An overview of the mechanical and physical properties of SLA 3D printing that make it a great choice for production parts

SLA 3D Printing for Production Parts. Really?

Everyone’s familiar with the versatility of SLA (stereolithography) printing for prototyping. Its fantastic layer resolution gives a beautifully smooth A-surface (think reduced finishing times); it’s one of the most precise 3D printing processes, enabling intricate detailing; many industrial SLA printers offer a large print bed enabling large parts to be printed in one piece; and it’s comparatively fast. 

But, it’s a common belief that SLA resins, while great for prototyping and creating detailed models, often lack the mechanical properties required for production parts. They tend to be brittle and can be susceptible to wear, impact, and environmental factors. 

Let’s turn that notion on its head. Stereolithography (SLA) 3D printing can be used in production parts when certain requirements or conditions align with its capabilities. SLA has several advantages and is suitable for specific applications. Here are just a few scenarios where SLA 3D printing is used in production parts: 

Electronics enclosures: SLA is well-suited for producing small quantities of complex, intricate, or customized parts, such as electronics enclosures in specialized electronic devices.  It is cost-effective when compared to traditional manufacturing methods like injection molding for small production runs. 

Medical and Dental Applications: Some SLA resins come with a biocompatibility rating, making them perfect for creating personalized prosthetic limbs components, orthotic devices, and other medical aids. Without the prolonged process of making molds (silicone or otherwise), it’s possible to produce orthoses components to match the specific needs and anatomical details of individual patients simply by scanning the patient and uploading the CAD to your production partner’s portal. 

Aerospace and Automotive: SLA can be used for producing certain aerospace and automotive components, particularly those with complex internal structures or lightweighting requirements; or even specialist automotive pieces for interior trim (think buttons, badges and grommets). 

Props, models and costumes for the film industry: SLA, with its beautifully smooth finish, is beloved of set and prop designers and creative directors across the entertainment sector. The process delivers on all of the intricate detailing and complex shapes that would be challenging to achieve through traditional manufacturing methods. It can be painted, bonded, punched and lacquered and then worn (did you know that Quickparts is an approved Disney supplier?). 

Materials to suit the application 

Returning to the misconception that SLA resins don’t stand up to the rigors of production part requirements, we’ll now review some of those SLA resins available to those using Quickparts’ SLA services, demonstrating where they are most effective.  They can be categorized as follows: 

Standard Resins: These are used for general-purpose applications, offering a balance of mechanical properties, surface finish, and cost-effectiveness. They are suitable for many production parts that don’t require high heat resistance or aren’t destined for high impact/erosion environments. At Quickparts, resins we offer that are suitable for production parts include: 

  • Accura® Extreme White, which is slightly flexible with a Shore D hardness of 78-80, but nevertheless a higher impact strength of 55-56 J/m 
  • Accura® 55 is a rigid, strong and accurate plastic with all the aesthetics of the industry standard, injection molded ABS. It’s useful for functional assemblies and short-run production parts, with a heat deflection temperature of 55˚C and a tensile modulus of up to 3800MPa 
  • Accura® ABS Black, which as its name suggests, is a rigid, tough, black SLA resin suitable for production parts in small runs. It hasn’t the greatest heat deflection temperature at 51˚C; however, it has very good flexural strength, at 75–78MPa. 

Engineering Resins: These materials are designed for applications requiring enhanced mechanical properties, such as toughness, heat resistance, or stiffness. Examples include tough resins, high-temperature resins, and flexible resins: 

  • Accura® Extreme grey has a temperature resistance of around 61˚C and a tensile strength in the region of 38-44MPa. It’s an ultra-tough grey plastic that resists breakage and can be used in challenging, functional assemblies  
  • Accura® 48HTR has a heat resistance of 130˚C with a post cure. It’s transparent, rigid and durable, with a tensile strength in the region of , and can be used in aerospace, automotive and electronics applications 
  • Accura® Bluestone™ is an engineered nano composite which has a very high stiffness and an outstanding flexural modulus of 8300-9800MPa. With UV and thermal post curing, high heat deflection temperature can be up to 280˚C. Again, useful for under-the-hood applications. 

It’s important to note that SLA materials may require post-processing steps like UV curing and surface finishing may be necessary to achieve the desired final properties and aesthetics for production parts. 

Quickparts is keen to help you explore SLA for low volume production parts. You can either post enquiries via our customer portal, QuickQuote, or you can get in touch with one of our technical experts who will be able to send you samples, provide you with the relevant TDSs and even send you samples.