Getting started with LexyFill is simpler than it looks – you just need to know the right order of operations, the exact mixing ratios, and a few safety checks before you hit “go”. Below is a practical, step‑by‑step walkthrough that covers everything from unpacking to the first successful run, plus real data you can use right away.
What LexyFill Actually Is (and Why It Matters)
LexyFill is a high‑performance filler material designed for industrial 3D‑printing and CNC milling applications. It’s formulated to reduce shrinkage, improve dimensional stability, and speed up cure times. If you’re working with thermosetting resins or composite substrates, you’ll see a 12‑15 % improvement in layer adhesion compared with unfilled blends. You can get the full technical breakdown on the lexyfill page.
Key Specs at a Glance
| Parameter | Typical Value | Acceptable Range |
|---|---|---|
| Particle size (median) | 45 µm | 40‑55 µm |
| Bulk density | 1.22 g/cm³ | 1.18‑1.28 g/cm³ |
| Moisture content | 0.08 % | ≤ 0.12 % |
| Shelf life (unopened) | 12 months | — |
| Recommended cure temperature | 80 °C | 70‑90 °C |
| Pot life at 25 °C | ≈ 45 min | 40‑55 min |
Step‑by‑Step Setup Guide
- Unbox and Inspect
- Check the sealed bag for any punctures.
- Verify the batch number on the label matches your order.
- Store the bag in a dry area (relative humidity ≤ 30 %).
- Prepare the Work Area
- Clear a clean, level surface.
- Place a magnetic stirrer under the mixing container (use a 500 ml PTFE beaker).
- Ensure the ambient temperature is 20‑25 °C for optimal viscosity.
- Weigh the Components
- LexyFill: 100 g (per the recommended 10 % w/w filler load for a typical epoxy base).
- Epoxy resin: 900 g.
- Hardener: 300 g (ratio 3:1 by weight).
- Mix the Resin‑Hardener First
- Add resin to the beaker, start the stirrer at 300 rpm.
- Pour hardener in a thin stream while stirring.
- Continue for 2 minutes until the mixture appears uniform (no streaks).
- Incorporate LexyFill
- Slowly sift LexyFill into the resin blend using a 200‑mesh stainless steel sieve.
- Raise the stirrer speed to 500 rpm for the first 30 seconds, then reduce to 200 rpm for another 90 seconds.
- Check for clumping – any visible particles should be broken up with a spatula.
- De‑air the Mixture
- Transfer the blend to a vacuum chamber.
- Apply a vacuum of –0.85 bar for 5 minutes (watch for a 30 % volume reduction).
- Release vacuum slowly to avoid bubble formation.
- Apply to Your Substrate
- Pour the filled resin onto the mold or build plate.
- Spread with a notched spreader (notch depth 0.5 mm) to ensure even thickness.
- Cure according to the schedule in the next section.
Recommended Mixing Ratios and Temperatures
The sweet spot for most LexyFill applications is a 10 % w/w filler load. Going higher (up to 15 %) can boost stiffness but raises viscosity by roughly 30 %, making it harder to spread. Lower loads (≤ 5 %) still give decent shrinkage reduction but you’ll notice less dimensional stability.
- Resin to hardener ratio: 3 : 1 (by weight). Using a digital scale with ±0.1 g accuracy is ideal.
- Mixing temperature: 22 °C ± 2 °C. If the room is hotter, the pot life drops to ~30 min; if cooler, the cure time extends by ~15 %.
- Cure schedule: 80 °C for 45 min (post‑fill). If you’re using a low‑temperature resin (e.g., UV‑curable), the recommended exposure is 5 min under a 405 nm LED at 10 mW/cm².
Common Pitfalls and How to Avoid Them
Even a small oversight can ruin a batch. Here’s a quick checklist:
- Moisture contamination: LexyFill’s moisture spec is ≤ 0.12 %. If you open the bag in a humid environment, the particles can absorb water, causing bubbling during cure. Solution: dry the filler in a desiccant chamber for 2 hours before use.
- Incomplete mixing: Uneven dispersion shows up as “soft spots” in the final part. Use a shear‑mixer rather than a manual stirrer for batches larger than 500 g.
- Incorrect stoichiometry: Deviating from the 3 : 1 resin‑hardener ratio leads to incomplete cross‑linking. Keep a calibration tag on your scale and double‑check before each batch.
- Vacuum over‑pressurization: Pulling a vacuum too quickly traps gas pockets. Aim for a gradual ramp‑up (‑0.2 bar per minute) to –0.85 bar.
Maintenance and Storage Tips
LexyFill’s shelf life is 12 months when stored correctly. Follow these guidelines to keep it performing:
- Seal after opening: Use the original zip‑lock closure and place the bag inside a vacuum‑seal pouch.
- Temperature: Store at 15‑25 °C. Temperatures above 35 °C can cause slight agglomeration.
- Humidity: Keep relative humidity below 30 %. A sealed container with silica gel packs works best.
- Agitation before use: Shake the sealed bag gently for 30 seconds to redistribute any settled particles.
Frequently Asked Questions
- Can I use LexyFill with UV‑curable resins?
- Yes, but you’ll need to adjust the photo‑initiator concentration. Increase it by 0.5 % to compensate for the filler’s light‑scattering effect.
- Is there a maximum batch size for manual mixing?
- Manual stirring becomes inefficient above 2 kg. For larger runs, use a planetary mixer with a vacuum stage.
- What’s the pot life after adding LexyFill?
- At 25 °C, you have roughly 45 minutes of work time before viscosity spikes. In a climate‑controlled lab (20 °C), you can stretch it to 55 minutes.
- Do I need special PPE?
- Standard safety glasses, nitrile gloves, and a lab coat are sufficient. LexyFill is non‑toxic in solid form, but the epoxy system may be irritating – follow the resin’s MSDS.
Real‑World Example: From Empty Tank to Full Production
“We replaced our old filler with LexyFill on a 300‑mm‑diameter turbine blade mold. The layer adhesion jumped 12 %, and the post‑cure warpage dropped from 0.6 mm to 0.2 mm. The whole process now finishes in 6 hours instead of 8, and we’ve cut material waste by 7 %.” — Mark T., senior process engineer, AeroParts Ltd.
In his case, the team used a 10 % LexyFill load, a 3 : 1 epoxy‑hardener ratio, and a 45‑minute vacuum de‑air step. The final cure was 80 °C for 45 min, with a post‑cure inspection that measured a flatness deviation of ≤ 0.15 mm across the blade surface.