Volumes of production
Medium to high levels of mass-production.
Unit price vs. capital investment
Although the process sounds complicated, it is actually based around a very simple principle that involves minimal tooling and fast setup times. This makes it unusual in that it is a high-volume process that is also cost-effective for short runs.
Speed
Simple shapes can be produced at a rate of 500 units per hour.
Surface
Rotary swaging gives an excellent, shiny surface as a result of the hammering, which acts to buff the surface. The finish is better than stock tubing that has not been swaged.
Types/complexity of shape
Because of the action of the rotating tool, options are limited to symmetrical and round shapes. All shapes of tubing, rod, and wire can be converted into round profiles using this process, but stationary-spindle swaging needs to be used to obtain non-round sections.
Scale
Depending on the type of machinery available at the manufacturer, dimensions can vary from 1/50 up to 13¾ inches.
Tolerances
Good control of both the inside or outside diameter, depending on how the dies are set up.
Relevant materials
Ductile metals are the most commonly used. Ferrous metals with high carbon contents can be problematic.
Typical products
Golf clubs, exhaust pipes, screwdriver shanks, furniture legs, and rifle barrels.
Similar methods
Machining (p.18), impact extrusion (p.146), and deep metal drawing (used to stretch a metal sheet into a variety of hollow shapes, such as cylinders, hemispheres, and cups).
Sustainability issues
Rotary swaging is most commonly cold-worked so does not require heat, which means energy use can be significantly reduced. Additionally, there is no loss of material during manufacture and parts have increased strength after being worked, which improves durability and product life-expectancy.
Further information
www.torrington-machinery.com
www.felss.de
www.elmill.co.uk
Pre-Crimp Weaving
Product |
architectural mesh |
Materials |
stainless steel and brass |
Manufacturer |
Potter & Soar |
Country |
UK |
Date |
2005 |
Architectural mesh can be produced to a wide range of specifications, to increase or decrease density, texture, and transparency. Different optical effects can therefore be created and, in addition, it is self-supporting so it can be used for ceilings and cladding, as well as ornamental balustrading and furniture.
Pre-crimp weaving is a great case study in how unexpected materials can be woven and used decoratively. In the same way that soft fabrics are woven for decoration, rigid lengths of wire can be woven to dress and adorn our urban landscapes. Industrial weaving takes many forms, from the chain mail of industrial fencing and fabrics to architectural cladding. Although not recognized as a major industrial process, pre-crimp weaving can be utilized as a way to design large-scale decorative metal screens.
It is a two-step process. The first involves lengths of wire being crimped at specific points. This simple process is based on the wire being fed between two rollers, with teeth biting a kink into the wire at specific distances. In the second step, the long strands of crimped wire are gathered and fed into an industrial heavy-duty loom, where they are cross-layered with another set of pre-crimped wires and woven into sheets.
1 The lengths of wire are fed into the crimping machine.
2 These toothed cogs show the simple way in which crimping is achieved.
3 Weaving commences on a giant weaving machine.
4 The lengths of woven architectural mesh begin to take shape.
– Adaptable, flexible production quantities.
– Produces a self-supporting rigid screen that can be formed and hold its shape.
– Can form only fixed-length panels, as opposed to rolls.
Volumes of production
From a minimum of 10 square feet, which may be expensive, to an unlimited number of sheets.
Unit price vs. capital investment
Because of the simple wheels used in the crimping, the process does not usually require tooling. The crimping wheels themselves can be cost-effective compared with other types of industrial tooling.
Speed
Varies, depending on the type of weave.
Surface
Good finish, which can also be electro-polished (a process that removes microscopic amounts of material from the metal).
Types/complexity of shape
Flat-sheet post forming can result in infinite possibilities.
Scale
The maximum width is 6½ feet. The length is restricted by the size of the manufacturer’s site.
Tolerances
Not applicable.
Relevant materials
Typically uses stainless steel 316L, galvanized steel, or any weavable alloy.
Typical products
Balustrades, external facades, staircase cladding, sunscreens, and ceilings that allow for lighting and sprinkler systems to be fitted above.
Similar methods
Perforating expanded metal (which uses a single sheet of metal that is then pulled open to create a series of slots, and which can sometimes be seen on the median strip on divided highways) and cable mesh—chain-link fencing that uses wire formed into a spiral, used typically in industrial security fencing.
Sustainability issues
Although entirely automated, pre-crimp weaving makes economical use of energy by crimping the wire in a separate stage prior to weaving, to ensure that the wires can be woven evenly and consistently when fed into the machine. Additionally, no heat is required during working, which significantly reduces energy use, while the woven form increases the strength and rigidity of the metal to ensure a prolonged product lifespan.
Further information
www.wiremesh.co.uk