The Figure (right) shows the typical X-Y measurement stage. In normal use the stage itself would be underneath the platform. The base consists of a tough plastic block with rollers mounted in cutouts to allow the board to be placed above the plastic blocks and suspended by intervals set by the roller spacing (100 mm center to center).

A PLC unit is used to control the x-y position of the measurement and the communications with the BQM unit and the external data bases and control systems. The PLC also allows the barcode to be read and interfaces to the multi-button keypad mounted to the side of the quality table that allows the user to select the mode of the measurement and enter details manually if required.

The table can measure box board areas up to 760 x 760 mm and accommodate most sized blanks.

Operation

(a) Manual operation

Manual operation is undertaken by positioning the BQM measurement device over the desired areas using the toggle keys at the side of the unit and then pushing the MANUAL button on the PLC handset. The board is placed on the measurement table and the measurement is displayed on the PLC screen. The BQM portable features are duplicated on the PLC screens in this mode. Refer to BQM-1 operational manual for details.

(b) Quality Control Mode.

Quality control mode is the most sophisticated measurement and lends itself to the implementation of continuous improvement, process control and historical analysis of board performance from a given corrugator or conversion line. In this mode the unit communicates with third party databases and scheduling software (for example Kiwi Plan) that hold BQM specifications and positional information related to nominated areas of interest on the blank design.

For a given job, the external data base holds the positions (x,y) of measurements to be made when a particular job is tested. Data is updated into the database and held as historical trend data if desired. Figure 4 shows a mapping for a box blank with nominated measurements 1 through 6 for this design. These measurements are specified on the basis that they represent block prints of colour 1 (1) and 2 (2), manufacturers joint (3), crease extension (4,5) and unprinted area – middle of panel (6).

Job/No. 98/0023-0567
Detail:			Date	25/10/2006	Time	09:32
Position	X	Y	BQM	BQM Aim	BQM LO	BQM HI
1	50	100	13	18	13	24
2	87	250	22	16	12	24
3	35	320	15	22	12	24
4	60	430	12	12	15	24
5	178	200	8	12	15	24
6	234	200	23	27	24	40

The value of trending positional values is the ability to follow improvements in quality for a given job or customer over time. Flags may be set to ensure that quality issues are met either before the next occurrence of the job or while set up is being carried out.

Advantages of the quality mode are:

The measurements provide a historical record of the main areas of performance on the particular job chosen. In this way improvements and degradation of process can be monitored from job to job.

The automation of the measurements and the selection of measured positions takes the task of measurement away from the operator allowing him to respond to the result efficiently.

Expert designers can arrive at the nominated points of measurement on the box blank to both ensure that the measurement is as fast as possible and also that the main characteristics of the blank have been determined and stored.

The specifications and measurement co-ordinates for a particular job are initially entered by the design or technical engineer using XQi’s input engine. This software, running on personal computer’s and Windows compatible allows the design engineer to call up a pdf of the job artwork and using a graphic interface click-and-point using a mouse or track ball to nominate the position for a measurement. The co-ordinates of the nominated point are calculated automatically and loaded into the job ready for calling by the measurement unit.

Aims and BQM limits and tolerances can be set either by manual entry (this might be done initially) or calculated values based on the historical average or variation seen in the job. It is possible to add constant or percentage increments to the average value and set these as aims. A one button selection undertakes this function. For example a manual setting for a box position may have been set manually to be a BQM value of 15. The average BQM value for that position over 11 makings is 18. The designer can reset the aims to the historical average (18) or the historical average plus an increment (for example 18+2 = 20 for new aim) or historical average + percentage (for example 18 - 10% = 16.2 for new aim). This can be accomplished with one button click and the entry of the interval required.

Limits around nominated aims may be set in similar ways.

Access to these editing facilities are limited by software passwords.

(c) Damage Mapping

The damage mapping mode is selected by the keypad attached to the controlling PLC. In this mode after the blank is inserted into the table the measurement proceeds across a grid of x and y spacing that can be set in the y (md) direction and remains at 100 mm for the x (cd) direction.

The data generated in this way can be stored either as a table of data points with x,y co-ordinates or it can be imported into mapping software that allows the generation of damage maps like that shown in Figure 4. Colours represent different values of local BQM and allow the damage map for the box or blank to be built up. Generally, “hot” colours (red and yellows) represent heavy damage and “cool” colours represent low damage areas.

The visual impact of a damage map can be very great and aids in the appraisal of box designs and the severity of process damage.