Plastic and silicone casting molds: what's the difference?

Plastic resin mold and silica gel mold are the two main molds we use to cast handicrafts or jewelry. Both resins are suitable for different types and quality of molds.Understanding the difference between plastic molds and silicone molds is important to get the results you want. Both types of molds can use a variety of resins, but understanding the limitations of each mold is very important to ensure the correct production of your products.

Here, we will outline plastic and silicone molds and their advantages and disadvantages.

 

Plastic resin mould

These reusable resin casting molds are usually made of polypropylene or polyethylene plastic sheets. They are usually made of templates and are partially flexible.

Benefits:

high quality and inexpensive. Plastic resin molds usually cost less than $10. (many are less than $5!) if or when you damage the mold, you usually don't spend a lot of money to replace it.

Easier to use. Plastic molds are a good place for new craftsmen to start. Compared with silicone molds for epoxy resin, they are easier to demould and maintain.

Disadvantages:

Castings cannot be shiny and shiny. Once removed from the mold, the casting surface contacting the mold surface may not be as shiny as you want. You either need to coat a layer of resin or cover a layer of resin gloss sealant spray.

It's easy to scratch. Although the softness of plastics is helpful, it makes it easier to scratch the surface. If you are not careful, things like toothpicks or nails will leave obvious dents.

It's hard to make it yourself. Making your own plastic resin casting mold requires vacuum forming plastic sheets around the template, which requires special equipment.

 

Understanding the difference between plastic molds and silicone molds is important to get the results you want. Both types of molds can use a variety of resins, but understanding the limitations of each mold is very important to ensure the correct production of your products.

Here, we will outline plastic and silicone molds and their advantages and disadvantages.

Plastic resin mould

These reusable resin casting molds are usually made of polypropylene or polyethylene plastic sheets. They are usually made of templates and are partially flexible.

Benefits:

high quality and inexpensive. Plastic resin molds usually cost less than $10. (many are less than $5!) if or when you damage the mold, you usually don't spend a lot of money to replace it.

Easier to use. Plastic molds are a good place for new craftsmen to start. Compared with silicone molds for epoxy resin, they are easier to demould and maintain.

Disadvantages:

Castings cannot be shiny and shiny. Once removed from the mold, the casting surface contacting the mold surface may not be as shiny as you want. You either need to coat a layer of resin or cover a layer of resin gloss sealant spray.

It's easy to scratch. Although the softness of plastics is helpful, it makes it easier to scratch the surface. If you are not careful, things like toothpicks or nails will leave obvious dents.

It's hard to make it yourself. Making your own plastic resin casting mold requires vacuum forming plastic sheets around the template, which requires special equipment.

 

Custom injection plastic molds can be made of a variety of materials, such as aluminum, steel, or alloys, and may contain various internal components such as pins, rails, bushings, and ejectors.

 

Silicone mold

These reusable molds are made of two parts of silica gel and can be used for many years if properly maintained.

Benefits:

Very flexible. Silicone molds allow you to make complex castings that can be removed more easily than plastic molds.

Custom mold. You can buy two-piece silicone and shape anything you want (assuming you have a model).

Castings may glow. I say "possible" here because the original model used to make the mold must be shiny. If so (like our geometric silicone mold), your casting should be as shiny as the original.

Disadvantages:

expensive. The price of silicone mold for epoxy resin and general process is two to three times that of plastic mold.

Need more care. Silica gel mold must be cleaned after use and placed in a cool and dry place.

Pressure casting may be required. Unless you use a transparent silica gel mold to make epoxy resin, you may not see all bubbles in the resin when pouring it into silica gel. You may need to use a pressure casting device to ensure that all bubbles are treated before the resin begins to cure.

So what kind of resin mold should I choose?

Any kind of resin casting mold can bring you excellent results. Choose your favorite style and shape and start creating!These reusable molds are made of two parts of silica gel and can be used for many years if properly maintained.

Benefits:

Very flexible. Silicone molds allow you to make complex castings that can be removed more easily than plastic molds.

Custom mold. You can buy two-piece silicone and shape anything you want (assuming you have a model).

Castings may glow. I say "possible" here because the original model used to make the mold must be shiny. If so (like our geometric silicone mold), your casting should be as shiny as the original.

Disadvantages:

expensive. The price of silicone mold for epoxy resin and general process is two to three times that of plastic mold.

Need more care. Silica gel mold must be cleaned after use and placed in a cool and dry place.

Pressure casting may be required. Unless you use a transparent silica gel mold to make epoxy resin, you may not see all bubbles in the resin when pouring it into silica gel. You may need to use a pressure casting device to ensure that all bubbles are treated before the resin begins to cure.

So what kind of resin mold should I choose?

Any kind of resin casting mold can bring you excellent results. Choose your favorite style and shape and start creating! WIT MOLD has lots of molds to get you started, all chosen by avid resin addicts who trust them for all their crafting.