Over 75% of manufacturing involves the cutting of materials, using various mediums; among them blades, cutting tools, and lasers. However, the majority of converting of materials is done by knives and blades with the actual cutting done by the edge of a knife and here is where our expertise comes into play. American Cutting Edge provides blades and knives to a myriad of industries. To provide the very best product for the job, we work closely with the customer to produce a tool that achieves a balance between form, function and performance. There’s a number of measures to be considered in the design of the optimal cutting tool for any process. One of the most important is the cutting edge. A customer comes to us and says: “I need a sharp blade”. What is sharpness? It’s the amount of force needed to overcome the resistance of the material being cut. But is a “sharp” blade actually the best blade for you? Would you perhaps be better served by a cutting edge with some geometry to the edge that will reduce sharpness but extend blade life? What’s most important to you, our customer? Precision of cut, blade life, or perhaps cost? Usually, it’s a combination of all three. This is when a consultation with one of our product managers can be helpful. ACE’s product managers are experts in our industry, with specialized training, continuing education and years of experience working within the converting industries. In helping our customer to design the best possible blade with the most effective cutting edge, your product manager takes into consideration a variety of factors, but these five are the among the most important to consider:
1) The base material of the cutting edge. What material will give you the best results for your application? Should you use a composite blade to get the best of both worlds?
2) What are the optimal angles for the cutting edge of your blade? For example, a steeper angle reduces the contact area of the cutting edge and reduces the force needed to make the cut, increasing keeness and decreasing friction, but also making the blade less durable. What’s more efficient for your application? Single, double or triple bevel? A single or double edge blade?
3) Honing not only removes burrs, but it removes some stress risers
from an edge and by putting a radius or some other geometric form in the edge, reduces friction and increases durability, but the trade-off is a reduction in sharpness.
4) Edge finish—a greater polish reduces friction and reduces stress
risers.
5) What’s your cutting speed? The faster your line goes, the more heat is generated and this can cause a problem with sharpness.
Other criteria that an ACE product manager will take into account is the shear strength of the material you are cutting versus how much force it takes to break the knife, or the TRS (transverse rupture strength). Also important is the depth of blade indention to initiate the initial cut–this calculation is called the “blade sharpness index”, or BSI. Are you slicing or cutting material? The thinner the blade, the less friction and the more precise the cut; a thicker blade crushes the material.
The opportunities for improved costs and throughput are not just limited to reduced unit cost of the knife. In some applications, knife users have millions of dollars invested in production equipment. An hour of down time is a lost opportunity to achieve maximum throughput. A recent customer was changing blades frequently and each change took about 1 hour. The productive output of this converting line was approximately $40,000 per hour. By shutting the line down to change knives, the customer was losing $40,000 in output, far more important than the cost of the knife. By improving the technology of the knife being used, ACE was able to increase knife life by a factor of 5, thus increasing throughput by almost $200,000 per knife change. By focusing on the customer’s need to maximize throughput and not on making the most inexpensive knife, ACE was instrumental in helping this customer improve productivity. Can we do the same for you?
Besides the engineering of the cutting edge, ACE is also able to suggest other ways to increase blade life and durability, through a special selection of materials, coatings, and metal treatments. These are all topics we’ll cover in future newsletters.
Article courtesy of American Cutting Edge Volume 2, Issue 1
