New Tool Measures Insert Accuracy
by Olivier Girod
Imagine preserving credibility with advertisers by measuring what you thought was the unmeasurable. The Washington Post is doing just that by using a new tool for capturing newspaper insert misses and multiples on the production line.
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Advertisers want their product promotions to reach specific consumers. In newspaper preprint packaging, this involves inserting the appropriate advertising preprint into the right newspaper jacket, which is then dispatched to the targeted zone or zones. Yet there is no way to know if the promotion made it to the right jacket without accurately monitoring what happens on the inserting machines.
A new caliper has been developed jointly by the Post; Prim Hall Enterprises in Plattsburgh, N.Y.; and Instrument Control Services of Pensacola, Fla., that brings some long-sought precision to tracking such information. The caliper, which measures the thickness of preprints during insertion, consists of a mechanical sensor and associated software. The sensor is mounted behind the rotating drum of inserter hoppers; the software is integrated into the packaging-line controls.
The calipers record the number of preprints pulled during each insertion cycle and resolve the shortcomings associated with the traditional fault-recording devices, such as the widely used miss photo-eye (an optical sensor) and multiple switch (a mechanical sensor). Regarding the first alternative, caliper performance is not affected by dust accumulation, a common problem with the miss photo-eye. In the latter case, the calipers do not require mechanical set-up each time a new insert is run, as is the case with the traditional multiple switch. Calibration needs only to be checked periodically, and the calipers perform well with single-sheet inserts, whereas the conventional switch is suboptimal with thin preprints.
In addition, the new calipers can detect outstanding multiples, which occur when many inserts of the same kind are pulled at once by the machine hopper (e.g., 10 inserts in one feed). The outstanding multiples can then be tracked and intercepted before they leave the production line. In contrast, the old switch can only detect that a multiple occurred, without being able to record the number of preprints in the multiple, so the old system offers fewer options to control accuracy.
Implementing the new calipers brought technical challenges, such as detecting the thickness of a three-thousandths-of-an-inch preprint six times per second. This is equivalent to a packaging line running a one-page insert at 20,000 cycles per hour.
While the Post provided resources for ensuring caliper technological integrity and coordinating the various project phases, Prim Hall focused mostly on the mechanical sensor and ICS on the control software. Major contributors at The Washington Post included representatives of the production, maintenance and engineering departments.
The endeavor took almost two years and unfolded in three phases: mechanical sensor research and development, software design, and full-scale implementation. Research and development on the mechanical sensor was carried out between March and October 1996.
Four prototypes and many hours of testing were necessary to reach the caliper's final design, which essentially has not changed since then. Between November 1996 and January 1997, The Washington Post ordered three more calipers, which were installed on one inserter, along with the last prototype. These four calipers were then made available to ICS for software enhancement and integration within the inserter control system, which occurred between March and August 1997.
This was not a continuous effort but rather a series of programming sessions, followed by extensive testing, mostly under regular production conditions. Finally, full- scale implementation was launched in September and took until November 1997. During that time, Prim Hall worked with Washington Post personnel on converting SLS-1000 hoppers to the new calipers.
The calipers are currently installed on 100 hoppers across The Washington Post's seven inserting machines at its Virginia facility. This new tool comes at a time of prosperity in an industry that processes close to 90 billion preprints a year. Ultimately, we know that if we want to maintain our competitive edge, we must address quality issues as efficiently as we handle productivity. In the mailroom, one of the first steps in addressing quality is producing accurate packages.
Olivier Girod is manager of industrial engineering for The Washington Post. E-mail, girodoa@washpost.com; phone, (202) 334-7630.