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SECTION 10 -  

Cylindrical Packing

(Covers: Introduction to types of pattern, Data entry, Cylinder Palletise, Cylinder Collation, Cylindrical results, Case design allowances, Palletising flower pots)

10.1 Introduction.

This section deals with both the collation of cylindrical items to form a case which is then to be palletised (using either Collation or Tertiary modes), and with the direct palletisation of cylindrical items (using the Palletise mode). It also includes in Section 10.7 discussion of the palletisation of tapered cylinders (buckets / flower pots etc), where improved palletisation may be achieved by 'top and tailing' the items. 

In all instances two distinct types of cylinder packing are examined. The simplest form is that in which cylinders MUST be arranged in such a way that adjacent units form strict rows and columns. We will call this a grid packing. A more powerful form is where cylinders can be grouped together to form more complex arrangements such as those shown below. We refer to this as nested arrangements. Solutions using both grid packing and any of the arrangements shown below (including ones rotated by 90 degrees) are produced by PALLETMANAGER. For any particular cylinder dimensions only a subset of arrangements will be appropriate. The three letters used to distinguish between these types of arrangement (X, Y and Z) have been chosen so as to help describe the precise form of nesting and are used as codes on tabular result pages. 

Z Grid

In describing the cylindrical packing facilities in this section it is assumed that the reader is familiar with the use of the normal Palletise and Collation modules (i.e. for 'rectangular' items) as detailed earlier in the manual

10.2 Data Entry.

Dimensional and orientation data for cylindical items is entered into the same data entry screens as normally used for palletise / collation / tertiary data entry. In both palletise and collation modes the specification of the cylindrical nature of the item to be packed can be carried out in 2 places - either on Screen 3 (where pallet size / packing style is selected, or by selecting the Advanced Options screen (Screen 4) from Screen 3. In Tertiary mode a check box for cylindrical items forms part of the standard initial data entry screen for this mode.

10.3 Cylindrical Solutions in Palletise Mode.

If a cylinder is involved then the grid solution together with any nested solutions which provide as large a number of packed cylinders, or more, will be reported. In all instances the cylinder will be placed upright on the pallet regardless of whether the height dimension has been specified as being vertical.

Once packings have been calculated then the normal Results Summary screen (Screen 5) will be displayed. This is similar to that presented in normal palletisation mode but it may (if applicable) have one extra item of information. When a nested pattern is being utilised then, following the reference number will be a letter (X, Y or Z). This code describes the type of nesting pattern used. If no code is given then a grid pattern is in use. Even when nested patterns have been stated as being acceptable, these will only be calculated if they provide at least as good a solution as that obtained using a grid pattern. A typical display from the Results Summary Screen is shown below.

As in normal Palletise mode you can select a particular result and view on screen the pallet layout. 

A palletisation specification, similar to that obtained in other modes may be printed and the solution may also be Stored for later re-print / re-run. It should also be noted that in Palletise Cylinder mode, whether or not a nested pattern is specified as being acceptable, the value for inter-case gap is set automatically equal to zero. In practice any such spacing (which might take the form of a protective sleeve), can be allowed for by increasing the cylinder diameter.

10.4 Cylindrical Solutions in Collation and Tertiary Modes.

In both Collation and TERTIARY modes data input for cylindrical problems is carried out on the standard input screens, with the cylinder height being input as one of the three primary (or sub-primary) dimensions and the cylinder diameter being entered as the other two dimensions.

As usual one of the dimensions can be stipulated as being vertical. If no vertical dimension is specified then packings examined may have the cylinder placed either horizontally or vertically in the collation. If one of the cylinder diameter dimensions is set to be vertical then the cylinder height dimension will always form one of the two base dimensions. In Tertiary mode a check box on the initial data entry screen allows you to specify that details of a cylindrical item have been entered. In Collation mode the cylindrical nature of the item is specified on the Advanced Options screen (Screen 4) selected from Screen 3 (Pallet & Style Selection).

In Collation mode with larger collation quantities (12/24 etc) there will typically be a large number of different case sizes produced, many of which will involve the use of nested patterns. When Alternate Collation quantities are also specified then a very large number of possible solutions would be produced, and PALLETMANAGER would only display the 'best' 99. For this reason, whenever Cylinder Collation / Alternate Collation is selected, the type of patterns examined will ONLY include those based on grid patterns. If you wish to compare collation quantities using nested patterns then each collation quantity should be investigate separately. 

10.5 Cylindrical Results.

The results screen (Screen 5) displayed in Cylinder mode is similar to that presented in normal collation mode but includes additional items of information relating to nested patterns. Following the reference number there is generally a letter (X, Y or Z). This code describes the type of nesting pattern used. If no code is given a 'grid' pattern has been used. In tertiary mode lower case letters (x, y and z) are used to indicate the same information. The printout obtainable from this screen also contains these codes and contains additional information to assist in solution selection.


You can also select the Collation button on this screen to display how details of how the cylinders are combined to form the case. Two such examples are shown above.

In the left hand example the cylinders are placed horizontally in the case to form a nested unit. The dark (brown on screen) thick horizontal line represents the pallet base when the case is loaded. The right hand example has no such 'thick line' and thus represents a top view of the case. Thus in this diagram the cylinders are placed vertically on the pallet.

If a grid pattern is used then the screen (and printer) display will present the cylinder in full 3D form rather than the side views used in nested arrangements. A typical 3D view is shown below.

When nested patterns are used then for clarity the side / top views of the arrangement are presented to the user (rather than the 3D picture above) so as to make the arrangement clearer to view.

10.6 Case Design Allowances.

When considering nested cylindrical packings the effect of the allowances entered on the pack style screen are somewhat different to those normally applied for rectangular cases.

1. Whenever a cylindrical item is specified, whether or not a nested pattern is specified as being acceptable, provision is made for all material and spacing allowances except for the gaps between each Primary. These are set equal to ZERO regardless of entries on the pack style screen. The gap constants and all other allowances are applied. If inter-primary gaps were allowed then the nesting arrangement would be made invalid. In practice any such spacing (which might take the form of a protective sleeve), can be allowed for by increasing the cylinder diameter.

2. All 'nested' patterns are restricted to designs where the number of layers used falls within the range set on the Pack Style screen but only in respect of nestings in which the cylinder height is vertical within the case. The lack of clear 'layers' in other orientations make the application of this constraint for other arrangements unsuitable.

With nested arrangements additions for headspace are always added to the height of the case, and where layer pads are specified the thickness of these is always added to the case dimension (height or otherwise) which is 'made up' of cylinder heights.

10.7 Palletising 'Bucket / Flowerpot' designs.

In Palletise mode the Advanced Options screen (Screen 4) allows you to select that the items being packed are not either cylinders or cuboid objects but of a bucket or flower pot form. Normally you can simply treat these as simply cylinders in the normal manner. However, if the 'buckets / flower pots' can be packed 'head to tail' - in which the tapering cylindrical shapes (buckets) are alternated - upright and then inverted - so as to potentially pack more on a pallet, then this option on the advanced input options screen may be selected.

When selected (see further information below) the packing is carried out using top and tail arrangements of shapes such as that above, producing load plans (plan view of the pallet) such as that below:

At first sight it might appear as if this packing involved 2 different circle sizes, but if one considers the diagram carefully as a plan view from above, then the larger circles might represent placements of the 'flower pot' in its 'normal' orientation (with larger diameters uppermost), and the smaller circles pots inverted (with their smaller base dimension uppermost).

This option will only be available (un-greyed) if:

(a) you select Palletise mode and input all 3 of the input product dimensions as different values - these giving details of the larger diameter of the 'flower pot', the smaller diameter of the 'flower pot' and the height of the 'flower pot'. If (say) the height is in reality exactly the same as the larger diameter then adjust one or other so that it differs sightly.

(b) the height value has been ticked as being the height. 

The diagrams produced will make maximum utilisation of the pallet by packing in the above manner. This will always be at least as good as the packings achieved using strict cylinder formations and will usually be better. 



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