Factors To Consider When Choosing Between Urethane And Silicone For Moulding


If you are planning for a moulding project in Vancouver, you will have to decide which rubber is more appropriate for your process:

Urethane or Silicone. Both urethane and silicone molding can be done within a day. Each product line has its advantages and disadvantages and a wide range of options. For example, the urethane line has over 30 individual options, each option being different regarding hardness, pour time, viscosity, and cure time, colour, and other factors. Three factors influence the decision between urethane molding and silicone molding. Let’s look at these factors in detail in detail:

  1. The casting material to be used

Concrete: Urethane mold rubbers are more effective and thus preferred over other materials for casting concrete. In some occasions, you might not require a release agent when casting concrete, depending on the components of the concrete mix. The hardness of urethane rubber options varies from A20 to D45. This hardness allows for a wider variety of concrete applications including form liners, concrete statuary, stamping mats, countertops and much more.

Plaster or wax: Polyurethane mold rubbers are the most common option for casting plaster or wax. Softer options in the line are used, which include Polygel Series and 74-Series.
Polyester and Polyurethane Resins: Silicone rubbers are referred to urethane when casting these resins. When designed and used correctly, one mold can be used to make many castings. A release agent is not required in most cases.

Epoxy Resins: Though silicone rubbers used for casting epoxy resins without a release agent, they are not very suitable as the corrosive curing agent present in epoxies wears down the silicone rubber resulting in limited castings. With an appropriate release agent, polyurethane rubber is better than silicone rubber for casting epoxy resins.

Polyurethane foam: Silicone rubbers do not require the application of a release agent before casting and last longer than polyurethane rubber molds. Therefore, they are recommended when casting polyurethane foam.

  1. Number of castings to be made

After having an idea of which products are more popular than others for casting certain materials, the other important consideration is quantity. When polyurethane rubber molds are well-designed, hundreds of these castings can be made. Contacting a reputable urethane molding company in Vancouver is the better option as you will save some money.

When casting polyester resins, polyurethane resins and polyurethane foam, hundreds of parts can be made through silicone molding. However, if you need fewer cast parts (10-20), you might consider using less expensive polyurethane mold rubber with a release agent.

Silicone rubber can be used when casting a few epoxy resins. A larger quantity of these castings requires polyurethane rubber and a release agent.

  1. Material used to make the model

When living creatures are used as the mold, careful consideration should be done and skin-safe materials chosen. In most cases, the model can get damaged during the molding process. Silicon rubber molds do not need release agents that could affect the model. However, oils from these rubbers can affect the model in various ways. It is recommended that a small test cure on the model be performed before making the entire mold.

For all your manufacturing and production processes, call the best urethane molding company in Vancouver today. Urethane is better for industrial applications due to its compression strength, tensile strength, hardness, impact resistance, tear strength and abrasion strength. It also has a long service life, thus lower operating costs and less downtime for the business.

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