If you’re searching for “casting rubber parts,” you likely want to know how to create durable, precise rubber components for your products—or how to choose the right ones. Проще говоря, casting rubber parts are rubber components made by pouring liquid rubber materials into molds, then curing them to take the mold’s shape. This process works for everything from small gaskets to large industrial seals, and it’s favored for its flexibility, экономическая эффективность, and ability to produce complex designs. By the end of this guide, you’ll understand how the process works, which materials to use, common challenges, and how to get the best results for your project.
1. What Are Casting Rubber Parts, и почему они имеют значение?
Прежде чем погрузиться в детали, Давайте проясним основы. Casting rubber parts differ from other rubber manufacturing methods (like extrusion or injection molding) because they rely on liquid rubber—no high pressure or heat is needed to force material into molds. Вместо, the liquid rubber flows naturally, сделать это идеальным для:
- Сложные формы: Сложные детали (like grooves, отверстия, или пользовательские логотипы) that are hard to achieve with other methods.
- Low to medium production runs: В отличие от инъекционного литья, который требует дорогого инструмента, casting works well for small batches (10–1000 единиц) or prototypes.
- Soft or flexible parts: Materials like silicone or urethane can be cast to be soft (for medical pads) or rigid (for industrial bumpers).
Пример реального мира: Medical Device Seals
A client in the medical industry once needed 50 custom seals for a portable oxygen device. Extrusion would have required tooling costs of $5,000+, and injection molding wasn’t feasible for such a small run. Мы использовалиliquid silicone casting to create the seals: the liquid silicone flowed into a 3D-printed mold (costing just $300), cured at 120°C for 20 минуты, and the final parts met FDA standards for biocompatibility. This saved the client 90% on tooling and delivered parts in 5 days—proving why casting is a go-to for niche or low-volume needs.
2. The Core Casting Rubber Process: Шаг за шагом
The casting process varies slightly by material, but the core steps are consistent. Below is a breakdown of the most common method: room-temperature vulcanization (РТВ) кастинг—used for silicone and urethane rubbers.
| Шаг | Действие | Ключевые детали |
|---|---|---|
| 1 | Подготовка плесени | Очистите форму (обычно из алюминия, сталь, or 3D-printed resin) to remove dust or debris. Применить агент выпуска (like silicone spray) to prevent rubber from sticking. |
| 2 | Rubber Mixing | Combine liquid rubber base with a curing agent (ratio depends on material: НАПРИМЕР., 10:1 for silicone). Mix slowly to avoid air bubbles—bubbles cause weak spots in the final part. |
| 3 | Залив | Pour the mixed rubber into the mold. Tilt the mold slightly to ensure the rubber fills all gaps (especially for complex shapes). Для больших частей, pour in layers to reduce air traps. |
| 4 | Дегазация (Необязательный) | Place the mold in a vacuum chamber for 5–10 minutes to remove air bubbles. This is critical for parts that need high strength (like industrial gaskets). |
| 5 | Выклятый | Let the rubber cure at room temperature (20–25 ° C.) for 4–24 hours, or use heat (60–120 ° C.) Чтобы ускорить отверстие (1-2 часа). Curing time depends on material thickness: a 1cm part cures faster than a 5cm part. |
| 6 | Демольд & Отделка | Remove the part from the mold. Trim excess rubber (называется «Flash») with a sharp knife or die cutter. Для точных частей, sand edges or polish surfaces. |
Pro Tip for Beginners: Avoiding Air Bubbles
Air bubbles are the #1 mistake new manufacturers make. During our work with a startup making silicone phone cases, Их первая партия была 30% of parts with bubbles. Исправление? They started mixing the rubber slower (200 RPM instead of 500 Rpm) and degassed the mold for 8 минуты (из 3). After that, bubble rates dropped to 2%—a simple adjustment that saved them time and material waste.
3. Choosing the Right Rubber Material for Casting
Not all rubbers work for casting. The material you pick depends on your part’s use case (НАПРИМЕР., температурная стойкость, химическая экспозиция) и бюджет. Ниже приведено сравнение самых популярных вариантов:
| Материал | Ключевые свойства | Лучшее использование | Расходы (За кг) |
|---|---|---|---|
| Liquid Silicone Rubber (LSR) | – Температурная стойкость: -60° C до 230 ° C.- Биосовместимый (FDA одобрено)- Low toxicity | Медицинские устройства (уплотнения, катетеры), детские продукты (teethers), Кухонные инструменты (baking mats) | $25- 40 долларов |
| Уретановая резина | – Высокая устойчивость к истиранию- Гибкий (Shore A 30–90 hardness)- Хорошая химическая устойчивость (масла, растворители) | Промышленные детали (ролики, бамперы), Автомобильные печати, игрушки | $15- 30 долларов |
| Neoprene Rubber | – Water resistance- Температурная диапазон: -40° C до 120 ° C.- Resistance to ozone and UV | Морские части (boat seals), Наружное снаряжение (wetsuit zippers), HVAC gaskets | $20- 35 долларов |
| Natural Rubber | – High elasticity- Бюджетный- Poor oil/chemical resistance | Общие части (erasers, door stoppers), low-stress gaskets | $10- 20 долларов |
Critical Data Point: Temperature Limits
According to the Rubber Manufacturers Association (RMA), choosing a material outside its temperature range can reduce part lifespan by 70%. Например, a natural rubber seal used in a car engine (который достигает 150 ° C.) will crack in 6 месяцы, while an LSR seal in the same spot will last 5+ годы. Always match the material to your part’s operating environment.
4. Common Challenges in Casting Rubber Parts (И как их исправить)
Even experienced manufacturers face issues with casting. Ниже приведены вершины 3 problems and proven solutions, based on our 10+ Годы в отрасли:
Испытание 1: Part Warping After Curing
Warping happens when the rubber cures unevenly—usually because the mold is too hot in some areas or the rubber is too thick.
- Решение: Use a mold with uniform thickness (no sudden changes from 1cm to 5cm). Для толстых частей, cure at a lower temperature (НАПРИМЕР., 60°C instead of 100°C) and extend curing time by 50%. We fixed a client’s warped urethane rollers by adjusting the mold design to have a consistent 3cm thickness—warping stopped entirely.
Испытание 2: Rubber Sticking to the Mold
Sticking occurs when the release agent is missing or the mold is dirty.
- Решение: Применить агент выпуска дважды (once before pouring, once after the first layer sets). For resin molds, use a petroleum-based release agent (silicone sprays can damage resin over time). A furniture manufacturer once wasted 20kg of rubber because they skipped the release agent—after adding it, demolding took 2 минуты на часть.
Испытание 3: Непоследовательная твердость
If some parts are softer than others, the rubber-curing agent ratio is off.
- Решение: Use a digital scale to measure the base and curing agent (НАПРИМЕР., 100g base + 10g curing agent for a 10:1 соотношение). Mix for exactly 2 минуты (no more, не меньше)—overmixing can break down the rubber. We helped a toy maker fix this by switching from a manual scale to a digital one; hardness variation dropped from 15 Берего А до 2 Берег а.
5. Applications of Casting Rubber Parts Across Industries
Casting rubber parts are everywhere—you probably use them daily without realizing it. Вот 4 key industries and their most common uses:
1. Автомобиль
- Уплотнения: Door seals, прокладки двигателя (made of neoprene for oil resistance).
- Бамперы: Small urethane bumpers to protect dashboard components.
- Hoses: Flexible silicone hoses for coolant systems (противостоять высоким температурам).
2. Медицинский
- Dental Trays: Custom silicone trays for teeth whitening (биосовместимый).
- Device Seals: FDA-approved LSR seals for insulin pumps and heart monitors.
- Masks: Soft silicone masks for respiratory therapy (comfortable for long wear).
3. Потребительские товары
- Kitchen Tools: Silicone baking mats, utensil grips (теплостойкий).
- Игрушки: Rubber wheels for toy cars (urethane for durability), silicone teething toys.
- Электроника: Rubber gaskets for phone cases (гидроизоляция).
4. Промышленное
- Ролики: Urethane rollers for conveyor belts (Устойчивый к истиранию).
- Уплотнения: Large neoprene seals for tanks and pipes (водонепроницаемый).
- Vibration Dampeners: Soft silicone dampeners for machinery (reduce noise).
6. Yigu Technology’s Perspective on Casting Rubber Parts
В Yigu Technology, Мы работали с 500+ clients on casting rubber parts, and one trend stands out: the demand forустойчивый, Высокопроизводительные материалы растет. More manufacturers are asking for recycled urethane or plant-based silicone to reduce their carbon footprint—without sacrificing quality. We’ve also noticed that small businesses (like startups) are increasingly choosing casting over other methods because of its low upfront costs. Наш совет? Don’t cut corners on mold quality: a well-made mold (even a 3D-printed one) will produce consistent parts and save you money long-term. We also recommend testing 5–10 prototype parts before full production—this catches issues early, like warping or incorrect hardness, that could derail a large order.
7. FAQ About Casting Rubber Parts
1 квартал: How long does it take to make casting rubber parts?
А: Для небольших деталей (НАПРИМЕР., 5cm gaskets), the process takes 1–2 days (mixing, залив, выклятый, отделка). Для больших частей (НАПРИМЕР., 50cm rollers), it can take 3–5 days (longer curing time).
2 квартал: Can casting rubber parts be recycled?
А: Да, but it depends on the material. Urethane rubber can be ground into pellets and reused for low-stress parts (like door stoppers). Silicone is harder to recycle, but some companies (Как Игу) offer take-back programs for used silicone parts to repurpose them.
Q3: Is casting cheaper than injection molding?
А: Для небольших пробежек (под 1,000 части), да. Injection molding requires tooling costs of $5,000–$50,000, while casting molds cost $300–$3,000. Для больших пробежек (10,000+ части), injection molding becomes cheaper per unit.
Q4: What’s the maximum size of a casting rubber part?
А: We’ve made parts as large as 2 метры (industrial tank seals) and as small as 1mm (micro gaskets for electronics). The limit depends on the mold size and the rubber’s ability to flow evenly—large parts may need multiple pouring steps.
Q5: Are casting rubber parts waterproof?
А: Most are, if made with the right material. Silicone and neoprene are naturally waterproof; urethane can be coated with a waterproof sealant for extra protection. Always specify waterproofing needs to your manufacturer—this ensures they choose the right material and mold design.