In Part 1 of our series on the Precision Alignment of Winders we discussed the effects of misalignment on product quality and winder components. In Part 2, we began our discussion on alignment techniques for the various areas of the machine starting with the Unwind and Lead-in Rolls. In Part 3, we continue with more on the alignment of the Slitter Section, Rider Roll Ways, Winder Drums, Rider Roll and Core Chucks.
Winder Inspection and Alignment
As discussed in our first two posts of our series on the Precision Alignment of Winders, it is very important to obtain a good picture of total winder alignment before before making any adjustments. A complete inspection and analysis of the data will provide the best plan for correcting the winder’s misalignment problems.
Inspections in the slitter section are necessary on the blade and band ways, on spreader assemblies such as bowed rolls and D-bars and on sectional rolls. Adjustments are performed, based on the inspection results, to align the components to precise tolerances and to insure that the slitter band penetration into the web is proper.
Slitter roll alignment can be a lengthy process. Both ends of each segment must be inspected to determine overall misalignment and any offsets between the segments. Misalignment exceeding the OEM’s specified tolerances requires correction. Care must be taken as aligning one segment of the roll can have an effect on the alignment of adjacent sections. Care is also necessary during adjustments to prevent roll binding in the bearings and/or between the shells of adjacent segments.
Rider Roll Ways
Inspection of the rider roll ways will determine whether or not they are parallel to each other and plumb in both the machine and cross-machine directions. If the ways are not parallel, the feasibility of adjusting the ways to improve the parallelism should be explored. If the ways are not parallel in either direction, rider roll misalignment will be present at various points of the building of the sets. Likewise, way out of parallelism can cause rider roll beam binding and/or looseness and result in uneven nip pressures on the sets. Any adjustable cam followers on the rider roll beam and core chucks should undergo adjustment for proper clearances to best fit the conditions and alignment of the ways.
Besides aligning the winder drums for the vertical and horizontal attributes, the elevation of the drums is important. For proper operation of the rider roll and core chucks, the plane formed between the top surfaces of the drums should be perpendicular to the ways (see image). For vertical ways, this would involve aligning the drums at the same elevation. For angled ways, the drums are set at different elevations, but the top surfaces form a plane perpendicular to the ways.
The drum gap size is an important consideration when aligning the drums. One should maintain the OEM’s recommended gap during adjustments.
When adjusting the drums, it is also necessary to consider the alignment of the drive components. Inspect and, if necessary, align each drive to its respective drum.
Two aspects of rider roll design offer additional alignment challenges:
- Rider rolls are typically segmented rolls. As discussed above, adjustments can affect the alignment of adjacent segments.
- The rider roll moves up on the ways as the set forms. Similar to the way parallelism mentioned earlier, worn or damaged mechanical components can greatly influence rider roll alignment as the roll travels along the ways.
Each segment of the rider roll requires inspection as discussed earlier for sectional rolls. The inspections are normally performed at the bottom, mid-point and top of its operating range to determine if the rider roll’s alignment changes with position. If the level condition changes, this often means that the chains, sprockets, or both, need replacement. In addition, the roll can be binding as it travels on the ways. If the horizontal alignment changes, this normally indicates way misalignment and/or worn hardware conditions.
After making all necessary hardware changes, the rider roll should then be aligned for both attributes. It is important when performing these adjustments that the rider roll centerline and drum gap centerline remain coincident.
Core chuck inspection typically occurs at selected points through their full range of operation. When aligning the chucks for both attributes, take care to ensure that the core chuck centerlines are coincident with the drum gap centerline.
In our final post of the Precision Alignment of Winders series, we will provide guidelines on tolerances for winder components.