Silicone Supplies
Silicones are widely used in many of the tools and objects that help make our lives comfortable. They are also used in healthcare applications like tubing, scar treatments, and implantable devices.
FDA approved silicones are non-toxic and don’t contain plasticizers that can leak chemicals such as BPA into foods. This makes them ideal for food-grade tubing, catheters and seals.
Mold Making Kits
A silicone rubber kit is a convenient way to give mold making a try. It contains raw materials and a set of tools that you can use to experiment with various molding, casting, lifecasting, or skin effect processes. These kits also contain step-by-step instructions to guide you through the process.
Silicones are derived from silicon metal and offer several benefits over organic rubber polymers. They are stable and non-toxic to humans and Silicone Supplies animals, and they are impervious to water, air, ozone, and many chemicals. They also have low surface energy and are non-polar, meaning they don’t readily bond or adhere to most surfaces without special primers and treatment.
RTV (room temperature vulcanized) silicones are typically one- or two-component systems that harden at room temperature to very soft or medium hardness. They are formulated for potting, sealant, and encapsulations, as well as adhesives and conformal coatings. These types of products are primarily used for industrial and consumer applications.
Solid or HTV (high temperature vulcanized) silicones are long-chained rubbers with the heaviest molecular weights. These are primarily formulated for high-performance parts like gaskets, seals, and hoses. They are cured at elevated temperatures using organic peroxides or platinum catalysts. These types of silicones are also used in ophthalmology to make eyedrops, silicone intraocular lenses after cataract extraction, and silicone tubes to keep a nasolacrimal passage open following dacryocystorhinostomy.
Silicone Molding Materials
Silicone mold-making materials can be used to create a variety of silicone parts for prototyping, commercial components and hobby projects. The process involves creating a master pattern of the item that is to be molded, making the mold and then pouring the liquid casting material into it. Once cured, the mold can be removed and the cast item made.
The raw material for making a silicone mold is RTV-2 silicone rubber. This is typically divided into a base and catalyst that must be carefully mixed together in accordance with the manufacturer’s instructions to create a complete system. If possible, this mixture should be dispensed into a container four to five times larger than its volume to minimize air bubbles that can affect the quality of the final cast.
Once the silicone mixture is properly mixed, a book or skin mold can be constructed. This type of mold is commonly used for complex items that have deep undercuts, tall Silicone Supplies vertical walls or both. The silicone is poured around the master and once the desired thickness is reached, the mold must be allowed to cure as per the manufacturer’s specifications.
The resulting silicone elastomer is often used to produce a variety of items for commercial, medical and household use. For example, the noise reduction and vibration dampening properties of silicone help reduce acoustics and unwanted vibration in aircraft, boats, automobiles and other equipment that operates at high speeds or at elevated temperatures.
Silicone Casting Materials
Silicones are used to make molds for casting a variety of resins and materials, such as polyurethane plastic and rubber, polyester casting resin, plaster, concrete, epoxy, soap, wax, low-melt metals, and some elastomeric paints. When a silicone mold is designed and used properly, a large quantity of castings can be produced from one mold. A release agent is typically required to ensure the mold separates easily from the cast material.
Many silicone moldmaking materials have passed rigorous health, safety and environmental risk evaluations. These RTV silicone elastomers can be used to make tough-yet-flexible molds that reproduce intricate details, and that are resistant to a wide range of chemicals.
These flexible silicone rubbers are also suitable for encapsulating electronic components to protect them from mechanical shock, vibration and radiation. The process is known as potting, and silicones are often chosen for this application because they can withstand a wide range of temperatures and have low moisture solubility.
Silly putty and other similar materials are made of a blend of siloxanes, including dimethyl siloxane, polydimethylsiloxane and decamethyl cyclopentasiloxane. These are the same ingredients found in medical-grade silicones used in scar treatment sheets and body-safe food-grade silicones sold for making utensils, kitchenware and toys like the 2013 fad “rubber band loom” bracelets. Unlike their synthetic, petrochemical counterparts, these rubbers do not contain any plasticizers that can break down into dangerous microplastics and are non-toxic when ingested.
Silicone Adhesives
Silicone adhesives and sealants are used in a variety of applications. They create waterproof and weather-resistant bonds for construction materials like concrete, tile, glass and plastics. They are also used to bind surfaces to each other in applications such as caulking cracks and bonding panes of glass to frames for aquariums.
They are even useful for basic tasks around the house, such as lubricating bicycle chains and releasing seized nuts and bolts. Their ability to resist water and other chemicals makes them well suited for aerospace applications, including sealing gaskets and engines and bonding aircraft components. Silicones are also often used in manufacturing and electronics for potting, sealing and coating.
Many silicones are available in different formulations to suit various uses. Silicones with a lower molecular weight (low Tg) are typically harder than higher Tg silicones. High Tg silicones have a higher degree of flexibility and can withstand greater shear stress.
A silicone sealant or adhesive can require time to cure fully. It is important to follow the manufacturer’s instructions for curing to ensure that the final product will have the desired properties. Some silicones are fast-curing, while others take as long as 24 hours to reach their full strength. Priming a surface before applying a silicone adhesive can speed up the curing process, as it will allow more chemical bonds to form between the substrate and the silicon adhesive. This allows for better adhesion durability in harsh service environments.
