Foam neoprene, also referred to as neoprene sponge, is formed during the neoprene manufacturing process when liquid neoprene is solidified into a cohered sheet. A foaming agent is released into the raw, liquid rubber, catalyzing chemical reactions that generate nitrogen gas within the material itself. This cumulates into an air-filled matrix within the physical structure of the now-solid rubber. This entrapment of gas within the rubber’s composition allows the resulting material to be more compressible and a better insulator. Neoprene foam’s natural elasticity works symbiotically with the free space within its structure, and these pockets of gas heighten the amount of energy that the material can absorb. These interior chambers act as layers that disperse energy as forces from impacts traverse the neoprene sponge rubber. All of these reasons allow for both open-cell neoprene and closed-cell neoprene to excel in applications where solid sheet rubber would be inadvisable or ineffective. The chief aim of this article is to explain exactly what foam neoprene is. To do so, we will explore the two different types of neoprene sponge, comparing and contrasting the two. In addition, we will answer a few questions along the way, guiding your thought process as you learn all about foam neoprene. These questions include the following:
• Is neoprene rubber or foam?
• What type of foam is neoprene?
• What is made from open-cell foam neoprene?
• What is closed-cell neoprene foam used for?
• What is neoprene foam rubber?
Is Neoprene Rubber or Foam?
Neoprene is a type of synthetic rubber, and it can be made in either solid or foam versions. Thus, neoprene is always a type of rubber, first and foremost. But it may or may not be foam neoprene. Foam neoprene maintains many of the resistances and tolerances exhibited by other rubber-sheet products. It is resilient against the corrosive effects of ozone and oxidation, maintains a tolerance to a wide range of temperatures, and offers moderate chemical- and oil-resistance, making it ideal for a variety of general-purpose applications. (This degree of versatility is the main reason for why neoprene is known as the general-purpose rubber.) However, not every foam neoprene material is structurally similar. There are two distinguishing categories of neoprene foam rubber: open-cell neoprene sponge and closed-cell neoprene sponge rubber.
What Type of Foam Is Neoprene?
When offered in a foam form, neoprene is available in either an open-cell variant or a closed-cell variant. Thus, neoprene foam does not come in just one type. These two forms of foam neoprene are produced differently and, consequently, have differing structures. Each one’s structure determines the applications for which it is best suited.
What Is Made from Open-Cell Foam Neoprene?
Open-cell foam neoprene is used to make products like sound absorbers. This specific form of foam neoprene is the less dense and more porous of the two. It is defined by the interconnectedness of the gaseous pockets within the material. That is, the chambers of nitrogen gas within open-cell neoprene foam are intentionally open, allowing air and liquids to permeate the material. Thus, open-cell foam neoprene is especially permeable, allowing energy and matter to diffuse throughout the structure of the material. Remarkably, foam neoprene, even when permeated, still maintains its structural integrity. To some, open-cell foam neoprene’s permeability may seem like a downside. After all, an open-cell structure defeats the point of many sealing applications. And its permeability likely reduces its effectiveness in aquatic settings. Yet, there is still good reason for why open-cell neoprene foam is such a highly-coveted commodity. Vibration absorption and—consequently—sound insulation is one type of application that benefits greatly from the use of open-cell foam neoprene. The ability to absorb sound is a hallmark of open-cell neoprene sponge sheets because of their expanded capacity for intaking sonic waves. When sonic waves come into contact with open-cell neoprene foam, this material’s open pores readily absorb these vibrations. Whereas, in the case of a non-permeable rubber mat, a larger proportion of a sonic wave’s force is rebounded off the mat—rather than absorbed. This level of absorption displayed by open-cell structures may seem counter-intuitive, but it is actually desirable in the case of vibration absorption. When open-cell foam neoprene absorbs a sonic wave, the force of the vibration enters the mat’s matrix of interior chambers. These chambers are non-uniform, which means that there is an element of randomness inherent to the internal layout of cell neoprene. This irregularity increases the number of edges, crevices, and curves that the sonic wave encounters as it travels through the mat. And as this force navigates open-cell foam neoprene’s structure, it steadily disperses. The vibrations become trapped and ricochet within the mat, decreasing in strength with every encounter with the mat’s internal terrain. Its proficiency at vibration absorption, coupled with its comparatively low density, allows the open-cell variant of foam neoprene to enjoy a spectrum of uses.
What Is Closed-Cell Neoprene Foam Used For?
Closed-cell neoprene foam is typically used for applications requiring heat insulation or shock absorption. This form of neoprene sponge is defined by the closedness of the gaseous pockets within the foam neoprene material. Unlike open-cell neoprene foam, closed-cell neoprene foam’s internal chambers are completely segregated—there are no openings connecting these pockets of gas. This structural difference may seem inconsequential, but it changes many of the circumstances to which the material can be applied. Closed-cell neoprene sponge tends to be harder and less flexible than open-cell neoprene sponge because its closed-cell structure does not permit air to escape when the mat is pressed or flexed. However, closed-cell neoprene rubber is water- and air-tight, and it resists compression better than its open-cell counterpart. Furthermore, its closed structure better prevents heat from escaping the material, making closed-cell foam neoprene better at insulating heat. These traits give the closed-cell neoprene sheet-material a stronger and more resilient structure when compared to an open-cell neoprene sheet. Thus, closed-cell foam neoprene is excellent for applications requiring both heat insulation and sealing capabilities—such as applications in aquatic settings. In short, closed-cell neoprene is better than open-cell neoprene in terms of structural stability and water- and air-tightness.
Review: What Is Neoprene Foam Rubber?
Neoprene foam is the sponge-like version of neoprene, and it is available in two types: open-cell neoprene foam and closed-cell neoprene foam. Neoprene foam is soft, shock-absorbent, insulating, and pliable, making for a neoprene material that is incredibly effective in a multitude of scenarios. A neoprene foam rubber sheet is often used in applications such as a neoprene floor-mount vibration-isolator, a closed-cell neoprene sill-sealer, and a neoprene wrap for PVC pipe.
As remarkable as sponge neoprene is, it took scientists a long time to develop neoprene into its many forms today. These foam neoprene materials have been around since the 1930s. It was in the year 1930 that scientists from the French chemical-firm DuPont originally manufactured neoprene. However, at this point, neoprene was rudimentary at best. It smelled awful, and it lacked many of the technical enhancements that makes it such a well-rounded material today. It took them several years to refine the material, but by 1937, the material that we know today as neoprene was officially commercialized, and consumers everywhere gained access to this amazing elastomer. In the decades following its initial arrival into the market, its popularity has only increased. Today, both the solid, open-cell, and closed-cell neoprene variants are used in a host of different applications. Neoprene sponge, especially, is used in applications ranging from laptop sleeves, aquatics, medical braces, electrical insulation, and general sheets and gaskets. With so many applications to which you can apply foam neoprene, it is exceedingly important to know which type or types of neoprene foam will suit your project the best.
In this article, we have given you a foundational understanding of foam neoprene. By comparing and contrasting the two categories of neoprene sponge, we hope to make your decision clearer the next time you look to buy neoprene. Indeed, anyone interested in acquiring foam neoprene for their application should know the key differences between open-cell neoprene and closed-cell neoprene. When both forms of sponge neoprene are applied in the same setting, you will find that one type of foam neoprene is more effective. To avoid choosing the wrong type of neoprene foam, consider whether you need—for instance—heat insulation or sound absorption. These factors will guide you toward which type of neoprene sponge you should get. That is, when purchasing foam neoprene, always know what you want the material to accomplish and apply that consideration toward your selection process as you purchase neoprene.
