TRIZ Tutorial #3

Alla Zusman and Boris Zlotin
Ideation International Inc.

THE ELEGANT INVENTION -- SEEKING IDEALITY

Problem 1: Removing layers of insulation

Certain metallic surfaces must be coated with a thick layer of insulating material. Removing this coating later is difficult, however. How might this be accomplished?

As mentioned in the second tutorial, applying the principle of prior action to the above problem leads to the suggestion that a steel wire be placed underneath the insulation layer (i.e., before the insulation is applied).  Pulling the wire then easily cuts the insulation. 

Although this is a good approach, it does not completely solve the problem. The next step is to select a wire of appropriate diameter. To withstand the pulling force, a relatively thick wire must be used; however, this requires more material (wire), and also necessitates greater force to cut the insulation. 

The following physical contradiction was formulated: the wire must be thick in order to withstand the pulling force and the wire must be thin to minimize the cutting force and reduce material consumption.

The principle of separation based on condition recommends placing the system in one state (either thin or thick, in this example) and trying to change the conditions of the environment or other adjacent systems to satisfy the opposite requirement.

To determine which should be the "basic" state, we must understand the conditions influencing the situation. And to do this we must consider the relationships between wire thickness, required cutting force, and mechanical strength. For example, by reducing the wire's diameter we proportionally reduce the required cutting force, but we also reduce (by the power of two) the strength of the wire, which is a function of its cross-sectional area. But the necessary strength of the wire also depends on the the hardness of the insulation layer that the wire must cut.  If we reduce the insulation hardness, a thin wire can be used.

One well-known way to soften a material is to heat it. This can be done by passing an electric current through the wire. The hot wire burns through the insulation layer, reducing the amount of pull required (and thus reducing the probability that the wire will break).

Problem 5. Producing pure copper

In the electrolytic process by which pure copper sheets are produced, a small amount of electrolyte liquid remains in the pores on the surface of the sheets. When the copper sheets are stored the electrolyte evaporates, creating oxide spots on the surface which reduce the value of the copper and result in substantial losses. 

The best way to solve the problem was to avoid creating the pores in the first place. This approach was immediately rejected by the manufacturer, however, because it required lowering the d-c current substantially, which would dramatically reduce productivity. Instead, they decided to reduce the financial losses by washing the sheets of copper prior to storage to remove the electrolyte from the pores. This was not only costly but inadequate, and attempts at improving the washing process continued for over 15 years.

For most of the students who responded, this problem was not a difficult one. Indeed, once the contradiction is formulated (the current must be low to avoid pores, and must be high to increase productivity) the solution can be reached in a fairly straightforward manner by applying the methods for dealing with physical contradictions. To do this, we ask ourselves the following: Where (if trying to resolve a contradiction in space) or when (for resolving a contradiction in time) do we really need the current to be low to avoid pores? The answer is obvious: we need low current at the end of the process to prevent the pores, while during most of the process the current can be high to ensure a high level of productivity. Given the fact that the complete cycle takes 72 hours, it was discovered that reducing the current for the last 30 minutes only was enough to produce pore-free copper.

Two important comments can be made:

Comment 1 -- Initially, this was not an easy problem at all. Indeed, for over 15 years (with millions in losses sustained every year) engineers from similar productions all over the world tried to solve this problem. They achieved very limited success, mostly by pursuing better ways to wash off the electrolyte. Those who worked on this problem during a TRIZ workshop were amazed that they could find an answer in half an hour. It is important, however, to emphasize why this problem became easy to solve:

• Psychological inertia was reduced by realizing that it is much better to eliminate the root causes of the problem (the pores, in this case) than to fight the harmful results of the problem (the poor appearance of copper sheets). Indeed, by focusing on the root causes, the entire problem statement was changed.
  
• The "impossible" (as noted in the previous tutorial, when asked if there was a way to eliminate the pores, the manufacturer stated that it was "impossible") was transformed into a contradiction.

• The Separation Principles were applied to resolve the formulated contradiction.

Comment 2 -- Experienced TRIZ specialists know that contrary to solving a problem by trade-off (which always produces less than ideal results), resolving a contradiction often yields unexpected additional benefits. In this case, while discussing the idea of lowering the current at the end of the process, it was revealed that the current normally used was not the best from a productivity standpoint. Rather, the current level was the result of a previous trade-off by which an "optimal" current was chosen. This optimal current didn’t provide the highest productivity level, nor did it completely eliminate the pores, although it reduced them. After this discovery, the recommendation was made to increase the current during the main part of the process (still reducing it at the end, of course), to increase productivity even more.

Automatic welding machines use a steel wire unreeled from a rotating drum as an electrode. A special motor in the welding head pulls the wire during the welding process. When welding stops the motor stops, but the drum continues to rotate under its own momentum and the wire becomes entangled as a result.

The idea of using brakes to stop the drum from rotating freely was considered and rejected because it necessitated a more powerful pulling motor and, hence, a heavier welding head. This idea could be reconsidered, however, after formulating the following physical contradiction: The brakes should be present to stop the drum from rotating, and should not be present to avoid expending additional energy.

It is quite obvious that this contradiction should also be resolved in time: that is, braking should be applied only when welding stops. Some respondents recommended the addition of movable brakes controlled by a special electronic device, which would monitor the process and signal the brakes when appropriate. And indeed, such systems had been designed, but they were costly and inconvenient.

Several respondents went further, noticing the similarity between this problem and invention 14, wire enameling method:

To manufacture a particular electronic wire, the wire is first passed through a liquid enamel bath and then through a die that  removes any excess enamel and sizes the wire. The die must be hot to ensure reliable calibration; however, if the wire feed is interrupted for several minutes or more, the enamel in the hot die hardens and firmly grips the wire. The process must then be halted while the wire is cut and the die cleaned.

The contradictory requirements (the enamel should be hot to ensure calibration and should be cold to avoid hardening) are separated in time as follows: 

The die should be in a hot zone while moving and in a cold zone when it stops moving. This is achieved by fixing the die to a spring. When the wire moves, it pulls the die into a zone where it is heated (either by induction or by contact with the hot chamber walls). When the wire stops, the spring pulls the die back into the cold zone.

This is an elegant solution: the required movement has been achieved automatically and, for all practical purposes, without special devices. The TRIZ specialist would say that this solution has a high degree of "ideality."

Genrich Altshuller, the creator of TRIZ, discovered that all technological systems evolve towards increasing ideality. Ideality is defined as the ratio of the sum of a system’s useful functions to the sum of its undesired factors or effects.  This ratio is a qualitative representation of the overall "price" we pay for the useful functions, including the cost of the system, the space it occupies, the energy it consumes, etc.

IDEALITY = Useful functions/undesired factors and effects

Based on the above definition, Altshuller developed requirements that an ideal system must satisfy: The ideal system performs its function without actual existing. Actually, we don't need the system itself -- what we need is the function. What's more, all harmful effects are associated with the system rather than with the function. For example, we need a means of transport rather than, specifically, a car. Of course, an ideal system is exactly that -- an ideal, a fantasy.  In reality we can only aspire to the ideal system, but very often we can approach it quite easily.

Testing a material’s resistance to aggressive mediums (acids) is usually performed by submerging a cube-shaped sample of the material in an acid. The acid is held at a fixed temperature for a predetermined length of time, after which the sample is rinsed, dried, and weighed to determine its loss in mass. Such tests are usually conducted in platinum vessels because platinum is very resistant to acids. Platinum is expensive, however, and thus most testing facilities have only one test vessel. As a result, testing must be performed sequentially -- a time-consuming process.

To improve the situation, it was suggested that the test sample itself should hold the acid, making the chamber unnecessary.

Invention 18. Date-stamping eggs

At poultry farms, eggs roll down into collecting trays. Workers then pack the eggs into cartons. To avoid introducing a special stamping machine, the gloves used by the workers can be fitted with an ink supply that feeds a date-stamp on one of the fingers. As the eggs are packed, they will then be date-stamped.

Invention 19. Self-restoring archery target

A typical archery target must be replaced after several rounds. An alternative target is made of an electromagnetic ring filled with a ferromagnetic substance. The ring is held vertically; the arrow holes are restored after each shooting.

Invention 21. Turning train wheels during operation

A train wheel must have a unique shape to be in optimal contact with the rail -- however, the wheel gradually wears and its shape changes. It must then be removed, set on a lathe and turned to restore the original shape. As an alternative method to restore their shape, train wheels can be turned by using their rotation during operation. This is done with the help of a special cutting tool fixed to the body of the railroad car.

The upward stream of air produced by convection from the heat of a light bulb can be used to rotate a lamp shade.

If a pump for spraying trees is fastened to the operator's boot, pump pressure can be created as the operator walks.

The ideal vision serves as a target for problem-solving. Even if the ideal solution is not 100% achievable, it directs you to the area where the most elegant and powerful solutions reside. To develop an ideal vision of a solution, try to think according to the following patterns:

• An element producing a required useful effect is no longer necessary
• An element causing a harmful effect is removed from the system
• A harmful effect withdraws itself
• A required useful effect is achieved without increase in cost or system complexity

Try to apply the ideal vision approach to find solutions for the following problems:

To reduce the hardness of the insulation layer -- i.e., to soften it -- we decided to warm up the material (see the beginning of this tutorial). What is the most ideal way to do this?

Problem 6. Silvering contact leads

When silver-coating copper lead wires attached to copper contacts, silver waste is minimized by using a plastic sheet with small holes to accommodate the lead wires. The sheet prevents the bodies of the contacts from entering the silver-plating electrolytic bath.  During the production run, however, the level of the bath changes slightly, resulting in defective parts. What can be done to avoid this?

Problem 7. Ideal cartridges

Each time an automatic rifle is fired, an empty cartridge case must be removed from the chamber. The cartridge case is made of brass, a relatively expensive material. Any suggestions?

Try to apply the ideality approach to things around you and to come up with a better approach.

© 2004 Ideation International Inc.