Products



Overview

Reels are saleable ones or parent reels (cutreels). The latter are wide reels to be slit again, for re-reelers, folios, cutsheets or laminates for cartons. Optimal widths for parent reels maximize winder efficiency or else, minimal or standard cutreel widths can be enforced.

Beyond width, length and quantity, orders may include factors for trade tolerance, multipack, position and delivery. Zero tolerance has some or all orders filled exactly. Exactness seems desirable, but has unexpected consequences, as explained below, in tutorials and in a special report.
Reels for sheets in two different diameters can run in the same program, those in one diameter to be used only if they improve results for the other. Free stock can also be included, with or without upper limits.

Stock and order data as well as options can be imported from downloaded files or be entered by hand. Reports are in text file format and include comprehensive as well as detailed cutting plans (reel cards).

Benefits to be gained

Our programs help in solving deckling problems untouched by human hands. Input can come from a data base, while output serves to update files for scheduling and shipping. Yet whether files are fully integrated or not, one can enter data manually, to practice, train or explore.

The optimizer should soon pay for itself in reducing stock usage, with current data as they stand. It may pay even more in clarifying various aspects of these data. The optimizer's speed encourages one to explore such aspects, aspects beyond the reach of manual deckling. Thus, if the people currently engaged in deckling fear for their job, one can tell them, "On the contrary, now you can do it effectively!".

Aspects to be explored are summarized below. Some have been elaborated and appear in reports under "Help, Further documentation".

  • Longer shortest runs. One prefers to keep a pattern running more than once and the preference is intuitively clear. Not so clear is the cost of enforcing long runs: if an otherwise optimal plan has single runs and one requires longer ones, more stock is used. Optimal extra usage tends to improve run length as well as setups and surplus, while yet staying well below the amount needed to top up short runs.

  • Multiset. Multiples, of cutreels or patterns. Cutreels must be available at the end of a run in given multiples if so many are to be slit or chopped at once. This is the "multiple on backstand". As for patterns, each may be forced to run as often as exactly fits a stock unit's diameter, without any leftovers. This is "multi-set", 8 for example.

  • Long vs short planning periods. Poor efficiency tends to be due to few orders being on hand. Few data rarely allow one to mix large units with small ones. One should then explore longer planning periods, to combine more data, weighing better deckle efficiency against longer leadtimes.

  • Free or preferred stock. Current orders may involve much broke or short runs. To improve either aspect without further actual orders, one could consider potential orders. Thus broke of 500 mm might be stocked rather than pulped. Yet, if one accepts stock at all, one may prefer reels of 800 or 400 mm. Or again, if 500 mm is feasible, including it as a free size has it listed as such rather than in the waste-column. Preferred or free sizes can be part of the raw data or they can be added after a poor first run, by hand or from a file appended to current data via CutWorks. Either way, one transforms waste into saleable units.

  • Re-reeler reels. Re-reeler reels, compulsory or optional. A narrow reel below a winder's knife settings must be slit on a second machine, necessarily. It will do so optionally if winder knives are wide enough, but too few. Then narrow reels could combine into wide ones on the winder, to be slit in a second pass on a re-reeler. 400s may run as such on a winder, but also as 800s, 1200s or 1600s (plus trim for the second pass): winder efficiency stands against the extra cost of re-reeling.

  • Optimal mix of stock widths. Where several stock widths are available, the optimizer will choose those which best fill current demand. This choice can be extended to examine which stock widths should be on hand. Where the stock's user is its maker, one finds a stock mix to minimize total loss, that of making on the one hand and of deckling on the other.

  • Standard cutreels. A variation of the stock mix problem concerns parent reels or cutreels, those subsequently slit into narrow reels. An optimal plan may use 1820, 1520 and 1220 mm cutreels: what if one allowed only one or two of such sizes? One weighs possibly lower winder efficiency against the benefits of standard reels.

  • Exact vs open-ended orders. A plan with reel numbers exactly as ordered seems desirable. The optimizer tends to yield such numbers because least stock usage leaves little room for surplus. If surplus does occur, it is to reduce waste and setups. Similarly, a few units deficit (explicitly allowed) tend to improve loss, setups and run length.

So, zero tolerance never saves stock, but forces into broke what could be surplus, at best. At worst, it means more setups and shorter runs. Finally, to insist on exact solutions and on long runs risks to make a solution impossible: longer runs yield more surplus.

In short, one can enforce exact reel numbers, but doing so tends to show that one should not. Some people find this hard to accept and need to be convinced, with their own data. So, while exactness is ill advised, the optimizer makes it possible if only for academic reasons.

Similar remarks apply to other options, discussed in the documentation help files.


CutWorks / CutPlan

The classic cutting stock problem is illustrated by the plans below. They yield 600 reels of 800 mm and 700 of 700:

            Plan |    6500 mm stock  368 double. Cutter  2400  50   3      | Broke
             1)  |------o------o------o-------o------o------o------o------o|
              50 x   800   800   800   800   800   800   800   800         |   100
             2)  |------o------o------o-----o-----o-----o------o-----o-----o
             100 x   800   800   700   700   700   700   700   700   700   |     0

             150 |  800 first   9  8 most. Big/low:    0  100    2 setups     5000
Reels come from a single stock width of 6500 mm. The first plan runs 50 times, slitting 800*8. Then a new setup is made, for 800*2 and 700*7 to run 100 times. Run lengths are integer numbers: a reel must not be wound partially. In turn, 50 + 100 makes 150, the stock units used.

Reels are sold as such or they are slit again, on another machine, into narrow reels or sheets. If so, on the main winder narrow reels should be grouped into parent reels such as 700 + 700 + 700 or 2100 mm, plus trim, to use the second cutter as effectively as the main winder.

Parent reels complicate the deckling problem, but they do not change its substance: parent reels are still reels.


BoxWorks / BoxPlan for Corrugator combining

Cartons of given width and length are wanted, for example:

             Width mm |   700   500   430
               Length |   600   300   300
              Cartons | 10000  5000  5000

                 1) |  1850 mm corrugator, includes 20 mm trim.           | Broke
              Meter |-------------------o-------------------o-----------o-|
               1500 |    700* 600    700* 600    430* 300                 |     0

               1500.00 m*1850    2775.00sqm    27000.00$   1.08%trim    .00%broke

                 2) |  1930 mm corrugator, includes 20 mm trim.           | Broke
              Meter |-------------------o-------------------o-------------o
               1500 |    700* 600    700* 600    500* 300                 |    10

               1500.00 m*1930    2895.00sqm    31000.00$   1.04%trim    .52%broke

              Linear m    Sqm used     Broke      $Value   %trim  %broke    %both
               3000.00     5670.00     15.00    58000.00  1.0582   .2646   1.3228
To get the numbers wanted, one keeps slitting and chopping an 1850 mm corrugator for 1500 meters, as in plan 1. 1500 meters at 600 mm per unit yield 2500 cartons 700 mm wide: these run 2-up, so one has 5000 cartons. 700s run on band A, chopping at 600 mm. Band B chops at 300 mm, to slit 430s run 1-up. Being half as long, they make the same total as the 700s.

Similarly for the second plan with a wider stock width, 1930 mm. 10 mm go to waste, as follows: 2*700 + 500 = 1900 mm, leaving 30 mm in 1930. 20 are (unavoidable) trim and 10 are broke. Sums appear in the bottom line, with total and relative usage.

A sheet cutter usually has only one chopper, but a corrugator may have two. Each can chop on its own, say one at 600 mm, the other at 300.

Both plans happen to run to full meters, but they need not: 1500.60 m would be quite correct, producing 4 more cartons in either plan.

Thus corrugator plans resemble those for reel deckling, yet they differ in several respects:

  • single/multiple chopper bands,
  • single/multiple stock widths,
  • integer/fractional run lengths.
Whether stock should come in several widths is to be studied critically. Yet it often does, at least to begin with, and one cannot show that a single width is desirable unless one can use several.

Run length must be integer for reels, winding a set until it reaches the diameter specified. Cartons are whole units, too, but chopping can stop as soon as the desired number is ready, neither reaching a full meter nor using up a full reel of stock.

In short, as deckling and corrugating differ in some aspects, so do the optimizers CutPlan and CutCart. Yet they share concepts, definitions and options. Also, either optimizer may run on its own or within a worksheet such as CutWorks, to manage options, input and output.