Lecture 8 part 2 Flashcards
What is the difference between 3d printing and Jetting?
3D printing prints secondary (e.g. binder) material onto powder base
Jetting deposits build (and support) material directly
What are the two major categories of RP jetting technologies?
1) Thermal phase change - materials deposited in liquid/molten form, rapidly cool and harden once deposited
2) Photopolymer phase change - material is deposited and curing (e.g. UV) solidifies the layers
What are the two major thermal phase change jetting systems?
1) 3D Systems Pro-jet
2) Solidscape (now owned by stratasys)
What are characteristics of 3D Systems Pro-jet thermal phase change jetting systems?
- Size and accuracy of systems vary
- Materials are mainly wax or acrylic based
- Example applications include: wax patterns for jewellery or foundry casting; hearing aids/other small personalized medical parts; Architecture
What are characteristics of Solidscape (Stratasys) thermal phase change jetting systems?
- Separate inkjet print-heads for build & support material
- Build & support material jetted onto substrate
- Cutter mills entire layer to ensure layer thickness, consistency and flatness
- Particle collector removes unwanted ‘debris
- Aimed particularly ate production of wax-like patterns for casting of small, intricate features - Dental applications, Jewellery etc…
What is the definition of laminated?
Formed or manufactured in a succession of layers of material
What are some examples of laminated products?
Plywood, Document protection, Transformer cores, Topological maps, windshields
What is the process for AM lamination?
- profiles of cross-sections cut from sheet material
- profiles stacked or bonded
- No single Laminate Manufacture AM system as the technique cannot be patented
- The material range includes any material available in sheet or plate form
What are the characteristics of laminated object manufacturing?
- Accounts for most commercial applications of AM lamination
- Paper based process
- Cross-section of paper sheets cut using laser/knife
- Paper sheets bonded in successive layers
- Areas to be removed after build are cross-hatched to allow removal
- bonding method may vary, different cutting methods can be used, individual sheets vs continuous roll etc…
What is the general process for laminated object manufacturing?
- Position layer of paper
- Cut cross-section and hatched support area
- Lower build platform by one layer
- Coat top layer with adhesive
- Position new layer of paper
- Heated roller bonds sheet
- Remove platform & parts from machine
- Post process
What is involved in post processing for laminated object manufacturing?
1) Block (part and supports) is detached from platform (e.g. fixed on with double sided tape)
2) Support areas broken away to reveal the part - normally requires a chisel, patience and time
3) Parts sealed to prevent ingress of moisture
4) Parts can be sanded, polished or painted
- High complexity levels can be achieved but finishing time must be considered, the higher the complexity - the higher the possibility of damaging part
What are the benefits of laminated object manufacturing?
- simple set-up and operation
- Low material costs
- Multiple parts can be nested (self supporting process)
- Build can be paused without creating weakness
- Relatively fast (laser system) - only cutting profile of cross section (compared to laser sintering where entire cross-section must be scanned)
What are some of the limitations of laminated object manufacturing?
- Removal of support blocks can damage part
- Sealing required to prevent moisture ingress (can cause part warping)
- Difficult to produce enclosed volumes due to support removal
- Not for functional testing
- Laser can cause charring of parts/fire hazard
What are some applications of laminated object manufacturing?
- Parts have similar appearance and ‘workability’ to wood
- popular for production of patterns for sand castings (traditionally use wood)
- Mainly used for tooling or visualization
