When it comes to making hard goods?(be it a plastic case for an electrical product, a new type of metal jewel, a new mechanical part…), making prototypes is an important part of the new product development process.
When the prototype is made by a?Chinese manufacturer, the buyer should know what type of prototype will be made. There are many prototyping processes available for product development teams to choose from. Here is a list of the most common ones.
1. Conventional machining
Ideally, a 3D CAD design is received by the machining center and?a?prototype comes out at the end. The machines might be numerically controlled (CNC) or not — this is often a great way of getting a few prototypes that should look the same as mass?production.
Advantages of Conventional machining
- Mature technologies that can produce high-accuracy components
- The?material can be?the same as mass production
- Any testing carried out on this form of prototype will be fully representative of the production intent design, therefore any material or strength issue found at this stage can be addressed and design modifications made.
Disadvantages of Conventional machining
- Parts tend to be machined out of solid blocks of material and there could be a lot of wasted material.
- A number of different machining processes may be required to complete the part. Each of these processes takes time and would normally be completed by skilled machinists. All this adds up from a cost point of view.
2. Stereolithography (SLA)
SLA produces fast, accurate prototype models using an additive manufacturing technology which employs a vat of liquid ultraviolet curable photopolymer “resin” and an ultraviolet laser to build parts’ layers one at a time.
Advantages of SLA
- Speed?—?within a day.
- Accuracy?within the tolerance of the thickness of each layer, which is typically 0.05mm (0.002”).
Disadvantages of SLA
- Typical size of parts that can be produced are 500mm x 500mm x 600mm (20” x 20” x 24”). Large parts cannot be made with SLA. Note that several parts can be glued together.
- The finished product can be quite brittle?(made from cured resin only).
3. Selective Laser Sintering (SLS)
SLS is also an additive manufacturing technique. A laser fuses several materials (plastic, metal, or ceramic powders).
Advantages of SLS
- Strong prototypes
- Wide range of materials
Disadvantages of SLS
- Less accurate than SLA due to the size of the powder granule.
4. 3D Printing
3D printing is yet another additive technique. An object is created by laying down successive layers of material.
Advantages of 3D Printers
- 3D printers are inexpensive. You can have one in house.
- You can run?multiple iterations?of new products at a low cost.
Disadvantages of 3D Printers
- Size constraints: it is hard to find a 3D printer that can make large parts.
- Material choice is relatively limited.
- The surface finish can be highly textured?(low accuracy)
5. Vacuum Casting
Silicone molds are created, and then the mold is used to create parts.
Advantages of Vacuum Casting
- Multiple parts can be produced. Good for making small quantities of a certain product.
- Parts are near perfect production quality.
Disadvantages of Vacuum Casting
- Products are usually in rubber material.
- Relatively high cost of producing the silicone mold and the parts.
A couple of precisions:
- The methods listed above are all available in China from many suppliers.
- Industries concerned are household products, office supplies, automotive parts, consumer electronics, medical devices, concept showcases, kitchen products, garden tools, industrial designs…