Additive Manufacturing Process Chain
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Questions and Answers

Which technology is utilized for reverse engineering data?

  • 3D printing
  • Virtual reality
  • Computer-aided design
  • Laser scanning technology (correct)

Architectural modeling designs only depict the exact productions of the final design.

False (B)

What is becoming more common in additive manufacturing processes?

Color and multiple material systems

Standardized software processes are needed as direct digital manufacturing becomes more ______.

<p>common</p> Signup and view all the answers

Match the following types of manufacturing processes with their descriptions:

<p>Additive manufacturing = Building up material layer by layer Subtractive manufacturing = Removing material from a solid block Hybrid manufacturing = Combination of additive and subtractive processes Direct digital manufacturing = Creating physical products directly from digital files</p> Signup and view all the answers

What is the first step in the Generalized AM Process Chain?

<p>Conceptualization and CAD (A)</p> Signup and view all the answers

The STL format describes the CAD model in terms of color and texture.

<p>False (B)</p> Signup and view all the answers

Name one application area of additive manufacturing that does not involve conventional CAD modeling.

<p>Medical modeling</p> Signup and view all the answers

The process of converting a CAD model to STL involves approximating the surface of the model with a series of __________.

<p>triangular facets</p> Signup and view all the answers

Match the following types of AM machines with their characteristics:

<p>Photopolymer based systems = Use liquid resin cured by light Powder-based systems = Utilize powdered materials for printing Molten material systems = Extrude heated materials to create objects Solid sheets = Layer materials that are cut then bonded</p> Signup and view all the answers

What type of file is created from the conversion of a CAD model?

<p>STL (B)</p> Signup and view all the answers

Energy density is a factor to consider in metal additive manufacturing.

<p>True (A)</p> Signup and view all the answers

List two design considerations for additive manufacturing.

<p>Part orientation, Removal of supports</p> Signup and view all the answers

What is one action required prior to building the part?

<p>Verify the part is correct (B)</p> Signup and view all the answers

All AM machines require the same setup parameters regardless of the material used.

<p>False (B)</p> Signup and view all the answers

What may be necessary for some parts before they are built?

<p>Shrinkage or coating allowances</p> Signup and view all the answers

The first few stages of the building process are ________.

<p>semi-automated</p> Signup and view all the answers

Match the actions with their descriptions:

<p>Verify the part is correct = Ensures specifications are met Machine setup = Adjusting specific parameters based on material Build phase = Layer-based manufacturing process Removal and cleanup = Preparing the part for final use</p> Signup and view all the answers

What can happen if an incorrect setup procedure is followed?

<p>The part will be built with unacceptable quality (C)</p> Signup and view all the answers

All AM machines will alert the user when the build is complete or when there is no material remaining.

<p>True (A)</p> Signup and view all the answers

What might some unusual cases require concerning STL files?

<p>Segmentation of STL files</p> Signup and view all the answers

Which of the following processes automatically generates support structures?

<p>Thermojet process (D)</p> Signup and view all the answers

Solid sheets used in lamination methods require support structures during processing.

<p>False (B)</p> Signup and view all the answers

What is one common issue experienced by paper-based systems?

<p>Handling problems</p> Signup and view all the answers

Part orientation, removal of supports, and hollowing out parts are all considerations for __________.

<p>Additive Manufacturing (AM)</p> Signup and view all the answers

Match the following issues with their relevant considerations:

<p>Laser technology = Fragility and monitoring Material exposure = Moisture and light Equipment maintenance = Clean environments Recycling material = Offline loading using software</p> Signup and view all the answers

Which of the following factors is NOT a concern for metal systems compared to polymer systems?

<p>Support structure (C)</p> Signup and view all the answers

Interlocking features are considered an advanced design element in conventional CAD modeling.

<p>False (B)</p> Signup and view all the answers

Name one application area for medical modeling that does not involve conventional CAD.

<p>CT or MRI</p> Signup and view all the answers

Why do some additive manufacturing machines require support structures?

<p>To prevent parts from collapsing or warping (C)</p> Signup and view all the answers

Post-processing is an automatic stage that requires no manual effort.

<p>False (B)</p> Signup and view all the answers

What may happen to parts created through additive manufacturing under mechanical stress?

<p>They may fail due to small voids or bubbles trapped inside them.</p> Signup and view all the answers

In additive manufacturing, the initial part of the __________ stage is the cleanup stage.

<p>post-processing</p> Signup and view all the answers

Match the terms related to additive manufacturing with their definitions:

<p>Void = An empty space within the material that can cause structural weakness Post-processing = The stage involving finishing and refining parts after production Anisotropic = Material properties that vary in different directions Support structures = Temporary frameworks that prevent part warping during production</p> Signup and view all the answers

What is the nominal layer thickness for most FDM Dimension machines?

<p>0.254 mm (C)</p> Signup and view all the answers

What is a potential downside of parts made via additive manufacturing compared to traditional methods?

<p>They may not behave according to standard material specifications (D)</p> Signup and view all the answers

Manual skill is unnecessary for the support removal stage in additive manufacturing.

<p>False (B)</p> Signup and view all the answers

Thicker layers in additive manufacturing lead to more precise parts.

<p>False (B)</p> Signup and view all the answers

What are some post-processing tasks that can benefit from the use of power tools?

<p>Abrasive finishing, polishing, or application of coatings.</p> Signup and view all the answers

What must be considered during post-processing that involves heat in additive manufacturing?

<p>Heat resistance or melting temperature of the material.</p> Signup and view all the answers

In powder-based systems, a bed of powder is deposited __________.

<p>layer-by-layer</p> Signup and view all the answers

Match the following types of additive manufacturing systems with their characteristics:

<p>Photopolymer-Based Systems = Use support from the same material as the part Powder-Based Systems = No need to use supports Binder Printing = Can create colored parts FDM Dimension = Has a nominal layer thickness of 0.254 mm</p> Signup and view all the answers

What is a disadvantage of photopolymer-based systems?

<p>Poor mechanical properties compared to others (D)</p> Signup and view all the answers

Newer resins in photopolymer-based systems degrade rapidly without proper UV protection.

<p>True (A)</p> Signup and view all the answers

What material processing category can affect the time and resources required in additive manufacturing?

<p>Use of different materials.</p> Signup and view all the answers

Which of the following is NOT a process discussed in vat photopolymerization?

<p>Stereolithography (B)</p> Signup and view all the answers

Photopolymerization reaction rates are independent of the irradiance and exposure time.

<p>False (B)</p> Signup and view all the answers

What is the purpose of using photo initiators in photopolymerization?

<p>To initiate the polymerization reaction upon exposure to light.</p> Signup and view all the answers

The __________ pattern is one of the scan patterns used in vector scan VP machines.

<p>WEAVE</p> Signup and view all the answers

Match the following components with their functions in vat photopolymerization:

<p>Monomer formulations = Building the polymer structure Photospeed = Rate of reaction based on exposure Laser-resin interaction = Curing the resin with laser Interpenetrating polymer network = Enhanced mechanical properties</p> Signup and view all the answers

Which configuration is used in Photopolymerization Processes that irradiates entire layers at one time?

<p>Mask projection (B)</p> Signup and view all the answers

Visible light is predominantly used in the microelectronic industry.

<p>False (B)</p> Signup and view all the answers

What is a primary benefit of the two-photon approach in photopolymerization?

<p>Recoat is unnecessary as the part is fabricated below the resin surface.</p> Signup and view all the answers

In the __________ scan approach, scanning laser beams are needed.

<p>vector</p> Signup and view all the answers

What type of radiation is primarily used in photopolymerization processes?

<p>Ultraviolet (UV) radiation (A)</p> Signup and view all the answers

Match the following photopolymerization configurations with their characteristics:

<p>Vector scan = Point-wise approach with recoating required Mask projection = Layer-wise approach with large radiation beam Two-photon = High resolution with no recoating needed Resin application = Reapplication of resin for each new layer</p> Signup and view all the answers

Photopolymers were developed in the 1980s.

<p>False (B)</p> Signup and view all the answers

Who is credited with the discovery of producing solid polymer patterns through UV curing in the mid-1980s?

<p>Charles Hull</p> Signup and view all the answers

Photo-curable resins are often used in __________ to seal deep grooves in teeth.

<p>dentistry</p> Signup and view all the answers

Match the following types of radiation with their applications in curing photopolymers:

<p>Gamma rays = Curing of photopolymers for coatings X-rays = Medical imaging and treatment UV radiation = 3D printing processes Visible light = Some photopolymerization systems</p> Signup and view all the answers

What is one of the primary advantages of vat photopolymerization technology?

<p>High accuracy and surface finish (D)</p> Signup and view all the answers

Current stereolithography materials possess high impact strength and durability compared to injection molded thermoplastics.

<p>False (B)</p> Signup and view all the answers

What is the minimum size of a hardened polymer unit produced in microfabrication applications?

<p>5 µm x 5 µm x 3 µm</p> Signup and view all the answers

The accuracy of the SLA-250 is __________.

<p>0.002 in/in</p> Signup and view all the answers

Match the following characteristics with their corresponding technologies:

<p>Mask Projection VP = Speed advantage over laser scan SL Two-Photon VP = Used primarily for high-resolution microfabrication SLA-250 = Precision of 0.002 in/in Microsterolithography = 5-µm spot size of the UV beam</p> Signup and view all the answers

Which of the following is a drawback of using photopolymers in additive manufacturing?

<p>Ageing leading to degraded mechanical properties (C)</p> Signup and view all the answers

Mask projection technologies are less efficient than laser scanning for SLA processes.

<p>False (B)</p> Signup and view all the answers

What constrains the chemistry of commercially used photopolymers?

<p>Acrylates and epoxies</p> Signup and view all the answers

Which types of radiation are most commonly used to cure commercial photopolymers?

<p>UV and electron beams (C)</p> Signup and view all the answers

Photopolymers are primarily used as photoresists in the biomedical field.

<p>False (B)</p> Signup and view all the answers

What is the role of a photoinitiator in photopolymer chemistry?

<p>To convert physical energy of light into chemical energy.</p> Signup and view all the answers

In laser scan vat photopolymerization, a UV laser selectively solidifies a liquid photopolymer resin to create __________.

<p>solid parts</p> Signup and view all the answers

Match the following types of polymerization with their respective materials:

<p>Free radical polymerization = Acrylate Cationic polymerization = Epoxy Vinylether polymerization = Vinylether Both types = Acrylate and Epoxy</p> Signup and view all the answers

What is the purpose of the recoater blade in the vector scan vat photopolymerization process?

<p>It smooths the surface of the vat and deposits new resin. (B)</p> Signup and view all the answers

Acrylates polymerize through a radical mechanism, while epoxides polymerize through a cationic mechanism.

<p>True (A)</p> Signup and view all the answers

What is the term for the network formation that occurs when acrylates and epoxides polymerize?

<p>Interpenetrating polymer network formation</p> Signup and view all the answers

Flashcards

Conceptualization and CAD

The initial stage of product design involving defining the product's appearance, functionality, and features using Computer-Aided Design (CAD) software. It encompasses sketches, models, and 3D representations.

Conversion to STL

Converting a CAD model into an STL (STereoLithography) file. This involves representing the model's geometry as a series of triangular facets, which the AM machine uses for fabrication.

Transfer to AM Machine and STL File Manipulation

Moving the STL file to the additive manufacturing (AM) machine and making any necessary adjustments to the file for optimal printing, such as scaling or orientation.

Machine Setup

Preparing the AM machine for the build by calibrating the build platform, adjusting settings based on the material and design, and ensuring proper functionality.

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Build

The process of creating the physical component layer-by-layer based on the STL file instructions, using the AM machine's specific material deposition or fusion techniques.

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Part Removal and Cleanup

Removing the completed component from the AM machine's build platform and subsequently cleaning any excess material or support structures.

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Post-processing of Part

Additional operations performed on the printed component to improve its surface finish, mechanical properties, or aesthetics, such as smoothing, sanding, or heat treatment.

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Application

The intended use or function of the manufactured component, ranging from prototypes and tooling to end-use products in various industries.

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Part Verification

Ensuring the accuracy and suitability of the 3D model (STL file) before starting the manufacturing process.

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Visualization Tool

Software that allows you to view, rotate, and manipulate the 3D model to understand its dimensions and details.

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Part Repositioning

Adjusting the position or orientation of the part within the build chamber to ensure it fits correctly and is accessible for printing.

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Multiple Part Builds

The ability to print several identical or different parts in a single build session.

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Shrinkage and Coating Allowances

Adjustments made to the 3D model to account for material shrinkage during the printing process or to accommodate coatings.

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STL File Segmentation

Splitting a large or complex 3D model into smaller, more manageable parts for printing.

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Machine Setup Parameters

Specific settings and configurations of the 3D printer that control aspects like material type, layer thickness, and printing speed.

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Build Process

The automated process of creating a 3D object layer by layer, controlled by the machine's software.

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Support Structures in AM

Some AM machines require these temporary structures to hold the part and prevent it from warping or collapsing during the build process.

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Support Removal

The process of carefully removing the support structures from the printed part after the build is complete.

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Post-Processing in AM

The manual stages of finishing the printed part for its intended application, including cleaning, smoothing, and applying coatings.

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Anisotropic Properties

AM parts can have different material properties in different directions. This is a characteristic of many AM processes.

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Voids and Bubbles in AM Parts

AM parts can contain tiny air pockets or bubbles trapped inside during the build process. These can cause problems if the part is stressed.

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Material Degradation in AM

Some AM processes can cause the printed material to weaken or change its composition during the build. This can affect the final properties of the part.

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AM Material Properties

Materials used in AM processes may not always perform like traditional materials. They might be less strong or have different characteristics.

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Applications of AM

The number of applications for parts produced by AM processes is rapidly increasing because of the technology's versatility and ability to create complex designs.

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Reverse Engineering Data

The process of analyzing a product to understand its design and functionality. This can involve taking measurements, creating 3D models, and analyzing materials.

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Laser Scanning Technology

A technology that uses lasers to create detailed 3D scans of physical objects. This data can be used to create 3D models for various applications, including reverse engineering and 3D printing.

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Architectural Modeling

The creation of digital representations of building designs using computer programs.

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STL File Format

A common file format used in 3D printing. It describes the surface geometry of an object using triangular facets.

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Hybrid Additive/Subtractive Manufacturing

A manufacturing process that combines additive and subtractive techniques. This may involve 3D printing followed by machining or cutting to create the final product.

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Support Structures

Structures used to support overhangs and complex geometries during 3D printing, ensuring a successful build.

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Thermojet Process

A 3D printing process where molten material is deposited in droplets, automatically generating support structures as needed.

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FDM Support Generation

In Fused Deposition Modeling (FDM), support structures can be generated automatically or manually by the user, providing flexibility in the design process.

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Lamination Methods

3D printing techniques where layers of material are first placed and then cut, eliminating the need for support structures.

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Waste Material Handling

The process of removing excess material from the final 3D printed part after lamination, ensuring a clean and accurate product.

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Metal 3D Printing Considerations

Factors like subtractive manufacturing, energy density, part weight, dimensional accuracy, and printing speed are crucial in metal 3D printing.

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Maintenance of 3D Printing Equipment

Regular maintenance, including monitoring laser/printer technology and avoiding dirty or noisy environments, is essential for optimal performance.

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Material Handling for 3D Printing

Proper material handling is vital, avoiding moisture and light exposure. Loading and recycling materials often involve software systems.

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Layer Thickness

The vertical height of each layer deposited during additive manufacturing. It can vary between AM technologies and even within the same machine.

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Post-processing

Steps taken after the AM build to enhance the part's properties or finish, such as removing supports, smoothing surfaces, or heat treatment.

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Powder-Based Systems

Additive manufacturing techniques that use a bed of powder as the build material. Layers are created by selectively fusing the powder using a laser, electron beam, or binder.

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Photopolymer-Based Systems

Additive manufacturing techniques that use liquid photopolymer material, which is cured by light exposure. Layers are built by selectively curing the photopolymer with a laser or UV light.

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Binder Printing

A powder-based AM technique where a binder material is selectively dispensed onto a powder bed to create the part. The binder acts as the glue, and the powder remains as part of the final product.

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Support Material

A temporary material used in AM to support overhangs and complex geometries. It is often easy to remove after the build.

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Photopolymerization

A chemical process where liquid resins or photopolymers are transformed into solid materials by exposing them to radiation, typically ultraviolet (UV) light.

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UV Curable Resins

Materials that undergo a chemical change (polymerization) when exposed to ultraviolet light, leading to a solid form.

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Applications of Photopolymers

Photopolymers have numerous uses, including coatings, printing, and dental procedures such as filling cavities.

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Stereolithography (SL)

A 3D printing technology that uses UV light to cure liquid photopolymer resins layer-by-layer, building up a 3D object.

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Radiation for Curing

Various types of radiation, including UV light, gamma rays, and x-rays, can be used to solidify photopolymer materials.

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Vat Photopolymerization

An additive manufacturing process where liquid photopolymer resin is selectively cured by UV light, creating a 3D object layer-by-layer.

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Photopolymer Chemistry

The study of how light triggers chemical reactions in photopolymer resins, leading to their hardening or curing. This involves photoinitiators, monomers, and polymerization reactions.

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Laser Scan Vat Photopolymerization

A specific type of vat photopolymerization where a laser selectively cures the resin, enabling precise layer-by-layer construction of complex 3D objects.

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Scan Patterns

Strategic arrangement of laser beam scans that create layers, like a blueprint for building a complex, 3D object. These patterns include WEAVE, STAR-WEAVE, and ACES.

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Mask Projection VP Technology

An additive manufacturing technique where a UV light is projected through a mask, exposing the photopolymer resin and curing specific areas to build the 3D object.

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SL Systems

3D printing systems that use UV light to cure liquid photopolymer resins layer by layer.

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Vector Scan

A method used in SL systems where a laser beam scans the resin surface, curing it layer by layer.

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Mask Projection

A method used in SL systems where all of a layer is exposed to UV light at once using a patterned mask.

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What are photopolymers used for?

Photopolymers are used as materials in the microelectronics industry, specifically as photoresists.

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What are two common methods for curing photopolymers?

Two prevalent methods for curing photopolymers are ultraviolet (UV) light and electron beam radiation.

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What are the two main types of photopolymerization?

There are two main types: free radical polymerization, often using acrylates, and cationic polymerization, involving epoxides and vinylethers.

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What is the role of a photoinitiator?

A photoinitiator converts the energy of light into chemical energy, triggering the polymerization reaction.

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What are the key steps involved in Laser Scan Vat Photopolymerization?

Laser Scan Vat Photopolymerization builds solid parts by solidifying liquid resin using an UV laser, layer by layer, creating a cross-section at a time. The final part requires cleaning, post-curing, and finishing.

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What is the function of a recoater blade in Laser Scan Vat Photopolymerization?

After a layer is cured, the platform dips down, a recoater blade distributes a new layer of resin and smooths the surface of the vat.

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What is the purpose of support structures in laser scan vat photopolymerization?

Support structures prevent overhangs and complex geometries from warping or collapsing during the build process. They need to be removed later.

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What is the typical machine hierarchy in Vector Scan VP machines?

The primary subsystems are: recoating system, platform system, vat system, laser and optics systems, and control system.

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Discretization

The stair-step effect caused by the layering process in 3D printing, where the layers are visible as steps on the surface of the object.

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ACES Scan Pattern

A specific pattern used in laser-based vat photopolymerization to create layers. It strategically moves the laser beam across the resin to create a desired shape.

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Micro-Vat Photopolymerization

A 3D printing technique designed for creating very small, intricate objects. It uses a focused UV beam to cure liquid photopolymer resin.

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SL-250 Accuracy

A measure of how close the printed object is to the design on the computer. The SL-250 printer can achieve an accuracy of 0.002 inches per inch.

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Surface Finish in SL

The quality of the surface on a 3D printed object. SL parts can have very smooth surfaces thanks to its layer-by-layer process.

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Photopolymer Limitations

3D printing materials based on photopolymers have limitations like limited material strength and a tendency to degrade over time.

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Process Benefits

Vat photopolymerization offers advantages like excellent accuracy and surface finish, making it ideal for creating intricate models and prototypes.

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Study Notes

Generalized Additive Manufacturing Process Chain

  • Additive manufacturing (AM) is a process chain with several steps
  • Key steps include conceptualization and CAD, conversion to STL, transfer to AM machine, machine setup, build, part removal, cleanup, and post-processing
  • The process sequence can vary from one AM machine to another, requiring different setup parameters and potentially different materials or layer thicknesses

Variations from One AM Machine to Another

  • Different AM machines have varying layer thicknesses, potentially impacting build precision
  • Factors like droplet size, laser diameter, or extrusion head influence detail in the build
  • Material properties (e.g., heat resistance, melting point) and post-processing requirements can vary significantly between machines
  • Methods (e.g., powder-based, molten material, or photopolymer; droplet deposition, or extrusion) create unique advantages and disadvantages in terms of support structures, build speed, material handling, cleanup
  • Some AM machines require support structures that may need to be removed manually, potentially impacting the quality of the finished part
  • Not all AM processes are based on layers, certain techniques may involve different approaches
  • Photopolymer systems are generally more accurate with thin layers but have poorer mechanical properties
  • Powder-based systems often don't need support structures
  • Molten material systems often use support structures and require different post-processing techniques
  • Solid sheet systems require different processes for managing leftover material and require careful considerations about part orientation
  • Metal systems need to take into account energy density, weight, and accuracy during the design process

Maintenance of Equipment

  • Some machines use vulnerable laser or printer technology that need careful monitoring (e.g., noise or vibration)
  • Material handling procedures should consider moisture and light exposure to avoid damage
  • Some machines recycle the material from a build that didn't form correctly
  • Different materials may require specific pre and post process considerations, like using of temperature controlled environment

Design for AM

  • Part orientation is crucial for successful builds
  • Support structures for parts are often necessary, but removing them can be complex
  • Complex features (e.g., undercuts, interlocking features) may be involved
  • Overall part count reduction can enhance efficiency
  • Designing for AM may involve additional consideration of support structures, part orientation, varying layer thickness and different material properties to ensure successful parts and minimal waste

Application Areas

  • AM can be used in areas outside conventional CAD modeling, like medical modeling (using CT, MRI, 3D ultrasound data), reverse engineering (using laser scanning), and architectural modeling
  • AM processes are often unique and have to be considered in design, and the use of the process can vary by machine type
  • AM processes increasingly involve not just one material, but combinations of different materials

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Related Documents

Additive Manufacturing Process Chain PDF
Vat Photopolymerization Processes PDF

Description

Explore the essential steps involved in the additive manufacturing process chain, from conceptualization to post-processing. Understand how variations in AM machines and their unique properties can affect the quality and precision of builds. Learn about equipment maintenance and material handling for optimal performance.

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