Vacuum Casting Material Selection
Vacuum casting is a manufacturing process used to produce high-quality prototypes and small to medium batch parts production. It involves creating a mold from a master model and pouring liquid casting material into it to make duplicate parts.
Vacuum casting is cost-effective and quick-running to make a small volume production without high-cost molding, yet the material is somewhat different from injection molding. You need to understand the requirements of the product to select the appropriate vacuum casting material, which will determine the physical properties, functionality, and surface treatment requirements of the prototype product, and ultimately determine the success or failure of your newly developed prototype.
Properties to consider when choosing a vacuum casting material
1. Strength
Strength plays a crucial role in determining the longevity and robustness of the final product. Opting for materials with high strength ensures that the parts can withstand mechanical stresses and loads, making them suitable for applications that demand structural integrity and durability.
Industries like aerospace, automotive manufacturing, and heavy machinery often require materials with high strength for critical components or load-bearing parts. Polyurethane resins with added reinforcement are commonly selected for such demanding applications.
2. Flexibility
The flexibility of a material is essential for parts that need to exhibit bending or elasticity. Materials with good flexibility are vital for applications where parts must adapt to varying shapes or absorb impacts without breaking, ensuring their resilience in different operating conditions.
Sectors such as medical devices, robotics, and consumer electronics frequently require flexible materials. Silicone rubbers are favored in these industries for their flexibility and ability to endure repeated deformation.
3. Heat resistance
Heat resistance is critical for components exposed to high temperatures during operation or processing. Materials with high heat resistance can maintain their properties and structural integrity under elevated temperatures, ensuring the longevity and reliability of the parts.
Industries like automotive, electronics, and industrial equipment often rely on parts with superior heat resistance. Epoxy resins are commonly chosen for their ability to withstand high temperatures in these demanding applications.
4. Durability
Durability is vital for components subjected to frequent use, wear, or harsh conditions. Opting for durable materials ensures that parts can withstand challenging environments, increasing their lifespan and maintaining functionality over time.
Industries such as manufacturing, tooling, and prototyping benefit from the durability of materials. Urethane rubbers and specific types of polyurethane resins are popular choices due to their durability in these industrial settings.
5. Finishing
The finishing properties of a material impact the surface quality and aesthetics of the final part. Materials with good flow characteristics can result in fine finishes, making them suitable for applications where visual appeal is as important as functionality.
Industries such as consumer electronics and high-end automotive components prioritize superior finishing. Clear resins and materials conducive to post-processing techniques like painting and polishing are preferred in these industries to achieve high-quality, visually appealing parts.
Vacuum Casting Materials Commonly used for Rapid Prototyping
In vacuum casting, a variety of resins are used to produce parts with different properties and characteristics. Some common materials used in vacuum casting include:
ABS-like Resin
ABS-like materials typically mimic the properties of ABS plastic, offering good strength, impact resistance, and toughness. This makes them suitable for producing functional prototypes and parts that must withstand mechanical stresses.
Benefits:
- It can achieve a smooth surface finish.
- Good dimensional stability
- Compatible with various post-processing techniques such as painting, printing, and plating.
- Cost-effective
| Types | Properties |
| DAI8150 | good heat resistance, heat resistance |
| 8263 | fireproofing UL-94V0 |
| UP6160 | high-temperature resistance |
| 8901 | good toughness, strong hardness, and resistance to 135° |
| PX-100 | General toughness, temperature resistance of 70° |
PMMA-like Resin
PMMA-like materials, which simulate the properties of acrylic (Polymethyl Methacrylate), offer several advantages for vacuum casting processes.
Benefits:
- It can replicate the optical clarity and transparency of acrylic.
- High UV resistance
- Chemical resistance
- high-quality surface finish with good clarity and smoothness.
- Good thermal stability
| Types | Properties |
| PX-521HT | high transparency, UV resistance |
PC-like Resin
PC-like material is the preferred choice for applications requiring robust, transparent parts that can withstand challenging environmental conditions.
Benefits:
- High impact resistance.
- Polycarbonate-like materials can mimic the transparency of polycarbonate.
- Good resistance to high temperatures。
| Types | Properties |
| PX-520 | high transparency |
PP-like Resin
PP-like resins are composed of a blend of polymers and additives designed to replicate the properties of polypropylene. The specific composition may vary depending on the manufacturer and the desired properties.
- Good chemical resistance.
- Low moisture absorption.
- Excellent thermal stability.
- Impact resistance.
Benefits:
| Types | Properties |
| UP5672/3 | impact resistance, low shrinkage |
| UP5690 | high toughness, impact resistance, flexibility |
Common Soft Rubber
Common soft rubber refers to a group of elastomeric materials that exhibit softness, flexibility, and elasticity.
Benefits:
- Flexibility and elasticity.
- With soft and comfortable texture.
- Good grip and traction.
- Weather resistance.
- Waterproof.
| Types | Properties |
| DPI8400 (white/black) | good elasticity |
Soft Clear Rubber
Clear soft rubber is a type of elastomeric material that combines the properties of transparency, softness, and flexibility.
Benefits:
- Transparency.
- Softness and flexibility.
- Weather resistance.
- Chemical resistance.
- Non-toxic and safe.
| Types | Properties |
| T-0387 transparent | good elasticity |
Factors Influencing Vacuum Casting Material Selection
When selecting materials for vacuum casting, several factors come into play to ensure the final product meets the desired specifications and requirements. Below are some key factors that influence vacuum casting material selection:
1. Mechanical Properties of Vacuum Casting Material
The mechanical properties required for the end product, such as strength, flexibility, impact resistance, hardness, and durability, determine the choice of material. Different materials offer varying degrees of these properties, and the selection must align with the intended use of the final parts.
2. Functional Requirements of Vacuum Casting Prototypes
Specific functional requirements, such as thermal resistance, chemical resistance, electrical conductivity, or insulation properties, play a significant role in material selection. The material chosen should meet these functional criteria to ensure the part performs as intended.
3. Cost of Vacuum Casting Material
Material cost is a crucial factor in manufacturing decisions. Balancing performance requirements with material cost is essential to ensure cost-effectiveness without compromising quality.
Conclusion
By carefully evaluating these factors and considering the specific requirements of the project, manufacturers can choose the most suitable materials for vacuum casting to achieve optimal results in terms of performance, appearance, cost, and compliance with various industry standards.
