Clear Parts - Rapid Prototyping (RP) and Low Volume Production
CNC, vacuum forming, injection moulding, or rapid prototyping techniques can produce clear parts. Factors that determine the optimal solution include the degree of clarity required, part complexity, quantity and timescales.
For low volumes the ultimate solution in terms of clarity has to be to use CNC and hand polishing in materials such as Perspex or Polycarbonate.
Rapid Prototyping offers other solutions. For example, Stereolithography, when combined with the right resins and some hand dressing will achieve very acceptable levels of clarity.
As quantities start to escalate Vacuum casting can be used with a pattern to generate a silicone tool and cast the desired part in clear Polyurethane (PU). Alternatively and if time permits, it may also be viable to lay down a prototype injection mould tool and achieve the production intent material.
These and others are covered though the links opposite to assist you in sourcing the most applicable option for your requirement. If you are in any doubt, then please contact Plunkett Associates directly.
Stereolithography
Stereolithography is the most well known of all the RP techniques and through careful resin selection can be used to produce clear parts. Hand polishing and possible lacquering are necessary to achieve acceptable clarity. Some earlier resins carry a tint, although this is constantly improving. Ideally suited to low volume, complex parts that are required clear or partially clear.
Machining (CNC)
Offering the possibility of using PC or acrylic, machining clear parts will offer the highest level of clarity, although hand polishing is still utilised to achieve the clarity. Suitable for a wide range of sizes from lenses to car lamps, even joining is possible. Global sourcing means that machining does not carry a price premium, yet can offer a finish that leaves alternative RP processes struggling.
Vacuum Casting
Ideally suited to producing a small batch of clear prototypes. Vacuum casting utilises a CNC or RP pattern to create a silicone tool. Finishing of the pattern is paramount in achieving acceptable clarity as the silicone picks up every detail. Subsequent cast parts require no further dressing and demonstrate good levels of clarity.
Injection Moulding
Usually only considered as a production process, injection moulding will give the production intent material properties. Surprisingly cost effective when the quantities rise above the economic threshold for CNC. Classic route for lightguides and lenses where real material is a necessity and circa 20 to 50 parts are required. Leadtime is very much a function of geometry.