Rubber prototypes—crafted from materials like silicone, TPE, TPU, and natural rubber—are critical for validating product functions like elasticity, sealing, and slip resistance. Unlike plastic or metal prototypes, their production requires specialized mold-making and molding processes to leverage rubber’s unique flexible properties. This article breaks down the full process from demand analysis to final testing, with comparisons, technical tips, and real-world examples to help you avoid common pitfalls and create high-quality rubber prototypes.
1. Pre-Production: Define Requirements & Plan Design
Antes de comenzar la fabricación, aclarar los objetivos de las pruebas y los parámetros de diseño para garantizar que el prototipo se alinee con sus necesidades. Esta etapa sienta las bases para la selección de materiales y la elección del proceso..
1.1 Clarify Core Requirements
Los prototipos de caucho tienen tres propósitos de validación clave: concéntrese en ellos para guiar su diseño:
| Categoría de requisito | Objetivos clave de la prueba | Ejemplo del mundo real |
| Validación funcional | Prueba de elasticidad (P.EJ., “Can the waterproof ring bounce back after compression?"), sealing (P.EJ., “Does it prevent water leakage?"), and slip resistance (P.EJ., “Does the grip stay secure when wet?"). | A phone manufacturer tests a silicone waterproof ring prototype to ensure it seals the charging port during 30-minute water submersion. |
| Material Property Testing | Verify temperature resistance (P.EJ., “Will it withstand -30°C to 150°C for automotive use?"), resistencia al desgaste (P.EJ., “Does the tire tread avoid tearing?"), y dureza (30°–70° Shore). | An outdoor gear brand tests a TPE grip prototype to confirm it retains flexibility after 1,000 hours of UV exposure. |
| Structural Compatibility | Ensure rubber parts assemble with metal/plastic components (P.EJ., “Does the rubber slot fit the plastic housing?") and optimize thickness/chamfers to prevent deformation. | A medical device team adjusts the thickness of a silicone tube prototype from 1mm to 1.5mm to avoid kinking when connected to a plastic connector. |
1.2 Design 3D Models with Rubber-Specific Rules
Utilice el software CAD (Solidworks, Gusto, y) Para crear un modelo digital, focusing on parameters unique to rubber:
| Design Parameter | Requirements & Consejos | Razón |
| Tasa de contracción | Account for rubber’s natural shrinkage (1.02–1,05%: silicone = 1.03%, polyurethane = 1.02%). | Prevents dimensional errors—e.g., a 100mm waterproof ring will shrink to 97mm if using silicone; model it as 103mm initially. |
| Espesor & Chames | Keep thickness 0.5–5mm (too thin = easy tearing; too thick = slow curing). Add 0.5–1mm chamfers to edges. | A silicone shock pad prototype with 0.8mm chamfers avoids cracking when compressed, unlike a sharp-edged version that breaks after 50 prensas. |
| Anti-Slip Patterns & Agujeros | Mark anti-slip textures (P.EJ., grid patterns for grips) and assembly holes (P.EJ., 2mm diameter for screws) with clear coordinates. | A power tool handle prototype with 0.5mm-deep grid patterns passes slip tests—users report 40% less hand fatigue than a smooth-surface version. |
1.3 Split Complex Parts (Si es necesario)
For curved or thin-walled rubber parts (P.EJ., a U-shaped sealing strip), split the 3D model into sections. This simplifies mold machining and prevents deformation during demolding. Por ejemplo:
- A curved silicone earbud prototype is split into “ear tip” and “body” sections—each fits into a smaller mold, reducing the risk of air bubbles compared to a single large mold.
2. Fabricación de moldes: Choose the Right Method for Your Batch & Precisión
Los prototipos de caucho requieren moldes personalizados: seleccione entre moldes mecanizados por CNC o impresos en 3D según las necesidades de precisión y el volumen de producción..
| Tipo de molde | Detalles del proceso | Ventajas | Desventajas | Ideal para |
| Molde mecanizado CNC | Utilice CNC para grabar bloques de acero o aluminio; Pulir la superficie a Ra0.8–Ra1.6 para reducir la fricción de desmoldeo.. | Alta precisión (± 0.05 mm), reutilizable (500+ ciclos), adecuado para cauchos duros como EPDM. | Alto costo (\(500- )2,000 por molde), tiempo de entrega lento (3–5 días). | Lotes pequeños (10–100 unidades) de piezas de alta precisión (P.EJ., sellos de dispositivos médicos). |
| 3D molde impreso | resina de impresión (SLA) o nylon (SLSS) moldes; post-proceso con lijado para alisar superficies. | Plazo de entrega rápido (1–2 días), bajo costo (\(100- )300 por molde), fácil de modificar para formas complejas. | Baja durabilidad (20–50 ciclos), limited to soft rubbers like liquid silicone. | Single or small batches (1–10 unidades) de partes complejas (P.EJ., irregular-shaped TPU overlays). |
Punta de llave: Para prototipos, start with a 3D-printed mold if you need to test 1–5 units quickly. Switch to a CNC mold if you require 20+ prototipos idénticos (P.EJ., for user testing).
3. Molding Process: Select Based on Rubber Type & Tamaño parcial
The molding method determines the prototype’s precision, elasticidad, y costo. Choose from three common processes based on your material and application:
3.1 Liquid Silicone Injection Molding (LSR)
- Applicable Materials: silicona liquida (30°–70° Shore hardness).
- Process Steps:
- Mezclar silicona liquida (Parte A + Part B) en 1:1 relación.
- Inject the mixture into a preheated mold (150°C–200°C).
- Cure for 5–15 minutes (Dependiendo del grosor).
- Demold and trim excess material.
- Ventajas: Alta precisión (ideal for micro-parts like phone waterproof rings), excellent elasticity, and no post-curing needed.
- Ideal para: Transparent medical parts (P.EJ., infusion tube fittings) and high-precision seals.
3.2 Solid Rubber Pressing
- Applicable Materials: Natural rubber, EPDM, and silicone rubber sheets.
- Process Steps:
- Cut rubber sheets into the approximate shape of the mold cavity.
- Heat the sheets to 120°C–180°C to soften them.
- Press the softened rubber into the mold with 10–20 MPa pressure.
- Cool for 10–20 minutes, then demold.
- Ventajas: Bajo costo, fast for large parts (P.EJ., automotive shock absorbing pads), and suitable for aging-resistant materials like EPDM.
- Ideal para: Sealing strips (P.EJ., juntas de puertas) and large slip-resistant mats.
3.3 Polyurethane Casting (UR)
- Applicable Materials: Polyurethane elastomers (TPU, TPE).
- Process Steps:
- Mix AB components (resina + endurecedor) en 1:1 relación.
- Degas the mixture under vacuum (-0.1MPA) Para eliminar las burbujas de aire.
- Pour the mixture into the mold slowly to avoid eddy currents.
- Curar a temperatura ambiente (24 horas) or heat (80° C para 2 horas).
- Ventajas: Mimics rubber’s flexibility, perfect for cladding metal/plastic parts (P.EJ., power tool handles with metal cores).
- Ideal para: Overmolded prototypes (P.EJ., silicone-coated plastic buttons).
Tabla de comparación: Molding Process Selection Guide
| Tipo de parte | Recommended Process | Ejemplo material | Tiempo de entrega |
| Micro-seals (≤5 mm) | LSR | silicona liquida | 1–2 días |
| Large shock pads (≥200mm) | Solid Rubber Pressing | EPDM | 2–3 días |
| Overmolded grips | Polyurethane Casting | TPU | 1–3 días |
4. Postprocesamiento: Refinar & Enhance Prototype Quality
Rubber prototypes require targeted post-processing to fix defects, mejorar el rendimiento, and add functional details.
4.1 Basic Trimming & Desacuerdo
- Use a sharp blade or grinding wheel to remove excess rubber burrs (common around mold edges). For small parts like silicone earbuds, use tweezers to peel off tiny burrs—avoid sanding (it can damage soft rubber surfaces).
4.2 Secondary Vulcanization (For Silicone)
- Bake silicone prototypes at 150°C–200°C for 2–4 hours. This step improves temperature resistance (por 30%) and aging resistance (extends lifespan by 50%), critical for automotive or outdoor use. Por ejemplo:
A silicone automotive seal prototype, after secondary vulcanization, withstands 150°C for 1,000 hours without hardening—vs. 500 hours for an unprocessed version.
4.3 Tratamiento superficial
Add functional or decorative finishes based on your needs:
- Anti-Slip Coating: Spray epoxy-based anti-slip paint on grips to boost friction (reduces slip by 60% for wet surfaces).
- Impresión de pantalla de seda: Apply logos, hardness labels (P.EJ., “50° Shore”), or warning text (P.EJ., “Medical Grade”).
- Material Bonding: Use rubber-specific adhesives to attach rubber to metal/plastic (P.EJ., a nylon + rubber overlay for a tool handle).
5. Pruebas & Mejoramiento: Validate Performance & Fix Issues
Test the prototype against your initial requirements, and address common problems like bubbles or deformation.
5.1 Key Test Items
| Tipo de prueba | Cómo realizar | Pass/Fail Criteria |
| Elasticity Test | Compress the prototype to 50% of its thickness, release, and measure recovery time. | Recovers to original shape in ≤1 second (P.EJ., a shock pad prototype passes this test). |
| Prueba de sellado | Submerge the prototype in water (for waterproof parts) or apply air pressure (for airtight seals). | No water leakage/air loss after 30 minutos. |
| Precisión dimensional | Use una pinza para medir las dimensiones clave (P.EJ., diameter of a waterproof ring). | Error within ±0.1mm (meets most industrial standards). |
5.2 Solve Common Defects
| Defecto | Causas | Corrección |
| Demolding Difficulty | High rubber elasticity, rough mold surface (Real academia de bellas artes >1.6), Sin pendiente de draft. | Molde polaco a Ra ≤0,8; agregar pendiente de calado de 1° a 3°; use aceite desmoldante específico para silicona. |
| Burbujas | Aire atrapado en caucho líquido., vertido rápido, sin desgasificación. | Goma degas debajo -0.1Aspiradora de AMP; vierta la mezcla lentamente (≤5ml/segundo); utilizar un molde con salidas de aire. |
| Deformación dimensional | Temperatura del molde desigual (±>5° C), tasa de contracción incorrecta. | Calentar el molde uniformemente (utilizar un horno con temperatura controlada); ajustar el tamaño del modelo 3D según la contracción del material (P.EJ., agregar 3% para silicona). |
6. Yigu Technology’s Perspective on Rubber Prototype Production
En la tecnología yigu, we’ve found that the biggest challenge in rubber prototype making is balancing flexibility with precision—many clients rush to choose LSR for high precision but overlook cost for small batches. Our approach is to match processes to needs: for 1–5 units of complex parts, we recommend 3D-printed molds + polyurethane casting (fast and cheap); para 10+ piezas de alta precisión, CNC molds + LSR (durable and accurate). Por ejemplo, a medical client initially chose LSR for a single silicone tube prototype (costo \(300), but we switched to 3D-printed molds + fundición (costo \)80) sin sacrificar la calidad. We also emphasize pre-testing material compatibility—e.g., ensuring TPE bonds well with ABS before overmolding—to avoid rework. Rubber prototypes thrive on attention to detail; small adjustments (like adding a 2° draft slope) can save days of troubleshooting.
7. Preguntas frecuentes: Common Questions About Making Rubber Prototypes
Q1: ¿Puedo utilizar la impresión 3D directamente para hacer prototipos de caucho? (sin moldes)?
A1: Rarely—most 3D-printed “rubber-like” parts (P.EJ., TPU filaments) lack the elasticity and sealing performance of true rubber. Molding processes (LSR, fundición) are needed to leverage rubber’s natural properties. For simple concept tests, 3D-printed TPU can work, but for functional validation, utilizar prototipos de caucho hechos con moldes.
Q2: ¿Cómo elijo entre silicona y TPE para mi prototipo??
A2: Elija silicona para resistencia a altas temperaturas (hasta 200 ° C) y transparencia (P.EJ., dispositivos médicos, anillos impermeables para teléfono). Elija TPE para obtener una mejor resistencia al desgaste y un menor costo (P.EJ., empuñadura, piezas de juguete). Por ejemplo, Un prototipo de tetina de biberón utiliza silicona. (no tóxico, a prueba de calor), mientras que un prototipo de neumático de coche de juguete utiliza TPE (más económico, durable).
Q3: ¿Por qué mi prototipo de goma tiene una superficie pegajosa??
A3: Las superficies pegajosas suelen deberse a un curado incompleto. (P.EJ., LSR curado a 140°C en lugar de 160°C) o exceso de aceite de liberación. Corrección: Vuelva a curar el prototipo a 160°C durante 1 hora; limpie el exceso de aceite con un paño sin pelusa. para silicona, secondary vulcanization also eliminates stickiness by removing residual low-molecular-weight compounds.