Silicone Parts Manufacturer

Silicone parts are used in a variety of industries and applications. From the cleanroom to the operating room, silicone is prized for its resistance to extreme temperatures and chemicals.

Custom manufacturer of injection and compression molded rubber parts. Also offers cleanroom assembly, engineering and in-house tool construction services. Serves the medical, automotive, consumer product and government safety and security industries.

Injection Molding

Injection molding is a common method for producing molded silicone parts. Liquid silicone rubber (LSR) is melted and injected into a mold cavity. The molded silicone cools down and solidifies into the desired shape. The injection molding process can be used to make a wide range of shapes and sizes, from thin silicone cords to thicker industrial silicone products.

A large amount of pressure is required to keep the mold closed during the injection process. The amount of pressure needed is influenced by the type of material being injected and its MFI (melt flow index), as well as the geometry and size of the injection machine’s barrel and screw.

When the melted plastic is allowed to dwell in the mold, it can shrink and form a “knot” or void. This is a result of the internal stresses caused by differences in wall thickness between areas of the molded part. This can occur in all types of silicone parts and is most likely to occur when there are abrupt changes in geometry, holes or ribs in the part design.

To avoid these defects, a draft angle should be included on all vertical walls in the design. This will help to reduce the formation of knit lines and allow a smoother ejection from the mold. It is also important that the ejector pins are not protruding above or indenting below the surface of the part to avoid this issue.

Compression Molding

Compression molding is a process of using a female mold to create the desired product. The material is preheated until soft and pliable then pressed into the mold. This is then allowed to set before being ejected from the mold. This allows for broad design flexibility and can also make Collapsible Silicone Dog Bowl for strong parts. It can be used for any thermoset material including silicone. This method is also often referred to as compression-casting.

Liquid Silicone Rubber (LSR) can be molded in this way to produce high-quality, high-performance prototype parts. A single metal mold can produce thousands of identical silicone rubber parts in a variety of colors and thicknesses. LSR is a good choice for applications where temperature and chemical resistance are critical, such as medical accessories, automobiles and appliances.

LSR can also be used for overmolded applications such as creating a slip-resistant handle or insulating electrical components. It is also popular for o-rings and gaskets as it can be molded into a wide range of shapes. It is also possible to create dual durometer products with this type of molding. This is common in automotive, manufacturing and construction equipment. Moreover, it can be used for static applications that require exposure to petrochemicals and steam. In addition to its flexibility, it offers a faster cure cycle than injection and transfer molding.

Insert Molding

The insert molding process is one of the most versatile and cost-effective manufacturing processes available. It combines the strength of metal or other materials with the flexibility of plastic resin to create a single, unified part. The process reduces the need for mechanical fasteners or connectors, resulting in components that are lighter in weight and smaller in size. It also helps parts withstand vibration or shock, improving the design’s reliability and performance.

Insert molding requires the use of preformed metal inserts that are loaded into a mold, either manually or automatically. Then, the molded plastic is injected over the insert to produce a final product. This process allows designers to incorporate a variety of inserts into their products, including threaded inserts, bushings, sleeves and more.

While this is a very flexible and versatile process, there are some unique considerations that must be made to ensure the best results. First, it is essential that the inserts chosen can withstand the extremes of temperature and pressure that are typically found in this type of molding. It is also important to consider how the inserts will be bonded to the rest of the molded product.

Insert molding is a popular choice for prototyping, especially for medical, electrical and automotive applications. For example, Dame Products, a Brooklyn-based startup, uses this technique to encapsulate internal hardware for customer beta prototypes and then coat the device with skin-safe silicone in vibrant colors.

Transfer Molding

A silicone parts manufacturer that uses transfer molding is able to produce medical device components with more complex Silicone custom geometries than injection and compression molds. The process utilizes a plunger-like device built into a mold to force a piece of uncured silicone rubber through small holes in the mold called runners and into a closed mold cavity, where it is cured. The material is then trimmed and the transfer pad and sprues (channels that lead from the runner to the mold cavity) are discarded.

The transfer molded silicone has the advantage of being able to maintain very tight tolerances on finished part dimensions. It is also a good choice for production runs that can’t be handled by compression molding.

Stockwell Elastomerics makes 12 x 12 spliced sheets of a wide range of standard and custom liquid silicone rubber grades 10 to 70 durometer (Shore A). The same compounds used to make transfer molded products are also available in sheet form to make water jet cut gaskets in-house for fast turnaround times. This capability combined with two transfer molding presses and four in-house water jet cutters allows the company to take complex molds from design to water jet cut gaskets in days instead of weeks. It is this unique capability coupled with the company’s expertise in a broad array of silicone manufacturing processes that makes it an exceptional partner for companies needing prototyping and short to medium volume production of molded silicone products.