SLA, SLS and MJF are common polymer additive processes for OEM prototypes before CNC or molding. Each trades surface quality, mechanical performance and cost differently. Choose based on why you need the part—looks, fit, or functional stress—not brand names alone.
SLA, SLS and MJF are common polymer additive processes for OEM prototypes before CNC or molding. Each trades surface quality, mechanical performance and cost differently. Choose based on why you need the part—looks, fit, or functional stress—not brand names alone.
Process snapshots
- SLA: resin photopolymerization; fine detail and smooth surfaces for visual models and some master patterns.
- SLS: laser-sintered nylon powder; tougher functional prototypes without supports in the SLA sense.
- MJF: powder bed fusion with detailing agents; strong nylon parts, good for engineering trials and small batches.
Comparison table
| Criterion | SLA | SLS | MJF |
|---|---|---|---|
| Surface | Excellent detail | Grainy powder texture | Fine grain, dyeable |
| Strength | Varies; often brittle grades | Good nylon toughness | Strong isotropic-leaning nylon |
| Supports | Yes (scaffold) | Powder supports | Powder supports |
| Typical use | Visual, form | Functional clips, housings | Functional + short runs |
| Post-process | Wash, cure, sand | Bead blast | Blast, optional dye |
When to leave printing for CNC or molding
Switch to CNC when material must match metals or engineering plastics with certified stock. Switch to injection molding when annual volume and dimensional stability justify tooling. Many programs use SLS/MJF for early UX and CNC for tolerance-critical mating parts.
RFQ tips for printed prototypes
- State whether the part is visual-only or load-bearing.
- Call out holes that must be reamed or tapped after print.
- Specify color dye or paint if brand review is needed.
HC-Mold context
HC-Mold supports rapid prototyping alongside CNC, molds and molding so you can graduate processes without changing commercial entities. Free DFM; ISO 9001:2015; Dongguan, China.
Material and end-use mapping
SLA resins include tough, high-temp and clear grades, but anisotropic behavior and UV aging differ from production thermoplastics. SLS and MJF nylons better approximate functional stiffness for clips and living features, yet moisture uptake still differs from injection-molded PA66 GF30.
For investor demos, prioritize surface and color. For drop tests, prioritize toughness and real wall thickness. For connector fit, measure critical interfaces and ream or machine after print when tolerances demand it. Document that hybrid process in the prototype report so stakeholders do not assume full printed accuracy.
Cost per part falls when you nest multiple designs in one powder bed build. Batch design reviews weekly rather than one-off uploads if your team iterates rapidly. HC-Mold can advise when printing stops being economical versus CNC plate prototypes.
Buyer checklist before you issue the PO
Confirm drawings are revision-controlled, materials are purchasable in China within your schedule, and inspection methods are agreed in writing. Ambiguity at PO stage becomes cost later. List secondary operations, packaging and labeling so they are not treated as free extras. If multiple factories are bidding, freeze the same specification package for all—do not let informal calls create hidden scope differences.
Align internal stakeholders: industrial design owns cosmetics, engineering owns function, procurement owns total cost and risk. A single RFQ owner should consolidate feedback so the manufacturer receives one voice. For export programs, involve logistics early on Incoterms preference and whether tools or finished goods will cross borders.
SLA vs SLS vs MJF decisions improve when data is complete. HC-Mold International Co., Limited in Chang'an, Dongguan, Guangdong, China operates under ISO 9001:2015 with free DFM on complete packages, reply within 12 hours, and quote within 24 hours when files, material, volume and finish are clear. Email contact@hc-mold.cn or call +86-769-85327002. Prototype CNC frequently supports MOQ of one piece when geometry is defined.
Documentation to keep in your program folder
- Final quote with assumptions listed line by line.
- NDA and tooling ownership clauses if molds are involved.
- Approved DFM screenshots and CAD revision that matches the PO.
- Sample reports (dimensional and visual) with clear accept/reject notes.
- Packaging photos and carton specs for repeat orders.
FAQ
Is MJF the same as SLS?
Both use nylon powder beds but fuse differently. Mechanical and surface results differ; qualify with real parts.
Can printed parts replace production forever?
Rarely for branded high volume. They excel as bridges and low-volume specials.
Which is best for clear parts?
Clear-capable SLA resins are usually preferred over powder processes for transparency.
How do I get a prototype quote?
Send STL or STEP, quantity and purpose to contact@hc-mold.cn. Reply ≤12h on complete RFQs.
Ready to source prototypes with the right process mix? Send your STEP/IGES drawings, material notes, volume band and finish requirements via our RFQ form. HC-Mold International Co., Limited is a direct OEM manufacturer in Chang'an, Dongguan, Guangdong, China (ISO 9001:2015). Contact: contact@hc-mold.cn · +86-769-85327002. Free DFM review; reply ≤12h and quote ≤24h on complete RFQ packages.
Talk to HC-Mold engineering
Free DFM · reply ≤12h · quote ≤24h on complete RFQ · ISO 9001:2015 · Dongguan, China