VP and Testing Accelerates Production Time for Hand-held Knife
Unique automotive and aeronautical influences
on an internally ribbed, knife handle design ensure perfect molding,
strength, cost-effectiveness and reduced manufacturing time.
Engineering Design Consultants, Ltd., EDC (Portland, OR) - a design firm - designed a hand-held knife with its target cost cut by 25 percent and manufacturability increased by more than 100 percent through the application of more advanced design and manufacturing techniques including:
- CATIA software was used (hand-held knives are typically designed by hand) to design the knife.
- The Black Out knife underwent FEA as opposed to manual physical testing.
- Injection molding was chosen for its speed as the method of production for the Black Out.
- Nylon 6 was chosen for its durability, and ease and speed of molding as the material for the Black Out knife handle.
Created in the same manner as a car or airplane, EDC's Black Out knife design is a landmark application of advanced design and material techniques in a consumer product area, which was until recently unfamiliar with the advantages of virtual prototyping. Using advanced CAD software, EDC was able to produce the hand-held Black Out knife in a little more than three months - less than half of the normal production time for a knife of its kind.
The Project
When Kershaw Knife Company (Wilsonville, OR) - an international knife
manufacturing and distributing company that prides itself on using
high-quality materials and state-of-the-art production techniques -
contacted EDC with a request to design a new pocketknife style; the
design firm accepted the rather unusual job. While performing some
consumer and computer engineering design work, EDC's main focus had
always been automotive and aerospace design for clients like
Freightliner, Textron, General Motors and Gulfstream.
To tackle this design job, EDC decided to move away from traditional methods of knife making that use inefficient hand-made designs, manual testing, and product material choices based on aesthetics and prior performance records, and instead chose to use powerful design software - CATIA - Finite Element Analysis (FEA) and advanced composite materials to complete the Black Out design at a greatly accelerated pace. The external and internal Black Out design was created using automotive and aerospace aesthetic and design principles. Like most new cars or airplanes, EDC wanted to simplify the knife design and give it a sleek and futuristic look. To achieve the goals of simplified look and small physical packaging, EDC engineers chose to trim the internal liners of the knife handle to achieve the target packaging envelope set forth by Kershaw.
An innovative rib design was created to give the knife a high level of stress load sustainability while allowing the designers to place the knife fasteners on the inside of the handle, keeping the outer look sleek.
The 3-D CAD design of the knife handle was originally created in CATIA. The design then underwent extensive FEA to ensure that the ribbed design would withstand appropriate stress. Until the Black Out design, no CAD or FEA work went into the production of a new knife. Typical knife prototypes undergo time-consuming physical stress field-testing before they can reach the consumer market. The FEA analysis performed on the CATIA-made virtual prototype of the Black Out substantially reduced the time-to-market for the knife.
To further decrease the time-to-market, EDC engineers also designed the asymmetrical knife handle internal ribbing design with a consistent wall thickness to facilitate injection molding. The consistent wall thickness enabled by the internal ribbing structure prevented sinks and surface defects that are common in injection-molded asymmetrical objects with varying wall thicknesses. The unique automotive and aeronautical influences on the internally ribbed knife handle design ensured perfect molding, strength, cost-effectiveness and reduced manufacturing time.
EDC chose durable, yet easily molded materials for the handle of the Black Out. A popular automotive part material, Nylon 6 was chosen for the handle exterior for its ease of mold, weatherability and durability. The entire plastics injection molding of the Black Out took less than 13 weeks.
The Results
By applying virtual prototyping and design engineering to the design of
a product traditionally made by hand, engineers were able to cut the
normal time-to-production for a hand-held knife from the usual eight
months to just over three - reducing their cost target by 25 percent
and increasing Kershaw's manufacturability more than 100 percent.
The Black Out knife design represents one of the first knives on the market to be designed in CATIA and to undergo FEA analysis. Subsequent knife manufacturers like Kershaw have begun to use the virtual prototyping and testing process; however, the Black Out is still the only knife on the market that uses internal fastening systems and a structurally superior injection-molded internal rib handle system. The Black Out knife, once honored by Blade magazine as the year's best buy, is still Kershaw's best-selling knife to date.
For more information contact Engineering Design Consultants, Ltd. (Portland, OR) at (503) 735-2100 or via its website at www.edc-ltd.com or Kershaw Knives (Wilsonville, OR) at (503) 682-1966 or via its website at www.kershawknives.com.
