What does the density of foam rubber mean: how to choose yours

When choosing upholstered furniture, it is important to pay attention not only to the external component of the product, but also to the filling. To avoid having to replace materials during operation, you need to choose high-quality foam rubber for furniture, which will serve for a long time and delight you with its elasticity.

Density

This is the most important characteristic of a material that affects its durability. The cost directly depends on it: the denser the foam rubber, the more expensive it is. The range of material densities is from 18 to 55 kg/m3.

What density of foam rubber is needed for a sofa? To do this, you may need material of different densities (kg/m3):

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• 18 – used in not very important important parts (drawbars, backdrops);
• 20 – used for making backrests and backrest cushions;
• 25 – suitable as a load-bearing layer of seat padding;
• 30-35 – optimal as a load-bearing layer of seats with increased weight;
• 40 – the use of a material of this density makes the furniture almost “eternal”, suitable for long-term intensive loads;
• 50 – the indicated density is used in special brands of foam: viscoelastic (Memory Foam), highly elastic (latex). This material provides maximum comfort due to anatomically correct body position.

Rigidity

The stiffness index determines the pressure at which the material is compressed by 40% relative to the original thickness. It determines the scope of application of the material.

You can buy foam rubber of soft and super-soft brands for sofa parts that are subject to less pressure, but require significant deformation (back cushions). Standard ones are used for the manufacture of standard parts, for example, seat cushions, and rigid and increased rigidity ones are used for office furniture and the shaping of upholstered furniture elements.

Basics of restoration

When restoring a sofa at home, you need to stock up on the following:

• Foam rubber, its quantity is calculated after measuring the sides, back and seat.
• Canvas, just measure the area of ​​the old upholstery.
• Upholstery fabric, depending on the pattern, should be taken 15-20% more. This will help to adjust the drawing and compensate for errors in calculating footage.

The repair consists of several stages:

• Furniture is disassembled into components. The sides are removed; if it is possible to detach the back, then you need to remove it too.
• You need to carefully remove the old trim, it will still come in handy; for this purpose, as a rule, a flat screwdriver is used; it is convenient to remove furniture staples.
• Now you can get rid of the old filler. There is no need to stand on ceremony with it; you need to strip it to the ground to ensure complete replacement of the soft parts.
• Now the most crucial moment: making the pattern. To do this, you should carefully steam and iron the old upholstery to avoid unevenness and distortions, because it is on this that the canvas and upholstery fabric will be cut. If in the case of canvas the error can be “covered up” with the right piece, then in decorative finishing this is impossible, it will ruin the appearance of the sofa. Before cutting fabrics, you need to decide: should you leave your sofa the same or change it, giving it additional volume and softness. If the choice is in favor of volume, then it is worth making an additional allowance when cutting.
• The foam rubber is laid on a wooden base with a small allowance, slightly folded towards the ends and secured with a furniture stapler. Before laying the foam rubber, it is necessary to lay a thick fabric on the spring block and secure it at the edges.

If additional volume is needed, then you need to put a second layer of the required thickness and secure it.

• Cover the foam rubber with cut canvas and, carefully stretching it, secure it to the base. Canvas helps improve the comfort of furniture and ensures a more even fit of the filling to the base of the sofa.
• The seat is almost ready, you can work on the back and sides. You need to work with the back in the same way as with the seat. If it does not serve as a sleeping place when unfolded (for example, a sofa-book), then a lower density material can be used on it, as for the sidewalls. You can generally save money on the sidewalls by adding volume to them using batting and padding polyester.
• The base of the sofa is ready, now using a furniture stapler you can attach the decorative trim, assemble the product and enjoy comfort.

Correctly selected foam rubber for a sofa can not only give a “second life” to furniture, but significantly improve its quality. Add softness to it, allow it to acquire the orthopedic properties necessary for a comfortable night's sleep and daytime rest.

How to choose and replace foam rubber for a sofa?

It's time to replace the filling for the sofa, and you don't know which one to choose? We recommend sticking with foam rubber. This is a fairly popular and popular material nowadays.

But then the question arises: how to replace the foam rubber of a sofa with your own hands? What are the selection methods and which one to choose foam rubber for furniture? We will try to answer all these and many other questions in this article.

Which foam rubber is best for furniture?

Foam rubber has many positive features, such as: it can be used and there is no fear that it will lose its shape or cause allergies in family members. It is not affected by temperature - this will allow you not to think about how dense the foam should be.

Replacing a Eurobook mattress in a sofa is quite a difficult step, so if you don’t have experience in replacing it, you need to contact a specialist. Replacing foam rubber on an accordion sofa should be carried out by professionals, because such a sofa has a very complex mechanism, and its replacement requires special fastening.

But still, with frequent use, marks may remain on it, and it can also sometimes lose its shape, become concave - if it is used incorrectly. This filler is characterized by the elements of rigidity, elasticity and density. Determine the level of rigidity of the material; it must be compressed tightly.

In order for furniture, and in particular foam rubber, to last as long as possible, you should choose only high-quality and reliable materials. It is extremely difficult to restore foam rubber in a sofa, so many people prefer not to waste time, but simply buy a new one.

It is worth noting that the density of the material used for the armrests and backrest may be lower than that for what will fill the seat. Therefore, when choosing and replacing foam rubber for a sofa, you need to be guided by how it will be used.

Expert opinion

Smirnova Ekaterina Anatolevna

7 years of experience in interior design, professional architect

The cost of filler, like any other product, depends on its quality. Foam rubber for a sofa can be bought in construction stores, and you can find pieces of it from furniture manufacturers either in their warehouses or in online stores.

Which foam rubber is better to use for a sofa and what density of foam rubber is needed for a sofa

For different types of furniture, you can choose different foam options:

Sofa-sofa

For people who are counting on a small budget, the EL2240 brand is perfect. If you need a hard and durable filler, then it is better to choose EL2842.

Sofa book

The filling of this type of sofa can be either foam rubber itself or consist of a spring block in combination with foam rubber. Since their design resembles a sofa, the same brands of fillers can be used here.

Sofas for guests

Guest sofas can be equipped with different mechanisms for transforming into a sleeping place. Foam rubber is suitable for them as for corner sofas or furniture with “dolphin” or “sedaflex” mechanisms. Which brand to choose depends on your financial capabilities.

Kitchen Area

To repair a kitchen corner in a kitchen made of chipboard or with a wooden frame, it is recommended to use a filler 2-3 centimeters thick of the EL2842 brand, and for a soft corner you can use a material 4-6 centimeters thick of the EL2842 or ST3542 brand.

Features of upholstery of upholstered furniture

During use, furniture becomes unsuitable for further use, and it is not always possible to purchase new furniture. Basically, the upholstery wears out, fades, breaks - it all depends on how high-quality the material is. Sofas trimmed with leatherette may become unusable within a few months. What to do in such a situation?

The appearance of the sofa has changed dramatically after restoration

Today, a service such as restoration of upholstered furniture at the owner’s home is available everywhere, so you can make a new one from an old sofa. After all, you will not only change the upholstery, but also repair many parts.

Soft sofa before and after replacing the upholstery and filling in the seat cushions

If you have a pet that has ruined the upholstery material, this problem can be solved using the above method. Of course, the work of a specialist is not a cheap pleasure. You can replace the upholstery yourself. As a rule, each part is worked on separately. If you are not satisfied with these options, you can purchase a special furniture cover in stores - this will preserve the original coating and increase its service life.

A beautiful cover for a corner sofa will help you fit existing furniture into any interior.

Of course, any things must be treated carefully, so if various stains appear, we try to remove them immediately. But this is not always the case, especially when there are small children in the house. Leather-covered furniture is much easier to care for than textiles - this material has moisture-repellent properties. Therefore, at the time of cleaning, it is enough to wipe with a cloth.

We remove stains from upholstered furniture using accessible methods

From this article you learned a lot of new things about foam rubber; if you decide to change the filling in your sofa, it will not be difficult for you to choose the appropriate option.

Foam rubber is a modern furniture filler

Properties of high-quality foam rubber for a sofa, its types and brands

The modern furniture industry uses many types of raw materials of both natural and artificial origin as fillers for sofas. But most often polyurethane foam is used, which is better known to a wide range of consumers as foam rubber.

This material has been popular since time immemorial; over the years of its existence it has undergone significant changes and has been improved as much as possible. Sometimes manufacturers combine foam rubber for a sofa with other analogues - padding polyester, latex, felt, but more often they use combinations of one filler of varying degrees of density.

What are the advantages and disadvantages of polyurethane foam, how do they affect the functional features of furniture, should be understood by every user who is in search of the ideal sofa.

Features of quality material

To ensure that upholstered furniture does not lose its original properties over time, when purchasing, you should pay attention to the characteristics of the filler. In the first place is the density of foam rubber for stuffing a sofa; it should have an indicator of 22 kg/m3.

In this case, the service life of the sofa will be long, the furniture will be able to withstand increased loads. The second important indicator of quality is the thickness of the foam rubber for padding the sofa; it should be at least 4 cm.

Manufacturers who neglect standards, the quality of furniture is low, so its service life is significantly reduced.

Expensive upholstered furniture is made from highly elastic foam filling. This type of polyurethane foam has a multi-stage “layer cake” structure.

In the classic version, it consists of a thin top sheet of low density and a lower layer, which is more elastic. The upper flooring has a high level of comfort, and the lower one provides reliable support.

Despite the fact that such material is expensive, it is in demand in furniture production, as it guarantees high quality products.

To obtain increased comfort, the material is combined with soft and extra-soft HS sheets.

What type of foam is used in the production of Barsky chairs?

Raising the quality level of the domestic armchair manufacturing industry is a responsible mission that requires not only new equipment, but also truly sincere love for one’s business. When choosing individual components for your branded products, it is important to consider that each user should be satisfied with the quality offered to him.

A comfortable chair is not only a soft back and seat, but also an anatomically correct design that provides support to all the muscles of the human body.

To understand what kind of furniture foam rubber is used in Barsky's production, and why it is the best of its kind, you need to decide on the design features of the soft filler.

Sandwich - design

The declared quality of foam rubber from different suppliers sometimes does not correspond to reality. Sometimes the density of 35 from two different manufacturers differs even by tactile definitions: for one it is a truly homogeneous soft structure, and for the other, in fact, the hardness is no more than 20. Thus, during the course of cooperation, our company has identified the main tasks for itself, and quality is a priority among them .

ACAT is a reliable manufacturing partner that ensures an uninterrupted supply of high-quality foam rubber. There are currently no alternative quality materials on the Ukrainian market.

Any chair manufactured at Barski’s production facility is produced using the following technology:

1. The first layer is reinforced beech plywood, which is visually slightly curved to provide the anatomical shape of the seat.
2. The second layer is recycled foam rubber 40 (BB 60), depending on the model.
3. The third layer is ultra-comfortable primary foam rubber ST 25 35. In comparison, other manufacturers use 10 at best, while the price of the chairs is lower, but you shouldn’t expect a long service life.

The “secondary” acts as a strong, non-squeezable base, and the “primary”, which has memory, guarantees comfort and softness when landing. If you consider the sandwich design, you can understand how it works: when you press on the top layer, the bottom one does not sag, providing support.

If you use low-density recycled foam rubber for the base, it will deform and crumble over time, and the product will not hold its shape. If you use low-quality primary foam to cover the secondary one, it will shake off and also crumble, and sitting on the seat will be hard and uncomfortable. Therefore, compliance with technology comes first.

Varieties

Sheet and roll foam rubber differ in softness and hardness. Products are:

1. Soft - this type of filler can be used in furniture only in combination with a dense foam base. This is the most plastic polyurethane foam (PPU), giving increased comfort to finished products. But it should be remembered that when using the material independently, the load created cannot exceed 60 kg.
2. Hard - hard, capable of withstanding heavy loads up to 100 kg.
3. Increased hardness - highly rigid polyurethane foam can withstand a weight of over 100 kg.
4. Elastic with increased comfort - foam rubber is best suited for upholstered furniture intended for sleeping. You can rest most comfortably on such a surface.
5. Elastic with an orthopedic effect - the products are characterized by healing properties, as they reduce the load on all parts of the body.

Foam rubber with an orthopedic effect is “adapted” to each person individually, the main thing is to select the material for the consumer’s weight category.

Exclusive offers on selected models

As mentioned earlier, the ST brand of foam rubber is considered to be the “gold standard” in the production of any upholstered furniture. However, there are also denser, more advanced polyurethane foam materials, which almost no one uses in their production today. The manufacturer Barski offers a choice of either standard high-quality models made of durable foam rubber, or improved options of ideal quality:

• HS – blue-colored high-strength foam rubber. For example, it is used to tighten Soft chairs in the so-called “working zones” - on the central part of the seat, back, where friction and pressure are most intense. It is interesting that such polyurethane foam does not shrink even when pulled onto the headrest frame, but remains just as soft and dense;
• EL 32 40 – increased strength polyurethane foam, which also helps to increase service life and is used in the production of the Chief series of chairs.

It is noteworthy that HS grade polyurethane foam is used in automotive production and has proven itself to be the most wear-resistant soft filler.

Many of the buyers, when choosing a comfortable chair for themselves, prefer to sit on it, try it out, as they say, during work, and this is correct. But we should also not forget that in many ways, the shelf life of such a product is a combination of several factors, the quality of foam rubber among which is also the most important. Trusting a trusted Ukrainian manufacturer means not only guaranteeing comfort at work and at home, but also ensuring trouble-free use of furniture for 5-10 years.

Brands of furniture foam rubber

Modern production uses the following grades of polyurethane foam:

1. ST is a standard raw material containing a polymer such as polyol (polyesters). The rigidity of products is achieved by selecting the ratio of the components of the main composition. The result is sheets that differ in characteristics. Basically, at least 2 types of polyol are used.
2. EL - increased rigidity.
3. HL - hard, consist of different types of polyol.
4. HS - soft and super soft. Special polyester is used in production instead of ST or in addition to it.
5. HR - high elasticity. The composition contains only polyols in 2 or 3 combinations.
6. Special - non-flammable, viscoelastic.

The first brand's recipe includes special melamine powder, PHD polyols from Bayer, and flame retardants as additives. Melamine provides fire resistance, but at the same time it negatively affects the properties of furniture foam rubber. Viscoelastic grades contain polyesters and isocyanates.

The most common brands of furniture filler are:

• HS2520 - monolithic amplifier is used on the back of a sofa with a load of 80 kg;
• HS3030 - maximum weight 100 kg;
• HS3530 is the best foam rubber for upholstered furniture; backrests with a load of 100 kg and seats with a load of 80 kg are made from it.

Foam rubber is marked according to 3 indicators: type, density and hardness . For example, brand EL2540 is a rigid sheet with a density of 25 kg/m3 and a hardness of up to 3.2 kPa.

What types of foam rubber for chairs are there: classification

When buying a chair or sofa in a store, the overwhelming majority of buyers count on the integrity and honesty of the manufacturer.
After all, if external signs of quality can be determined, then it is impossible to calculate whether polyurethane foam of the same density is used for soft filler without cutting the upholstery. However, the service life of upholstered furniture and its attractive appearance depend on this material. In the last article we discussed the advantages of molded foam rubber, but, as mentioned earlier, such material is used in the manufacture of top-class products for the reason that its price is an order of magnitude higher than regular polyurethane foam.

For the manufacture of furniture, polyurethane foam is used:

• block;
• molded;
• sheet;
• roll

In turn, foam rubber is distinguished by type:

• primary;
• secondary.

By marking:

• ST;
• EL;
• H.L.;
• HS;
• HR;
• HR+.

Marking implies the designation of density, hardness and thickness. For example, the marking “PPU ST 35 42, 40” means: standard foam rubber, density 35 kg/m3, hardness 4.2 kPa and thickness 40 mm.

There is a separate line of products for contour parts. Such elements are manufactured by the manufacturer according to the buyer’s order, and, as a rule, are used for sewing a headrest, armrest or leg console. But, most often, a frame (polyurethane or fiberboard) and stretched foam sheets are used as separate structural elements of the chairs.

Density

Perhaps the main parameter on which the service life of the product depends: the higher the density, the better the quality of the polyurethane foam. This is explained by the fact that due to the higher percentage of substance per unit volume, high-density foam rubber does not wear out so quickly and does not lose its shape and size so quickly. These products better withstand static and dynamic loads.

Simply put, density is the percentage of foam rubber per unit volume, a value indicating the number of kilograms of polyurethane foam per 1 kg/m3. The optimal density for soft chairs is 30 kg per cubic meter.

Density is often confused with hardness, but this is not true. These indicators, regardless of their similarity, are different definitions. For example, soft foam rubber can be high-density, but less rigid, and vice versa. But, in fairness, it is worth saying that the density determines the lower and upper rigidity of polyurethane foam. They, in turn, are achieved for a given density value within one foam class.

Rigidity

It is characterized by the value of “compressive stress”. Why is this necessary? Stiffness clearly shows how much pressure is needed to compress the existing volume of foam rubber, for example, by half. The most rigid polyurethane foam is used as the base of the seat, and guarantees the rigidity of the base. While comfort is provided by the top layer - soft primary foam rubber. The calculation of the maximum permissible load depends on the degree of rigidity - the weight of the consumer, at which the lower part of the soft upholstery will not be pressed too much.

Permanent deformation

A key criterion for the quality of polyurethane foam, showing how well the material can maintain its original dimensions and shape during operation. To determine this value, the test sample is compressed by 50% and left for 10-15 seconds in a room with a certain temperature and humidity. After the load is removed, measure the time it takes for the foam to return to its previous shape. The longer this indicator, the lower the quality of the material.

Polyurethane foam with a high rate of residual deformation is not used in the production of upholstered furniture and armchairs.