Design for Vat Photopolymerization 305

3D printing

The process of producing a 3D object using a specialized tool that creates successive layers of material. 3D printing must technically involve the use of a print head or nozzle, but the term is often used interchangeably with additive manufacturing (AM).

ABS

Acrylonitrile-butadiene-styrene. A thermoplastic material with good heat-, chemical-, and impact- resistance. ABS is commonly used to manufacture medical equipment housings.

acrylonitrile-butadiene-styrene

ABS. A thermoplastic material with good heat-, chemical-, and impact-resistance. Acrylonitrile-butadiene-styrene is commonly used to manufacture medical equipment housings.

additive manufacturing

AM. The process of successively layering materials to make an object based on a three-dimensional computer model. Additive manufacturing allows for rapid prototyping, mass customization, and increased part complexity.

anchor point

Sources of security or strength on an object. Anchor points supply a secure hold or support for something else.

biocompatible resins

A material that can be used in living tissue without being toxic or causing injury. Biocompatible resins are frequently used with vat photopolymerization to make medical implants.

boss

A raised, circular peg or protrusion. A boss often has a hole in the center and is used to improve assembly.

bridges

A vertical column that holds up a horizontal part feature. Bridges are used in additive manufacturing to prevent structural sagging.

brittle

Resistant to being drawn, stretched, or formed. Brittle materials can fracture when subjected to mechanical forces.

calibrate

Comparing and adjusting a device with unknown accuracy to a device with a known, accurate standard. To calibrate a device requires eliminating variation for increased accuracy.

castable resins

A liquid photopolymer material that hardens to create an expendable patterns or molds when exposed to ultraviolet (UV) light or heat. Castable resins typically have high green strength and can be used for jewelry and investment casting.

castings

A part formed by pouring or injecting heated material into a mold. Castings take shape as the material cools and solidifies.

ceramics

Consists of both metallic and nonmetallic atoms held together by a strong primary bond. Ceramics, which include metal oxides, nitrides, and glasses, are sometimes used as build material in additive manufacturing.

computer-aided design

CAD. Computer software used to create a 3D model of a part before it goes into prototyping or production. Computer-aided design models are digital representations of the different aspects of a part.

conceptualization

To form an idea about a possible part or manufactured good. Conceptualization is one of the initial stages of design for manufacturing (DFM) or design for additive manufacturing (DFAM).

cupping

Excess build material or air becoming trapped within a a hollow part causing it to warp or deform. Cupping ruptures typically occur during bottom-up stereolithography processes.

cure

To cause a material to bond and solidify by permanently cross-linking its molecules. Curing techniques for thermosets include exposing the material to ultraviolet light during the production process.

curling

Physically bending, twisting, or deforming. Curling can be caused by uneven heating and cooling and by a lack of reinforcement in a part component.

design

In the five-step design for additive manufacturing process, the creation of the actual part specifications. Design involves creating the blueprints and prototypes for a part.

design for additive manufacturing

DFAM. The methodology of planning, testing, and creating an additively manufactured part that functions optimally. Design for additive manufacturing allows engineers to primarily focus on part functionality.

desktop

A machine designed to fit easily on a standard desk. Desktop models of AM machines are more affordable but less precise than larger, more advanced models.

digital light processing

DLP. A vat photopolymerization process that uses a specialized device to create an entire part layer in one flash of light. Digital light processing builds parts more quickly than some other vat photopolymerization processes.

DLP

Digital Light Processing. A vat photopolymerization process that uses a specialized device to create an entire part layer in one flash of light. DLP builds parts more quickly than some other vat photopolymerization processes.

end-use

Designed to be used directly by a consumer or directly in another manufactured product. End-use products created by additive manufacturing (AM) include medical implants, custom dental devices, and camera equipment.

environmental factors

The characteristics that make up the surroundings in a given place. The workplace environment consists of various environmental components, including noise and air quality.

exposure time

The length of time during which light remains in contact with a thermoset. Exposure time affects the quality of curing during vat photopolymerization.

finishing

A process applied to a manufactured part that goes beyond making the part to the correct shape and size. Sanding, filing, heat treating, and painting are examples of finishing.

G code

A programming language that uses letters and numbers to form commands for machine tools. G code programs are used to direct tool movements in additive manufacturing, CNC machining, and hybrid machining.

heat resistance

The ability to resist degradation when exposed to extreme heat. Heat resistance is important for plastics that will be exposed to heat on a regular basis.

investment casting

A casting process that creates intricate shapes using an expendable pattern and mold. Investment casting patterns can be made using additive manufacturing processes.

iterating

Repeating actions and steps in processes. Iterating is an important aspect of part design because it allows for constant and quick re-designs during initial stages.

lasers

A device that generates an intense beam of light that can be precisely aimed and controlled. Lasers are used in many additive manufacturing processes.

layer adhesion

The measure of bond strength in additive manufacturing (AM) processes. Layer adhesion in vat photopolymerization can be affected by under-curing or over-curing.

light-emitting diodes

LEDs. A semiconductor device that emits a narrow spectrum of light in a forward direction. Light-emitting diodes are sometimes used as light sources in vat photopolymerization.

master patterns

A replica of a part or casting that is used to create a negative impression in a mold. Master patterns for molding and casting processes are traditionally made of plastic, wood, or metal.

mating part

The object that a workpiece has been manufactured to fit. Nuts and bolts are mating parts.

mineral oil

A naturally occurring oil derived from petroleum. Mineral oil is used as a lubricant, finish, and coolant.

overhangs

Structure on a part that extends without support beneath them. Overhangs that extend beyond a 30-degree angle typically require support structures in vat photopolymerization processes.

part orientation

The position a part will be manufactured in during an additive manufacturing process. Part orientation, when set properly, minimizes build time and maximizes part quality.

photopolymers

A material that chemically reacts to exposure to ultraviolet (UV) light. Photoreactive resins solidify and harden when exposed to UV light.

photoreactive resins

A material that chemically reacts to exposure to ultraviolet (UV) light. Photoreactive resins solidify and harden when exposed to UV light.

planning

A step in the part design additive manufacturing process that assesses the best ways to create the conceptualized part. Planning involves initial considerations of the design and of the practical concerns related to the manufacturing process.

polypropylene

PP. A polymer that is tough, flexible, and resistant to fatigue. Polypropylene is commonly used to make translucent products such as food packaging.

post-processing

A procedure used to clean, improve, or otherwise finish a part for use by a manufacturer or consumer. Post-processing additively manufactured parts includes abrasive finishing, heat treatment, and painting.

PP

Polypropylene. A polymer that is tough, flexible, and resistant to fatigue. PP is commonly used to make translucent products such as food packaging.

production

The manufacturing of a finished part for delivery to a customer. Production is the final stage of design for additive manufacturing (DFAM).

proprietary

Designed by a specific company for use only with its own systems. Proprietary software, files, and materials are sometimes used with specific additive manufacturing (AM) machines.

prosthetics

An artificial implant, device, or limb that replaces a missing body part. Prosthetics may also refer to the design, fabrication, and fitting process involved with these devices.

rapid prototyping

A product development technique in which additive manufacturing (AM) methods are used to create prototypes for a traditional manufacturing operation. Rapid prototyping allows engineers to quickly create a number of prototypes in a short time period, reducing lead time.

recoater

A device that slides forwards and backwards over the surface of photopolymer material held in a vat. Recoaters are used by stereolithography (SLA) systems to smooth photopolymer material layers over a build platform.

repeatability

The ability of a manufacturing process to produce uniform results. Repeatability enables the production of parts with a high degree of consistency.

resolution

The amount of pixels and detail in an image. High-resolution images have better details than lower-resolution images.

rib

A structural component that provides shape and support. Ribs are used to reinforce a thin section of a part, such as a wall.

single-snap features

Interlocking component, often made out of metal or plastic, that easily fasten together when force is applied. Single-snap features can simplify assembly since they are fastened by one quick application of pressure.

SLA

Stereolithography. A vat photopolymerization process that traces a focused light beam over a layer of photopolymer to selectively cure it. SLA is often used for making softer parts that require a high degree of customization, such as dental aligners or hearing aids.

slicer

A computer program that divides an STL file into layers for additive manufacturing (AM). Slicers, or slicing programs, can either be separate computer programs or part of the machine interface.

software

Coded instructions or programs that control computer hardware functions and operations. Software is used to design additively manufactured parts and command machine tool movements during part creation.

standard resins

A liquid photopolymer material that becomes stiff and brittle when exposed to ultraviolet (UV) light or heat. Standard resins have a smooth surface and are typically low-cost, which makes them ideal for prototyping with vat photopolymerization.

stereolithography

SLA. A vat photopolymerization process that traces a focused light beam over a layer of photopolymer to selectively cure it. Stereolithography is often used for making softer parts that require a high degree of customization, such as dental aligners or hearing aids.

stiffness

The ability of a material to resist bending or stretching. Stiffness is sometimes called rigidity.

STL

Software that can create or convert digital design files, which represent 3D models, into a series of interconnected triangles. STL software is used in additive manufacturing processes.

strength

A material's ability to resist forces that attempt to break or deform it. Additive manufacturing processes such as vat photopolymerization create parts with poor strength.

stress fractures

A hair-like crack that appears on the surface of a part when the material has been exposed to excess tensile or shear stress. Stress fractures often lead to part failure.

support structures

A reinforcing component used to hold the weight of an additively manufactured part as it is being constructed. Support structures are removed from the part once the build is complete.

testing

In the five-step design for additive manufacturing process, examining a part to ensure that it performs its intended function and that it can be satisfactorily manufactured. Testing indicates whether the part needs additional planning or if it is ready for production.

thermoset

A group of plastics that are permanently hardened by light or heating. Thermosets can be used as build materials in some additive manufacturing methods, such as vat photopolymerization and material jetting.

topology

The arrangement of geometric or material components in a part. The topology of additively manufactured parts is particularly complex because it is capable of creating intricate shapes and various gradients of material in a part.

tough resins

A liquid photopolymer material that becomes tough and impact-resistant when exposed to ultraviolet (UV) light or heat. Tough resins are often used with vat photopolymerization to imitate the capabilities of engineering-grade plastics.

translucent

Able to permit the passage of light without being fully clear. Translucent materials are used in additive manufacturing to make parts used in fields such as optical, lighting, and consumer electronics.

transparent resins

A liquid photopolymer material that becomes clear or translucent when exposed to ultraviolet (UV) light. Transparent resins used with vat photopolymerization can have varying degrees of transparency.

ultraviolet

UV. A potentially harmful wavelength of light that is below, or shorter than, violet on the light spectrum. Ultraviolet light is used to selectively harden a photopolymer in vat photopolymerization processes.

UV

Ultraviolet. A potentially harmful wavelength of light that is below, or shorter than, violet on the light spectrum. UV light is used to selectively harden a photopolymer in vat photopolymerization processes.

vat photopolymerization

An additive manufacturing (AM) method that builds a part by curing layers of photopolymer with light. Vat photopolymerization processes include stereolithography (SLA) and digital light processing (DLP).