mill-internal treatment such as sheeting. 

The machine on which reel slitting is done is commonly called a winder. Basically, wunders consist of equipment for parent roll change, an un-wind station for the parent rolls, a slitting station and a rewind station. 

After the lubricant is removed, the tape is slit to the desired width by leading it under a slight tension over stationary or rotating cutting blades. The slit tape is reeled onto small spools. An outline of the process is shown in Figure 4.11. 

Figure 7.27 Slip-casting process showing the addition of a drying zone, to remove the slip liquid, cutting or slitting and tape-takeup reels.

The lay-flat film is then either kept as such or the edges of the lay-flat are slit off to produce two flat film sheets and wound up onto reels. If kept as lay-flat, the tube of film is made into bags by sealing across the width of film and cutting or perforating to make each bag. This is done either in line with the blown film process or at a later stage. 

I was still reeling from the shock of change. Selden Manor had been a hellish place of silence and isolation, but still I couldn t take in the tumult and enclosure of the city. When I saw the parrot, I found myself thinking. My father will be interested in that bird. He will test its green feathers to discover the nature of their pigment, measure its cranium to see how it compares with other, less-able birds, and when it dies slit its little throat to examine its larynx. 

All paper merchants market the papers and boards to users many convert the paper or board into a form in which it can be used directly. The latter type of merchant has substantial quantities of machinery to slit the jumbo reels down for reel-fed printing equipment or slit, sheet and pack for sheet-fed equipment. The slit reels are usually delivered on end to the printer, but the sheets could be anything from packed on special skillets to wrapped in Kraft paper parcels. 

Most films are flexible and fairly strong. Some resist tear but usually tear easily once a tear point is initiated (slit, V-shaped notch, etc.). Most plastic films remain reasonably consistent for several years under reasonable storage conditions. Films generally age more rapidly when exposed and not in reels. 

Taking a reel of material with regular cross-direction slits (as used on Servac suppository machine). A male/female mechanical forming operation is carried out between each slit. This mechanical operation forms the foil and the slit area moves (opens), thereby preventing any high degree of stress (uses 12.5 bm OPP/40 bm foil/HSL). 

Machines for automatic winding of blown and cast film, which includes winding and slitting, are available they handle all types, widths, and thicknesses, and different winding characteristics, produce different reel diameters on various core sizes, and divide film webs into different lane widths during production. Reel changes are automatic, and reel production can continue for one or two shifts without operator intervention, because of the incorporation of a reel-bar storage system. 

Another factor is the size of the coils being rewound in relation to their strand width. In the Introduction, we mentioned slitting a 0.020-in.-wide strip. This width strip typically is rewound with the use of an oscillating rewinder for each strand, as it is virtually impossible to rewind it in pancake form. However, if the strip is 0.060-0.187 in. wide, you may consider utilizing cardboard reels or dedicated plastic spools. 

Having now mixed, coated, calendered, and slit the tape into the appropriate lengths and widths, the final task is to load and assemble the cassettes or to add flanges to reels. 

There is a choice of several winding systems. For lines with a line speed less than 200—400 m/min, a winder with inline slitting is normally used. Thus, a web of the required width and length is directly produced in the winder. The edge trim can be fed into a recycling extruder and from there into the main extruder. For lines with a higher line speed, a jumbo-reel winder with a slitter rewinder unit is used. The non woven is reeled by the jumbo-reel winder to a diameter of up to 3.5 m, and this reel is rewound and slit to the required lengths and cut sizes in the slitter rewinder. 

Winders have a series of basic operations in common, e. g. unwinding, slitting, reel and set change etc. These operations will be reviewed in the following. Later, special attention wiU be paid to the various winder types and their suitability for obtaining optimum winding results for the main paper grades. 

Figure 10 depicts a t5 ical production process for cylindrical cells. The winding operation uses reels of anode and cathode from the coating, calendaring and slitting operations. The size of the reels is determined largely by the ability of the operator to lift and position them on the winding machine and the desire for continuous operation. The process for fabricating prismatic cells is very similar to that for cylindrical cells and is shown in Figure 11. Each manufacturer has proprietary methodology to implement each of the cell fabrication steps.

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