quickchangeover : Message: [quickchangeover] Lean Changeover Newsletter March 2006 Changepart design and Pigs

(+)+(+)(+)+(+)(+)+(+)(+)+(+)(+)+(+)(+)+(+)(+)+(+)+(+)+(+)+(+)+(+)
(+)+(+)(+)+(+)(+)+(+)(+)+(+)(+)+(+)(+)+(+)(+)+(+)+(+)+(+)+(+)+(+)
(+)+(+)
(+)+(+) S.M.I.L.E(sm)
(+)+(+)
(+)+(+) Setup Minimization Improves Line Efficiency
(+)+(+)
(+)+(+) The Lean Changeover e-letter
(+)+(+)
(+)+(+) Published monthly by Changeover.com
(+)+(+)
(+)+(+) Written by John R Henry, CPP
(+)+(+)
(+)+(+)
(+)+(+)(+)+(+)(+)+(+)(+)+(+)(+)+(+)(+)+(+)(+)+(+)+(+)+(+)+(+)+(+)
(+)+(+)(+)+(+)(+)+(+)(+)+(+)(+)+(+)(+)+(+)(+)+(+)+(+)+(+)+(+)+(+)

###############################
###############################
###
### MARCH 2006
###
###############################
###############################
============================================================

This newsletter is a free service of Changeover.com. Visit our website at
http://www.changeover.com or contact us at
john@...

Please feel free to forward this newsletter to anyone you think might be
interested

To subscribe send a blank e-mail to: quickchangeover-subscribe@yahoogroups.com

To unsubscribe send a blank e-mail to: quickchangeover-unsubscribe@yahoogroups.com

Past issues are indexed and archived at www.changeover.com/newsletter.htm

=============================================================
ANNOUNCEMENTS

I will be presenting several talks on changeover in April and May.

On April 2 & 8 I will present a 2 day (16 hour) workshop titled “Achieving Lean Changeover under the auspices of the Polytechnic University of PR. More info is available at http://www.pupr.edu/continuinged/PDF/cepaprogram2006.pdf on this and other continuing professional education programs.

On April 2-6, 2006, TS3, Inc will be presenting a workshop titled “A Six Sigma Approach to Product and Process Validation for Pharmaceutical and Medical Device Manufacturers”. I will be speaking for about an hour on changeover in pharmaceutical plants on Thursday afternoon. Full info at http://www.ts3inc.com/

On May 2 I will speak at the “Back to Basics” seminar of the Eastern Packaging Equipment Committee. This will be in Somerset NJ, near Newark. My topic will be, what else? “Quick Changeover Packaging Lines” Complete info is online at http://www.easternequipment.org/program.htm

At all of these events, please mention where you heard about them.

SOME THOUGHTS ON...
CHANGEPART DESIGN

A “changepart” is a product specific machine component whose purpose is to convert a machine from handling one product to another. Examples include starwheels, timing screws, bottle clamps, cap tracks to name a few. Changeparts are used to avoid the need to make adjustments to a machine. Instead of adjusting bottle spacing in an inline filler, a timing screw, cut specifically for each bottle, is mounted. In some places they are called “tooling”.

There are some benefits to changeparts over adjustments:

1. Adjustments are built into the part and require minimal skill to set up. This may allow operators instead of mechanics to do the changeover.

2. Since there are no adjustments possible, this precludes “tinkering” with it’s lost time and production problems

3. They can be designed, in most cases, so as not to require the use of tools.

4. Where cleaning is required, they can be cleaned externally to the changeover. (ie; while the line is running)

On the other hand, they do have some disadvantages as well:

1. If there are variations in the packaging materials or components, it is often difficult or impossible make any adjustments to compensate.

2. They are often stored off-line and time may be lost fetching the changeparts for the next product to be run. It shouldn’t be, the parts should be brought to the lne before the end of the run. They often aren’t.

3. They can be damaged in operation or in storage. When this happens, the machine is down until they can be repaired or replaced.

4. If a new product is to be run, new changeparts must be purchased. This will generally take 4-6 weeks at a minimum.

In short, the decision about how and when to use changepart based machines versus adjustable machines is one that requires careful consideration.

Assuming that changeparts will be used, some thought needs to go into their design. Here are some things to consider:

1. Separate the changeparts from the mounting hardware. Most manufacturers these days have designs that do this. A starwheel will generally consist of a plastic disk with pockets in the periphery and a mounting hub to mount it to the machine. In the past, each disk had its own hub. A better practice is to design a single hub that can be left permanently mounted. It will have pins and quick lock fasteners to allow only the disk to be removed. This allows toolless changeover. It also means that only the flat disk needs to be stored and handled. This reduces storage space and employee effort.

2. The mounting hardware is an expensive component of most changeparts as it needs to be machined out of metal. The part itself can often be made out of an engineering plastic such as Delrin, UHMWPE, impregnated linen or similar. This is much easier and cheaper to machine. Delivery of a purely plastic component will usually be quicker than of a complete assembly.

3. Choose an adequate material. Plastics are suitable for many applications but sometimes will just not have the strength and wear characteristics needed. If running metal cans, metal parts will usually be required to achieve a reasonable running life. Machines producing sterile pharmaceutical products will need components that can be cleaned with harsh disinfectants and even steam autoclaved.

4. Build ‘em rugged. This may be easier said than done. Timing screws may wind up with very thin threads. Starwheels may need to have ears rather than pockets and these may be subject to breakage. These may break in operation or in storage. It is easy to say that jams and mishandling will be minimized, reducing breakage. It is tough to do this in practice. If it can be broken, it will be.

5. Use tongue and groove or “jig-saw” construction to keep the parts small enough for easy handling and mounting. This allows larger parts to be broken in two for handling but still has the necessary rigidity for running.

6. Identify all parts by machine, line, and product. This identification should be engraved into to the changepart itself wherever feasible. It should be readily visible even after the part has been mounted.

7. Even better, use colored materials to identify each part. If all parts for a 20oz bottle are orange, it is readily apparent if any incorrect part has been used.

8. Provide good storage. Too often parts are simply piled on a wheeled cart, carried to a storeroom and piled on a shelf. This leads to breakage and loss. Specialized changepart carts should be provided for ease of handling and storage. The carts should include a shadowboard so that any missing part will be readily apparent.

Changeparts vs adjustments? Don’t ask me, I certainly don’t have a one size fits all answer for you. Both have there advantages and disadvantages. Either will work well in some applications and poorly in others. In other words, it is something that needs to be thought out. In most cases, a plant will wind up with a mix of both.

If the above tips are followed in specifying and using changeparts, the disadvantages will be minimized.

TIP OF THE MONTH...
PIGS

No, not the four legged, “oink-oink” kind.

In liquid filling operations it is necessary to remove the product from the piping prior to the next run. If the product is water-like, this is usually not hard in a well designed system. Ideally the piping should pitch down to a low spot and allow complete drainage. If the filler itself can be the low spot, almost all the product can be run out. Once the residual product has been drained, cleaning of the piping can commence.

Viscous products are more problematic. No matter how steeply pitched the piping, they will never drain. Many plants run out as much as they can and then flush the rest out using water or solvent.

Pigs are rubber or plastic plugs that fit inside the piping. They fit tightly enough to provide a good squeegeeing of the tube wall but not so tightly that they cannot be pushed through. The motive force can be compressed air, nitrogen, water or even the succeeding product.

The two big advantages of pigs are that they greatly reduce the amount of cleaning required (and its attendant waste) and that they increase the amount of usable product at the filler.

A number of companies supply pigs and can provide detailed advice on the design of a proper pigging system. One such company is Hygienic Pigging Systems at http://www.hps-pigging.com/ A Flash demonstration as well as case histories and other information can be found at their site. As always, tell them I sent you.

Best,

John R Henry CPP

Yahoo! Groups Tips

Did you know...

Messages

Yahoo! My Yahoo! Mail
	Sign In New User? Sign Up
		Finance - Groups - Help

Yahoo! Groups Tips

Did you know...

Best of Y! Groups

Messages