A gasket is a part that is placed between two static connecting components to prevent leaks, provide stability, and control vibration. Gaskets can be made out of silicone, rubber, synthetic rubber, foam, plastic, and many other materials. The most durable and versatile materials for gaskets are elastomers such as rubber and silicone.
There are also many different methods of gasket fabrication, each of which addresses different manufacturing and production needs. For example, a manufacturer may choose injection molding over rotary die cutting due to differences in the cost of the material. It's important for manufacturers to understand the benefits of each different method. Here are the five most common forms of gasket fabrication.
1. Rotary Die Cut Gaskets
This is one of the quickest methods of fabricating gaskets. The die is on a rotating cylinder and the material is fed through. As the die rotates, it makes contact with the material and cuts out the desired shape.
This method is ideal for producing a high volume of gaskets in a short period of time. The rotating die also takes up minimal space on the manufacturing floor, which is perfect for smaller spaces. Manufacturers can use any material for rotary die-cut gaskets.
2. Compression-Molded Gaskets
For simple rubber gaskets, manufacturers may use compression molding. This method utilizes a heated mold to create the shape of the gasket. Essentially, the gasket material is placed into the heated mold and then compressed. Once the material has cured, the mold is opened to release the final product. It is ideal for low production volume and less intricate gaskets.
This is also a smaller machine, which is great for those with limited manufacturing space. Compression-molded gasket fabrication is best for flexible materials such as rubber.
3. Flatbed / Steel Rule Die Cutting
With flatbed/steel rule die cutting, the die is placed on a flat surface rather than a rotating cylinder. The material is placed under the flatbed and the gaskets are punched out.
This method of production is best for thick materials, larger gaskets, and lower production volumes. Flatbed/steel rule die cutting is not as quick as other forms of gasket fabrication and the machinery may take up more room on the manufacturing floor. This option is more suitable for very specific needs but can be used on just about any material.
4. Injection Molded Gaskets
This form of gasket fabrication is among the quickest and best for high production volume batches. Injection molding works by melting down the material and putting it into the injection machinery. The material is then injected into the open mold which will be cooled or vulcanized to cure. When the gaskets come out of their molds they have little to no flash, which reduces production time that may otherwise be spent trimming the gasket flashes.
This method is ideal for especially intricate gaskets or those which require high precision. Rubber and other elastomers are the most common material used in injection molding.
5. Digital Knife / Dieless Cut Gaskets
This is the most precise method of fabricating gaskets. Digital knife / dieless cutting-sometimes referred to as flash cutting-utilizes a high-speed, computer-controlled knife to cut through a sheet of material. Many digital knife machines can achieve other cutting functions such as engraving, shaving, and more.
Manufacturers like using this method when trying to avoid any distortion that other methods may cause. While dieless cutting is more precise, many manufacturers only use it for prototypes or sample pieces as it produces small batches of parts or products. This method is best for soft materials, such as elastomers, and thick materials.