24' 12GA sheet metal handeling Woes

[Silentnox]

Our company has recently purchased a new 20' acupressure 750ton break and we are having problems with the material handling aspect of moving light gauge (12ga) sheets around. The largest sheet we will move is 24'x8'. We get the sheets delivered on four 4"x4" blocks and so when our fork lift picks it up the pile of sheets bows an incredible amount. In addition trying to get one of these 24' sheets off the stack and onto our cutting table is giving a lot of problems. We dont think vacuum will work because of the dirt and grease on the sheet and with magnets it will try and pick up multiple sheets.

Does anyone out there have an approach strategy to this problem or a device/company that can supply a solution?

Thanks in advanced for you help.

 

[MikeHalloran]

Fabricate a really big pitchfork for your forklift? Say, four tines, ~6' each, spread along a 16 foot crossbar?

Here's something along that line:

http://www.budgetforklift.com/fork-spreaders.html

Mike Halloran
Pembroke Pines, FL, USA

 

[smcadman]

We used vacuum lifters on an overhead crane system. The vacuum lifter was very similar to this:

http://www.anver.com/document/vacuum lifters/electric-lifters/e1280m4-200f.htm

"Lifting & Handling Metal Plate, 20 ft x 8 ft (6.1 m x 2.4 m) weighing up to 12,800 lb (5806 kg)"
We lifted 16 ft x 4 ft hot-rolled sheets (which are dirty and scaly) with one lift, but I don't know if you will need 2 or a longer one. This moved the material around.

Forming on the brake press, we used vertical plate clamps similar to these:

http://www.lkgoodwin.com//more_info/vertical_plate_clamps/vertical_plate_clamps.shtml

Hope this helps.

Flores

 

[FACS]

Paralysis of Analysis.......

So you don't "think" vacuum will work... what did the manufacturer of the vacuum system say?

Charlie

http://www.facsco.com

 

[Silentnox]

I looked into what was the actual standard and I was right in

"that Anver Corporation designs and builds vacuum lifters in strict conformance with ANSI/ASME SPECIFICATIONS B30.20 "Below The Hook Lifting Devices."

Within those specifications it is stated that the loads must be "clean and free of loose particles".

Therefore, we cannot advocate the use of our Vacuum Lifters without conformance to the above referenced ANSI Specifications"

Which just wont work for us.

Any other thoughts?

 

[griffengm]

Silentnox,
We use an expanding cradle below the hook to handle our sheet stock. These are available in various sizes according to needs. Sorry but I do not recall the manufacturer and am on the road just now so I cannot check the equipment.
As far as separating sheets in the stack there are devices called Fanners that will sepparate the sheets with the topmost having the most separation at the ends of the sheet. Best I can describe is running your thumb across the end of a deck of playing cards. These tools are a good idea on material coated with oil or moisture (or grease?) because capillarity makes the sheets stick together so that lifting the top sheet by any means will move the entire stack.

Good luck and wish I could be more specific on the brand for the cradle.

Griffy

 

[BillPSU]

SilentNox
B30.20 is a construction industry standard which you can set as your standard but is not necessarily the standard used in the general industry.

In several plants I have worked at vacuum lifts have been utilized for lifting up to .50" x 60" x 144" hot finished steel. Your 12Ga material will have far less scale than .500 material. I also do not want you moving the sheet 20ft in the air over long distances. I am talking about moving the sheet from a pile in front of or beside the machine, lifting the sheet from the pile to the machine. The bundle when it is moved should be moved with bundle lifting equipment.

In fact there are automatic sheet loading equipment available for plasma punch machine which utilize vacuum lifting equipment.

If this is still not acceptable then you can also puchase pickled and oiled material or temper milled material or even cold finished material if it is available in the width you need. The oiled finish will actualy contribute to better vacuum lift attachment.

You haven't given an information about the final use of the parts made from the sheets but I expect being a formed sheet that they will be welded. The scale will be detrimental for welding and if the material is standard hot rolled the forming operation will require good consistency between parts and within a single sheet. Another issue you will face when cutting the part is coil memory. The material is a decoiled product and when you cut parts from the sheet coil memory from the end of the coil will cause the parts to form a banana shape. I would recommend laser quality or from Robinson Steel RPS steel. The scale will be minimized, the product extremely flat, no coil memory, consistency across the sheet in thickness and consistency from sheet to sheet.

 

[MechanicalChef]

I can't gaurantee this will help, but I feel inclined to share: If memory serves me, back in school one of the teams in my engineering-enterprise was given a task which seems somewhat similar. The company deals w/ large pieces of sheet-metal, and they needed a way to move large sheets of material from one area to another and feed it into their machines.

The solution was a relatively table designed which functioned similar to a motorcyle lift.

http://www.kendonindustries.co.uk/images/review1.jpg

Once the material was on the table, it could be raised and lowered as needed (the lifting mechanism was compressed air driving a hydraulic cylinder), depending on the height of the equipment or height of the stack of material. From there, material could be slid off by hand into their equipment, or onto roller-tables inside their automated machines. The lift table was on casters, so it could be pushed around as needed.

I don't know if anything is available off the shelf, but concievably, with some basic calculations you should be able to design and fab a similar table to suit your needs.

Good luck.