Создание а plastic injection molding prototype is a critical step in product development—it lets you test design feasibility, подтвердить производительность, and avoid costly mistakes in mass production. В отличие от массовых деталей, prototypes prioritize speed, экономическая эффективность, и адаптивность, while still following core injection molding principles. Below is a complete, actionable breakdown of the prototype development process, from material pick to final application.
1. Material Selection for Prototypes
Выбор правильного материала является первым (and often make-or-break) step for prototypes. The goal is to balance Свойства материала with prototype goals—whether you’re testing durability, появление, или стоимость. Here’s how to navigate key choices:
| Материальная категория | Ключевые примеры | Key Considerations for Prototypes |
| Термопластики | Стр, АБС, ПК, Нейлон, ДОМАШНИЙ ПИТОМЕЦ | Most common for prototypes—melt and re-solidify, Легко отрегулировать. Ideal for testing form, соответствовать, and basic function. |
| Термоссе | Эпоксидная смола, Фенольные смолы | Harden permanently after molding—good for high-heat or chemical-resistance tests. Less common for prototypes (hard to modify). |
| Добавки | Наполнители (стеклянное волокно), УФ -стабилизаторы, огнестойкие | Add only if the prototype needs to mimic final part performance (НАПРИМЕР., glass fiber for stiffness). Skip non-essential additives to cut costs. |
| Цветовые средства | Liquid dyes, masterbatches | Use only if appearance testing is critical. Clear or natural resins save time and money for functional prototypes. |
Для чаевого: Расставить приоритеты экономическая эффективность for early-stage prototypes—opt for common resins like PP or ABS instead of high-end materials like PEEK. For supplier selection, choose vendors who offer small batch sizes (1-5 кг) to avoid waste. Также, check плотность (affects part weight) и скорость потока (ensures the resin fills small prototype mold cavities easily).
2. Design Considerations for Prototype Success
Prototype design should be “mold-friendly” to speed up production and reduce defects. Even small design tweaks can save days of rework. Here’s a checklist of critical factors:
Core Design Elements & Советы
- Part Design: Keep it simple—avoid overcomplicating with unnecessary features (НАПРИМЕР., intricate logos) in early prototypes. Focus on testing the part’s core function.
- Толщина стены: Стремиться к 1-3 мм (uniform across the part). Толковые стены (<1 мм) cause short shots; thicker walls (>3 mm) lead to sink marks. Use gradual transitions if thickness must change.
- Проект углов: Добавлять 1-3 degrees to all vertical surfaces. This lets the prototype eject smoothly from the mold—no more stuck parts or scratches.
- Ребра & Боссы: Ребра (for stiffness) should be 0.5x the wall thickness; bosses (для винтов) should have a diameter 2x the screw size. Добавить филе (radius = 0.5 мм) to avoid stress cracks.
- Подписаны: Minimize them! Подписаны (НАПРИМЕР., side grooves) require complex mold slides, which increase prototype cost and lead time. При необходимости, use temporary solutions like post-machining.
- Допуски: Loosen tolerances for early prototypes (±0.1 mm is enough for fit tests). Плотные допуски (<± 0,05 мм) add cost and slow production.
Design Validation Tools
Before finalizing the design:
- Использовать CAD Modelling (НАПРИМЕР., Солидворкс, Слияние 360) to create 3D models—share these with your mold maker to avoid miscommunication.
- Run Моделирование потока плесени (НАПРИМЕР., Autodesk Moldflow) to test resin flow. This catches issues like air traps or uneven filling early.
- Для частей высокого стресса (НАПРИМЕР., Автомобильные кронштейны), использовать Анализ конечных элементов (FEA) to test strength—this avoids building prototypes that fail under load.
3. Mold Preparation for Prototypes
Прототип форм (called “soft tools”) are simpler and cheaper than mass-production molds. They’re often made from aluminum (instead of steel) to speed up machining. Вот ключевой процесс:
Mold Components & Шаги подготовки
| Компонент | Цель | Prototype-Specific Tips |
| Mold Base | Provides structure for the mold | Use standard-sized aluminum bases (НАПРИМЕР., 150×150 мм) to cut costs. |
| Полости & Cores | Shape the prototype (cavity = outer surface; core = inner surface) | For single-cavity molds (most prototypes), machine cavities directly into the aluminum—faster than multi-cavity molds. |
| Выбросы | Push the prototype out of the mold | Использовать 2-4 маленькие булавки (3-5 мм диаметр) — place them near thick areas to avoid warping. |
| Каналы охлаждения | Cool the mold to set the resin | Drill simple straight channels (instead of complex curved ones) — aluminum cools quickly, so basic channels work. |
| Heating Elements | Warm the mold (for resins with high melting points) | Skip unless using resins like PC (точка плавления >220° C.). Aluminum retains heat well, so extra heating is rarely needed. |
Mold Making Process
- Mold Machining: Use CNC milling for simple shapes; использовать Эдм (Электрическая обработка) only for fine details (НАПРИМЕР., маленькие дыры). Aluminum machines 5x faster than steel—perfect for quick prototypes.
- Mold Polishing: Polish cavities to a #4 заканчивать (матовый) for functional prototypes. High-gloss finishes (#8) are only needed for appearance tests.
- Mold Assembly: Assemble components loosely first—test fit with a dummy resin (НАПРИМЕР., воск) to ensure alignment. Tighten screws only after test fitting.
- Mold Testing: Run 5-10 test shots with scrap resin. Check for leaks, смещение, or stuck parts—fix issues before running the actual prototype batch.
4. The Injection Molding Process for Prototypes
Prototype injection molding focuses on speed and flexibility—you’ll often run small batches (10-50 части) and adjust parameters on the fly. Here’s how to execute it smoothly:
Key Machine Settings (for ABS Prototype Example)
| Параметр | Оптимальный диапазон | Почему это важно для прототипов |
| Clamping Force | 50-100 тонны | Lower force works for small prototypes—avoids damaging the aluminum mold. |
| Давление впрыска | 60-90 МПА | Too high = flash (excess resin); too low = short shots. Start low and increase if needed. |
| Расплавлять температуру | 210-240° C. | Keep 10-15°C lower than mass production—prevents resin degradation in small batches. |
| Время цикла | 30-60 секунды | Longer than mass production (gives aluminum molds time to cool). Rushing leads to warped parts. |
| Винт скорость | 60-100 об/мин | Slow speed mixes resin evenly without generating excess heat. |
| Drying Process | 80° C для 2-3 часы (для пресса) | Critical for resins like nylon or PC—moisture causes bubbles. Skip only for dry resins like PP. |
Step-by-Step Molding Workflow
- Материал кормления: Нагрузка 1-2 kg of resin into the hopper (small batches reduce waste). Add a few pellets of colorant if needed.
- Дизайн сопла: Use a small-diameter nozzle (3-5 мм) to fill narrow prototype cavities. Keep the nozzle 1-2 mm from the mold to avoid leaks.
- Injection Speed: Start at 40-60 мм/с. If the part has thin walls, increase to 70-80 mm/s to avoid short shots.
- Packing Pressure: Применять 80-90% of injection pressure for 2-3 секунды. This fills any small gaps in the prototype.
- Время охлаждения: Let the mold cool for 15-25 секунды (aluminum cools fast!). Eject the part only when it’s cool to the touch.
Common Issue Fix: If the prototype has flash (excess resin), reduce injection pressure by 5-10 МПА. If it has short shots, increase melt temperature by 5-10°C.
5. Post-Processing and Finishing for Prototypes
Post-processing turns raw molded parts into usable prototypes. Focus on tasks that support your test goals—skip unnecessary steps to save time.
Essential vs. Дополнительная пост-обработка
| Задача | Цель | When to Use |
| Deburring/Deflashing | Remove excess resin from edges/parting lines | Always do this—sharp burrs ruin fit tests. Use a hand file (Для небольших партий) or rotary brush. |
| Обрезка | Cut off runner systems (the plastic channels that feed resin) | Always do this—runners make prototypes hard to test. Use scissors (for soft resins) или полоса. |
| Обработка (Сверление/Нарезание резьбы) | Add holes or threads for assembly | Only if testing assembly (НАПРИМЕР., attaching the prototype to another part). Use a handheld drill for small holes. |
| Painting/Plating | Improve appearance | Only for appearance tests (НАПРИМЕР., showing the prototype to stakeholders). Используйте распылительную краску (dries in 30 минуты) for quick results. |
| Сборка | Join multiple prototype parts | Использовать Ультразвуковая сварка (быстрый, no adhesives) или клейкая связь (бюджетный) Для небольших партий. Avoid rivets (permanent, hard to modify). |
Для чаевого: Для функциональных прототипов, skip painting/plating—focus on deburring and trimming. For appearance prototypes, использовать печать (НАПРИМЕР., pad printing) for logos instead of expensive plating.
6. Applications and Uses of Injection Molding Prototypes
Prototypes are used across industries to de-risk product development. Here’s how different sectors leverage them:
Industry-Specific Uses
- Автомобильные детали: Test fit of interior components (НАПРИМЕР., приборные клипы) or durability of small parts (НАПРИМЕР., Дверные ручки).
- Потребительская электроника: Validate the size of phone cases or the fit of charging port covers.
- Медицинские устройства: Test the ergonomics of syringes or the compatibility of plastic parts with liquids.
- Упаковка: Check if a bottle prototype holds liquid without leaking or if a lid seals properly.
- Игрушки: Test safety (НАПРИМЕР., no small parts that break off) и долговечность (НАПРИМЕР., withstands dropping).
- Аэрокосмические компоненты: Test lightweight parts (НАПРИМЕР., пластиковые кронштейны) for strength under low pressure.
Prototype Stages in Product Development
- Concept Prototype: Early-stage, бюджетный (НАПРИМЕР., Части пресса) to test basic form.
- Функциональный прототип: Mid-stage, uses final material (НАПРИМЕР., ПК) to test performance.
- Pre-Production Prototype: Late-stage, identical to mass-produced parts—used for final validation.
Yigu Technology’s View
В Yigu Technology, we know prototype success hinges on balancing speed, расходы, and clarity of goals. For plastic injection molding prototypes, we prioritize aluminum molds (быстрый, рентабельный) and common thermoplastics for early stages, then shift to final materials for functional tests. We integrate CAD, Mold Flow, and FEA to catch issues before molding, сократить время переработки 30%. Our focus is on delivering prototypes that solve real problems—whether it’s testing a fit, validating a design, or impressing stakeholders.
FAQs
- Q.: How long does it take to make a plastic injection molding prototype?
А: 1-2 weeks for simple prototypes (aluminum mold + Части пресса). Сложные прототипы (with undercuts or FEA testing) брать 3-4 недели.
- Q.: Can I use the same mold for prototype and mass production?
А: Rarely—prototype molds are aluminum (мягкий, wears out after 1,000+ выстрелы), while mass-production molds are steel (жесткий, длится 100,000+ выстрелы). Use the prototype mold to refine the design, then make a steel mold for production.
- Q.: How much does a plastic injection molding prototype cost?
А: \(500-\)2,000 for a simple prototype (aluminum mold + 10-50 части). Costs rise to \(3,000-\)5,000 Для сложных дизайнов (EDM machining, FEA testing, or final materials like PC).