When it comes to the fabrication of molds, RTV-2 silicone is often the preferred material. However, there are numerous types of silicone rubbers available, making it a perplexing task for beginners or inexperienced mold manufacturers to determine which type of silicone is best suited for their projects. To help resolve this dilemma, we have created a comprehensive buying guide for RTV-2 silicone materials.
Choosing the right silicone material is crucial for improving production efficiency, reducing costs, and achieving finely detailed castings. To ensure optimal mold outcomes, several factors need to be considered, such as the type of silicone, its hardness, viscosity, color, and other relevant aspects. Below, we will delve into a more detailed analysis to help you make an informed decision.
RTV-2 silicone material
1. Types of Silicone
The first step in selecting liquid silicone materials is choosing the appropriate type. RTV-2 silicone materials are available in two types: tin-cured silicone and platinum-cured silicone. Tin-cured silicone is commonly used in industrial mold making and may have a slight odor. On the other hand, platinum-cured silicone is free of harmful substances and can be safely used in contact with food and skin. For a more detailed comparison between tin-cured silicone and platinum-cured silicone, please refer to: Differences Between Tin-Cured Silicone and Platinum-Cured Silicone.
2. Silicone Hardness
Another crucial factor to consider is the flexibility of silicone, which is determined by its hardness value. When selecting silicone, the hardness is chosen based on the shape and size of the cast product. For smaller sizes and deeper undercuts, it is recommended to use lower-hardness silicone as it makes demolding easier. On the other hand, for larger-sized and architectural models, a higher-hardness silicone is more durable and less prone to deformation.
Additionally, it is important to note that the optimal tear strength for RTV-2 silicone materials falls within the range of 20-30 shore A hardness. When the hardness surpasses or falls below this range, its tear strength gradually diminishes. For detailed guidance on silicone hardness selection, please refer to "How to Choose the Appropriate Hardness of Silicone".
3. Silicone Viscosity
Viscosity is also a significant factor when selecting RTV-2 silicone materials. For those who don't have a vacuum pump or are DIY enthusiasts, it is recommended to use platinum-cured silicone due to its lower viscosity, which helps reduce the presence of air bubbles. Additionally, liquid silicone with lower hardness generally has a lower viscosity compared to higher-hardness silicone.
Understanding viscosity is crucial for achieving optimal results in mold-making. It plays a pivotal role in determining the flow and ease of application of the silicone material. If you would like to delve deeper into the topic of viscosity, we recommend referring to the "Reference Guide for Evaluating Liquid Material Viscosity". This guide provides valuable information to help you make informed decisions when selecting silicone viscosity for your specific project requirements.
4. Working Time & Curing Time
The working time and curing time are crucial factors when using RTV-2 silicone materials. If the working period is too short, there may not be enough time to work with the liquid silicone before it starts solidifying. Conversely, if the curing time is too long, it can negatively impact production efficiency. Therefore, it is essential to select silicone materials with appropriate working and curing times.
5. Production Process of Molds
The most commonly used techniques for silicone mold making are pouring and brushing. The brushing technique is suitable for creating intricate sculpture models. Typically, a 20-30 Shore A hardness condensation-cure silicone is used, although some users may opt for addition-cure silicone. On the other hand, the pouring technique involves creating a single-piece or two-piece mold, depending on the shape and size of the product model. The hardness of the silicone chosen is based on the specific requirements of the product.
6. Appearance Color
The default colors for tin-cured silicone are white and translucent, while the default colors for platinum-cured silicone are translucent and transparent. If you wish to create other colors using white or translucent liquid silicone materials, it is customary to add pigments to the B component for coloring. Naturally, the option to incorporate silicone pigments during usage is also available.
Summarize
The above are several factors to consider when selecting RTV-2 silicone materials for mold making. In summary, choosing the appropriate silicone allows for the creation of exquisite molds while also saving costs and avoiding unnecessary waste. To make a better decision, we recommend referring to the showcased examples of RTV-2 silicone applications. This can assist you in determining the most suitable product for your needs.
