Volumes of production
From small batches of around a hundred units, to thousands.
Unit price vs. capital investment
The low cost of the cutters makes this a highly economical process even for small runs. Sheets of material may be fed individually but if the material comes on a roll there will be a massive reduction in the cost of the final products.
Speed
Die cutting is one of the predominant manufacturing processes for packaging, with production cycle times of up to thousands of products per hour. Unlike in molded products, the cutting speed is not affected by the complexity of the shape. Assembly, however, is more labor-intensive.
Surface
The surface is dependent on the material. The cut edge, however, is clean, precise, and with a very, very fine radius where the cutter has cut through the material. As you might expect, the sheets can be finished with various forms of printing or embossing, or a combination of the two.
Types/complexity of shape
The complexity of the shape is really dependent on the size of the cuts. Very fine slots of less than about 1/5 inch can be difficult to cut. One of the design issues to bear in mind is that the excess plastic around the part needs to be removed and cleaning plastic from fine holes can be difficult.
Scale
Most manufacturers should have no problems at all in cutting sheets of up to 1,000 by 28 inches, and some are able to go slightly larger and cut straight from a roll. However, material choice is more limited if it comes on a roll. Printing on large sheets, above 1,000 by 28 inches, may be difficult due to the limited availability of large-scale printing machines.
Tolerances
Very high tolerances.
Relevant materials
A large proportion of the material used is polypropylene due to its ability to form a strong integral hinge. Other standard materials include PVC, polyethylene terephthalate (PET), paper, and all sorts of cardstock.
Typical products
Die cutting is extensively used for packaging, especially boxes and cartons. For this type of product, assembly is required to construct the three-dimensional structures. Other, more product-focused, applications include lampshades that require complex assembly (pictured), toys, and even furniture.
Similar methods
For cutting flat sheets, try laser (p.46) or water-jet cutting (p.42).
Sustainability issues
Die cutting can be more economical in terms of material use if shapes are nested and material wastage is reduced. The nature of the material determines whether waste (of which there will be a considerable amount) can be reheated and recycled.
Further information
www.burallplastec.com
www.ambroplastics.com
www.bpf.co.uk
Water-Jet Cutting
AKA Hydrodynamic Machining
Product |
Prince chair |
Designer |
Louise Campbell |
Materials |
water-cut EPDM (ethylene propylene diene monomer) on laser-cut metal, and felt |
Manufacturer |
Hay |
Country |
Denmark |
Date |
2005 |
The decorative pattern on this chair illustrates the potential of water-jet cutting to cut intricate patterns into a three-dimensional material.
From as early as the mid-nineteenth century, water jets have been used as a method of removing materials during mining. The modern-day process (also known as hydrodynamic machining) has been cranked up to produce an incredibly fine jet of water, typically 1/50 inch, which is forced out of a nozzle at a pressure of 20,000–55,000 psi (pounds per square inch) at velocities of up to twice the speed of sound. Water-jet cutting produces a fine cut using water alone, but with an additional abrasive, such as garnet, it can be used to cut through harder materials.
– A cold process, so it does not heat the material.
– No tool contact, therefore no edge deformation.
– Can be used to cut very fine details in a variety of materials of different thicknesses.
– In particularly thick cuts, the jet can move from its original course as it eats into the depth of the material.