Make the most of shutdowns with machine clothing checks: scheduled paper machine shutdowns offer an excellent opportunity to change out, inspect, clean, and optimize machine clothing.Thomas Edison wrote that "opportunity is missed by most people because it is dressed in overalls and looks like work." At no time is that more true than during a paper machine's planned shutdown shut·down n. A cessation of operations or activity, as at a factory. shutdown Noun the closing of a factory, shop, or other business Verb shut down . Although a silent machine may be anathema anathema (ənă`thĭmə) [Gr.,=something set up; dedicated to a divinity as a votive offering], term that came to denote something devoted to a divinity for destruction. In the Bible, the term is herem. to the corporate accountants, it is a positive boon for maintenance personnel willing to take advantage of the easier access a shutdown affords. Scheduled shutdowns offer an excellent opportunity to change out, inspect, clean, and optimize machine clothing in every position. Most mills have designed customized maintenance routines for use during scheduled shutdowns; procedures may vary depending on the mill's needs, the length of the shutdown, and the availability of personnel. Solutions! asked clothing supplier" representatives to offer their suggestions For the "must-do" items during shutdown-related clothing checks. We have encapsulated encapsulated Localized Oncology adjective Confined to a specific area, surrounded by a thin layer of fibrous tissue; encapsulation generally refers to a tumor confined to a specific area, surrounded by a capsule. See Islet encapsulation. their responses into the checklist on the next page. When inspecting, cleaning, or repairing machine clothing, procedures differ depending on whether the clothing has been removed or remains on the machine. "If clothing is to be left on the machine, a very careful approach must be taken to any cleanup efforts," said Randy Kimpfbeck, papermaking pa·per·mak·ing n. The process or craft of making paper. pa  per·mak services manager at Albany International Corp., Albany, New York For other uses, see Albany.Albany is the capital of the State of New York and the county seat of Albany County. Albany lies 136 miles (219 km) north of New York City, and slightly to the south of the juncture of the Mohawk and Hudson Rivers. , USA. "For instance, care must be taken not to wash rust and grease into the wire run when washing up. Many times mills do chemical cleaning around the machine and fail to adequately rinse the cleaning chemicals. This can result in the evaporation evaporation, change of a liquid into vapor at any temperature below its boiling point. For example, water, when placed in a shallow open container exposed to air, gradually disappears, evaporating at a rate that depends on the amount of surface exposed, the humidity of water and high chemical concentrations, leading to later clothing issues." Kimpfbeck recommends that, during all shutdowns, mill personnel should examine the general condition of clothing and associated equipment in sections. "The guideline on all pieces of clothing must be examined and documented," he said. "In addition to the guideline, each section has its own set of clothing and machine parameters to check while down. The shutdown is also the time to do shower maintenance, which should be an every shutdown occurrence." Me suggested that, before every shutdown, operators make a list of plugged nozzles on every shower on the machine so these nozzles can be changed quickly. Steve Carmichael, sales/service engineer; Southeast for Weavexx, Wake Forest, North Carolina Wake Forest is a town in Wake County, North Carolina, a suburb of Raleigh. The population was 12,588 at the 2000 census. The town was the original home of Wake Forest University. The former Wake Forest campus is the current home to the Southeastern Baptist Theological Seminary. , noted that in the forming section, rolls are one of the key items to monitor. "Check your vacuum rolls for plugging and wear, and other rolls for wear," he said. "Surface smoothness (RA) should also be monitored by mill or roll cover supplier When outage out·age n. 1. A quantity or portion of something lacking after delivery or storage. 2. A temporary suspension of operation, especially of electric power. conditions allow, speed matching should be done to drive rolls without clothing." GETTING DOWN TO WORK To make the most of the shutdown's limited duration, mill personnel should be sure to have the proper inspection tools ready, and know how to use them. "Typical tools used by clothing suppliers and the mill include optical magnification Magnification A measure of the effectiveness of an optical system in enlarging or reducing an image. For an optical system that forms a real image, such a measure is the lateral magnification m devices (with or without digital cameras), caliper caliper Instrument that consists of two adjustable legs or jaws for measuring the dimensions of material parts. Spring calipers have an adjusting screw and nut; firm-joint calipers use friction at the joint to hold the legs unmoving. gauges, a protractor protractor Instrument for constructing and measuring plane angles. The simplest protractor is a semicircular disk marked in degrees from 0° to 180°. A more complex protractor, for plotting position on navigation charts, is called a three-arm protractor, or station , a ruler, a long measuring tape for sections, a permeability permeability /per·me·a·bil·i·ty/ (per?me-ah-bil´i-te) the property or state of being permeable. per·me·a·bil·i·ty n. 1. The property or condition of being permeable. 2. measuring gauge, fabric and felt mending or sewing kits, good flashlights, levels, and a sealing iron," noted Steve Carmichael, sales/service engineer at Weavexx, Wake Forest, North Carolina. Voith Fabrics sales/service representative Mike Garrick also suggested a roll surface analyzer and noted that digital cameras are especially useful for comparing wear from shutdown to shutdown. "The most important tools to engage in this effort are the brain-power and experience of the supplier-operator team," added Garrick. WHO IS ON THE TEAM? The total number of operators that should be assigned to clothing duties during a shutdown win vary somewhat from mill to mill. "Typically, you have one or two operators that work primarily with the former and press after everything is down (excluding clothing installation)," said Carmichael. "They would work with their maintenance, roll, doctor, and clothing suppliers in inspection. One or two operators would also be responsible for the dryer sections." According to according to prep. 1. As stated or indicated by; on the authority of: according to historians. 2. In keeping with: according to instructions. 3. Albany International's Kimpfbeck, machine tenders are best suited to handle inspections and work in the forming area; one individual dedicated to the tasks (other than cleanup) should be sufficient. In the press section, the same would apply for backtenders. "If time is an issue, the jobs could be split between two people," he said. The dryer section requires more people, due to the number of positions involved to check, Kimpfbeck continued. "The number depends somewhat upon the number of sections, but a minimum of four people should be dedicated to checking on the condition of fabrics. The clean-up in all sections should be handled by as many people as possible, but adequate training must be done so everyone is aware of the types of materials used in clothing construction and their somewhat delicate nature when compared to the machine in general." Machine clothing inspection areas can be broken into three sections: forming, pressing, and drying. To most effectively allocate resources, mills should perform as much inspection as possible before the shutdown, and coordinate the planned cleaning, repair, and inspection activities between each section. (The checklist on this and the next page has been organized into sections accordingly.) Prior to shutdown, the best approach is to identify areas of concern, suggested experts from AstenJohnson, Charleston, South Carolina South Carolina, state of the SE United States. It is bordered by North Carolina (N), the Atlantic Ocean (SE), and Georgia (SW). Facts and Figures Area, 31,055 sq mi (80,432 sq km). Pop. (2000) 4,012,012, a 15. , USA. They recommend reviewing past fabric analyses for areas of abnormal wear and observing machine equipment and forming fabrics for abnormal conditions. When the shutdown work is complete, take the time to perform a "pre-startup check." AstenJohnson recommends that personnel make sure that there is proper clearance A clearance for entry of units into specified defense areas by civil or military authorities having responsibility for granting such clearance. between fabric and apron apron, n a piece of clothing worn in front of the body for protection. apron band, n a labioincisal or gingival extension of an orthodontic band that aids in retention of the band and in proper positioning of the bracket. ; check edge deckle/fabric clearance; check the function of the guide mechanism; and ensure proper fabric tension. A good last step? "Hose any loose material from fabric surfaces prior to running the fabric," they say. Then enjoy the benefits of well-maintained machine clothing, and relax ... until the next shutdown. S! IN THIS ARTICLE YOU WILL LEARN: * Top items to include on your machine clothing outage checklist. * The inspection tools necessary to check machine clothing during a shutdown * What to look for during a shutdown inspection. ADDITIONAL RESOURCES: * "A combined future: tracking the trends in machine clothing," by Alan Rooks Alan Rook edited the 1936 issue of New Oxford Poetry and he was a Cairo poet.[1][2] After the war, he became a wine-trader. References 1. ^ [1] 2. , Solutions!, January 2003, page 53 * For a complete listing of articles, technical papers, TAPPI TAPPI Technical Association of the Pulp and Paper Industry Tips, and other information on this topic, search far "machine clothing" at www.tappi.org FORMING SECTION "First the fabric should be inspected closely while in crawl, to determine if any damage has taken place that requires repair. While the machine is down, the condition of the fabric should be assessed. Make a magnified image of the inside and sheet side of the fabric, using a digital camera; this can be used to determine if the wear on the fabric is sheet side or inside," said Randy Kimpfbeck, papermaking services manager, Albany International Corp. "If the forming fabric has been removed from the machine, this is the time to check and change equipment. While the machine is down and the fabric is off, is also the best time to change doctor blades." CHECKLIST: From Steve Carmichael, sales/service engineer, and Roy Jones, Manager--Forming Fabric Applications, Weavexx: * Check for wear streaks (machine side and paper side). * Check for ridges (inspect ridges on both machine and paper side to identify if ridges originate from wear streaks). * Headbox deckle deckle - /dek'l/ (From "dec-" and "nibble"; the original spelling seems to have been "decle") Two nickles; 10 bits. Reported among developers for Mattel's GI 1600 (the Intellivision games processor), a chip with 16-bit wide RAM but 10-bit wide ROM. boards--wear, adjustment and lubrication lubrication, introduction of a substance between the contact surfaces of moving parts to reduce friction and to dissipate heat. A lubricant may be oil, grease, graphite, or any substance—gas, liquid, semisolid, or solid—that permits free action of ports if equipped. * Is there proper slice-to-fabric clearance? Minimum 0.200 in., recommended 0.250-0.300 in. Check with feeler gauge A feeler gauge is a simple tool used to measure gap-widths. Feeler gauges are mostly used in engineering to measure the clearance between two parts. They consist of a number of small lengths of steel of different thicknesses with measurements marked on each piece. . * Ceramic blades/foils in former--wear, piano keying, cracking, alignment, unusual buildup build·up also build-up n. 1. The act or process of amassing or increasing: a military buildup; a buildup of tension during the strike. 2. . * Poly blades in former--wear, alignment, and any unusual buildup. * Vacuum boxes checked for plugging, deckle wear, end unusual wear. * Suction suction /suc·tion/ (suk´shun) aspiration of gas or fluid by mechanical means. post-tussive suction a sucking sound heard over a lung cavity just after a cough. boxes--what is condition of surface? Check levelness of all boxes. * Lubrication, cleaning, and trimming shower nozzles--for plugging and nozzle An orifice in an inkjet print head through which ink is sprayed onto the paper. Print heads with six thousand or more nozzles are common in today's printers. Nozzle integrity. * Forming board, hydrofoils, vacufoils: Check for sharp edges. If blades are ceramic, diamond file-poly, use small hand plane. * Doctor blades--check for wear and proper loading pressure and angle--unusual wear can be an indicator of uneven roll wear or carryover carryover n. in taxation accounting, using a tax year's deductions, business losses or credits to apply to the following year's tax return to reduce the tax liability. (See: carryback) problems. * Rolls--check vacuum rolls for plugging and wear, other rolls for wear. When outage conditions allow, speed matching should be done to drive rolls without clothing. * Cleaning fabric--does it need cleaning? Will chemical affect fabric--do you need to rinse? * Fabric condition--usually done by a clothing supplier. Magnified visual and edge caliper are typical. Seams can also be inspected. From Mike Garrick, Paul Kelly, Jr. and Alvin Paul, sales/service representatives, Voith Fabrics: For fabrics on machine, check: * Caliper * Dimensions * Stability (skew (1) The misalignment of a document or punch card in the feed tray or hopper that prohibits it from being scanned or read properly. (2) In facsimile, the difference in rectangularity between the received and transmitted page. ) * Tension * Overall wear/edge ravel * Stretch/guide mechanisms * Shower function If fabrics have been removed, check: * Roll surfaces: wear, cracks, etc. * Table elements: surface wear, chips, cracks, sharp edges. * Clean fabric run thoroughly. From Rod Backer, forming product manager; Jack Burgher burgh·er n. 1. A citizen of a town or borough. 2. A comfortable or complacent member of the middle class. 3. a. A member of the mercantile class of a medieval European city. b. , sales/service representative; Ron Christman, forming product manager; and Richard Watry, fanning product manager, AstenJohnson: * Examine the fabric with a magnifying glass magnifying glass: see microscope. magnifying glass traditional detective equipment; from its use by Sherlock Holmes. [Br. Lit.: Payton, 473] See : Sleuthing ; include both papermaking and wear surfaces on both the front and back sides of the machine. * Pinpoint areas of abnormal wear, determine cause and correct, if possible. * Check fabric edge seal for integrity-raseal entire edge if necessary. * Examine stationary former elements, including foils, suction boxes, etc. * Remove any deposits on the outside edges of stationary equipment. * Examine roils and doctors for non-uniform wear; non-uniform roll diameters will cause fabric distortion and uneven wear. * Rolls should be free turning and doctor blade pressure set so as not to impede im·pede tr.v. im·ped·ed, im·ped·ing, im·pedes To retard or obstruct the progress of. See Synonyms at hinder1. [Latin imped roll rotation. * A well-planned roll grinding/covering swap-out program should be in place. * Showers: free of plugs, replace worn nozzles. * Shower oscillators should be checked for correct function; check shower angle and distance from the fabric. * Inspect former frame and headbox for rust and corrosion that can damage forming fabrics on the run; inspect for dried stock and remove. PRESS SECTION "The surface of all press fabrics should be inspected for loss of batt material and general surface condition. If seam seam (sem) a line of union. osteoid seam on the surface of a bone, the narrow region of newly formed organic matrix not yet mineralized. fabrics are run, the seams should he spotted for inspection. This inspection should include flap wear, seam integrity, and condition of sewing at the ends of the seam," Kimpfbeck recommended. "A complete cleanup of the press section also must be done, but take care not to wash materials into the fabric that could either damage the fabric on startup or plug the fabric. When the fabrics are off, all rolls should be inspected for damage; inspect the suction rolls and the grooved rolls thoroughly for plugging. Quite often the grooved rolls are overlooked and can create problems that look as if they are fabric related." CHECKLIST: From Steve Carmichael, sales/service engineer, Weavexx: * Uhle box strips/covers--ceramics for wear/buildup, cracking and piano keying, poly for wear and buildup. Both types have deckles that should he inspected far condition and positioning. * Uhle box bodies--check for plugging. * Rolls--check vacuum rolls for plugging and wear, other rolls for wear. Surface smoothness (RA) should also be monitored by mill or roll cover supplier. Nip impressions should be performed on a regular basis to assure uniform loading (twice per year, if no problems). * Felt doctors--check for wear and positioning, inspect load/unload system if equipped. * Roll doctor blades--check for wear and proper loading pressure and angle. Unusual wear can be an indicator or uneven roll wear or carryover problems. * Lubrication and cleaning shower nozzles-for plugging and nozzle integrity. * Shower oscillation Oscillation Any effect that varies in a back-and-forth or reciprocating manner. Examples of oscillation include the variations of pressure in a sound wave and the fluctuations in a mathematical function whose value repeatedly alternates above and below some systems--clean slides/bushings, filters if water driven. * Does felt need cleaning? Will chemical affect felt--do you need to rinse? * Guiding systems, palms, and roll movement devices--preventative maintenance is very important in preventing damaged clothing. * Felt condition--usually done by a clothing supplier, visual, caliper, edge condition, and caliper check if desired. From Mike Garrick, Paul Kelly, Jr. and Alvin Paul, sales/service representatives, Voith Fabrics: For fabrics on machine, check: * Caliper * Dimensions * Stability (skew) * Overall wear/edge ravel * Seam flap integrity * Stretch/guide mechanisms * Shower function If fabrics have been removed, check: * Roll surfaces: wear, cracks, etc. * Uhle box covers: plugging, surface wear, chips, cracks, sharp edges. * Clean fabric run thoroughly. DRYING SECTION "While shutting down, as many of the dryer fabric seams should be spotted for inspection as is possible. In the dryer section, the fabric edges should be checked for hydrolysis hydrolysis (hīdrŏl`ĭsĭs), chemical reaction of a compound with water, usually resulting in the formation of one or more new compounds. , edge seal should be checked to make certain it is intact, seams should be checked for open areas, the seam area should be checked for wear as well as the body of the fabric being checked for wear. If the fabrics are off the machine, blow boxes and any vacuum rolls should be checked for signs of filling and cleaned if needed," said Kimpfbeck. CHECKLIST: From Steve Carmichael, sales/service engineer, Weavexx: * Guiding systems, palms, and roll movement devices--preventative maintenance is very important in preventing damaged clothing. The hot environment is hard on these systems, * Roll condition surface smoothness, buildup and wear. * Look for abrasion abrasion /abra·sion/ (ah-bra´zhun) 1. a rubbing or scraping off through unusual or abnormal action; see also planing. 2. a rubbed or scraped area on skin or mucous membrane. or plugged areas of fabric. * Vacuum / blower rolls--check for plugging in hole openings. * Blow box--check for cleanliness Cleanliness See also Orderliness. Cleverness (See CUNNING.) Berchta unkempt herself, demands cleanliness from others, especially children. [Ger. Folklore: Leach, 137] cat continually “washes” itself. of blow slots and proper clearance between felt and box. * Felt condition--usually done by a clothing supplier, visual, edge condition, seam condition, permeability, seam skew, and felt body integrity. From Mike Garrick, Paul Kelly, Jr. and Alvin Paul sales/service representatives, Voith Fabrics: For fabrics on machine, check: * Dimensions * Stability (skew) * Tension * Overall wear/edge ravel * Hydrolyzed condition * Seam condition * Stretch/guide mechanisms If fabrics have been removed, check: * Roll surfaces: wear, cracks, etc. * Dryer can condition: rust, pitting. * Clean fabric run thoroughly. Edited by JANICE BOTTIGLIERI, Senior Editor |
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