When choosing 3D printing for your project, two technologies stand out for durable, Funktionsteile: Selektives Lasersintern (Sls) UndHP Multi-Jet-Fusion (MJF). But the final quality of your part doesn’t just depend on the technology—it hinges on picking the right material and surface treatment. Kunden fragen oft: “Will this part’s surface be smooth enough?” oder“Is this material strong enough for my use?” This guide answers those questions by breaking down SLS and MJF materials, their natural surface finishes, and how to refine them. We’ll use real-world examples to help you avoid mistakes and pick the perfect combo for your project.
What Are SLS and MJF 3D Printing? A Quick Overview
Before diving into materials and surfaces, let’s recap how SLS and MJF work—this helps you understand why their finishes and materials differ.
Selektives Lasersintern (Sls)
Sls uses a high-powered laser (usually a CO₂ laser) to melt and fuse nylon powder layer by layer. The laser follows a 3D model’s cross-sections, Sintern (heating without fully melting) the powder until the part is built.
- Schlüsselmerkmal: No need for support structures—unsintered powder holds up overhangs. This makes SLS great for complex parts like gears or brackets.
- Natural Surface: Almost always grainy (Wie feines Sandpapier) because of the powder particles.
HP Multi-Jet-Fusion (MJF)
MJF (a patented HP technology) spreads a thin layer of polymer powder, sprays a “fusing agent” on areas that need to harden, then uses an infrared heat source to sinter the entire layer at once. It repeats this until the part is done.
- Schlüsselmerkmal: Faster than SLS and more consistent—MJF parts often have slightly better mechanical properties (Wie Zugfestigkeit) than SLS equivalents.
- Natural Surface: Also grainy, but some materials (like Nylon PA11) are smoother than SLS’s finishes.
SLS 3D -Druck: Materialien, Natural Finishes & Oberflächenbehandlungen
SLS excels with nylon-based materials, which offer strength and chemical resistance. Below’s a breakdown of the most common SLS materials, their natural surfaces, and how to improve them.
1. Nylon PA 12 (Grey, White, Full Color)
Why Choose It: The workhorse of SLS. It has balanced mechanical properties—strong, flexibel, and resistant to most inorganic chemicals (like ammonia and sulfuric acid). It’s also heat-resistant, with a melting point of178–180°C.
- Natural Surface Finish: Körnig (think fine sand).
- Available Colors: Grey, Weiß, and full color (you can print it in any shade you need).
- Surface Treatment Option: Media rolling (tumbling the part with small, abrasive media like ceramic beads). This smooths the surface to a satin matte finish—no more grainy feel. You can also dye it any color after treatment.
Beispiel für reale Welt
A custom gear manufacturer uses SLS Nylon PA12 for small transmission gears. The natural grainy surface caused too much friction, so they added media rolling. The satin matte finish reduced friction by 20%, and dyeing the gears black made them match the client’s machine aesthetic.
2. Nylon PA 12 GB/GF (Glasgefüllt)
Why Choose It: A reinforced version of Nylon PA12—mixed with glass beads (GB) or glass fibers (GF) to boost hardness and thermal stability. It’s perfect for parts that need to withstand heat or pressure, like engine covers or industrial brackets.
- Natural Surface Finish: Körnig (similar to standard Nylon PA12, but slightly rougher because of the glass particles).
- Surface Treatment Option: Media rolling works here too! It smooths the surface to a satin matte finish, though the glass particles mean it won’t be as smooth as standard PA12.
Für die Spitze
Avoid painting glass-filled PA12— the rough surface makes paint peel easily. Stick to media rolling and dyeing if you need a different color.
MJF 3D -Druck: Materialien, Natural Finishes & Oberflächenbehandlungen
MJF offers more material variety than SLS, including flexible TPU. Each material has unique surface traits, so let’s break them down.
1. Nylon PA 12 (Grey, Full Color)
Why Choose It: Similar to SLS PA12 but with better mechanicals—MJF PA12 has slightly higher tensile strength and elongation at break (meaning it can stretch more before breaking).
- Natural Surface Finish: Körnig, like a sugar cube.
- Available Colors: Grey and full color.
- Surface Treatment Option: Media rolling smooths it to a softer matte finish—ideal for parts like phone cases or cosmetic containers where feel matters.
Beispiel
A startup made custom phone grips with MJF Nylon PA12. The natural grainy surface was uncomfortable to hold, so they added media rolling. The smoothed surface boosted customer satisfaction by 40%.
2. Nylon PA 12 GB/GF (Glasgefüllt)
Why Choose It: Same benefits as SLS glass-filled PA12—harder and more heat-resistant than standard PA12. Great for parts like drone frames or tool handles.
- Natural Surface Finish: Körnig (matching MJF’s standard PA12, with subtle texture from glass particles).
- Surface Treatment Option: Media rolling reduces grain but won’t eliminate it entirely—this is normal for glass-filled materials.
3. Nylon PA 11
Why Choose It: More flexible and UV-resistant than PA12. It’s perfect for outdoor parts (like garden tool handles) or parts that need to absorb impact (like protective cases).
- Natural Surface Finish: Grainy but smoother than PA12—the powder particles are finer, so the surface feels less rough.
- Surface Treatment Option: Media rolling takes it to a soft, almost silky matte finish—no need for extra coatings.
Fallstudie
An outdoor gear brand used MJF Nylon PA11 for hiking pole handles. The natural smooth-grain surface was already comfortable, but media rolling made it grip better when wet. They saw zero returns from customers complaining about slippery handles.
4. Estane 3d TPU M95A
Why Choose It: A flexible elastomer with high tear resistance and a Shore hardness of 95A (similar to a car tire’s rubber). It’s for parts that need to bend or bounce, like phone case edges or watch bands.
- Natural Surface Finish: Smooth rubber texture—no grain! This is unique to MJF TPU; SLS doesn’t offer a TPU with this smooth feel.
- Surface Treatment Option: Rarely needed— the natural rubbery surface is usually perfect. If you want a matte look, a light media roll (with soft media) can reduce shine without losing flexibility.
Sls vs. MJF: Material & Surface Finish Comparison Table
Um es einfach zu vergleichen, here’s a side-by-side look at SLS and MJF materials, their natural finishes, und am besten verwendet:
| 3D Technology | Material | Natural Surface Finish | Surface Treatment Option | Schlüsselstärken | Ideale Anwendungen |
|---|---|---|---|---|---|
| Sls | Nylon PA 12 | Körnig | Media rolling → Satin matte; Dye | Chemischer Widerstand, Wärmewiderstand | Getriebe, Klammern, chemical containers |
| Sls | Nylon PA 12 GB/GF | Körnig (slightly rougher) | Media rolling → Satin matte | Hohe Härte, Wärmestabilität | Engine covers, industrial brackets |
| MJF | Nylon PA 12 | Körnig (sugar cube-like) | Media rolling → Soft matte; Dye | Higher tensile strength than SLS PA12 | Telefonkoffer, Kosmetische Behälter |
| MJF | Nylon PA 12 GB/GF | Körnig | Media rolling → Matte | Wärmewiderstand, Steifheit | Drohnenrahmen, Werkzeuggriffe |
| MJF | Nylon PA 11 | Körnig (smoother than PA12) | Media rolling → Silky matte | UV -Widerstand, Flexibilität | Outdoor handles, Schutzfälle |
| MJF | Estane 3d TPU M95A | Smooth rubber texture | Light media roll (optional) | Tear resistance, Flexibilität | Phone case edges, watch bands |
How to Choose the Right Material & Oberflächenbehandlung
Picking the right combo isn’t hard—just ask yourself three questions:
1. Was wird der Teil tun??
- If it needs to bend: Choose MJF Estane TPU (smooth rubber surface) or MJF PA11 (flexibel, smooth-grain).
- Wenn es mit Wärme umgehen muss: Go for glass-filled PA12 (SLS or MJF)—media rolling will smooth the surface without reducing strength.
- If it’s outdoors: MJF PA11 (UV-resistent) is your best bet—its natural smooth surface works for most outdoor parts.
2. How Important Is Surface Feel?
- Smooth and rubbery: MJF TPU (no treatment needed).
- Soft matte: Media roll MJF PA11 or SLS PA12.
- Color-critical: Dye SLS or MJF PA12 after media rolling—full-color printing is also an option for both technologies.
3. Was ist Ihr Budget??
- Billiger, Schneller: MJF is often faster than SLS, so it’s better for high-volume runs (wie 1000+ Teile).
- Komplexe Teile: SLS is slightly more cost-effective for very complex designs (no supports save material).
Yigu Technology’s Perspective on SLS and MJF Materials & Surfaces
Bei Yigu Technology, Wir sehenSLS and MJF as go-to technologies for functional, durable parts—but success depends on material and surface choices. We’ve helped clients fix missteps: Zum Beispiel, a client once chose SLS PA12 for a phone grip (too grainy) and switched to MJF TPU (smooth rubber) after our advice. The new grips had a 50% higher customer approval rate. We also recommend media rolling for most SLS/MJF parts—it’s a low-cost way to boost feel without losing strength. Wenn sich der 3D -Druck weiterentwickelt, we’re excited to see more materials (like higher-temperature PA12) expand what SLS and MJF can do—helping clients build better parts, Schneller.
FAQ
- Can I get a completely smooth (mirror-like) surface with SLS or MJF?
No—SLS and MJF’s powder-based process means their natural finishes are grainy, and even media rolling only gets you to a satin/matte finish. If you need a mirror surface, you’ll need to use a different technology (like SLA resin printing) or add a post-processing step like painting or coating (though this can add cost and reduce flexibility). - Is MJF Nylon PA12 stronger than SLS Nylon PA12?
Yes—MJF PA12 typically has slightly higher tensile strength (ability to resist pulling) and elongation at break (ability to stretch before breaking) than SLS PA12. Zum Beispiel, MJF PA12 might have a tensile strength of 50 MPA, while SLS PA12 is around 48 MPA. This makes MJF better for parts that need to handle more stress, like small load-bearing brackets. - Can I use SLS or MJF materials for food-contact parts?
Most standard SLS/MJF materials (like Nylon PA12) are not FDA-approved for direct food contact—they have small pores that can trap food particles and bacteria. Jedoch, some specialized food-safe versions (like medical-grade PA12) exist. If you need food-contact parts, ask your 3D printing provider for FDA-compliant materials and add a sealing treatment (like epoxy coating) to close pores.