Archive for October, 2009
Lubrication is not the answer to shot sleeve wear
Shot sleeve wear and consequent replacement, can be an ongoing and costly problem for die casters. Many mistakenly assume that sleeve wear results primarily from the gap between the plunger and the shot sleeve shrinking as a result of unequal thermal expansion. Actually the opposite is true. If the temperatures of both the shot sleeve and the plunger tip are not constantly and accurately controlled, the clearance may increase sufficiently to allow the aluminum alloy to penetrate the gap. The abrasive silica in the alloy then soon erodes the sleeve. This is in fact the principal cause of shot sleeve wear.
Effectively managing the clearance between the plunger and the shot sleeve is a prerequisite for any successful light metal extrusion system. Clearance problems can only be resolved by good design and thermal management, not by lubrication. The primary purpose of shot sleeve lubricant therefore, is simply to reduce the friction between the sleeve and the plunger, and to thus ensure the smooth passage of the plunger through the sleeve. This is essential for consistent shot velocities, and to extend the operating life of both the shot sleeve and the plunger tip.
Too Little or Too Much?
The amount of lubricant used must be adequate, but care should be taken to avoid any excess. Lubrication should therefore be kept to an absolute minimum.
Every effort must be made to eliminate the possibility of any non-metallic substance getting into the mold. Graphite-based lubricants, for example, can cause porosity in the casting. Lubricant should be applied where it is needed . . and only where it is needed. Any excess lubricant not actually used, is an unnecessary cost and a workplace pollutant.
Boron Nitride
Boron nitride is just now universally accepted as the most effective lubricant yet available for the aluminum die casting industry. Its unmatched lubricity far exceeds that of all other traditionally used lubricants. It is also completely benign, producing no toxic fumes.
Application
For small diameter sleeves of 4in. (10cm.) or less, a Lube-Drop system is usually adequate. This incorporates an internal lubricant groove machined into the sleeve, combined with a metered dropper.
For larger and longer sleeves, it is difficult to adequately lubricate the complete interior. This can be ensured with a Lube-Spray system A carefully measured amount of liquid boron nitride is vaporized to form a fine mist. This is blown throughout the length of the shot sleeve, ensuring that the surface is completely and evenly coated with a thin film of lubricant. The lubricant spray and air nozzle assembly is securely mounted just behind the pour hole of the shot sleeve.
Spray pressure and duration are both adjustable. This ensures complete coverage without costly overspray. A metered dosage injection pump provides the precise amount of lubricant required for each process cycle, with no danger of excess to contaminate the casting.
The problem with change
They have found that the brain is highly plastic, and that new behaviours can be learned and entrenched behaviours changed. The problem with change is FEAR. Therefore any efforts to make change must help employees feel good about themselves.
1. Praise performance
2. Create a perception of certainty
3. Allow employees to execute their own decisions
4. Build an environment that allows social interaction
5. Be fair, fairness is essential to a high-performing workplace
Human behaviour is not intractable.
Hunter S. Thompson wrote this review on a Ducati motorcycle, prior to his death 3 years ago
Hunter Thompson, one of my favourite writers, wrote this article about my favourite bike. I identify with his passion, and hope that you do, as well. I do not necessarily agree with his methods. Leave a comment, share your thoughts on the article or your personal passion.
Song of the Sausage Creature
by Hunter S. Thompson
There are some things nobody needs in this world, and a bright-red, hunch-back, warp-speed 900cc cafe racer is one of them – but I want one anyway, and on some days I actually believe I need one. That is why they are dangerous.
Everybody has fast motorcycles these days. Some people go 150 miles an hour on two-lane blacktop roads, but not often. There are too many oncoming trucks and too many radar cops and too many stupid animals in the way. You have to be a little crazy to ride these super-torque high-speed crotch rockets anywhere except a racetrack – and even there, they will scare the whimpering shit out of you… There is, after all, not a pig’s eye worth of difference between going head-on into a Peterbilt or sideways into the bleachers. On some days you get what you want, and on others, you get what you need.
When Cycle World called me to ask if I would road-test the new Harley Road King, I got uppity and said I’d rather have a Ducati superbike. It seemed like a chic decision at the time, and my friends on the superbike circuit got very excited. “Hot damn,” they said. “We will take it to the track and blow the bastards away.”
“Balls,” I said. “Never mind the track. The track is for punks. We are Road People. We are Cafe Racers.”
The Cafe Racer is a different breed, and we have our own situations. Pure speed in sixth gear on a 5000-foot straightaway is one thing, but pure speed in third gear on a gravel-strewn downhill ess-turn is quite another.
But we like it. A thoroughbred Cafe Racer will ride all night through a fog storm in freeway traffic to put himself into what somebody told him was the ugliest and tightest decreasing-radius turn since Genghis Khan invented the corkscrew.
Cafe Racing is mainly a matter of taste. It is an atavistic mentality, a peculiar mix of low style, high speed, pure dumbness, and overweening commitment to the Cafe Life and all its dangerous pleasures… I am a Cafe Racer myself, on some days – and it is one of my finest addictions.
I am not without scars on my brain and my body, but I can live with them. I still feel a shudder in my spine every time I see a picture of a Vincent Black Shadow, or when I walk into a public restroom and hear crippled men whispering about the terrifying Kawasaki Triple… I have visions of compound femur-fractures and large black men in white hospital suits holding me down on a gurney while a nurse called “Bess” sews the flaps of my scalp together with a stitching drill.
Ho, ho. Thank God for these flashbacks. The brain is such a wonderful instrument (until God sinks his teeth into it). Some people hear Tiny Tim singing when they go under, and some others hear the song of the Sausage Creature.
When the Ducati turned up in my driveway, nobody knew what to do with it. I was in New York, covering a polo tournament, and people had threatened my life. My lawyer said I should give myself up and enroll in the Federal Witness Protection Program. Other people said it had something to do with the polo crowd.
The motorcycle business was the last straw. It had to be the work of my enemies, or people who wanted to hurt me. It was the vilest kind of bait, and they knew I would go for it.
Of course. You want to cripple the bastard? Send him a 130-mph cafe-racer. And include some license plates, he’ll think it’s a streetbike. He’s queer for anything fast.
Which is true. I have been a connoisseur of fast motorcycles all my life. I bought a brand-new 650 BSA Lightning when it was billed as “the fastest motorcycle ever tested by Hot Rod magazine.” I have ridden a 500-pound Vincent through traffic on the Ventura Freeway with burning oil on my legs and run the Kawa 750 Triple through Beverly Hills at night with a head full of acid… I have ridden with Sonny Barger and smoked weed in biker bars with Jack Nicholson, Grace Slick, Ron Zigler and my infamous old friend, Ken Kesey, a legendary Cafe Racer.
Some people will tell you that slow is good – and it may be, on some days – but I am here to tell you that fast is better. I’ve always believed this, in spite of the trouble it’s caused me. Being shot out of a cannon will always be better than being squeezed out of a tube. That is why God made fast motorcycles, Bubba….
So when I got back from New York and found a fiery red rocket-style bike in my garage, I realized I was back in the road-testing business.
The brand-new Ducati 900 Campione del Mundo Desmodue Supersport double-barreled magnum Cafe Racer filled me with feelings of lust every time I looked at it. Others felt the same way. My garage quickly became a magnet for drooling superbike groupies. They quarreled and bitched at each other about who would be the first to help me evaluate my new toy… And I did, of course, need a certain spectrum of opinions, besides my own, to properly judge this motorcycle. The Woody Creek Perverse Environmental Testing Facility is a long way from Daytona or even top-fuel challenge-sprints on the Pacific Coast Highway, where teams of big-bore Kawasakis and Yamahas are said to race head-on against each other in death-defying games of “chicken” at 100 miles an hour….
No. Not everybody who buys a high-dollar torque-brute yearns to go out in a ball of fire on a public street in L.A. Some of us are decent people who want to stay out of the emergency room, but still blast through neo-gridlock traffic in residential districts whenever we feel like it… For that we need Fine Machinery.
Which we had – no doubt about that. The Ducati people in New Jersey had opted, for some reasons of their own, to send me the 900ss-sp for testing – rather than their 916 crazy-fast, state-of-the-art superbike track-racer. It was far too fast, they said – and prohibitively expensive – to farm out for testing to a gang of half-mad Colorado cowboys who think they’re world-class Cafe Racers.
The Ducati 900 is a finely engineered machine. My neighbors called it beautiful and admired its racing lines. The nasty little bugger looked like it was going 90 miles an hour when it was standing still in my garage.
Taking it on the road, though, was a genuinely terrifying experience. I had no sense of speed until I was going 90 and coming up fast on a bunch of pickup trucks going into a wet curve along the river. I went for both brakes, but only the front one worked, and I almost went end over end. I was out of control staring at the tailpipe of a U.S. Mail truck, still stabbing frantically at my rear brake pedal, which I just couldn’t find… I am too tall for these new-age roadracers; they are not built for any rider taller than five-nine, and the rearset brake pedal was not where I thought it would be. Mid-size Italian pimps who like to race from one cafe to another on the boulevards of Rome in a flat-line prone position might like this, but I do not.
I was hunched over the tank like a person diving into a pool that got emptied yesterday. Whacko! Bashed on the concrete bottom, flesh ripped off, a Sausage Creature with no teeth, fucked-up for the rest of its life.
We all love Torque, and some of us have taken it straight over the high side from time to time – and there is always Pain in that… But there is also Fun, the deadly element, and Fun is what you get when you screw this monster on. BOOM! Instant take-off, no screeching or squawking around like a fool with your teeth clamping down on our tongue and your mind completely empty of everything but fear.
No. This bugger digs right in and shoots you straight down the pipe, for good or ill.
On my first take-off, I hit second gear and went through the speed limit on a two-lane blacktop highway full of ranch traffic. By the time I went up to third, I was going 75 and the tach was barely above 4000 rpm….
And that’s when it got its second wind. From 4000 to 6000 in third will take you from 75 mph to 95 in two seconds – and after that, Bubba, you still have fourth, fifth, and sixth. Ho, ho.
I never got to sixth gear, and I didn’t get deep into fifth. This is a shameful admission for a full-bore Cafe Racer, but let me tell you something, old sport: This motorcycle is simply too goddamn fast to ride at speed in any kind of normal road traffic unless you’re ready to go straight down the centerline with your nuts on fire and a silent scream in your throat.
When aimed in the right direction at high speed, though, it has unnatural capabilities. This I unwittingly discovered as I made my approach to a sharp turn across some railroad tracks, saw that I was going way too fast and that my only chance was to veer right and screw it on totally, in a desperate attempt to leapfrog the curve by going airborne.
It was a bold and reckless move, but it was necessary. And it worked: I felt like Evel Knievel as I soared across the tracks with the rain in my eyes and my jaws clamped together in fear. I tried to spit down on the tracks as I passed them, but my mouth was too dry… I landed hard on the edge of the road and lost my grip for a moment as the Ducati began fishtailing crazily into oncoming traffic. For two or three seconds I came face to face with the Sausage Creature….
But somehow the brute straightened out. I passed a schoolbus on the right and got the bike under control long enough to gear down and pull off into an abandoned gravel driveway where I stopped and turned off the engine. My hands had seized up like claws and the rest of my body was numb. I felt nauseous and I cried for my mama, but nobody heard, then I went into a trance for 30 or 40 seconds until I was finally able to light a cigarette and calm down enough to ride home. I was too hysterical to shift gears, so I went the whole way in first at 40 miles an hour.
Whoops! What am I saying? Tall stories, ho, ho… We are motorcycle people; we walk tall and we laugh at whatever’s funny. We shit on the chests of the Weird….
But when we ride very fast motorcycles, we ride with immaculate sanity. We might abuse a substance here and there, but only when it’s right. The final measure of any rider’s skill is the inverse ratio of his preferred Traveling Speed to the number of bad scars on his body. It is that simple: If you ride fast and crash, you are a bad rider. And if you are a bad rider, you should not ride motorcycles.
The emergence of the superbike has heightened this equation drastically. Motorcycle technology has made such a great leap forward. Take the Ducati. You want optimum cruising speed on this bugger? Try 90mph in fifth at 5500 rpm – and just then, you see a bull moose in the middle of the road. WHACKO. Meet the Sausage Creature.
Or maybe not: The Ducati 900 is so finely engineered and balanced and torqued that you *can* do 90 mph in fifth through a 35-mph zone and get away with it. The bike is not just fast – it is *extremely* quick and responsive, and it *will* do amazing things… It is like riding a Vincent Black Shadow, which would outrun an F-86 jet fighter on the take-off runway, but at the end, the F-86 would go airborne and the Vincent would not, and there was no point in trying to turn it. WHAMO! The Sausage Creature strikes again.
There is a fundamental difference, however, between the old Vincents and the new breed of superbikes. If you rode the Black Shadow at top speed for any length of time, you would almost certainly die. That is why there are not many life members of the Vincent Black Shadow Society. The Vincent was like a bullet that went straight; the Ducati is like the magic bullet in Dallas that went sideways and hit JFK and the Governor of Texas at the same time.
It was impossible. But so was my terrifying sideways leap across the railroad tracks on the 900sp. The bike did it easily with the grace of a fleeing tomcat. The landing was so easy I remember thinking, goddamnit, if I had screwed it on a little more I could have gone a lot farther.
Maybe this is the new Cafe Racer macho. My bike is so much faster than yours that I dare you to ride it, you lame little turd. Do you have the balls to ride this BOTTOMLESS PIT OF TORQUE?
That is the attitude of the new-age superbike freak, and I am one of them. On some days they are about the most fun you can have with your clothes on. The Vincent just killed you a lot faster than a superbike will. A fool couldn’t ride the Vincent Black Shadow more than once, but a fool can ride a Ducati 900 many times, and it will always be a bloodcurdling kind of fun. That is the Curse of Speed which has plagued me all my life. I am a slave to it. On my tombstone they will carve, “IT NEVER GOT FAST ENOUGH FOR ME.”
If it’s Tuesday, this must be Kuala Lumpur.
Sounds more like an exotic vacation tour than a serious business trip, doesn’t it? But “Castool serves a global market” is becoming increasingly familiar to extruders and die casters throughout the world. I leave Toronto on TuesdayNov.3 for Seoul, Korea, the first stop on a 31/2 week business trip that will take me to Korea, China, Japan, and Malaysia
In Seoul, I have meetings arranged with several Korean extruders by Castool’s Korean representative, Jae-Hoon Song.
On the weekend(Nov.7-8) I’ll fly to Tokyo where I’ll be joined by Danny Dunn (Extrusion Product Manager, ) and David Purdy (Die Cast Product Manager). Danny and I will visit several major Japanese extruders along with our local representatives Sigeyushi Takagi and Nobou Nagayama, while David calls on some large die casters with Yasuhiko Watanabe.
The following weekevd, (14-16) David and Danny wil return to Toronto, and I fly to Kuala Lumpoor, the capital, and also the largest city in Malaysia. There I will meet with our local reoresentative, Justin Kumar, Our intention is to visit several Malaysian extruders, and also to investigate the possibility of having Castool single cell die ovens fabricated in Malaysia for the entire Asian market.
The following weekend (21-22) I will travel to Hong Kong where, along with our local representative I will visit several major Castool customers.
There is a common fallacy that the main purpose of any offshore business trip is to gain new customers, Wrong. Adding new customers is of course of vital importance, but the first priority is service your existing customers. Call on them first if possible. Smother them with service. You may not see them again for some time, Also a well satisfied customer is the best advertising you will ever have in a foreign land.
During this important forthcoming trip, I plan to share some of the highlights with you by both dialogue and photos.
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For Survival, Cut Downtime
The real purpose of an aluminum die casting machine is not to make aluminum castings, it is to make money. And it makes money only when it’s running. When the machine is stopped during a working shift, except for the cost of the alloy, virtually all of the expenses of the entire company continue unchecked. The accumulated cost of downtime when no money is being made can make the difference between profit and loss.
The light metal die casting industry is just now well served by many capable producers. Capacity, however, exceeds demand in almost all areas. Price levels are market-driven. To retain long term customers, and to keep their machines running, die casters now often accept orders at dangerously near the break-even level. Very little then separates profit from loss. Under these conditions, focused and consistent cost control is essential to survival.
There are basically just three ways for a die caster to increase his revenue. First, sell more. This is not always possible. Second, increase your prices. In today’s market, this is seldom possible. And third, reduce manufacturing costs. For most die casters, this is the only practical option.
A die caster is not actually a manufacturer. He seldom produces a completely finished product. He takes aluminum alloy, melts it, then converts it into castings. In doing this, he adds value. This added value is really all he has to sell. The die casting process is not labour-intensive, therefore optimizing machine time and particularly controlling downtime is absolutely vital.
The real cost of downtime is usually underestimated. In accounting, for example, direct labor is usually considered a variable cost, and charged only when a production machine is running. In terms of downtime, however, when the machine is stopped, to changer a plunger tip for example, the operator is still paid although no revenue is being generated. Similarly, the alloy continues to be heated, and so on.
To calculate the approximate true cost of downtime, simply subtract the actual cost of the alloy used per hour from the selling price of the castings produced per hour. This also applies to the cost of time spent replacing scrap.
It is often said, “If it doesn’t get measured, it doesn’t get done.” The very first step in reducing downtime, therefore, is to accurately measure it and record it. This must, of course be done for each machine. . the life of plunger tips recorded in shots, and actual downtime recorded in hours and dollars.
Downtime reflects directly on your bottom line. The financial statement doesn’t care about machine hours, its only concern is profit or loss. Also, the actual savings in dollars is a much better motivation for everyone involved than a downtime reduction in minutes or hours.
When an order is taken at a competitive price, often production is nearly completed before the revenue generated has offset the total cost. There is then very little time left to make a profit.
Machine time is your stock in trade. It is your most valuable resource. Don’t let this most critical commodity be eroded by unnecessary and avoidable downtime.
Be sure you always have enough time left to make a profit.
10 Worst Extrusion Practices
Worst Practices Check List
ڤ Press is not precisely aligned.
ڤ Die is not uniformly and adequately preheated.
ڤ Die is too strong.
ڤ Die bearings are badly oxidized.
ڤ Billet is poorly cut, surface is not clean.
ڤ Billet is insufficiently taper heated.
ڤ Dummy block is no longer contracting.
ڤ Container is overheating.
ڤ Container liner exit temperature is vertically inconsistent.
ڤ Too much DAG is being used.
Much has been written about Best Practices for the extruder. A number of major multi-plant extruders already have Best Practices manuals. These are usually very detailed, and are meant to ensure that all their facilities anticipate anything that may prevent 100% quality, and maximum productivity. The obverse to this is the Worst Practices List. This includes common but avoidable problems in the production system between the billet and the die. From this preliminary list, an extruder may identify some of the areas in his process that can be improved. Few extruders can honestly claim to have none of these problems.
The die is the heart of the extrusion process and, until fairly recently, it was the main focus of the extruder’s attention. Now, however, many die makers can provide dies that will make perfect product from the first push. But only if the alloy is at the optimum temperature for maximum speed as it enters a properly preheated die. The prime focus of the extruder is now on improving the efficiency of his production process.
No attempt has been made to prioritize these problem practices since their real importance and frequency is impossible to quantify.
For the extruder who is sincerely committed to ongoing improvement, concentrating on the basic purpose and function of each component involved in managing the temperature of the billet, plus the use of some of the state-of-the-art technology currently available, is a certain formula for immediate improvement of both productivity and profit.
In discussing the function and effect of different parts of the extrusion process for the purpose of improving efficiency, it is advisable to avoid evaluating any part individually, and without regard for its interaction with other components. Maximum productivity can only be achieved if all parts of the process work together as a coordinated interactive system.
- Press is not precisely aligned.
Press alignment should always be the first item on any list of extrusion practices. Good extrusion depends on all components of the press being physically in precise alignment, and the die being mounted exactly in the centre of the container. If this is not done, good extrusion is impossible. Regular inspection at operating temperature is essential, with emphasis always on preventing rather than correcting misalignment.
- Die is not uniformly and adequately preheated.
The die is usually designed to already be completely at operating temperature when the first push begins. If it isn’t, a perfect profile is usually impossible until one or two billets are wasted in heating the die.
The answer to this problem is the single-cell die oven. This will bring the die quickly and uniformly to operating temperature. To avoid the initial capital expense of a complete battery of single-cell ovens, dies may be held at a moderate temperature for some time in a traditional chest oven, then the necessary heating quickly completed in a single-cell oven when the die is needed.
An extruder today should be able to assume that his die will produce good product immediately, and concentrate on optimizing his production process.
- The die is too strong.
Anything that prevents the die from creating good product at maximum speed, and with minimum scrap, is counter-productive. Unfortunately the die maker usually does not have the luxury of making a perfect die for perfect operating conditions. In real life he must provide a die that is best suited for its anticipated actual use.
If the die maker knows that his die will not likely be uniformly at operating temperature before the first push, he must make it strong enough to withstand the resulting high breakthrough pressure. Press speed can then never be maximized.
A strong die is a slow die.
If the die maker knows that the die will be uniformly at operating temperature before the first push, the breakthrough pressure may be reduced by 30-40%.
A lower breakthrough pressure allows cooler billet temperatures, and thus faster press speed.
The die corrector used to modify dies primarily to bring the profile to the required tolerances. The integrity of the profile can now usually be taken for granted The die corrector’s prime function now is to provide feedback on temperatures and breakthrough pressures to help the die maker to provide more productive dies.
Very high breakthrough pressure, for example, can bend the die, and cause the core to deflect and distort the profile. Once this danger has been understood and included in the design equation, large, thin, complex shapes that were previously thought impossible to efficiently extrude, now become viable.
- Die bearings are badly oxidized.
When a die is held too long at or near operating temperature in a chest oven, the bearings will oxidize. A satisfactory finish cannot then be obtained on the extruded product. The solution to this problem is, of course, the rapid and controlled heating of single-cell die ovens.
- Billet is poorly cut, and surface is not clean.
To avoid the air entrapment and blisters from poorly sheared and two-part billets, logs can now be precisely cut with an in-line narrow-cut saw, then welded together before being automatically cut into billets. When the end of the current log is detected, a new log from the magazine is positioned in the cutting line. The logs are then locked firmly in place, and their ends welded together. The joined logs then pass through the cutting and loading process as if no weld existed.
Billets should always be kept clean, because the skin may be inadvertently carried into the product. Scrap will inevitably result.
- Billet is insufficiently taper heated.
The friction of the die bearings causes heat to be increasingly generated in the alloy as it is pushed through the die. In order to achieve isothermal extrusion, that is, to allow the alloy to pass through the die at its maximum operating temperature and speed at all times, the billet must be initially heated to a temperature that reduces from front to back in order to compensate for this heat of friction.
Taper heating the billet can best be achieved by electrical induction heating. To combine the economy of gas heating with the accuracy and repeatability of induction heating, billets may be first preheated to a base temperature in a gas-fired oven. The hot billets are then transferred to an auxiliary induction billet heater where multiple separately controlled heating zones are programmed to quickly and accurately provide the necessary taper heating. Once the taper heating program for any shape has been confirmed by both calculation and experience, it can again be successfully used for even a single billet.
If the temperature of the billet is not adequately tapered before extrusion begins, maximum press speed is impossible.
- Dummy block is no longer contracting.
For the dummy block to work properly, a thin film of alloy must, of course, remain between the block and the container liner at all times during the extrusion process. Its thickness should be uniform. With a soft alloy, the clearance that creates this film will be only about 0.006 in. If the clearance is more, the alloy will penetrate the gap in the first push. If much less, this essential film of alloy will be stripped from the liner.
Stripping the film of aluminum off the liner results in scrap due to blisters, and also to inferior alloy being carried into the extrusion, instead of being discarded in the butt.
An effective dummy block must expand quickly under load. It must separate cleanly from the billet at the end of the stroke, then contract immediately and return through the container without stripping the film of alloy from the liner.
The measure of the real value of a dummy block is its ability to continue to contract fully after an unusually large number of pushes, before it takes a permanent set and no longer contracts.
There is a very considerable difference in the operating life of contemporary dummy blocks.
- Container is overheating.
If the container temperature sensors and heating elements are not close to the liner, overheating can easily occur. Inconel sheath heaters, unless properly controlled, can reach temperatures of 1300-1400F. The container mantle is usually of 4340 steel which may begin to temper and soften at 1000F. If the mantle softens, bellying of the liner will likely occur. This will allow a build-up of impurities from the billet skin that will eventually end up in the extrusion. Scrap will result..
- Container liner exit temperature is vertically inconsistent.
At the die end of the container, the temperature of the top of the liner is usually considerably higher that at the bottom. This is caused primarily by the heat rising inside the container housing. The result is that the alloy entering the die at the top is less viscous than at the bottom, and therefore flows at a greater velocity through the upper apertures.
A rule of thumb is that every 10°F difference between the top and bottom of the liner will cause 1% difference in the runout length. On a long table, unless the upper die apertures are choked, major problems will occur, especially when using a puller. The solution is for the container thermal control system to have top and bottom as well as axial temperature control zones.
- Too much dag is being used.
In the billet delivery system, the final factor is the introduction of lubrication. Ideally, the dummy block would pass smoothly through the container liner, and at the end of the stroke, the butt would fall off. Unfortunately this just doesn’t always happen.
Too much lubrication has always been anathema to extruders. The old saying used to be, “Use no lubrication, then wipe off any surplus.” We have learned much about extrusion since then, and much about the necessity and the effective use of lubrication.
At the end of each extrusion cycle, the fixed dummy block must separate instantly and cleanly from the butt, without pulling the extruded section from the die. Also, without breaking the mandrel or stud in the dummy block. Sticking can be a serious problem. It is essential, therefore, that both the dummy block and the billet are properly lubricated to provide immediate and effortless separation.
Effective lubrication ensures instant and clean separation of the dummy block from the butt. It also ensures clean butt release from the shear. It keeps the container seal face clean and free of alloy, and reduces scrap due to blisters.
Powder or liquid boron nitride, developed specifically for light metal extrusion, is today universally considered to be the ultimate lubricant.
Conclusion
Over the years, the buying practice of most extruders has gradually evolved. At one time, relationship buying was a common practice. The extruder’s supplier very often became a personal friend. He then usually had an opportunity to meet any competing supplier’s price.
Next, almost all tooling was treated as a commodity, and price took precedence over all else.
Now, the astute extruder is making every effort to measure the real value of his purchases. He understands the importance of the interaction between some components, the value of undivided responsibility whenever possible, and the need for a detailed and tight specification to ensure that competing suppliers will provide products of at least equal value.
The successful extruder’s focus now is on improving his profit by improving his productivity. He can no longer afford any poor practices.
Maximum productivity and maximum profit are today actually achievable for the first time by light metal extruders.
Sellers can teach their customers
Sellers know things about their customers’ businesses that the customers don’t know. Because they come in contact with many and varied buyers, sellers have a bird’s-eye view of the forest. This is in contrast to customers, who often see only the trees. Very often sellers can use their wide range of experience to teach customers about their own businesses.
This isn’t a matter of divulging confidential aspects of clients’ businesses to their competitors. The challenge is to translate an industry-wide perspective into knowledge that customers can use. To educate your customers. Companies that can do this successfully reduce their customers’ costs or operating risks and are rewarded in turn with customer loyalty, pricing flexibility or both.
Knowledge generated by having a view of the forest can be as simple as an anecdote or as complex as a cause and effect model tested on large data samples. Such knowledge should help a company answer one of three questions that it cannot address on its own: What will happen if ….? Customers want an answer to the first question so that they can learn from the experience of others; they seek to avoid the cost, time and effort needed to reinvent the wheel. The second question arises because customers’ restricted view prevents them from precisely locating their current position in the forest. Customers find it difficult and expensive to gauge how they stack up against competitors or peers on key dimensions, such as productivity levels or market prospects. The third question relates to issues that lie outside the experience of any single company. Sellers are in a position to extrapolate answers to “What if …?” from the collective experience of their customers.
For suppliers to capitalize on their bird’s-eye view, they must establish systems to collect, aggregate, adapt and share customer experiences. That process by itself is neither unique nor revolutionary, but what makes it remarkable is how few players in the industry are able to develop and use their unique perspective to build customer value. Perhaps because most companies are so busy pushing product out the door, they are unable to step back and systematically develop such systems. Yet those that do are often able to earn a respite from the ravages of commodity competition or to build a sustainable differentiation that generates customer loyalty.
There are three strategies a company can adopt to turn a view of the forest into value for customers and competitive advantage for the business. Each strategy answers one of the questions that customers pose. To carry out the first, the supplier simply relays experience from one part of the forest to another. To implement the second, the company establishes benchmarks, rankings and maps for the players in the forest that allow them to understand their position along key dimensions. To engage in the third, the supplier uses aggregated customer experiences to help customers predict outcomes that they would find too costly or risky to attempt on their own.
Relaying Experience
This approach is the simplest way to create value with a bird’s-eye view, as a supplier transfers learning that took place in one part of the forest to customers in another. This seems like it should be a relatively straightforward process – and on an ad hoc basis it is. But as a strategy, relaying experience requires more than a one-time transfer of a solution from one customer to another. Customers will reward suppliers for their view of the forest only if they can consistently and systemically bring innovative solutions to thorny problems. Companies seeking a competitive advantage with this approach must institutionalize the relaying function across a network of customer and market contract points.
Benchmarking
Customers often lack the information they need to map their own position or performance level in their industry. Benchmarking allows them to draw that map, showing them where they stand in comparison with peers. It helps them answer such questions as, Is my productivity above or below industry standard? And AM I spending more or less than others on information technology?
Internal benchmarking efforts to answer such questions take a lot of time, and the data may not be easily obtainable. For those reasons, such projects are often abandoned or found to be unsatisfactory when they are completed. But the value that companies place on comparative data is evident in the growth of the third-party benchmarking industry. Seller-conducted benchmarks are even more valuable to companies, as suppliers often have access to data that third parties have difficulty obtaining.
When executed successfully, benchmarking can begin to drive customer behaviour and even the agenda and behaviour of entire industries. The benchmarking measures can quickly become proxies or indicators of performance for the industry. The choice of variables is therefore critical: The seller must select those that resonate with their customers’ understanding of their key business drivers. It must also have credibility in the way it processes and presents the data.
Uncovering and Predicting
At the most sophisticated end of the spectrum, companies can combine their knowledge of customers experiences into a bigger picture of the industry – one that customers on their own cannot construct. In this sense, each customer possesses a piece of a larger puzzle, but the picture is evident only when all of the pieces are assembled. Suppliers add value by bringing together the disparate pieces of information that customers hold, assembling the puzzle and interpreting its meaning.



