Volumes of production

Individual pieces can be made, but the process is more suited to batch or mass-production volumes.

Unit price vs. capital investment

The setup costs involved are low, because the printed resist removes the need for any hard tooling. However, the unit costs are not likely to be drastically lower for batch items than for mass-produced items.

Speed

Depends on the complexity of the artwork.

Surface

Due to the corrosion of the metal, any half-etched surface has a rough and matte texture. However, this texture often becomes a decorative feature. Cut edges are free of burring.

Types/complexity of shape

The process is ideal for cutting thin sheets and foils. It also allows for highly intricate shapes and details to be cut without any blemishes such as the burn marks that are sometimes caused by laser cutting (see p.46).

Scale

Generally limited to standard sheet sizes.

Tolerances

Tolerance levels are determined by the thickness of the material. The holes must be larger (typically 1 to 2 times) than the thickness of the metal, which gives a material with a thickness of between 1/1000 and 1/500 inch a tolerance of ±1/1000 inch.

Relevant materials

A range of metals can be used in the process, including titanium, tungsten, and steels.

Typical products

Electronic components such as switch contacts, actuators, microscreens, and graphics for industrial labeling and signs. The process is also used for industrial components, and the military use it to make a flexible trigger device for missiles. The trigger is so fine that it changes according to air pressure the closer it gets to its target.

Similar methods

Electron-beam machining (p.24), laser cutting (p.46), blanking (see metal cutting, p.59), and electroforming for micro-molds (p.250).

Sustainability issues

Although the process involves the use of harmful chemicals, responsible disposal has been introduced through a cleaning process that removes contaminants and allows the liquids to be recycled back into the process. This reduces waste along with water consumption. Additionally, the complexity and accuracy of the etching means no secondary processing is necessary, saving further resources and energy. Unlike with mechanical cutting methods, waste material is not available to recycle.

Further information

www.rimexmetals.com

www.tech-etch.com

www.precisionmicro.com

www.photofab.co.uk

Die Cutting

Product	Norm 69 lampshade
Designer	Simon Karkov
Materials	polypropylene
Manufacturer	Normann Copenhagen
Country	Denmark
Date	2002

The 69 lampshade (above) is sold, flat, in boxes of pizza-size proportions. The flat pieces of die-cut plastic that are contained in the box take the customer about 40 minutes to fold and assemble into this complex structure.

The simplest analogy for this process is to think of a cookie cutter for making shapes from dough in the kitchen. Just as easily applied to paper or plastic, die cutting is a simple process that involves a sharp edge being brought down onto a thin material to cut a shape in a single step. A die-cutting tool has two functions: The main function is to cut a shape from the sheet; the second is to apply creases to the material to allow it to form an accurate bend. The creases are necessary when constructing three-dimensional shapes and integrated hinges from a sheet.

–  Low setup costs and cost-effective for batches.

–  Can easily be combined with printing.

–  Many shapes can be cut in a single cutting action.

–  Three-dimensional products need hand assembly and are limited to a set of standard constructions.