1、TR7SECOND EDITION, January 2006 NOTICEDisclaimerThe use of any information contained herein byany member or non-member of The AluminumAssociation is entirely voluntary. The AluminumAssociation has used its best efforts in compilingthe information contained in this book. While theAssociation believes
2、 that its compilationprocedures are reliable, it does not warrant, eitherexpressly or implied, the accuracy orcompleteness of this information. The AluminumAssociation assumes no responsibility or liabilityfor the use of the information herein.All Aluminum Association published standards,data, speci
3、fications and other technical materialsare reviewed and revised, reaffirmed orwithdrawn. Users are advised to contact TheAluminum Association to ascertain whether theinformation in this publication has beensuperseded in the interim between publicationand proposed use.About The Aluminum AssociationTh
4、e Aluminum Association, based in Arlington, VA, with offices in Detroit, MI, represents U.S.- and foreign-based primary producers of aluminum, aluminumrecyclers and producers of semi-fabricated products as well as suppliers to the industry. Member companiesoperate almost 200 plants in North America
5、and manyconduct business worldwide.ALUMINUM ASSOCIATION SHEET AND PLATEDIVISION COMPANIESAlcan Inc.Alcoa Inc.Aleris Rolled ProductsAMAG Rolling GmbHARCO Aluminum, Inc.Coastal Aluminum RollingMills, Inc.Corus Aluminium RolledProducts, USAGolden AluminumGulf Aluminium Rolling Mill Co.Jupiter AluminumC
6、orporationKaiser Aluminum andChemical CorporationKoenig Allow wrapping materials to remain intact (repair iftorn) until the aluminum is used; Store away from outside doors where the metalcould be subjected to rapid temperaturefluctuations; Store away from high humidity areas (such as paintor anodizi
7、ng lines) where the dew point is usuallyhigh.The Aluminum Association publication, Guidelines for Minimizing Water Staining of Aluminum providesprecautionary measures to prevent stained material.B. Flat Sheet and Plate StorageVarious types of storage racks are being used today,and circumstances may
8、warrant these racks beingsecured permanently into the building structure. Butan ever-changing product-mix demanded by industryhas stimulated development of simple, rugged, self-supporting racking systems that can be erected,modified, or moved quickly and easily. Severalmanufacturers offer systems of
9、 this type. The next two figures present typical examples.The cantilever rack shown in Figure 2 is self-supporting and easily erected from standardcomponents. Arms of various lengths and capacitiesare interchangeable. They can be moved up or downby one employee to accommodate changing storagerequire
10、ments. The type of rack shown in Figure 3 isalso easily disassembled and moved.Figure 1B - Water Stain on Sheet Figure 1A - Water Stain on CoilFigure 2 - Typical type of cantilever rackFigure 3 - Typical type of storage rack7C. Coil StorageSince coils concentrate many pounds of metal in acompact, st
11、able package, storage may or may not be a critical problem. Original skidded coil packages canusually be stacked three or four high. But this is notalways the most satisfactory answer for locationswhere coils are frequently removed and returned to thestorage area. Storage of partially used coils can
12、 createtheir own problems. Coils should be tightly rebanded,or if tape is used, new tape should be used to securethe outer wrap to the coil as old tape can release itself.Figure 4 gives an example of loose wraps, which cancause scratches when processing the coil (as discussedin section 9B). An examp
13、le of the “tension” scratchesthat occurs when the loose wraps are tightened duringsubsequent processing is shown in Figure 5. Anexample of the “oscillation” scratching that can occurwhen coils with loose wraps are transported is shownin Figure 6. Storage of skidded coils under thecantilever arms of
14、flat product storage units solves theproblem of full floor-space utilization, providing directaccessibility to individual coils.If coils are stored “eye-horizontal” and on the floor,they should at the very least be placed on some debris-free padding between the coil and the floor as isshown in Figur
15、e 7A. Additionally, all coils need to besecured (braces, chucks, or chains) in a manner thatprevents rolling. The wedge shape of the paddingdevice shown in Figure 7B can serve this purpose.Figure 4 - Loose Wraps on a CoilFigure 5 - Example of a Tension Scratch Figure 6 - Example of Oscillation Scrat
16、chesFigure 7 - (A) Storage of Coil on Protective Padding (B) Example of Wedge-shaped Protective Padding6. HandlingA. Coil ProductsFork trucks: Most coil stock is shipped with the ID orarbor in the vertical position. (“eye to the sky”). Thefork truck is the most common method of unloadingand transpor
17、ting skidded material. When handlingcoils with a fork truck, care must be taken to avoidstriking the material or the skid with sufficient force tocause either direct fork damage or side wall damagethrough the movement of coil against coil or coilagainst skid. In addition, as shown in Figure 8, theve
18、rtical portion of the fork should be padded toprevent damage to the coil. The skid weight must be uniformly distributed on theforks when lifting the skid. Normally, this is not aproblem if the skid is properly designed and the forksare of sufficient length. Care must be taken to ensurethat the forks
19、 are not so long as to strike the coilbehind the one being lifted. A common type of sidewall damage occurs when the weight of the skid issupported by the point of the fork causing it to breakthe skid decking and/or penetrate the package. Thisusually occurs when the skid is much larger than thelength
20、 of the forks, causing an imbalance. Care shouldalso be taken to ensure that, when properly loaded, thecoil does not exceed the rated capacity of the forktruck due to extending the load center beyond that forthe stated truck capacity. For example, a 15,000 pound(6820 kg) coil measuring 48“ wide x 68
21、“ OD (120 x170 cm) can be picked up safely “eye to the side” witha truck which is rated for 15,000 pounds (6820 kg) ata 24“ (60 cm) load center. However if the same coil isdown ended onto a skid “eye to the sky” the loadcenter has moved out to at least 34“ (85 cm) whichhas the effect of reducing the
22、 safe lifting capacity ofthe truck to only 10,588 pounds (4810 kg). A8Figure 9 - Fork Truck with Curved Lifting ArmFigure 8 - Padding on Forklift to Protect CoilsWhile stacking coils directly upon each other in apyramid type configuration is not recommended, if this is done then care should be taken
23、 to avoiddamaging the outer wraps and / or collapsing theinside diameter (ID) of the coils. Additional bracingmay be necessary to prevent movement of the coils in the stack.When skidded, eye-vertical coils are stacked uponother coils, it is important that there is proper edgeprotection and a smooth
24、coil side wall with nooscillation. The height of the stacking will dependupon a number of issues such as floor loading,handling equipment limitations and safetyconsiderations. Many of these same issues will applyto eye-horizontal coil stacking.Several manufacturers provide storage rack systemsrugged
25、 enough for individual storage of coils in thevertical or horizontal position. The type of rackselected will depend upon individual requirementsand types of handling equipment available. Storagesystems planning should allow for expansion. Itshould take into account the trend toward larger coilsas we
26、ll as variation in coil sizes.9movement out of the load center of only 6“ (15 cm) to30“ (75 cm) has the effect of reducing the capacity ofa 15,000 pound (6820 kg) rated truck to only 12,000pounds (5455 kg). Intermediate handling of coil products consists ofmoving stock from storage, unpacking and pr
27、eparingthe material for loading on equipment. Removingstock from storage usually involves the sameprocedures used during unloading. Once the coil hasbeen turned to a horizontal ID position (see“Upenders”) and unskidded, it can be handled by forktruck. Several precautions should be taken: (1) Theresh
28、ould be a fixture that provides a rounded uppersurface matching the curvature of the inside diameterof the coil which can be picked up by the fork truckprior to lifting the coil (a typical example is given inFigure 9); (2) The vertical portion of the fork shouldalso be padded to prevent damage to th
29、e insidecircumference of the coil; (3) Care must also betaken when lowering coils so that the inside diameterdoes not collapse. (A severe blow can cause this typedamage.) Coils should be lowered slowly onto aprotected area by the fork truck. In preparing thematerial for further processing, however,
30、additionalequipment is sometimes required. Upenders: Nearly all coil stock is shipped in avertical ID position. It is necessary, therefore, toupend coils to the horizontal ID position beforeloading on equipment mandrels. Various types ofupenders, such as that shown in Figure 10, areavailable. They a
31、llow for fast, safe unskidding andturning of coils. Vertical Coil Grabs: When coils must be handledwith the ID vertical, vertical coil grabs (Figure 11)are the preferred method. Vertical coil grabs are usedin conjunction with a crane. The portion of the grabthat comes intocontact with thecoil edges
32、shouldbe padded toprevent damage. “C” Hooks andHorizontal CoilGrabs: Using a“C” hook with acrane, shown inFigure 12, issimilar tohandlingFigure 10A - Loading Coil on UpenderFigure 10B - Upender Changing Coil from“Eye Vertical” to “Eye Horizontal”Figure 11 - Overhead Crane w/Vertical Coil GrabFigure
33、12 - Overhead Crane w/ Coilon a “C” Hook10Figure 15 - Moving Coils with a Vacuum Lifthorizontal ID material with a fork. The coil, however,must be properly centered on the hook to maintain ahorizontal ID If the load is not properly centered, itwill tilt and when returning it to the floor one edgewil
34、l support the entire weight of the coil causing edgedamage to the outside diameter. Padding should beplaced wherever the metal can come in contact withthe hook (see Figure 13). Horizontal Coil: Horizontal coil grabs used with a crane, Figure 14, are usually best for handlingmaterial in the horizonta
35、l ID position; however, thegrabs should be padded to prevent edge damage. Vacuum Lifts Vacuum lifts are another method ofmoving coils (see Figure 15), but they require a verysmooth coil sidewall. If automated coil movers are used, such as is shownin Figure 16, attention must be given to the protecti
36、vepadding that is used on the coil cradle to ensure thatno damage or debris is present.Automated coil movers (also called automatic guidedvehicles or AGVs), Figure 16, have no humanoperator and are programmed to transport coilsbetween work stations. Attention must be given to tothe protective paddin
37、g that is used on the coil cradleto ensure that no damage or debris is present.Collision avoidance systems are typically employed in AGV design, but since they may begin movingwithout warning, pedestrians should keep a safedistance away and take care not to place themselvesbetween the AGV and immova
38、ble objects. B. Flat Sheet and Plate Products Fork Trucks: The same comments regarding coilstock handling apply to flat sheet and plate. Handlinglong skidded material with short forks will presentproblems. While neither method is recommended, thepractice of pushing or pulling long skids is commonwhe
39、n overhead equipment is unavailable. Of thesetwo methods, pushing the skid with the fork truck isless likely to cause metal damage. Damage to the skidand possibly the metal is the common result ofpushing large skids with a fork truck. Slings: Slings, as shown in Figure 17, are a commonmethod for han
40、dling flat sheet and plate. They caneither be steel cable or nylon belts. Since slings wrapthe load, edge damage can result if the material is notFigure 13 - C-Hook w/Padding to Protect CoilsFigure 14 - Crane w/Horizontal Coil Grabs11sufficiently protected from the cable. Nylon belts havean advantag
41、e over cable in that they distribute theload over a greater area, thereby reducing the chancefor damage. They are also less prone to slip. Grabs: Grabs, Figure 18, are the preferred methodfor handling flat sheet and plate with a crane althoughcare must be taken to avoid gouging the sides of thesheet
42、. In general, they offer excellent support andminimize the chance for damage.Figure 16 - Automated Coil Mover Figure 17 - Slings for Handling Skidded Sheet and PlateFigure 18 - Grabs for Handling Plate and Flat Sheet7. Turning Flat Sheet This operation sounds so simple that many peopleoverlook its i
43、mportance. In spite of new equipment inuse or in development, size limitations, problems oflocation, and the need to inspect both sides of thematerial still make hand turning a widely used methodof transferring sheet and light plate from one skid orstack to another. (See Figure 19)Bright finished sh
44、eet as well as mill finished sheetwill mark easily if dragged across another sheet. Thescratches at the far edge of bottom sheet in Figure 20were caused when the top edge was dragged over it. If operators are careless, the top sheet will also slipdown and scratch its lower surface on the edge of the
45、bottom sheet.Figure 19 - Manual Turning of Flat Sheet12Sheet must be picked up cleanly and swung intoposition. A swishing sound as the sheet is picked up orlowered almost certainly means a marked surface. Thesolution is perfect timing with the operators lifting inunison. Some service centers and pla
46、nts keep a skidwith a few samples of various sheet types and sizes toallow new operators to practice before attempting toturn valuable metal. Another danger is kinking, asshown in Figure 21. Pull must always be straight back,especially on thinner sheet. Clean gloves should be worn to prevent finger
47、printsor smudging of the sheet as well as for operator safety.The salt from perspiration may etch fingerprints intothe metal. In hot weather, it is sometimes necessary toprevent perspiration dripping from the operators ontothe metal. Working height should be no higher than acomfortable level and no
48、less than 24 inches (60 cm)(Figure 22.) Distance between sheet stacks should befrom 4 to 12 inches (10 to 30 cm). More may put anoperator off balance; less can cause skinned knucklesand insufficient room for metal to swing clear.A. Guidelines for Turning Sheet by Hand The current pallet and the new
49、one should be locatedno more than a few steps from each other. Thepallets should be aligned so operators do not have to walk forward/backward while turning the sheets. The pallet height should allow proper liftingpostures for the sheet weight. This may meanelevating/lowering one or both of the pallets as the operation progresses. The corner closest to the new pallet will be thebottom hand when the sheet turns and the operatorshould hold the corner of the sheet. The bottom hand simultaneously pulls on the sheetedge to keep it straight and guides the sheet cornerto its new locati
