- •1 Cut from Solid
- •2 Sheet
- •3 Continuous
- •4 Thin & Hollow
- •5 Into Solid
- •6 Complex
- •7 Advanced
- •8 Finishing Techniques
- •Introduction
- •Volumes of production
- •1: Cut from Solid
- •1 A very simple setup for milling a chunk of metal. The cutting tool, which resembles a flat drill bit, can be seen fitted above the clamped work piece.
- •2 A straightforward setup for a lathe operation in which the tube of metal to be cut is clamped into a chuck. The cutter is poised ready to make a cut.
- •Volumes of production
- •1 The individual sheets of cut plywood are clamped together before being machined.
- •2 View showing the machined internal structure before the external surface is cut.
- •Volumes of production
- •Volumes of production
- •1 The mortar bowl is being turned by hand, using a profiled metal tool to achieve a precise profile.
- •2 A ceramic pestle being finished using a flat smoothing tool.
- •Volumes of production
- •Volumes of production
- •2: Sheet
- •Industrial Origami®
- •Inflating Metal
- •Volumes of production
- •Volumes of production
- •Volumes of production
- •Volumes of production
- •Volumes of production
- •Volumes of production
- •Volumes of production
- •Volumes of production
- •Volumes of production
- •1 Preparation of the wooden mandrel.
- •2 The metal is pushed against the mandrel as both metal and mandrel are spinning.
- •3 The metal component taking shape over the mandrel.
- •Volumes of production
- •Volumes of production
- •Industrial Origami®
- •Volumes of production
- •Volumes of production
- •Volumes of production
- •Volumes of production
- •Inflating Metal
- •Volumes of production
- •Volumes of production
- •Volumes of production
- •Volumes of production
- •Volumes of production
- •3: Continuous
- •Volumes of production
- •Volumes of production
- •Volumes of production
- •Volumes of production
- •1 Individual strands of fiber are fed into a die where they will be soaked in resin and formed into their final profile.
- •2 A finished tube emerges through the cutter, ready to be cut to length.
- •Volumes of production
- •Volumes of production
- •Volumes of production
- •Veneer Cutting
- •Volumes of production
- •4: Thin & Hollow
- •1 A mass of molten glass is gathered onto the end of a steel tube, ready to be blown.
- •2 Various hand tools are used to shape the hot glass, in this case a stack of wet fabric.
- •Volumes of production
- •Volumes of production
- •Volumes of production
- •Volumes of production
- •Volumes of production
- •Injection Blow Molding
- •Injection stretch molding is a method used for high-end products (such as bottles) made from polyethylene terephthalate (pet) which uses a rod to stretch a pre-form into the mold before blowing.
- •Volumes of production
- •Volumes of production
- •Volumes of production
- •Volumes of production
- •1 Empty plaster molds.
- •2 Molds filled with slip.
- •Volumes of production
- •1 An example of the tooling and the die cavity into which the metal is placed.
- •2 Semifinished hydroformed components.
- •Volumes of production
- •Volumes of production
- •Volumes of production
- •Volumes of production
- •Vacuum Infusion Process (vip)
- •Volumes of production
- •Imagine impregnating the thread on a cotton reel with resin and then being able to pull the wound thread off its reel to form a rigid plastic cylindrical part: this is the essence of filament winding.
- •Volumes of production
- •Volumes of production
- •5: Into Solid
- •Volumes of production
- •Volumes of production
- •Volumes of production
- •Volumes of production
- •Volumes of production
- •Volumes of production
- •Inflating Wood
- •Volumes of production
- •Volumes of production
- •Volumes of production
- •Volumes of production
- •6: Complex
- •Injection Molding
- •Volumes of production
- •Volumes of production
- •Volumes of production
- •Volumes of production
- •Insert Molding
- •Volumes of production
- •Volumes of production
- •Volumes of production
- •Volumes of production
- •Volumes of production
- •Volumes of production
- •Volumes of production
- •Investment Casting
- •Volumes of production
- •Volumes of production
- •Viscous Plastic Processing (vpp)
- •Volumes of production
- •7: Advanced
- •Inkjet Printing
- •Volumes of production
- •Volumes of production
- •Volumes of production
- •Volumes of production
- •Volumes of production
- •1 Winding onto the purple Smart Mandrel begins.
- •2 The Smart MandrelTm is heated and softened for easy removal from the completed winding.
- •Volumes of production
- •Incremental Sheet-Metal Forming
- •Volumes of production
- •8: Finishing Techniques
- •In his visionary book The Materials of Invention, Ezio Manzini defines the surface of objects as “the location of the points where an object’s material ends and the surrounding ambient begins.”
- •Vacuum Metalizing
- •Vapor Metalizing
- •Vitreous Enameling
- •Inflating metal 10-11, 76-7
Volumes of production
This is a CAD-driven process so it is suited to both one-off and batch production, though, obviously, the molded side remains constant, so “one-offs” only differ on their milled side.
Unit price vs. capital investment
The tooling (the mold, in this case) is made using the same machine that makes the component, which means precise-cast prototyping is highly cost-effective.
Speed
Milling of the mold typically takes between half an hour and two hours; casting and curing of the resin and milling of each part takes a minimum of an hour, depending on the part’s complexity.
Surface
The surface quality corresponds with the normal quality of milled surfaces.
Types/complexity of shape
The shape is limited only by the CAD drawing and the cutter (or cutters), though extremely complex shaped parts or undercuts in the inner contour can be made by five-axes milling only (that is, one cutter moving along five trajectories) and undercuts in the outer contour require special mold inserts or silicone parts.
Scale
The scale of the parts made on a standard machine is 10 by 10 by 6 inches.
Tolerances
Depending on the machine’s accuracy, commonly some 10 microns.
Relevant material
A two-component resin.
Typical products
Complex shaped parts with high-tolerance outer surfaces and low-tolerance inner surfaces. The process is used for the rapid prototyping of bodies of cell phones, cameras, automobile parts, and electric and computer accessories.
Similar methods
Conventional milling (p.20) and casting methods. Other prototyping techniques, including stereolithography (SLA) (p.246).
Sustainability issues
Molding, creating the form, and machining the part in a single process allows for incredible energy efficiency on many levels. By reducing the machinery used, energy consumption is cut dramatically, along with the emissions from transportation of parts between manufacturing locations. Alterations to the milled surface can be carried out immediately without the need for a whole new mold and test runs, significantly reducing material use.
Further information
www.fraunhofer.de
6: Complex
Injection Molding
Reaction Injection Molding (RIM)
Gas-Assisted Injection Molding
Mucell® Injection Molding
Insert Molding
Multishot Injection Molding
In-Mold Decoration
Over-Mold Decoration
Metal Injection Molding (MIM)
High-Pressure Die-Casting
Ceramic Injection Molding (CIM)
Investment Casting
Sand Casting
Pressing Glass
Pressure-Assisted Slip Casting
Viscous Plastic Processing (VPP)
Parts with complex shapes and surfaces
These processes can be described as “plastic-state forming” because of the soft, malleable, and, generally, hot state of the materials as they are molded. It is these methods of production that are most responsible for the explosion in the number of cheap, molded plastic products now available. Nevertheless, the payback for achieving complexity at a low cost per unit is the level of investment required for tooling. This chapter contains many of the established methods of high-volume mass-production, such as injection molding in plastic and die-casting in metals. It also investigates methods of adding finishing materials to complex shapes.