Industry Technologies
By Dr. Trevor Little, Professor Emeritus, North Carolina State University and Needle's Eye Correspondent
Almost every time anyone in the industry talks about cutting, they refer to “High Ply Cutting”. It may be useful to trace the origins of high ply cutting as it is much different from “Low Ply” cutting.
Recent exhibitions (Furniture Manufacturing Expo in Hickory, North Carolina and IFAI Expo in Charlotte, North Carolina) were great examples of low ply cutting reinforcing the relevance of low ply cutting in the industry. Today, we need to focus on high ply cutting and the requirements thereof.
CAD/CAM – Computer-Aided Design and Computer-Aided ManufacturingIf a manufacturer is going into high ply Cutting, an up-to-date CAD/CAM system is essential. Cutters will do what the CAD/CAM systems dictate. This means that CAD/CAM operators need to know the requirements for high ply cutting.
Cutting productivity depends on a few parameters:• Height of compressed spread• Number of straight lines in the pattern• Number of curved lines in the pattern• Number of notches in the patterns
The reasons are obvious: straight lines cut faster than curved lines and notches slow down the cutting.
For many years, the cutting height of the compressed spread was 3.5 inches (9.144 cm) but recent machines are claiming 4.33-inch (10.998 cm) compressed spreads (that’s just over a 23.7% more productive system).
Knife intelligence High ply cutting requires knife intelligence. This is well documented in Joe Gerber‘s patent and that patent kept Gerber Cutters as leaders until that patent expired after twenty years.
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Dr. Trevor Little
Check out previous Spreading/Cutting Room Optimization articles:(Part 1: Fabric Spreading) Issue #14 – August 2022
(Part 2: Introduction to Low Ply Cutters) Issue #16 - October 2022
This image shows a cross-section of a typical needle knife (used in high ply cutters), the paper underneath that sits on a bristle bed for vacuum, and a layer of plastic on top. The vacuum and plastic on top are used to create the compressed height. Compressed height gives the productivity of the cutting system.
The needle knife is turned toward the forces that bend the blade so that the parts are the same from top to bottom. Some firms have justified high ply cutters based on sewing automation as all parts are cut in the same size and shape.
High ply cutting is not trivial as many individual components are involved. Just obvious things like perforated paper underneath the spread, bundle papers that are porous, thin plastic on top, and of course, Part ID (identification).
The marker is electronic. So, Part ID could be a printed paper (like a marker) or a separate device that applies Part ID stickers. For all products that are put together, Part Tracking is most important. The configuration of the cutting room has also changed. One cutter can move between spreading tables. The actual configuration very much depends on orders, spreading table length, type of fabric, spreading speed, etc. Spreading machines can also move from table to table. How the cutting room is configured leads to optimum productivity. It is also important that your fabric supplier knows of your requirements. In fact, all of your suppliers of papers, plastics, stickers, etc. All this plus one or more trained CAD/CAM individuals.
Cutting rooms of this type are known to operate around the clock as there are a lot of costs to be amortized. They are most productive when operating efficiently.
Parts are often problematic. It is an important consideration and manufacturers and vendors need to advise accordingly. Meaning that parts can be housed at the vendor, manufacturer, or a third party.
A question
I must ask your opinion here. Basically, does a patent hinder or help ingenuity? I am pondering this issue.
On one hand, the patentee firm benefits by controlling the market for 20 years. As a manufacturer, that 23.7% increase in productivity often keeps the firm in business.
So, what is the path forward because that’s where we are going?
