What Are The Sorts of Coil Foam Mattress

Mattress Coil Types

For comfort, a mattress must provide balanced pressure relief and spinal support. The vast majority of mattresses do this by pairing a firm base with a softer comfort section. The materials and design of these layers contribute to the price point and determine how the mattress performs for different types of sleepers. The most commonly used material in support cores is mattress coils.         

Commonly used in innerspring and hybrid mattresses, mattress coils are metal springs that are arranged in some pattern to support the weight of the sleeper. There are several different types of spring, each optimized for a different function. In addition to the Bonnell spring, continuous wire spring, and pocketed spring used in the support core, some mattresses use smaller coils in the comfort layer. Understanding how different styles of coils affect the feel and durability of your mattress can help you decide which type is best for you.            

What Are Mattress Coils?

Mattress coils are metal springs that support the mattress and create a durable sleeping surface. They are designed to flex in response to pressure and movement, providing increasingly firm support as more pressure is applied to the mattress. Most mattress spring are made of tempered steel. The process uses repeated heating and cooling to increase the coil's elasticity, allowing it to return to its original shape after prolonged use.        

Coil-based mattresses tend to be responsive and fairly durable. They also sleep cooler than full-foam mattresses because the coils leave room for airflow. Depending on factors such as coil type, gauge, total number of coils, and overall mattress design, coil-based mattresses may be more or less supportive. The four main types of coils used in mattress support cores include Bonnell coils, continuous wire coils, and pocketed coils. The design may also vary slightly among the main types of coils. We'll discuss what you can expect from each type of coil to help you choose the best mattress for how you sleep.

Mattress Coil Types

Each mattress coil style offers certain advantages and disadvantages for different sleeping positions, body types, and budgets.          

Bonnell Coils

Bonnell coils are hourglass shaped, with the top and bottom wider than the middle. Thinner sections are designed to flex in response to minimal pressure, while thicker sections can withstand more pressure. Each coil is knotted at the end and connected to adjacent coils by a network of thin helical helixes. Since the Bonnell coils are interconnected, they move as a unit. This allows them to provide more support, but it means they cannot accommodate different body weights and sleeping positions and other mattress coil styles. There may also be some noise from friction from the coil. Bonnell coils are the original type of mattress coil used to make mattresses. They are also one of the cheapest types of mattress coils. Bonnell coils are fairly sturdy, they usually have solid edge support, but they can tend to sag in the center of the mattress.            

Continuous Wire Coil

Continuous spring are constructed from a single wire, forming rows of loose coils connected by helical wires. This simple design is very durable and inexpensive. The helix throughout the frame provides even spacing for the coils. This helps limit motion transfer, although because of their tight connection, successive coils may still transfer some motion in response to pressure. For the same reason, continuous coils are not as quiet as biased coils. Continuous coils are strong and stable, but they do not provide the same level of profile as biased coils. They are suitable for mattresses with thick comfort layers. Continuous coils require less time and money to produce, and they are generally less expensive than other coil types.           

Pocketed Coils

Pocketed coils consist of multiple smaller coils individually wrapped in non woven fabric. The fabric sleeves are sewn or glued together, allowing each spring to move independently within its fabric shell. Also known as Marshall coils, pocketed coils are especially common in hybrid mattresses. Since each coil only moves when direct pressure is applied, the pocketed coils better conform to the shape of the body. This design also allows the pocketed coils to respond freely to motion without transmitting motion to surrounding coils. People who share a bed are less likely to wake their partner on a pocketed coil mattress.

Pocketed coils have a cylindrical shape that distributes pressure evenly in each spring, so the center is better supported than other types of mattress coils. Pocketed coils are generally less prone to degradation than hourglass springs. More complex pocketed coil constructions usually command a premium price. However, while individually wrapped coils are more expensive than other coil types, they also tend to be more durable and supportive.