Silicone molding is a manufacturing process that transforms liquid or semi-solid silicone raw materials into elastomeric products with specific shapes and properties. It serves as the backbone of producing everything from daily necessities (Par exemple, Ustensiles de cuisine) to high-precision industrial parts (Par exemple, scellés). But with multiple molding techniques available, how do you choose the right one for your project, and what key factors ensure success?
1. A Comparison of 6 Core Silicone Molding Methods
Different silicone molding techniques are designed for specific scenarios—from mass production to small-batch customization. The table below breaks down their core features, candidatures, and key controls:
| Méthode de moulage | Caractéristiques clés | Applications typiques | Critical Control Parameters |
| Moulage par compression | Haute précision; adapté aux structures complexes; production de masse | High-precision seals, joints automobiles | Température de moisissure (160–200 ° C), pression (5–50MPa), vulcanization time |
| Moulage par injection | Grande efficacité; low scrap rate; automatisé | Miniaturized parts (Par exemple, electronic buttons, connecteurs conducteurs) | Vitesse d'injection (staged control), mold vacuum exhaust, plasticization temperature |
| Extrusion Molding | Continuous production; equal-section profiles | Tuyaux, bandes d'étanchéité, rubber hoses | Die design, barrel segmented heating, laser diameter monitoring |
| Moulure de portail | Flexible; low-cost for small batches | Transparent crafts, Prototypes de moisissure, bijoux personnalisés | Vacuum defoaming, layered infusion (Pour les pièces épaisses) |
| Revêtement & Impregnation | Mince, uniform coverage; adheres to substrates | Fabric coating, PCB waterproof films, biomedical coatings | Coating thickness, adhésion (grid test), centrifugation speed (for impregnation) |
| Special Molding | Novateur; solves complex needs | Cold runner: zero-waste parts; 3D printing-assisted: complex textures; Co-création: silicone + metal/plastic inserts | Isolation (cold runner), Type de résine (3D Impression), insert positioning (co-molding) |
2. Step-by-Step Guide to 3 Common Molding Processes
For beginners or those selecting a method, here’s a linear breakdown of three widely used workflows:
UN. Moulage par compression (Ideal for High-Precision Seals)
- Préparation des matériaux: Weigh raw rubber, remplissage, and vulcanizing agents per formula; mix evenly via a refiner.
- Plastification: Reduce compound Mooney viscosity using the thin-pass method to improve plasticity.
- Preforming: Cut the compound into blanks that match the rough shape of the final product.
- Mold Vulcanization: Place blanks into the mold; heat and press in a flat vulcanizing machine (160–200 ° C, 5–50MPa).
- Post-traitement: Couper l'excédent de matériau; conduct secondary vulcanization to remove volatiles and boost stability.
B. Moulage par injection (Best for Miniaturized, Mass-Produced Parts)
- Alimentation: Automatically feed granular or strip compound into the machine’s barrel.
- Plastification: Heat the barrel to soften the compound (temperature varies by silicone type).
- Injection: Use high pressure to inject the softened compound into the closed mold cavity.
- Packing & Refroidissement: Maintain pressure until the compound is initially cured; cool slightly to set shape.
- Démêlé: A manipulator automatically removes the finished product—no manual trimming needed for most designs.
C. Extrusion Molding (Great for Continuous Profiles)
- Die Design: Customize the die opening to match the product’s cross-section (Par exemple, round for pipes, rectangular for strips).
- Chauffage & Extrusion: Heat the barrel in segments (front: plasticization; middle: constant temperature; rear: formation); push compound through the die.
- Surveillance: Utiliser un laser diameter gauge to real-time check product dimensions and adjust extrusion speed if needed.
- Traction & Coupe: Pull the extruded profile via a track system; cut it to the set length automatically.
3. Dépannage: Défauts communs & Solutions
Even with proper process design, defects can occur. Below is a cause-and-effect guide to fix the most frequent issues:
| Defect Phenomenon | Cause première | Practical Solution |
| Bubble Holes | Air trapped during mixing; gas released during vulcanization | Utiliser vacuum defoaming before molding; adopt gradient heating for vulcanization (avoids sudden gas expansion) |
| Glue Shortage (Remplissage incomplet) | Low silicone fluidity; insufficient glue injection volume | Augmenter la pression d'injection (pour le moulage par injection); optimize gate position to improve flow; preheat silicone slightly |
| Sticky Surface | Incomplete vulcanization; mold surface contamination | Extend vulcanization time or raise temperature; clean the mold with a solvent (Par exemple, alcool isopropylique) avant utilisation |
| Écart dimensionnel | Uneven curing shrinkage; inconsistent mold temperature | Reserve a 1.5%–3% shrinkage allowance in mold design; ensure uniform mold heating (use temperature sensors) |
4. Matériel & Equipment Selection Guide
Choosing the right materials and equipment directly impacts product quality. Use this table to match your needs:
| Demand Scenario | Recommended Silicone Type | Supporting Equipment |
| Food-Grade Products (Par exemple, silicone spatulas) | FDA-certified liquid silicone | Vacuum casting equipment (avoids contamination) |
| High-Precision Seals (Par exemple, automotive oil seals) | Silicone with vapor-phase silica filler (stimule la dureté) | Precision compression molding machine |
| Conductive Parts (Par exemple, electronic buttons) | Precipitation-method conductive silicone rubber | Vertical injection machine + static elimination device |
| High-Temperature-Resistant Parts (Par exemple, industrial pipes) | Phenyl silicone rubber (resists up to 300°C) | Extruder + laser diameter gauge |
5. Yigu Technology’s Perspective on Silicone Molding
À la technologie Yigu, we see silicone molding as a driver of product innovation—not just a manufacturing step. For clients in healthcare, we’ve optimized coating molding to create biocompatible silicone films for medical devices, garantissant 99.8% adhesion and meeting global safety standards. Pour les clients automobiles, notre moulage par compression process reduces seal defect rates to below 0.5% by refining temperature control and using high-purity fillers.
Looking forward, we’ll focus on two priorities: 1) Developing eco-friendly silicone materials that cut waste by 30% et 2) Integrating AI into moulage par injection to real-time adjust parameters, boosting efficiency by 20%. We aim to make silicone molding more sustainable, précis, and accessible for all industries.
FAQ
- Which silicone molding method is best for small-batch custom products (Par exemple, 50–100 unités)?
Gate molding is ideal—it’s low-cost, flexible, and doesn’t require expensive molds. Use additive liquid silicone for high transparency (Par exemple, custom crafts) and vacuum defoaming to ensure quality.
- How to ensure food-grade safety in silicone molding for kitchenware?
D'abord, sélectionner FDA-certified liquid silicone (no toxic additives). Deuxième, use dedicated equipment (avoid cross-contamination with industrial-grade silicone). Troisième, conduct post-production tests (Par exemple, leachate testing) pour répondre aux normes de sécurité alimentaire.
- What’s the main difference between compression molding and injection molding for silicone parts?
Compression molding is better for complex, pièces de haute précision (Par exemple, scellés) but has longer cycle times. Injection molding is faster (ideal for mass production of mini parts like buttons) and has lower scrap rates, but requires higher initial mold investment.