Rethinking the paper machine: creativity as a best practice: should we build paper machines that can be "run into the ground" much as we do with our automobiles? It's not such a crazy idea.

Editor's Note: This article will be discussed at a session to be held at the Paper Summit on Wednesday, March 6, from 8:00 am to 12 noon, Room 167, at the Georgia World Congress Center, Atlanta. For there information on participating in this session, contact the author using the information at the end of this article.

The paper industry lacks creativity--so charges the financial community based on the economic state of the industry (1) and its lack of return on capital. The North American industry cannot continue to sustain itself earning 2.8% less than the cost of capital. This poor performance is coupled with the fact the European paper industry has been able to generate greater returns than its North American counterparts (see Figure 1, page 26) have and in the process has been able to transform its mills into modern, efficient performers.

Clearly, the North American industry needs to improve its financial performance to change Wall Street's mind set.

LOSING GROUND

The North American industry is losing ground in the worldwide pulp and paper arena (2). For the most part, the North American industry invests in rebuilds for older machines in an attempt to make them more efficient. Yet, after spending millions of dollars on rebuilds, we still have machines that trim poorly, produce less than desirable quality and use more energy than their modern counterparts. Today, the paper industry is North America's third largest industrial consumer of energy (3), and our share of global paper production is dropping (see Figure 2, page 26). We must chang these trends to survive.

In the early 1990s, the industry attempted to transform the linerboard business with the introduction of the mini-mill (4) concept. Paper companies built more than seven single machine, recycle-based mini-mills. Today, they are low cost producers.

The North American industry must modernize. Yet, in the process, we cannot continue to spend US$1.25 (or more) for every dollar of revenue; we must spend US$ 1.00 (or less) per dollar of revenue. To do so, the industry must use every capital effectiveness best practice available (5,6), including applying state-of-the-art technologies. Creativity is a "best practice." The paper' machine is just an example of where we need to deploy capital creatively--we most also rethink the entire mill.

RETHINKING THE PAPER MACHINE

The following ideas represent a model, the mere beginnings of a process the paper industry needs to pursue. The goal is to design a machine that uses 50% less energy; has an overall machine efficiency (OME) of 95% based on 365-day operations; approaches zero effluent discharge (7); uses a four person crew from the high density (HD) towers through roll wrapping, including testing (a fifth crew member is added it-a size press is used); and requires at least 20% less capital to install than traditional machines. (Note: % OME is defined as % saleable x % available in excess of 95%. For example, 0.95 available x 0.97 saleable = 0.92% OME.)

STOCK PREP

The following items are initial thoughts for the stock prep area (See Figure 4, page 27.):

[FIGURE 4 OMITTED]

* For HD storage, our model mill could install San-Ei[TM] type towers, a Japanese design installed at several recycle linerboard mills. They were initially used as soak towers, but can be used for a variety of HD storage. Their bottom-mounted wing rake design offers uniform consistency control, blending of stock and low energy requirements (typically 90% lower than traditional towers). Our model mill requires three towers (hardwood, softwood, and broke); an additional tower would be required if recycle fiber is used. These towers should be sized to optimize both operations and maintenance.

* The mill has high consistency, fine slotted (0.004-in. to 0.006-in. slot width) screens between the HD towers and the refiners to remove contaminants. Cleaners are optional and probably not required for most grades due to the high screening efficiency. The broke stream would use a deflaker ahead of the screen and refiner. Sand cleaners would be installed before secondary screens.

* Hybrid refiners--which combine the benefits of disk refiners (low or no load energy, ease of plate changes) width the refining characteristics of Jordans--should be used. Inline freeness and fiber length measurement devices--along with feedback from paper testing sensors--am used to control refining (8). We need to maximize fiber potential.

* Stock chests after the HD towers are not required when using technology such as POM Teehnology's POMix[TM] stock processor. Individually refined stock streams are mixed and blended in the mixing device before being pumped to the suction of the fan pump via a variable speed stock pump. This eliminates the basis weight valve and stuff box; only a magnetic flow meter and consistency meter are in line, to provide feedback control.

* The digital order entry system and computer based grade receipts would trigger automatic grade changes that include adjusting furnish blends, refiner settings and chemical additions, including dyes.

* Water recovery systems use a combination of savealls and modern solids removal devices, such as the Petax[TM] filter from AES, and engineered membranes. White water is conditioned for reuse in various processes including in needle showers and internal roll lubrication showers. Our model mill could use separate sewer systems to recover stock, white water, and clean process/cooling water. Along with the recovery of water and stock, the system also must be able to recover energy.

PAPER MACHINE

The following items are initial thoughts for the paper machine area of our model:

* The heart of the modern machine is the compact wet-end concept, which eliminates white water silos. A series of inline deaerating devices produce 100% deaerated water and feed it to the fan pump. This model eliminates deculators, yet the machine has superior formation due to the lack of air in the stock. This system also allows faster grade changes, reduces chemical consumption, and simplifies wet end management.

* Our model paper machine uses a dilution profiling headbox with gap formers. Slice lips are rigid. Headbox adjustments are computer controlled for each specific grade. Multiply plies would be used--even on graphic grades--to optimize paper properties. We also need to rethink the optimum stock consistency for forming: is it really 0.5%?

* Is a suction couch really the best use of energy and capital?

* The model press section consists of a suction pick up followed by a single or double shoe press, depending upon basis weight. Seamed felts eliminate the need for cantilevering systems. Transfer is automatic, without any open draws, including into the dryer section.

* Our model vacuum system would combine pumps and blowers to optimize performance at minimum energy. New processes would recover water and energy in seal water.

* Machine clothing and press roll changes would be designed for installation by a standard four-person machine crew, plus the minimum on-shift maintenance crew. In our model mill, maintenance and machine crews operate as an integral unit. Rolls are removed vertically rather than horizontally, reducing the need for wide tending side aisles.

* The model machine uses single tier dryers to improve sheet runnability and energy efficiency. Dryers are customized for position (pressure, etc.).

* Starch application--if needed for strength or surface characteristics--would use a non-applicator roll, non-contacting spray device operating at higher solids levels.

* Modern calendering on the machine promotes excellent printing charactreristics without diminishing bulk and strength.

* The wet end and drying sections promote chemical interactions as needed for paper properties and synthetic cellulose/paper composites.

* The use of single tier dryers and compact wet ends means that the machine room is now a single level building. To reduce costs, the machine room provides only limited functions. The roof is used as a structural platform for equipment such as fans. House cranes are installed in required areas and do not travel over the dryer section. Dryers, when and if they are removed, slide out through the side of the machine building by mobile cranes after the siding is removed.

* A low level mill will prompt the reevaluation of couch, press pit, and dry end pulper installations.

* Dryer hoods no longer stand alone--they are integrated with the paper machine building. There is no separate hood roof inside the machine room.

* The model machine uses AC machine drives; however, we need to investigate use of hydraulic drive motors. All motors are high-energy efficiency.

* Winders would be semi-automatic; all winder settings/set information would be input directly using digital order information data. Roll handling-including roll information, plugging, weighing, wrapping, and labeling--is automatic. Installing the winder at grade minimizes foundation requirements.

* The roll wrapping system reads bar codes and automatically conveys rolls to the proper warehouse location for shipping. Automatic truck loaders may be used.

* The machine crew, using online sensors and gauges calibrated by off-line automatic testers, is responsible for paper testing and quality assurance.

* Many subcomponents for the modern mill are built offsite as modular units and installed as complete, large modules.

* We must rethink construction materials. We can no longer consider only concrete, steel, bricks and mortar; we must think of plastic, composites and engineered materials and components. Mills should be designed to last 20 years!

* Equipment maintenance considerations and equipment reliability are incorporated into the design.

* Circulating glycol systems move excess heat from one process and transfer associated energy to applications requiring heating in another part of the mill.

* The general population has always viewed water vapor from the dryer hoods as air pollution. In the future, we will eliminate this issue by condensing the water vapor and using it for chemical make-up systems.

PLANNED OBSOLESCENCE 

We generally run cars for about 150,000 miles before we junk them; we should think about doing the same with paper machines. The technological age of obsolesce for a paper machine is about 10 years. Machines operated longer are generally not competitive. While mills can efficiently rebuild some machines to run specialty grades, the majority should be retired rather than rebuilt. Europe is proposing legislation to prohibit use of cars more than 9 years old because they do not meet environmental regulations and are energy inefficient compared to current models. The same logic applies to old paper machines; they should be run for about 10 to 20 years, than scrapped rather than rebuilt or sold for reuse.

How will the industry justify installation of these modern machines? We must look at the industry's long-term good, which includes generating returns greater than cost of capital. Reducing total investment cost is just part of the answer. We also need to reevaluate the logic used in our financial considerations. One way is to use an approach that gives credit for future scenarios, unlike current economic calculations (9).

OLD TECHNOLOGY

Let's face it, today's paper machine is just an improved version of the Fourdrinier Brothers' early 1800s machine. Completely rethinking the fundamentals of the paper machine will take more time than currently available. The pulp and paper industry must reduce the technological age of its machines now.

The industry has the creative talent to design a more efficient and lower cost machine. The model described here is doable but needs to be refined; it is not the best design possible since it is based on the thoughts of just one person. The industry needs to assemble a multi functional group of experts to help brainstorm the machine of the future. The Paper Summit in Atlanta, Georgia, USA, March 3-7, 2002, would be a wonderful place to begin this process. Who wants to help?

Figure 1: Percent return on capital investments

RETURN ON CAPITAL, %

                     North America    Europe

5+ Year Return
on Total Capital         8.7            9.7
5+ Year Cost
of Capital              11.5           11.7
2001 Return
on Capital               6.4           10.0
2001 Cost
on Capital               9.0            9.2

Note: Table made from bar graph.

Figure 2: changes in paper and board production

WORLD PRODUCTION, %

                 1990    2000

North America     36      32
Europe            33      30
Asia              24      31
South America      5       5

Note: Table made from bar graph.

References

(1.) McNutt, J. Where is the Cheese?" TAPPI Engineering, Project Managers Committee Luncheon, San Antonio, December 2001

(2.) Kinstrey, R. B., "The North American Paper Industry, Is it in a "Death Spiral?" Global Outlook Conference, New York, NY October, 2001

(3.) Kinstrey, R. B., "Opportunities for Energy Reduction--Case Studies", Introspect Energy, Management Conference Minneapolis, MN, October 2001, Paperloop's Extra Edition, October 2001 & TAPPI TeleSeminar, December, 2001

(4.) Kinstrey, R. B., "Mini Mills: The Beginning of a New Trend," TAPPI Recycling Symposium, New Orleans, LA, March 1993

(5.) Kinstrey, R. B., "Doing the Right Job--No Option," American Paper Machinery Manufacturers Association's Annual Meeting, Phoenix, AZ, February 1998

(6.) Kinstrey, R. B., "Tools for Doing the Right Job, Right" TAPPI Engineering Conference, Miami, FL, September 1998

(7.) Kinstrey, R. B., TAPPI J., 79(12):47 (1996)

(8.) Kinstrey, R. B., "Stock Preparation and Approach Flow Systems," TAPPI Multi-Ply Forming Forum, Atlanta, GA, February 1998.

(9.) Parthasarathy, V.R. (Perry and Cenatempo, D. "Real Option Value Rule Provides New Strategy far Capital Management," Pulp & Paper, August 2001

Bob Kinstrey is director, paper, forest products and packaging for Jacobs Consultancy, Greenville, South Carolina, USA. He has 34 years of consulting, operating and technical experience in the manufacture of pulp and paper. Contact him by phone at [phone], or by email at [e-mail]