Plastic compound mold processing—also known as vacuum injection molding or soft mold casting—is a cost-effective manufacturing method for producing plastic parts using reusable silicone-based molds. Unlike traditional steel mold processes, it prioritizes speed, Гибкость, and detail replication, making it ideal for small-batch production and product development. В этой статье разбираются его основные определения., пошаговый рабочий процесс, выбор материала, преимущества, and limitations—with clear comparisons and real-world examples to help you optimize the process for your projects.
1. Основное определение & Ключевые принципы
Перед погружением в процесс, it’s critical to understand what makes plastic compound mold processing unique and how it differs from traditional methods.
| Аспект | Plastic Compound Mold Processing | Traditional Steel Injection Molding |
| Материал плесени | Primarily silicone rubber (гибкий, эластичный, and detail-retaining). | Rigid materials like сталь или алюминий (highly durable but costly to machine). |
| Основной принцип | Replicates parts by pouring liquid plastic into a silicone mold (created from a prototype), then curing and demolding. | Injects molten plastic into a steel mold under high pressure (10–150 МПа) Для массового производства. |
| Пригодность партии | Идеально подходит для небольших партий (10–500 единиц) и прототипирование. | Designed for mass production (10,000+ единицы) to offset high mold costs. |
| Ключевое преимущество | Low mold cost, Быстрый поворот, and ability to replicate complex shapes/textures. | Высокая эффективность производства, superior part accuracy, and long mold life (100,000+ цикл). |
Key Question: Why choose plastic compound mold processing?
For projects where speed and cost matter more than ultra-high volume—such as new product testing, niche market parts, or custom crafts—silicone-based molds eliminate the need for expensive steel tooling, cutting both time and upfront investment.
2. Step-by-Step Processing Workflow
Plastic compound mold processing follows a linear, repeatable workflow that starts with a prototype and ends with finished plastic parts. Each step directly impacts the final part’s quality and the mold’s durability.
2.1 Этап 1: Prototype Preparation (The “Master Model”)
The prototype serves as the template for the silicone mold—its quality determines the detail and accuracy of all subsequent parts.
| Prototype Manufacturing Method | Ключевые характеристики | Идеально подходит для |
| 3D Печать (SLA/DLP) | – Высокая точность (± 0,05 мм) for intricate details (НАПРИМЕР., логотипы, текстуры).- Гладкая поверхность отделка (RA 0,8–1,6 мкм) reduces post-processing.- Быстрый поворот (12–24 hours for small parts). | Сложные части: Электронные оболочки устройства (Телефонные чехлы, TV remote casings), decorative items with fine patterns. |
| Обработка с ЧПУ | – Ultra-high accuracy (± 0,01 мм) for tight tolerances.- Suitable for hard materials (металл, Жесткий пластик, древесина).- Ideal for flat or geometrically precise parts. | High-precision components: Автомобильные кронштейны, Корпуса медицинского устройства, parts requiring strict dimensional consistency. |
| Hand Engraving/Crafting | – Low cost for simple shapes.- Flexible for one-of-a-kind designs.- No specialized equipment needed. | Simple decorative parts: custom keychains, small figurines, low-precision prototypes for visual testing. |
Критический совет: Ensure the prototype is clean and defect-free (no dust, масло, or scratches). Even tiny flaws will be replicated in the silicone mold—for example, a dusty prototype will create a mold with embedded particles, ruining the finish of plastic parts.
2.2 Этап 2: Создание силиконовой формы (The “Negative Template”)
This stage transforms the prototype into a reusable mold. Proper silicone mixing, залив, and curing are essential to avoid bubbles, слезы, or incomplete detail capture.
Шаг 1: Mold Frame Setup
- Frame Selection: Choose a frame material (древесина, пластик, или металл) large enough to fit the prototype with 5–10mm of space on all sides (ensures even silicone coverage).
- Запечатывание: Use masking tape or acrylic sealant to seal frame edges—prevents silicone leakage, which wastes material and distorts the mold shape.
- Prototype Positioning: Secure the prototype in the frame with clay or double-sided tape—keep it centered to ensure uniform silicone thickness.
Шаг 2: Silicone Mixing
- Выбор материала: Use two-component silicone rubber (Часть а: база; Part B: лечительный агент) with a mixing ratio specified by the manufacturer (обычно 1:1 by volume/weight для добавки силикона, 10:1 для конденсационного силикона).
- Mixing Rules:
- Stir slowly and thoroughly (2–3 минут) to avoid air bubbles—uneven mixing causes weak spots in the mold.
- Для больших партий, Используйте vacuum degassing machine (1–2 minutes at -0.1МПА) to remove trapped air—critical for parts with tiny details (НАПРИМЕР., 0.5mm-wide slots).
Шаг 3: Silicone Pouring & Выклятый
- Техника заливки: Tilt the frame at a 45° angle and pour silicone slowly along the frame wall (Не прямо на прототип)—reduces bubble formation. For thick molds (>10mm), использовать layered pouring: залить 1/3 of the silicone, ждать 30 minutes for bubbles to rise, then add the next layer.
- Curing Parameters:
| Силиконовый тип | Температура отверждения | Время лечения (for 5mm Thickness) | Post-Curing Tip |
| Добавка (Platinum-Cure) | 20°С–25°С | 2–4 часа | No post-curing needed; ready to demold once firm. |
| Condensation | 20°С–25°С | 4–8 часов | Cure for an extra 1 hour if mold is thicker than 10mm. |
| High-Temperature Resistant | 20°С–25°С (исходный); 80° C. (post) | 6–10 часов (исходный); 2 часы (post) | Post-cure in an oven to activate heat resistance (до 200 ° C.). |
Шаг 4: Demolding the Prototype
- После вылечения, gently peel the silicone mold from the prototype—silicone’s elasticity ensures easy removal without damaging either the mold or prototype.
- Обрезаем излишки силикона (вспышка) from mold edges with a sharp knife—creates a clean, precise mold for plastic casting.
2.3 Этап 3: Plastic Part Production (The “Replica Process”)
С силиконовой плесенью, this stage produces finished plastic parts through pouring, выклятый, and demolding.
Шаг 1: Plastic Material Selection
Choose a material based on the part’s end-use (сила, Гибкость, теплостойкость):
| Пластиковый материал | Ключевые свойства | Идеальные приложения |
| Полиуретан (Пута) Смола | – Быстрое отверждение (1–2 hours at 20°C).- Good wear resistance and flexibility (Shore A 30–80).- Бюджетный ($20–40 per kg). | Функциональные части: кнопки пульта от телевизора, игрушечные компоненты, flexible gaskets, small electronic housings. |
| Эпоксидная смола | – Высокая сила (предел прочности: 50–80 МПа) and chemical resistance.- Теплостойкий (120°C–180°C после отверждения).- Низкая усадка (0.5–1%). | Структурные части: Автомобильная внутренняя отделка, Медицинские устройства ручки, parts requiring durability under stress. |
| Поливинилхлорид (ПВХ) | – Low cost and good chemical stability.- Rigid or flexible variants available.- Suitable for food-contact parts (when food-grade). | Custom containers, декоративная отделка, low-stress household items. |
Шаг 2: Залив & Выклятый
- Залив: Pour liquid plastic into the silicone mold slowly (use a small funnel for narrow openings) to avoid bubbles. For complex parts with internal cavities, использовать sectional pouring: fill one section, ждать 10 minutes for partial curing, then fill the next—ensures full cavity coverage.
- Выклятый:
- Отверждение при комнатной температуре: PU Strain (1-2 часа), эпоксидная смола (4–6 часов).
- Ускоренное отверждение: Use a low-temperature oven (50°С–60°С) to reduce time by 50% (НАПРИМЕР., epoxy resin cures in 2–3 hours).
Шаг 3: Демольд & Пост-обработка
- Gently peel the silicone mold from the plastic part—silicone’s flexibility prevents cracking or deformation.
- Trim excess plastic (вспышка) with scissors or a utility knife. For better finish, sand the part with 400–800 grit sandpaper.
3. Advantages of Plastic Compound Mold Processing
This method solves key pain points for small-batch and prototyping projects:
| Категория преимуществ | Ключевые преимущества | Пример реального мира |
| Бюджетный | – Silicone mold cost is 50–70% lower than steel molds (НАПРИМЕР., \(200 против. \)5,000 for a small part mold).- No expensive machining equipment needed for mold production. | A startup producing 50 test samples of a new smartwatch casing saves $4,800 by using a silicone mold instead of steel. |
| Быстрый поворот | – Entire process (prototype → mold → parts) takes 3–7 days, против. 2–4 weeks for steel molds. | A consumer electronics company needs 20 TV remote prototypes for user testing—plastic compound processing delivers them in 4 дни, enabling faster design iterations. |
| Complex Detail Replication | – Captures tiny textures (0.1мм - 0,5 мм), Изогнутые поверхности, and internal structures that steel molds may struggle to replicate. | A jewelry brand replicates a hand-sculpted pendant with fine engravings—each plastic part retains the pendant’s intricate patterns, which would require costly steel mold machining. |
| Гибкость | – Easy to adjust mold design (НАПРИМЕР., modify a prototype and make a new silicone mold in 1–2 days).- Switch plastic materials or colors without changing the mold. | A phone case manufacturer tests 3 цвета (черный, белый, синий) using the same silicone mold—no need for multiple molds, cutting color-testing costs by 60%. |
4. Ограничения для рассмотрения
While highly effective for specific use cases, plastic compound mold processing has constraints:
- Limited Mold Life: Silicone molds last 20–500 циклов (против. 100,000+ for steel molds). Parts with sharp edges or high friction (НАПРИМЕР., пластиковые зажимы) wear down molds faster—after 50 цикл, a mold may start to lose detail.
- Lower Part Accuracy: Dimensional accuracy is ±0.1mm–±0.3mm (против. ±0.01mm for steel injection molding). This is sufficient for most consumer parts but not for precision components like aerospace parts.
- Lower Production Efficiency: Each part requires manual pouring and demolding—production speed is 1–10 parts per hour (против. 100+ parts per hour for steel injection molding). For batches over 500 единицы, it becomes slower and more costly than traditional methods.
5. Yigu Technology’s Perspective on Plastic Compound Mold Processing
В Yigu Technology, we see plastic compound mold processing as a “development enabler”—it lets clients test designs fast and avoid overinvesting in unproven products. A common mistake we address is clients overusing it for large batches: one client tried to produce 2,000 phone cases with a silicone mold, only to face mold wear and inconsistent parts after 300 цикл. We advised switching to steel molds for mass production, сохраняя их 40% в переработке затрат. Для прототипирования, we recommend additive silicone (1:1 соотношение) for detail retention and PU resin for fast functional testing. Our key insight: This process shines when paired with a clear transition plan—use it for 10–500 units, then scale to steel molds if demand grows.
6. Часто задаваемые вопросы: Common Questions About Plastic Compound Mold Processing
1 квартал: Can I use plastic compound mold processing for high-temperature parts (НАПРИМЕР., parts exposed to 150°C)?
А1: Да, but use heat-resistant materials. Выбирать high-temperature silicone (service temp: 200° C - 300 ° C.) for the mold and heat-resistant epoxy resin (вылеченная температура: 120°C–180°C) для части. Сначала протестируйте образец — выдержите его при температуре 150°C, чтобы 24 часов, чтобы гарантировать отсутствие деформации. Избегайте стандартного силикона. (максимальная температура: 150° C.) или полиуретановая смола (максимальная температура: 80° C.) для применения в условиях высоких температур.
2 квартал: How can I extend the life of my silicone mold?
А2: – Очищайте форму мягким мылом и водой после каждого использования. (избегайте агрессивных растворителей, таких как ацетон, которые разрушают силикон).- Apply a thin layer of silicone oil to the mold before pouring plastic—reduces friction and wear.- Хранить форму в прохладном, сухое место (влажность <60%) и не сгибайте и не растягивайте его — предотвращает разрывы.
Q3: Are parts made via plastic compound mold processing suitable for food contact?
А3: Только если вы используете пищевые материалы.. Выбирать food-safe silicone (certified by FDA or EU standards) for the mold and food-grade plastic resins (НАПРИМЕР., food-grade PU, ПВХ, or epoxy). Regular materials may leach chemicals into food—always test the final part for compliance (НАПРИМЕР., FDA 21 CFR 177.2600 for resin) перед использованием.