Progressive Cutting Tools

Written By Mark Batson Baril

What is a "Progressive Cutting Tool" and should everyone be using this type of tooling in their diecutting operation?

There are many different types of tooling for many different specialty applications that involve diecutting. Progressive cutting tools typically fall into the category of male/female or matched metal tooling. They can also include steel rule die or milled punch shapes as well. For the sake of this answer we are talking about a single tool where all of the component cuts are made within this one tool. What this type of tool does so well is cut very complicated shapes from difficult to process materials (AKA - the stuff nobody wants to work with). The shape will often include interior knock-out, slits, embosses, and unusually shaped perimeter cuts. Because the tool would be very difficult to build as a one stage, one strike does it all type of tool, the final shape is accomplished through a series of steps that the material progresses through. As to whether or not everyone should be using this type of tooling - the answer lies in the complexity of the shapes you tend to cut and whether or not you have the type of machinery, designers, and tool makers to run a tool like this.

The Machine:
The typical machine that runs a progressive tool is a punch press or a flatbed platen type press with some type of accurate incremental feed system. The key to having all your options open during the tool design phase is to have a machine that has an open bottom or clearing bolster plate, an open back or side(s) for clearing waste and feeding, and a feed system that is tied directly to the motion of the machine. For moderately to large tolerances (± .062" 1.57mm) the feed system must hold the material accurately the entire time it is in motion and while it is stopped. In this type of tool there is no registration while in the tool except for side guides. For more accurate alignment throughout the process (±.005" .127mm) the feed unit must hold and place the material accurately and then just as the impression is made the feed unit must allow the material to move freely and settle on the pre-punched locating holes (pilots). Having a finely tuned feed unit with a material release is critical to the entire process.

The Tool:
The typical tool layout will have a series of stages where various cuts take place. The natural stages occur in this progression -

1. The material enters the tool and the first impression cuts a series of two or four pilot holes that will allow for exact registration during the balance of the cuts. The more piloting holes you have the more accurate the product will be. The pilot holes make the location by sliding onto or being centered by a tapered male pin in each stage of the tool. Other part related holes, shapes or slits can also be cut at this point. 2. During the second, third, or fourth stage(s), other cuts, embosses, etc…, can be made all in perfect registration using the pilot holes. The real beauty of the cuts made during the several progressive stages of cutting is that extremely unusual or complex shapes can be made via multiple cuts at one image. 3. During the last stage, the final perimeter cut is made and the final finished part is typically blanked through the tool into the part collector below. Because of the way the stages have been planned, the final part will have no chance of nicks or uncut areas in any of the normal joint areas related to a steel rule die.

During all the cutting, the material web is never asked to carry a part that has been pushed back into the web after a cut as is often the case with a steel rule or combo male-female/steel rule die. Each cut stage strips the waste away and only during the final cut does the web become weakened by the missing part. Because of this, the press can be run at maximum speed and accurate parts can be delivered waste free very quickly given just about any material type or part shape.

All in all this type of tool should win the "REALLY COOL TOOL AWARD".
This is one of those great areas to explore with just the right project and I hope that one day you have the need to buy, help plan, or run one in your shop too.

Cutting Registration to Printed Fabric Materials

Written By Mark Batson Baril

A brief question:
I am in the promotional product's business. Currently I am preparing to manufacture a product where I will need to cut sheets of fabric, such as neoprene and ultraseude (polyurethane) into (140) 3 inch (76.2mm) X 1/2 inch (12.7mm) printed strips. I have contacted various die cutting facilities but there are potential accuracy problems since the sheets may not be perfectly shaped and may not align perfectly. I am assuming that some form of laser guided cutting would illiminate this concern?

And a brief answer:
Right off the bat I can think of a few ways to approach the project you are talking about. The fact that your printing may wander and not be in accurate/consistent registration to any corner of the sheet is the main problem.

Registration marks could be printed at the same time as your main printing. These could be designed as either simple slash marks or simple target type circles. This then opens up your options.

1. Use the registration marks to align your materials in any type of cutting machine. Diecutting, guillotine, and laser immediately come to mind. A simple retractable and clear overlay that has been pre-struck acts as your line-up. Each individual sheet of material to be cut is lined up under the retractable sheet. Once the part is aligned and fixed to the cutting bed the clear overlay is moved away and the impression is made for a near perfect cut every time. 2. Other tooling methods would include using see through tools that could be registered one at a time on press by the operator. A clear Polycarbonate (*Lexan) or Acrylic based steel rule die or clicker type die may be your best bet. 3. Circle type registration marks can be used with a *Spartanics type machine that will automatically pre-punch a perfect hole at the mark. This can then be used in conjunction with a tool that has retractable registration pins. This method is used all the time in the membrane switch and flex-circuit industry.Optical registration is also an option on many diecutting machines and may be a good method for your particular job.

Each of these methods will result in accuracy of ± .010"-.015" (.254mm) depending on the operator. These ideas are slow but luckily your quantities are small. If you increase your quantities you will have to inquire about better ways to register to the flexible material you are using.

Rotary Steel Rule Diecutting Hard Anvil

Written By Mark Batson Baril

I recently read a press release that said that a rotary steel rule die could be used cutting against a hard steel anvil. I thought that you could only cut into a soft blanket with this type of die? Could you give a brief explanation of the benefits vs. soft anvil, differences in the tool/press, make-ready differences or comparisons to flatbed steel-on-steel and anything else that could clue me into this new technology? Is it new technology?

This is not new technology. It has been around at least 20 years. Marumatsu Company manufactured a 1350mm & 1700mm (53" & 67") diameter bottom cutter with a stripping section. United Machine has also made a 1.700mm (66") S-S top cutter with a stripping section.

The die is built in some ways similar to a flat die with extra considerations such as the straight rule is always mitered to curved and curved cut pieces are usually no longer than 10 inches. Soft anvil rule is serrated in order to penetrate the urethane blanket where as the S–S rule is a continuous bevel (non-serrated). The rule used in S-S cutting is 4pt center bevel edge hardened with a soft base. The idea here is to run-the-rule-in so that it levels itself off before actual diecutting begins. Rule heights around the cylinder vs. across the cylinder are varied by about ,075mm to ,127mm (.003" to .005") and the final heights are established during the run-in process on press. The hard anvil cutting surface is made out of an 85+ Rockwell steel and stands up to a great deal of pressure. As you can imagine, much of the success you achieve with this process comes from good maintenance of the press and well made and maintained tooling. The rule must be consistently perpendicular to the base surface and that tool base material must be able to maintain a perfect curvature. Excellent tool building and on-press “tricks” account for the success or failure of this process.

The benefits over soft anvil rotary cutting are that you can achieve the same rotary speed with the accuracy and cut quality of flat-bed diecutting. Because the surface you are cutting against is consistent, you avoid the dimensional variance that you get during soft anvil diecutting. Recent improvements in blanket re-surfacing and tool calibration to the soft cutting surface during prodcution have improved finished part tolerances, however there is still a big difference between the two processes.

Typically a stripping blanket is manufactured with each cutting die. The blanket is made from a ,75mm (.030") mounting material with "T" and "L" shaped stripping pieces attached to push off scrap in a section immediately after diecutting.

Because the cylinders run 1:1 in their gearing (opposite to a soft anvil cutting where the soft blanket cylinder will strike the cutting blades in a different spot every turn), the make-ready process can be made in several ways. Upon running the die and beginning the diecutting process and after achieving 80 percent good cutting, make-ready tape is applied to the die cut anvil in the non-cutting areas. This raises the substrate and helps the cutting in the non-cutting areas. Some companies will also make-ready under the die for fine tuning. This is typically the wrong way to go when making ready in flatbed applications but because there is no secondary steel cutting plate on top of the cutting cylinder, behind the die may be the only choice. The tricks here are in choosing a rule that will self-level and having an operator that is level headed enough to make it self-level. The 1:1 gearing/cylinder ratio also lends itself well to using matrix or other counter materials to form the scores.

From what we can see out there, this process seems to be a fairly rare one. Not many presses were made with this capability and the tricks of the trade needed to be successful seem to have taken a toll on its popularity. The companies that are using steel to steel rotary with SRD’s are enjoying some terrific benefits!

Some of the stories that helped answer this question and put together this summary were told by;

Thomas A. Sporleder – Printron

Mike Porter – The Rayner Company

Tommy Moore – Stafford Cutting Dies

Thanks Guys!

Laser Cutting

Written By Mark Batson Baril

(LASER) Light Amplification by Stimulated Emission of Radiation

Lasers come in many different shapes and sizes. They range in usage from the standard supermarket scanner to those being developed as part of military defensive systems. The laser has existed in usable form since the mid 1960's.

The type used almost exclusively for cutting a wide range of materials is the CO2 gas laser. Hole drilling is typically done with solid state YAG lasers.

A laser beam is created by the introduction of gas and electric current to a sealed chamber. As the electricity breaks down the gas an energy is released and resonates between mirrors within the chamber. As it resonates it increases in intensity and at it's optimum is released through a partially transmissive mirror. The beam is then directed to a focusing lens and is further intensified. At this point the laser beam becomes a usable cutting device.

Some advantages of cutting with lasers include, the ability to cut incredibly complex shapes with no tooling or set-ups. This makes them perfect for production or prototype runs for a huge variety of different products.

Laser cutting systems cut quickly and very accurately through a wide range of materials. In general, for steel, laser cutting lies between cutting with wire EDM, which is more precise but slower, and plasma, which is less precise but faster. They go well beyond the range of these other methods as well in that they can cut through just about anything within certain thicknesses.

Given the right material and type of system, tolerances can be held to ±.0005"(.0127mm). Lasers can be found most commonly being used to cut:

• Most types of steel and aluminum. Large lasers will cut up to 1"(25.4mm) steel and .250"(6.35mm) in aluminum.
• Paper
• Wood, plywood, hardwoods
• Rubber
• Most Plastics - Acrylic

When matched to a suitable motion control system, laser cutting provides extremely accurate cuts with a high degree of repeatability over a wide range of materials and shapes.

DIe Cutting Wood

Written By Mark Batson Baril

The question/problem came to Cut Smart basically in this form:

Designs in Wood, Inc.(alias name for case study) manufactures over 400 different sizes and shapes of small wooden parts in Eastern White pine ranging in thickness from 1/8" (3mm) to 1/4" (6mm) with a surface area under 6 square inches (152mm). Generally the surface areas are 3 to 4 square inches (75 - 100mm).

Our current process involves bandsawing 8/4 stock and then slicing and sanding each part. This is time consuming and we are looking for a way to lower our manufacturing costs. We have looked at laser cutting but have ruled it out because our secondary process requires a finished, unburned edge.

I am not completely familiar with steel rule die cutting, and wonder if it is something that we might be able to use. I would be interested in the following:

• Can this type of wood be cut with a steel rule die (tolerances of .010" to .020" (.25 to .50mm are OK)?
• What kind of equipment (press tonnage/manufacturer) would be required?
• The cost of a typical steel rule die?
• The life of such tooling in terms of number of impressions?
• The finished edge appearance?

We answered in this way;

Because we don't know all the shapes you are cutting it is hard to say what your final results will be. The more flowing and rounded your shapes are the better the results will be. Sharp corners and thin areas of image will be tough to cut. There are several types of dies that could work including steel rule dies, clicker dies, EDM cut specialty punch dies and matched metal tooling. All of these are possibilities depending on the shapes you are cutting and your overall volume. Tolerancing like you mentioned will be tough to hold on any but the machined tools and punches.

Eastern white pine is a fairly soft wood that can be cut on a steel rule die. The 1/8" (3mm) thickness will be a great deal easier and will give much better edge results than the 1/4" (6mm) material. We have worked with several companies that build models from wood. They use steel rule dies as well as other cutting tools that cut in one hit. They have had excellent results with all of the types of cutting dies mentioned above. Tools other than the steel rule die will work well, but the steel rule die may be the place to start because of its relatively low cost.

The type of press and the tonnage needed would largely be a factor of how many you plan to cut at the same time on a sheet. One at a time like you describe would require very little tonnage 1 - 5 tons and a very common hydraulic type press would work well. Costs may range from $5,000 used to $20,000 (USD) new depending on the size and style.

A simple one up steel rule die would cost in the range of $100 to $300 (USD) depending on the shape and who you buy it from. The more images you add to the tool the cheaper each image becomes. Specialty punches and machined tools would cost substantially more.

Although we have seen manufacturers with millions of impressions on their tools, the material you are cutting is tough. I would estimate no better than 10,000 hits from a tool before it needs a reknife.

Generally you will find that an extremely hard, thin rule with a very long bevel will work well. Support the rule as high as you can with your base material for best results. There is a rule called "Razor Rule" that works excellent for cutting wood. If diecutting is still something that sounds like it would fit your needs, I suggest connecting up with a local qualified diemaker or diecutter that would be willing to cut a few samples for you. This will show you the type of product you can get and how economical this process may be for you.

Depending again on the shape of the cut, your edge results will probably have a slight roundness to the top and a square, sharp bottom. Grain, moisture content, sharpness of the tool, cutting surface wear, will all effect the results. Your with grain cut will most likely be of better quality than the cross grain cut. Knots will be a problem!

High speed CNC routering is another method we have seen used that performs the same way the laser does without the burned edges. Although slow compared to cutting with a die, the method may make sense if laser cutting came close to making sense for you.

Die Cutting with Rule Joiners

Written By Mark Batson Baril

Cut Smart recently dealt with this question:

Does anybody out there know how to create a perfect joint where radii come into one another on a steel rule die? We have more than one customer that insists that their radius cornered gaskets be run with a common cut in both directions to save material. On the other hand we have a diemaker that insists that he must have a double knife in order to put in the radius corners. There must be a way but we’re diecutters not diemakers and have no idea how. Should we find a new diemaker or is there some information out there they could use? Thanks!

For the common application where a steel rule die will be used in some type of flatbed cutting operation, the best answer we can give is to use Rule Connectors - A.K.A. - Rule Joiners - These are a love/hate product. Some people swear by them; others swear at them! Rule Connectors are a solid steel machined punch which replaces the regular steel rule at tough to make joints. Rule Connectors typically replace normal rule where rules meet at a radius corner.

The Plus Side is this -

• At the point where most diemakers have an major problem making a joint that works and is accurate, especially in tough materials, the rule is replaced by a virtually indestructible piece of machined steel that is perfect. The joints are moved to an easier and more desirable location usually on a straight-away and the problem is solved.
• They are readily available, in a variety of different radii.
• The Custom possibilities are endless.

There are two main drawbacks -

• One is how the rule and punch is installed. Rule Connectors typically have "V" notched ends that join rule to the punch. If you do not cut the rule to the right size or the bevel on your rule is off-centered, you will pull your hair out trying to get the tool to work properly. However, if it is installed correctly, you will have virtually no spaces or natural nicks in the rule pattern. When you put it together right, it works great, especially on materials that love to separate rule.
• The other drawback is the cost of the Rule Connectors. They cost roughly $20 to $30 (USD) each. Most of the time the cost can be justified by eliminating downtime, rule repairs and material waste. If you have a small run, the cost may be prohibitive.

To answer the question more pointedly –

The diemaker may be right! Even though there are rule joiners on the market, you will leave yourself open for more actual natural nicks than if you had allowed for space between your cavities and had made only one or two natural nicks in each cavity. Depending on your customer’s final product, this may be a big factor when selling the job in the first place.

Other answers in a case like this one are numerous - Could the product be more easily cut in a rotary application where a solid machined or chemically etched tool may be of use? No joints here! Also it may be worth thinking about a fully machined punch or die that actually outlines and cuts the entire image without any joints. More expensive, but in some cases that doesn’t matter at all. Have you thought about, for short runs, laser cutting, waterjet cutting or CNC Knife cutting machine production? All of these are methods that are being used and are working well in the right situations.

Rule joiners are not new to the market. As is the case in many situations, the usual for one manufacturer is the unusual for the next. Good luck in all your cutting adventures.

Thin Foam Diecutting

Recently a manufacturer came to us with a production problem. It went something like this:

We have been over the edge with one particular job recently and could use some advice. We have a customer who has us diecut promotional models from 1/16" (1.587mm), fairly dense, polystyrene(foam cups are made of this). About ten different models are cut on separate steel rule dies. Each die runs the same part in up to a twenty on configuration. All the dies run between 1,000 and 2,000 inches of cut and are approx. 24" x 36" (610 x 918 mm). We use a 1 1/2 pt long double bevel rule and the dies are all rubbered solid with relieved areas in the bigger open spaces. We cut this job on a large clamshell type press and have had very good results cutting into a nylon (plastic) plate. Our problem is that we have run into one particular tool that just will not cut. Some areas will cut and others will not. We have made-ready forever on this job and feel like we know what we are doing, yet we get no where! Our diemaker has checked and rechecked the rule and says it is still good. The problem areas tend to be in areas of more rule concentration, some rules being as close together as 1/8" (3.175mm), yet similar situations have yielded better results. Help !

OK lets approach this with pure logic. Given your information filled question we can make a few assumptions;

Since you have run similar jobs before and had good results…

Tonnage Factor or what pressure your press is able to develop is adequate to get the job done. If you had not run similar jobs well, this would be extremely important to look at.

Die Materials meet the needs of the job at hand. A double long bevel ("razor rule") or sometimes even a micro-serrated rule usually will work great with this type of foam. Side-face rule may even work better for you in some areas depending on the shape.

Cutting Plate made of a dense and durable plastic such as nylon is well suited. We often recommend that diecutting, especially in long runs, be made as a steel blade onto a steel cutting plate, but foam is a totally different animal. If it works with the rest of your dies it should work with this one.

Areas to look at a little more closely are;

Ejection material - By rubbering a tool with a solid piece of ejection material many problems can be both eliminated and created. In this case where you have what sound like some very small areas you may be creating zones in which the foam cannot be easily compressed into. Remember the idea of ejection is to move freely with the stroke of the cut and then still have enough "kick" to remove that part. It may be worth trying a denser "gum type" rubber that fits your narrow areas ("areas of concentration" as you put it), more loosely. This will allow the ejector to move downward and still have the power to pop that part out. You could start by removing all the rubber. Can you get it to cut now? If so, then more than likely some experimenting with different materials for this one tool will yield good results.

Die Ruling can also be changed to incorporate side bevel rules in the area giving you problems. By taking the material being cut and pushing it towards larger open spaces rather than crushing it into the small slot, you can relieve pressure and perhaps gain some cutting power in that area.

Material Type - Are you sure the foam material you are purchasing is the same density and make-up as last time you cut for this customer. A slightly different material may knock out some of the earlier assumptions we made. I know this is a weak point, but in some situations you need to look at every angle!

The Impossible Image - We have certainly run across situations before where an image cannot be cut. In this case, where you have rules that are very close together compared to the thickness of the material, you may have to take a step back and look at the actual design of the part and the limitations of the die / press / material / etc... . Can the image be changed to eliminate the problem areas ? Will your customer kill you if you even suggest such a thing? Can this be avoided in the future by working with the designer of the part?

So logically, assuming that we have all the information correct, we have eliminated the tonnage factor, die materials, cutting plate problems and make-ready. Material type is a weak one so lets forget it for now. I would concentrate on ejection material problems first, die ruling second, and then as a last resort start talking and investigating problems with the design of the part vs. the capabilities of the process.


As it turned out in this case the ejection material was able to be changed enough to solve the problem. From that point on the diecutter became involved in the design process from the very beginning and new projects seem to be flowing smoothly.