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The Best Practices in Silicone Molding Process

by Nice Rapid | Jul 06,2022 | Silicone Molding

Silicone molding is a manufacturing technique employed to transform an uncured or unvulcanized silicone rubber into a pre-designed shape. There are several molding techniques including injection molding, compression, and extrusion. Choosing the perfect method that would fit a project depends on the size and complexity of the project, the required quantity, and the budget for tooling.

One of the manufacturing methods we recommend is molding. It is an ideal process for silicone rubber components. In the technique, the pressure of the press ensures that the material occupies all the spaces of the cavity and the heat cures the silicone rubber, ensuring that it retains its shape.

Here are some of the best practices in using silicone molding.

How to keep the molds clean and hygienic

Silicone molds are an excellent option for manufacturing items that need to be clean and hygienic. Unlike traditional molds made from other materials, silicone molds do not absorb bacteria or allow mold to grow. They are also easy to clean - simply wash them with soap and water, or place them in the dishwasher.

Additionally, silicone molds are heat-resistant, so you can use them in the oven or microwave without fear of melting or warping. If you're looking for a safe and easy way to keep your food clean and healthy, silicone molds are a great option.

silicone bubble toys

The right silicone compounds

There are three types of silicone rubbers: methyl, vinyl, phenyl, and others. Based on the ASTM D1418 standard, the organization manages the system of classification for rubber and rubber lattices. It classified the silicone rubber according to the following:

  • Methyl group - This is also known as dimethyl silicone elastomer/rubber or simply just methyl silicone rubber.
  • Methyl, Phenyl, and Vinyl Groups - It is referred to as PVMQ and is excellent for low-temperature performance.
  • Methyl and Phenyl Groups - They are also known as methyl-phenyl silicone elastomer/rubber or phenyl silicone rubber. PMQ for short, they have low-temperature performance.
  • Fluoro, Vinyl, and Methyl Groups - These are known as fluorinated rubber or Fluoro silicone rubber,
  • Methyl and Vinyl Groups - They are methyl vinyl silicone elastomers.

The silicone rubber is divided into three groups and has the following uses and applications:

  • Solid Silicone Rubber - it contains polymers with high molecular weight and relatively long polymer chains. It’s available in an uncured form and requires traditional rubber processing techniques.
  • Liquid Silicone Rubber - it contains polymers of low molecular weight and shorter chains. This type of silicone has better flow properties.
  • Room Temperature Vulcanized - Silicone RTV is silicone rubber made from one-part or two-part component systems where their hardness ranges from very soft to medium. They are used for potting, sealants, encapsulations, and others.

How to deal with color configurations

Color configuration is an important aspect of product design, and there are a few different ways to deal with it. One common method is silicone molding, which allows for the creation of three-dimensional products in a wide range of colors. This process begins with the creation of a silicone mold, into which liquid silicone is injected.

Once the silicone has cured, it can be removed from the mold and finished as desired. Another popular method for dealing with color configuration is spray painting. This technique can be used to create a wide variety of textures and finishes, and it is often used for products that will be visible from multiple angles. Spray painting is a relatively simple process, but it requires careful planning to ensure that the colors are evenly distributed.

Important points in pouring

With silicone molding, it is important to pour slowly and evenly. If you pour too quickly, the silicone can bubble and create defects in the finished product. On the other hand, if you pour too slowly, the silicone can start to set before it has had a chance to fill the mold. As such, it is important to find the perfect medium when pouring silicone.

In addition, it is important to make sure that the mold is completely level before starting to pour. Otherwise, the silicone will not evenly distribute throughout the mold, and you will end up with an uneven final product.

Finally, it is important to be careful not to overfill the mold. If you do, the silicone will spill out and create a mess. By following these simple tips, you can ensure that your silicone molding project goes off without a hitch.

Post curing setup

When silicone molding is used to produce parts, a process is known as post-curing is often necessary to ensure the desired properties are achieved. During post-curing, the silicone mold is placed in an oven and heated to a specific temperature for some time. This process can help to improve the physical properties of the silicone, such as its tensile strength and elongation.

In addition, post-curing can also help to improve the appearance of the silicone part by reducing shrinkage and surface defects. While post-curing is not always necessary, it can be an important step in the silicone molding process.

Silicone molding opens new doors to breakthroughs and innovations, especially in the medical industry. However, the process also presents some technical challenges. The above best practices can help resolve them.

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