Manufacturing
- Designers sometimes engineer products in such a way that they are easy to manufacture.
- Design for manufacture (DfM) exists in almost all engineering disciplines, but differs greatly depending on the manufacturing technologies used.
- This practice not only focuses on the design of a product’s components, but also on quality control and assurance.
Design for Manufacture
- Designers design specifically for optimum use of existing manufacturing capability available.
- Therefore if a company has injection molders available then the designer designs the product with that manufacturing machine in mind and considers the material needed (thermoplastic) and its related properties and workability.
Manufacturing Techniques
We distinguish various manufacturing techniques:
- Joining techniques
- Additive techniques
- Subtractive techniques
- Shaping techniques
Joining Techniques
- Methods that are used to join two similar or dissimilar materials together.
- We distinguish permanent (adhering, fusing and wood joints) and temporary joining techniques (fasteners).
Additive Techniques
- Manufacturing techniques that add material to a model in order to create it.
- Often through fusing or layering.
Rapid prototyping techniques:
- Fused deposition modelling (FDM)
- Selective laser sintering (SLS)
- Laminated object manufacture (LOM)
- Paper-based rapid prototyping
- Stereolithography (SLA)
Subtractive Techniques
- Manufacturing techniques that cut away material in order to create a component.
- Subtractive techniques are:
- Cutting
- Drilling
- Milling
- Turning
- Abrasing.
- All these manufacturing techniques can be machining.
Machining
- Machining is the removal of material by a tool that moves across the material by use of a machine or large equipment.
- The procedures of machining are precise and their execution is highly mechanized and can be automated (CNC: computer control of machines).
Shaping Techniques
Manufacturing methods for modifying the shape of a material. Shaping techniques are:
- cast moulding,
- blow moulding,
- resin moulding,
- injection moulding,
- rotational moulding,
- compression moulding,
- thermoforming,
- laminating,
- casting,
- knitting
- weaving.
Injection Molding
- Small melted plastic pellets (or another material) are injected into a two-piece mold.
- Once the plastic cools, the mold separates and releases the now solid molded part.
- Used for many different plastic parts.
Blow Molding
- A small amount of plastic is placed into the mold.
- Air is then blown into the plastic, causing it to expand and fit to the walls of the mold.
- Used for creation of hollow objects such as plastic bottles.
Rotational Molding
- Plastic pellets are put into a mold and heated up.
- As the mold rotates, the plastic aligns evenly to the surface of the mold.
- Often used to create hollow objects such as garbage bins for example.
Compression Molding
- A predetermined amount of plastic is put into a mold.
- The upper half of the mold then closes down on it, squashing it into shape.
Laminating
- Covers pieces of material such as paper or wood with a plastic material that adheres to it when a type of glue is heated up.
- Used as a protective coating.
Thermoforming
- A plastic sheet is heated up.
- Then a mold is pushed up from below.
- The heated plastic then conforms to the shape of the mold.
Casting
- Liquid metal is poured into a mold.
- Molds are often made of metal but sand can also be used, making it relatively cheap but somewhat inefficient.
Weaving
- Thin strips of flexible material is woven into sheets by interlocking the different strips.
3D Printing at Home
- Advancements in 3D printing have resulted in the ability to have a 3D printer at home.
- Consumers can download plans for products from the internet and print these products themselves.