Open Cell and Closed Cell Silicone Sponge Sheet: What is the Difference?

Silicone sponge sheets are sealing solutions used in multiple applications that a standard rubber could never perform. 

A silicone sponge sheet comes in different grades, such as the typical commercial varieties, such as soft, medium, and firm. The classification depends on the ability to withstand force. For instance, soft is between three and eight pound-force per square inch (psi). Meanwhile, the medium and firm grades feature from 6-14 psi and 12-20 psi, respectively.

However, manufacturers also have their distinct grades, which separate them from the competition. They can also customize a solution for your unique needs. 

People often take for granted the dishwashing sponge they see in the kitchen, but it represents a huge industry.

For example, the sponge rubber has an estimated compound annual growth rate of 3.6% from 2019 to 2024. By 2024, the industry will reach $7.4 billion from $5.9 billion in 2019. Silicone rubber is noted for its versatility. It has countless applications across multiple segments.

Open Cell and Closed Cell Explained

An open cell silicone sponge sheet means that each cell is openly connected to the next. It means there is a gap in between. So, you can expect water and dust to fill the holes. 

A typical example of an open cell is the standard dishwashing sponge you have at home. When you drop the sponge on a canister, you will see that the material will soak in the liquid until it is full. You need to squeeze it tightly again to get rid of the excess water. 

The sponge is also designed to absorb the liquid temporarily, so that you can transport it to another location. Think of the sponge that you use to wash your car, for instance. 

In contrast, a closed cell silicone sponge sheet features a very tight cell structure at subatomic levels, which prevents moisture from seeping in. Instead of marked gaps, the air is trapped within each cell. The rubber is a great solution when you need to seal holes and crevices because of the sponge’s minimal water absorption capability.

Which One Should You Use?

As you can see, the open cell and closed cell feature different characteristics, which determines their function. 

The makeup sponge, for instance, features a closed cell, while soundproofing rubbers are categorized as an open cell. You can always know by the density of the material. 

A closed cell silicone sponge sheet is heavier and denser. It also does not expand as much as an open cell silicone. The closed cell also has a higher heat resistance and lower water absorption rate compared to the other product. 

One advantage of the open cell rubber is its flexibility. You can insert it into tight corners and nooks in your home or commercial establishment for insulation purposes. If you need to seal some areas in your building, you purchase gaskets and sealers, which are types of closed cell silicone. 

In conclusion, you choose the silicone solution according to your needs. But whatever you do, choose a manufacturer that can guarantee to provide you with a non-toxic product and food grade for optimum safety.