Silicone mold processing is a precision manufacturing technique that transforms liquid silicone rubber (LSR) or condensed silicone rubber into elastic, detail-rich molds. By infusing uncured silicone onto prototype surfaces, it replicates complex structures—from 0.05mm micro-textures to large architectural components. Its core strengths (niedrige Kosten, short cycle, high customization) make it a go-to for rapid sampling, Small-Batch-Produktion, and personalized crafts. But how does the process work, what materials are best, and how to avoid common pitfalls?
1. Key Materials for Silicone Mold Processing: Match to Use Cases
The performance of a silicone mold depends entirely on material selection. Below is a breakdown of silicone types, ihre Eigenschaften, and ideal applications—aligned with core material traits from industry standards:
| Silikontyp | Schlüsselmerkmale | Compliance -Standards | Typische Anwendungen |
| Medical-Grade Silicone | Withstands high-temperature steam sterilization (121° C+); Biokompatibel (no skin irritation) | FDA 21 CFR §177.2600; ISO 10993 | Medical orthosis production (Z.B., custom braces), food-contact molds (Schokolade, Süßigkeiten) |
| Industrial-Grade Silicone | Adjustable hardness (Shore A 5–60°); balances tear strength (>3kN/m) and resilience | Gb/t 5574 (industrial rubber standards) | Resin handicraft molding, architectural decoration component duplication, industrial part prototyping |
| Specialty Conductive Silicone | Contains conductive fillers (Z.B., carbon black); maintains flexibility | IEC 60093 (electrical conductivity) | Electronic device packaging (Z.B., sensor gaskets, anti-static mold inserts) |
| Condensed Silicone Rubber | Niedrige Kosten; cures via moisture absorption (releases ethanol); easy to mix | Industrial-grade only (no food/medical use) | Low-criticality crafts (Z.B., simple plaster molds), temporary seals |
2. Step-by-Step Workflow of Silicone Mold Processing
Silicone mold processing follows a standardized 4-stage cycle—each step critical to capturing details and ensuring mold durability. The process is linear, with clear quality checkpoints:
Bühne 1: Prototype Pre-Treatment (Legen Sie das Fundament)
- Reinigung: Wipe the prototype (3D print, physical object, or master model) with isopropyl alcohol to remove oil, Staub, or fingerprints. Even tiny debris causes mold defects (Z.B., pockmarks).
- Festsetzung: Secure the prototype to a flat base (Z.B., Acrylplatte) using double-sided tape. Ensure it’s centered—this prevents uneven silicone distribution.
- Trennmittelanwendung: Sprühen Sie eine dünne Schicht von PVA water-soluble release agent or silicone-specific release spray. This reduces adhesion, making demolding easier (critical for fragile prototypes like resin models).
Bühne 2: Silicone Blending (Mix for Uniformity)
- Component Ratio: Mix silicone main agent and curing agent in a precise ratio (common ratios: 10:1 for industrial-grade, 1:1 for LSR). Use an electronic scale (±0.1g accuracy) to avoid curing failures.
- Zusatzstoffe (Bei Bedarf):
- For color-coded molds: Add non-toxic pigments (1–2% of total weight) to the main agent before mixing with curing agent.
- For heat-resistant molds: Incorporate thermal powder (Z.B., Alumina) to boost temperature tolerance (bis zu 200 ° C.).
- Entschäumen: Die Mischung langsam umrühren (30–50 RPM) for 2–3 minutes, then place in a vacuum chamber (-0.1MPA) für 15–20 Minuten. This removes air bubbles—without it, the mold will have holes that ruin details.
Bühne 3: Gate Molding (Capture Details)
- Containment Setup: Build a frame (wood or acrylic) around the prototype. The frame should be 5–10cm taller than the prototype’s highest point to prevent silicone overflow.
- Gießentechnik: Slowly pour the blended silicone over the prototype’s edges (nicht direkt oben) at a rate of 1–2cm/min. This lets silicone flow into micro-details (Z.B., 0.05mm texture lines) without trapping air.
- Leveling: Tap the frame gently 2–3 times to release surface bubbles. Für tiefe Hohlräume, use a small brush to guide silicone into gaps—avoiding air pockets.
Bühne 4: Heilung & Entformen (Finalize the Mold)
- Curing Conditions:
- Room-temperature curing: Let stand for 24–48 hours (ideal for condensed silicone; humidity 40–60% works best).
- Accelerated curing: Heat in an oven at 60–80°C for 2–4 hours (speeds up LSR curing; reduces cycle time for small-batch production).
- Entformen: Einmal geheilt (test by touching the silicone—should be firm, not sticky), peel the mold from the prototype’s edges. Use a plastic spatula to lift stuck areas—never pull hard (this stretches the mold).
- Post-Trim: Cut off excess silicone (Blitz) with sharp scissors. Sand the mold’s inner edges with 400-grit sandpaper for a smooth finish (improves the quality of cast parts).
3. Vergleich: Silicone Molds vs. Traditional Molds
Silicone molds outperform traditional options (Stahl, Epoxidharz) in key areas—especially for small-scale or custom projects. The table below highlights the differences:
| Besonderheit | Silikonformen | Stahlformen | Epoxy Resin Molds |
| Ausrüstungsinvestitionen | Niedrig (no large machines needed; works with basic tools) | Hoch (requires CNC machining centers; $50k+ setup) | Medium (needs mold frames and mixing equipment) |
| Detail Replication | Exzellent (captures 0.05mm microstructures; ideal for textures) | Gut (limited to 0.1mm details; best for smooth parts) | Gerecht (prone to bubble traps; loses detail in deep cavities) |
| Dienstleben | Mäßig (30–50 cycles for industrial-grade; 10–20 for craft-grade) | Lang (100k+ cycles; für die Massenproduktion) | Kurz (5–10 cycles; brittle and prone to cracking) |
| Materialkompatibilität | Breit (supports polyurethane, gypsum, Zement, Harz, and low-temperature metals) | Beschränkt (best for plastic injection molding) | Eng (only works with low-viscosity resins) |
| Zykluszeit | Schnell (24–48 hours per mold) | Langsam (2–4 weeks for machining) | Medium (3–5 days for curing) |
4. Häufige Herausforderungen & Solutions in Silicone Mold Processing
Even experienced operators face issues—most stem from poor process control. Below is a cause-and-effect guide to troubleshooting:
| Herausforderung | Grundursache | Practical Solution |
| Mold Dimensional Deviations | Ambient temperature/humidity fluctuations; uneven curing shrinkage | – Cure in a temperature-controlled room (20–25 ° C., 40–60% Feuchtigkeit).- Verwenden Sie Silikon mit niedrigem Verknüpfung (<0.5% Schrumpfrate; Z.B., LSR).- Add a 1–2% dimensional allowance to the prototype. |
| Bubbles in the Mold | Fast pouring; inadequate vacuum defoaming; stirring too vigorously | – Pour silicone at 1cm/min; avoid splashing.- Extend vacuum time to 25 Minuten; repeat if bubbles remain.- Stir at 30 Drehzahl (use a slow-speed mixer if available). |
| Difficult Demolding | Insufficient release agent; prototype surface roughness | – Apply a second thin layer of release agent (focus on textured areas).- Sand rough prototype surfaces with 600-grit sandpaper before pre-treatment. |
| Mold Tearing During Use | Low tear strength silicone; thin mold walls (<5mm) | – Switch to industrial-grade silicone with tear strength >4kN/m.- Make mold walls 8–10mm thick for high-cycle use (Z.B., 50+ casts). |
5. Best Practices for Silicone Mold Maintenance
Proper care extends a silicone mold’s service life from 10 cycles to 50+. Follow these tips:
- Clean Immediately Post-Use: Wipe the mold with warm water and neutral detergent (Z.B., Spülmittel) after each casting. Avoid harsh chemicals (acetone dissolves silicone).
- Gründlich trocknen: Pat the mold with a lint-free cloth, then air-dry in a cool, shaded area. Moisture trapped in cavities causes mold growth.
- Store Correctly:
- Lay flat (never fold) to prevent permanent creases.
- Für langfristige Lagerung (1+ Monat), dust the mold’s inner surface with talcum powder to prevent sticking.
- Repair Minor Damage: Fix small tears with a drop of silicone main agent + Härtungsmittel (10:1 Verhältnis). Heilen für 24 hours before reuse.
6. Yigu Technology’s Perspective on Silicone Mold Processing
Bei Yigu Technology, we see silicone mold processing as a catalyst for rapid innovation—especially for small businesses and creators. For architectural firms, our industrial-grade silicone (Shore A 20–30°) has replicated 1:10 scale building facades with 0.05mm texture accuracy, cutting prototyping time by 60% vs. epoxy molds. For medical device makers, our medical-grade LSR molds meet FDA standards, enabling custom orthosis production with 24-hour turnaround.
We’re optimizing two key areas: 1) Developing eco-friendly condensed silicone (reducing VOCs by 30%) for sustainable crafting; 2) Integrating 3D scanning to automate prototype pre-treatment (sicherstellen 100% silicone coverage). Our goal is to make high-precision silicone mold processing accessible—no large equipment required.
FAQ
- Can I reuse a silicone mold made via this process, and how many times?
Yes—reusability depends on the silicone type: Industrial-grade molds last 30–50 cycles; medizinische Grade (LSR) molds last 50+ Zyklen; craft-grade condensed silicone lasts 10–20 cycles. Proper cleaning (warmes Wasser + detergent) and storage (Wohnung, trocken) extend life.
- What’s the best way to avoid curing shrinkage in silicone molds?
Verwenden Sie Silikon mit niedrigem Verknüpfung (Z.B., LSR with <0.5% Schwindung) and control curing conditions: Cure at 20–25°C (avoid extreme temperatures) and 40–60% humidity. For large molds, add a 1–2% dimensional allowance to the prototype (Z.B., a 10cm prototype becomes 10.1cm to offset shrinkage).
- Can silicone mold processing be used for high-temperature casting materials (Z.B., niedrig schmelzende Metalle)?
Ja – aber wählen Sie das richtige Silikon: Use industrial-grade silicone with thermal powder additives (heat resistance up to 200°C) for low-melting metals (Z.B., Zinn, Schmelzpunkt 170°C). Avoid medical-grade or condensed silicone—they deform above 120°C. Always test a small mold sample first to confirm heat tolerance.