Pulmac's Master Screen

Pulmac Inc's Master Screen is a low consistency screening device designed to mechanically separate contimanants such as shives, dirt, and/or stickies from fiber.

The Issue The issue is pulp. Period. You make pulp — and excellent pulp — most of the time. While we won't presume to tell you what's best for your operation, we would like to share with you how Pulmac Inc. might be able to help you track how you're doing with respect to the stuff in your pulp that you might like to keep to a minimum.

Qualification Quantification Your pulp is made up of fiber and stuff that isn't quite what you can call fiber. That other stuff can be called contaminants or, for the more sophisticated, contraries. More specifically these bits can be shives, or dirt, or in re-cycle pulps, stickies. But whatever you call them the presence of this stuff that isn't fiber has to be controlled. To be controlled, contaminants must be first qualified and quantified.

On-Line or Off-Line There are two basic means for this: on-line optical methods and off-line screening approaches.
Optical methods look at particles in pulp fibers as they stream by. They can tell much about particle length, shape and color. They generate tables of numbers which, through skilled analysis, can give excellent information about how a pulping operation is doing with respect to contaminant levels.
But on-line methods do not lend themselves to giving a 'feel' for the pulp they produce, their maintenance and calibration is always an issue, and on-line devices do not distinguish stickies.

Pulmac screening Pulmac screening first separates contaminants (rejects) from fiber (accepts). Rejects are gathered and displayed or weighed or both. They can also be scanned for image analysis, thereby exploiting the objectivity of optical approaches.

While off-line screening generates the numerical data so necessary for objective analysis, Pulmac screening has the additional advantage of allowing operators and testers to really get to 'know' their pulp. In the short time it takes to prepare results for measurement, testers get to see the distribution of reject material laid out on a filter paper. They learn to recognize and qualify the characteristics of the reject material in a way far superior to what is generally the case from studying the tables of data produced by on-line systems.

Pulmac screening will calibrate on-line systems and can also be adapted to provide the quantification of stickies in recycle pulp that defies on-line systems.

So, Pulmac screening not only stands on its own as a window on pulp particle distributions, but it also backs up and calibrates on-line monitoring all the while helping operators to master a qualitative appreciation of their product.

Pulmac's Master Screen: Sample at any place — any time

Over 200 Installations World Wide

Benefits:

The Master Screen by Pulmac Inc provides a rapid and repeatable method for concentrating and collecting shives, stickies and/or dirt.

For shives, it allows you to pinpoint problems that occur in areas such as digesters, cleaners, refiners, grinders and screens.

For stickies, it allows you to pinpoint problems that occur in repulpers, cleaners, and screens.

This data will allow you to reduce the frequency of dirt, shives or stickies in the final product, leading to improved process efficiency.

• Stickies quantification is rapidly and repeatably achieved to label re-cycle pulp quality (ONP, OMG, MOW, etc.) Shive numbers are also rapidly and repeatably generated to label virgin pulp quality (BCTMP, TMP, GWD, MDF)
• Troubleshooting recycle mill operations (raw material in repulper, holes in screens, disparger, cleaners, floatation. Monitoring pulp mill quality (stickies to papermachine) Optimizing pulp mill operations (stickie removal efficie cies, etc.)
• Troubleshooting pulp mill operations (poor cooks, holes in screens, chip refiner plate wear, log grinders, dirt reduction in bleaching operations, etc.) Monitoring pulp mill quality (shives to screens, shives to bleach plant, shives to papermachine) Optimizing pulp mill operations (screen and cleaner efficiencies, etc.)

Shives or Dirt

Shive and dirt particles have distinctly different shapes so when they are deposited on a filter paper they can be analyzed following a single scan of the Master Screen image analysis system. The screen plate slot size will determine the size distribution of the reject material deposits.

Stickies & Shives

White calcium carbonate paper is hotpressed onto black filter paper. The melted stickies then become whitened by the calcium carbonate which does not adhere to shive or dirt. The stickies and shives can then be measured and reported as distinct particle classes using the Pulmac Master Screen IA method.

Stickies

A filter paper with screened rejects is overlayed with a clear plastic sheet and passed through a regular office laminator. The stickies melt and transfer to the sheet. After a clean and contrasting paper sheet is placed over them, they are quantified with the Master Screen image analysis module.

Some clients, such as AFR Fiber, use the Pulmac Master Screen numbers as a key Pulp Quality Specification and many of the industry's support labs, such as Paprican in Montréal, Canada and Metso's Mechanical Pulping Technology Center in Anjalankoski, Finland use Pulmac laboratory screening for shive and stickies analysis.

Auto Filter for rapid results — displays rejects in less than 10 minutes.

Features

• Over 200 mill installations world wide
• All wood pulps and secondary fiber can be screened
• Simple to operate (easy as 1-2-3)
• In-plant operations and maintenance training
• CE compliant
• Conforms to TAPPI T274 sp04 Laboratory Screening of Pulp
• Screens up to 100 grams (oven dried equivalent)
• 5 to 15 minute test cycle
• Results in 5 to 10 minutes
• Standard screen plates available with 100 or 150 micron slots
• Auto Filter to rapidly display reject contaminants
• Auto Filter's air mix offers even distribution on an 8" - 2Ocm- filter paper
• Auto Filter cartridge allows easy removal & replacement of filterpaper display
• Auto Filter vacuum system removes water automatically
• Feed tank accepts samples up to 100 grams, oven dried
• Feed tank mixer to maintain uniform consistency
• Three distinct test cycles to match sample size and screenability
• Active back flushing of screen plate during test
• Screen plates are laser cut with high precision radial slots
• Screen plates available in two standard sizes (100/.004 and 150/.006 microns/inch)
• Custom sized slotted screen plates available. (smallest size - 75 microns/.003 inch)
• Screen plate mounted vertically
• Pulp is metered into the screening chamber
• Quick deposit of reject material onto filter paper
• Even distribution of contaminants on the filter paper
• Quick removal and replacement of filter paper
• Agitation in feedtank
• Master Screen Image Analysis (option available). Pulmac Master Screen Image Analysis Module developed by VerityIA.

Service and Hardware Requirements

1. 30 litres per minute of filtered water
2. 3/4 female hose or 1/2 MPT fitting for water supply
3. 1 1/2 MPT male fitting and floor drain for waste water
4. Single phase, 115VAC, 20 Amp or 220VAC 10 Amp, 50 or 60 Hz
5. Compressed air 485 Kpa at 4.72 liters/sec
6. 1/4" or 6 mm OD Hose for air supply

Feed Tank Cut-Off Valve Enhancement

Air-operated 3/4" pinch valve

Pulmac's Feed Tank Cut-Off Valve Enhancement (for B1 and B2 Models) can screen higher consistency pulps by preventing stock flow from entering the screening chamber during the dilution/screen sequence.

Lab Master Screen Parts List:

• 3/4" Pinch Valve
• 1/4"pinch valve
• Top seal block fitting
• Valve actuator
• Manual over-ride switch
• PLC Program upgrade
• Air mix feed tank upgrade (Optional)

©2007 Pulmac Inc. All trademarks are the property of their respective owners. Micrograph fiber scans courtesy the Paper Project - http://paperproject.org