Polyurethane foam is indispensable. Try to imagine the furniture industry without it—it would be a completely different picture. And in many other areas of life, things would be much more complicated. After all, this material is used to make literally everything: from sofas and mattresses to car seats, soundproofing panels, and even home insulation.
But simply knowing what polyurethane foam is isn’t enough. The secret is that foam comes in different grades. Some are soft, some hard, some highly elastic, and even specialized. They differ in their characteristics—density, rigidity, and structure. These parameters determine how comfortable and durable the finished product will be.
Besides types, there are also grades of foam: ST, EL, HL, HR, HS, and others. These are a kind of “code” with clear numbers and letters that describe specific properties. For example, soft HS and hard EL perform completely differently, although they are the same material. This determines whether furniture will last for years or shrink after just a few months.
A Brief Introduction to Polyurethane Foam (Foam Rubber)
So, what is PUF? Polyurethane foam, or more simply foam rubber, is a foamed polymer that appeared in the 1930s. It has unique properties: lightness, elasticity, and safety in use. This material is used to make upholstered furniture, mattresses, acoustic panels, and insulation.
For companies working in the furniture industry, polyurethane foam has become a basic filler—it ensures comfort, durability, and consistent product quality.
What are the criteria for classifying polyurethane foam (foam rubber)?
To understand which polyurethane foam is needed, it’s important to know its basic parameters. These determine whether the material is suitable for sofas, mattresses, seats, or specialized industrial applications. Without this information, it’s easy to get confused, as there are many types of foam rubber.
Density
Varies from 18 to 55 kg/m³. The higher the density, the greater the load the material can withstand and the longer it will last. For example, low density is suitable for decorative elements, while high density is suitable for seats, sofas, or mattresses.
Rigidity (elasticity, compression ratio)
The kPa value indicates how well the polyurethane foam resists loads. For example, 4.2 kPa means that a corresponding force is required to compress it by 42%. The higher the number, the harder the material.
Structure Type (Open- or Closed-Cell)
There are open-cell (permeable to air, comfortable for furniture, seats, and cushions) and closed-cell (retains heat, used in insulation, soundproofing, and even in construction).
Purpose
Its applications vary. These include upholstered furniture, mattresses, acoustic panels, transport seats, and construction insulation. In fact, polyurethane foam can be found in almost every area of life.
Special Properties
There is foam with fire-retardant additives, with an anti-mold antiseptic, and even with a memory effect, which “remembers” the shape of the body.
Marking (Type Code)
An alphanumeric code (e.g., ST2542) indicates the type of polyurethane foam, its density, and hardness. The foam grade acts as a material specification, helping you avoid confusion.
Main Types of Foam
Soft Polyurethane Foam
This is the classic material that most furniture starts with. Its main purpose is to provide comfort and a cozy feel. Soft polyurethane foam is often used as the top layer in sofas or armchairs to give the backs and armrests a soft feel. This material makes relaxing significantly more enjoyable, especially when you need to spend a few hours reading a book or watching a TV series.
Rigid Polyurethane Foam
This is a different story. It holds its shape and doesn’t sag even under heavy loads. If you need a durable seat or mattress, rigid foam is essential. It is also widely used in industry, where materials must be as durable as possible. It acts as a kind of “foundation” on which everything rests.
High-density flexible polyurethane foam
The combination of elasticity and wear resistance is what sets it apart from others. In luxury furniture, this material is responsible for durability. It withstands hundreds and even thousands of use cycles while maintaining its original shape. This creates the feeling that the furniture was created especially for you. These characteristics are especially prized in mattresses and premium products, where quality must be impeccable.
Specialized types (fire-resistant, antiseptic, memory foam, etc.)
Foam Brands
Below are the main brands of polyurethane foam:
- ST (Standard Foam) — standard furniture foam, universal, optimal balance of hardness and softness.
- EL (Extra Load) — increased hardness, withstands heavy loads, replaces spring blocks.
- HL (Hard Load) — very hard option, used for vehicles and specialized furniture.
- HS (High Soft) — ultra-soft, ideal for top layers, armrests, and backrests.
- HR (High Resilience) — highly elastic, comfortable for premium furniture, durable.
- VE (Viscoelastic Foam) — foam rubber with a “memory effect”, used primarily in mattresses and pillows.
- SB — a chameleon-like material, modeled after a real sea sponge. It also eagerly absorbs water and retains it. That’s why our everyday kitchen sponges, so essential for cleaning, are made from it.
Advantages and Disadvantages of Different Types of Foam
Pros:
- Durability with the right density. If the material is matched to the specific load, it can last for years without losing its elasticity or appearance.
- Wide range of applications. Foam is used in furniture, transportation, construction, and even medicine—it’s truly versatile.
- Hygienic and mold-resistant. It doesn’t accumulate moisture, doesn’t harbor fungi, and is easy to care for.
- Ability to create products of any complexity. It’s easy to create both simple pillows and complex designer shapes with smooth lines and varying levels of firmness.
Cons:
- Cheaper foam brands wear out faster. Such foam can lose its shape after just a few months of active use.
- Incorrect density selection leads to rapid loss of shape. For example, too soft a foam in the seats will simply sag during use, requiring replacement of the entire component.
- Specialized types are more expensive. Fire-resistant, antiseptic, or memory foam offer significant advantages, but their price can be significantly higher than standard materials.
Comparison table of foam brands by key characteristics
| Brand | Density | Hardness | Heat Resistance | Wear Resistance | Recovery Forms |
| ST | Medium | Medium | Medium | Medium | High |
| EL | High | High | Medium | High | High |
| HL | High | Very High | Medium | Very High | High |
| HS | Low | Low | Average | Low | High |
| HR | High | Average | Average | High | Excellent |
| VE | Average | Low | Average | Average | Excellent |
| SB | Low | Low | Low | Average |
What is each type of polyurethane foam used for?
Different brands of polyurethane foam have their own “roles” – some are good at withstanding loads, others create a soft feel, and others are ideal for applications where safety or durability are important. To avoid confusion with these abbreviations, it is worth knowing where exactly each type is most often used.
- ST — a basic option, ideal for standard sofas and mattresses. This versatile “working” option is suitable for most furniture in the home.
- EL — designed for heavy-duty use. This applies to convertible sofas or those used daily. It will withstand the stress of full-time use.
- HL — denser and more durable. It is used in vehicle seats or furniture for cafes, offices, and waiting rooms. These are areas where hundreds of people pass through each day.
- HS — softer, used as padding for armrests, backrests, or decorative elements where comfort and softness are needed, rather than extreme durability.
- HR/LR — this is the premium level. It is used in expensive sofas, mattresses, and sleeping bags, where maximum comfort and durability are essential.
- VE — a memory foam option that “remembers” the shape of the body. It is this material that creates that noticeable wow factor in modern mattresses and is often used in medical products.
- CMHR is a specialized type with increased fire resistance. Ideal for hotels and hospitals where safety is paramount.
- BB is a dense and durable material for gyms, office furniture, partitions, and soundproofing panels. A true “silent” hero.
How to choose the right type of polyurethane foam for your needs?
For businesses, choosing the right polyurethane foam brand is a strategic decision. It affects not only the quality of the product but also the company’s reputation with the end customer.
Key tips for choosing foam:
- Determine the load. Foam for sofas and mattresses—at least 25–30 kg/m³. For premium solutions—from 35 kg/m³.
- Evaluate the intended use. For office furniture production, it’s better to use harder types of foam (EL, HL). For home furniture, use ST or HR.
- Pay attention to special requirements. If fire resistance or antiseptic properties are required, choose CMHR or specialized HR/LR.
- Don’t skimp on quality. Cheap polyurethane foam sheets will quickly lose their shape, which can lead to complaints, returns, and reputational risks.
Highfoam cooperates with furniture manufacturers, companies in the transportation, medical, and construction industries. If you would like to discuss the supply of foam as part of our collaboration or receive a consultation, please contact us at contacts.
Kyiv, st. Stetsenko, 6, office 506
+38 (044) 200 25 69
office@acat.com.ua