Paper arrives from the mill in jumbo “parent” rolls – imagine an 8-foot-wide, one-ton spool of paper or linerboard. These giant rolls are too big for most printers or packaging machines. That’s where paper slitting and rewinding come in: specialized converting machines slice those parent rolls into narrower rolls that are easy to handle. In simple terms, a slitter rewinder unwinds a huge roll, cuts (slits) the web to the desired widths, then rewinds the strips onto new cores. This process is essential for converting large parent rolls of paper into more manageable sizes suitable for various applications. Modern slitter-rewinders can handle a wide range of materials – not just paper. They process everything from kraft and linerboard (heavy packaging grades) to thin printing papers , even films and foils. For example, Cauthorne’s machines will happily slit thick brown kraft paper (used for bag-making or interleaving), sturdy linerboard, or lightweight coated print stock. The key is versatility : by changing blades and settings, the same machine can tailor rolls of chipboard, tissue, waxed paper, and more. In fact, paper slitting machines are capable of processing various types of paper and flexible materials, including paperboard, film, foil, nonwovens, and laminates. This means whether you need narrow rolls of release liner for tape, long sheets of kraft for insulation, or standard print rolls, slitting/rewinding has you covered. A slitter-rewinder machine processing a giant roll of paper. The unwound web will be cut by blades and rewound into smaller-diameter rolls. The slitting & rewinding process works in three main steps: Unwinding: A giant parent roll is mounted on the machine’s unwind shaft. Heavy-duty arms or powered shafts support the roll. The web (paper) is pulled off the roll at speed. Slitting: As the web unwinds, it passes through a row of precise knives. These circular or razor blades slice the web along its length into narrower strips. For thin printing stocks, razor blades quickly and cleanly cut the paper. For heavier board or kraft, heavier-duty shear blades (like scissors) may be used. (Shear slitting uses top-and-bottom circular knives and is ideal for very thick or tough materials.) The number of knives (and cut widths) is fully adjustable. Rewinding: After slitting, each cut strip of paper is immediately rewound onto a new core. Multiple rewind shafts (sometimes on a rotating turret) allow continuous operation: one roll winds while the next core is loaded. Tension controls and guide rollers keep the roll tight and even. When finished, you end up with many smaller rolls – each the exact width and diameter the customer needs. Aside from slitting, these machines often include trim slitting and other finishing. Trim slitting cleans up the edges, and center perforation or embossing units can add features. Safety covers and sensors ensure operators stay protected. Today’s slitter-rewinders are often computerized, so an operator can dial in exact widths (even to 0.001″ tolerance), automatically align edges, and monitor tension. The result of slitting and rewinding is a variety of customer-ready rolls. For example, a corrugated box maker might need 24-inch-wide rolls of linerboard from a 100-inch jumbo parent roll. The slitter-rewinder would slice that roll into four 24″ rolls (with a bit of trim) and rewind them to new cores. Each new roll can be any length or diameter; Cauthorne’s equipment lets us rewind to custom lengths or roll sizes. This custom slitting is a key part of our paper cutting services – it saves customers the cost and hassle of buying oversized material and then cutting it themselves.