Before, we introduced the reasons for the edge wave phenomenon in the slitting line. In fact, the edge wave phenomenon is one of the sheet deformations. Today, Bangzhou will introduce to you what are waist creases and wrinkles.

Waist crease 

The through creases produced in the width direction of the steel plate are called waist creases. There are many reasons. Several representative reasons are detailed below:

1. Waist crease produced by the reeling knife: if the outer diameter of the rubber ring on the side of the product is too small, the steel strip will be wound into the knife.

The way to prevent it is to increase the height of the rubber ring as much as possible without producing a knife mark. However, the use of beading in narrow-width and multi-strip processing can effectively prevent curling.

2. Waist crease caused by the shape of the raw material: When the steel coil is stretched in the middle of the steel plate, the waist crease will also be produced on the decoiler. Three rolls are used for leveling and processing to effectively prevent creases.

3. The waist crease produced by the expansion and contraction drum blade of the winder: the first layer of the coil is in close contact with the expansion and contraction drum. Waist creases will occur after expansion. Pay attention to the straight angle of the head of the steel strip when it is cross-cut. The deformed part of the head, such as folding and bending, is shaped with a hammer to make it flat and compact, which can effectively prevent creases.

Take-up printing 

The surface shape of the expansion and contraction drum of the winder, such as the seam of the blade, the unevenness caused by the surface bump, and the imprint caused by the top pressure on the surface of the coiled steel strip. 

Wrinkles 

There are many reasons for wrinkles on the surface of the steel plate:  

1. Wrinkles caused by lining paper: when the lining paper is rolled into the steel coil, the wrinkles of the lining paper and the overlap printing on the steel plate will produce wrinkles. Thin sheets of soft materials are more prone to occur. Adding back tension to the backing paper can prevent the backing paper from wrinkles. Adding a divider can also prevent wrinkles caused by overlap.

2. Wrinkles caused by the rubber ring: The rubber ring, spring, etc., which are equipped with the knife on the slitting machine shaft, are slack, have gaps, the back tension from the uncoiler is too strong, and the side guide is too tight, etc., will cause longitudinal wrinkles. When slitting thin plates, the knives should be as close as possible without gaps to prevent such wrinkles. When processing thin plates, it is better to use a bead than a rubber ring.

3. Wrinkles caused by improper adjustment of tension pressure plate: Wrinkles caused by excessive tension at both ends of the plate and loose middle winding operation. Winding after setting the same tension in the width direction can prevent such wrinkles.

Wuxi Bangzhou Machinery Manufacturing Co., Ltd. is a company specialized in steel coil straightening machine, slitting line, cut to length line and flat bar straightening and chamfering machine. Our company is a professional slitting machine manufacturer. If you are interested in slitting machines, don’t hesitate to contact with us.