Furniture production requires high-quality, soft and resilient filling. The material should support the spring block of the sofa or bed, help with the design of comfortable seat seats and ensure the filling of the backs and armrests. Professional furniture makers have such an abbreviation as PPU. Many have heard such a name as polyurethane foam, and the simple word “foam rubber” is familiar to ordinary people. In fact, these are different names for one material. It is the density of the foam that affects the scope of its application and the quality of the resulting product.
Qualitative characteristics of polyurethane foam
The main mechanical properties of PPU include the following characteristics:
- foam density;
- rigidity;
- elasticity;
- breathability;
- tensile strength;
- cell size
- the possibility of lengthening;
- bearing ratio.
The cell size and the support coefficient are considered on highly elastic samples.
Not only the quality of the material depends on the characteristics given, but also how much the furniture will be durable and comfortable, as well as the breathability of the product.
Quality parameters of foam rubber. Density
Furniture foam rubber is evaluated primarily by its density. The lifetime depends on this parameter. The higher the density, the longer it can be used without compromising the quality characteristics.
This fact is explained by the fact that furniture foam rubber is subjected to heavy loads, and the brand with the highest density can withstand dynamic and static weighting better. To understand the mechanism of action, it is necessary to present the number of PPU per unit volume. It is clear that in a place where there is more of it, dents and scuffs will not appear so soon.
Do not confuse the density of foam rubber with an indicator of its rigidity. These concepts are interconnected, but not identical. There are PPU brands with low density and high rigidity.
Scope of application
Polyurethane foam is quite common and is used in various areas of production:
- furniture;
- construction (sound and heat insulation);
- sports (mats, punching bags);
- medical (orthopedic goods);
- sewing soft toys and clothes.
Foam rubber differs depending on the destination in quality and price category. Durability, density, rigidity and elasticity depend on the composition.
Advantages of polyurethane foam
The material is very popular in various fields of production because of its significant advantages. So, it has high wear resistance. In addition, it is completely hypoallergenic, which is why it is absolutely safe for the production of not only furniture, but also children's goods, orthopedic products.
Foam is moisture resistant, therefore not susceptible to the formation of harmful microorganisms in it. At the same time, it fully retains its qualitative characteristics with a rather extensive temperature range (from -40 to 100 degrees).
Due to its good acoustic insulation, foam rubber has been successfully used as an insulating material. And elasticity allows you to use it in creating products of any size and shape.
With its advantages, PPU withstands a fairly high period of active use. Depending on its density and purpose - from 5 to 15 years.
Stamps of foam rubber
In furniture production, various PPUs are used, which are divided into certain brands.
Brand ST. It is considered a standard material, from the characteristics of which other types are counted. It is mainly used for stuffing armrests or chair seats.
Brand of increased rigidity EL. This is a modified standard material with greater rigidity. This density of foam rubber for the sofa is most suitable because it can withstand static and dynamic loads. In addition, this brand is used in the manufacture of hard mattresses.
Highly elastic brand (HR) . The most comfortable material that combines elastic properties and a rather low initial stiffness. Due to this property, the material is used in the manufacture of quality furniture and for filling seats. So, the HR brand is the ideal density of foam rubber for chairs and orthopedic mattresses.
Choices
In the production of foam, the main emphasis is on thickness and density. From these indicators depends on what needs he can go.
So, high density foam rubber is used in the manufacture of sofa seats, because softness is good, but at the same time a person will simply fail. Dense material is also important in the manufacture of mattresses, because a solid and even surface for sleeping is preferable for many.
At the same time, the sofa does not consist of one seat. It is necessary to equip the armrests, frame, side walls, etc. They also need a soft arrangement, depending on the purpose, they select the brand of foam rubber.
For seats choose elastic and hard foam. At the same time, the thickness of the foam is not important, because comfort and convenience are not provided by a single layer. To achieve the best effect, use several sheets of material. Moreover, for the production of any type of furniture using various brands of foam.
Special purpose foam rubber
If foam rubber (density 40) is often used in the manufacture of furniture, then less dense is used in many other areas. So, for sanitary and hygienic needs (kitchen and bath sponges) a material is required that will not crumble, will foam well and withstand frequent contact with water. For this, special additives are used that improve the quality characteristics and at the same time do not cause allergies.
There are viscoelastic brands that have found their application in the production of medical goods. Widely used in the manufacture of linings used for burns. The material takes on the contours of the body and less injures the affected area.
Contour products, such as rollers, cylinders, drawers, are obtained from block foam polyurethane. It is completely uniform and quite elastic.
Highlights for Foam Care
To preserve the consumer properties of PPU and extend its service life, it is worth applying a few simple rules:
- remove dust with a vacuum cleaner without using mechanical means;
- do not use cleaners that contain alcohol that destroys the fibers of the material;
- Do not expose to too high temperatures, in particular, do not iron.
These simple rules will maintain the density of foam rubber in proper quality, respectively, the deformation of the product will not occur.
Foam for the mattress
In the manufacture of a bed, beds use furniture foam. What density is needed for the mattress depends on the expected stiffness of the product.
The standard brand PPU is used for the manufacture of children's mattresses. Its density is 25 kg / m 3 .
For elite beds and longer use latex foam, which is marked HR and VE.
The brand of increased rigidity EL withstands loads up to 100 kg. View EL2240 is a budget option that is suitable for infrequent use or for a service life of up to 5 years.
More durable and elastic is considered the brand EL2842, which will last more than 10 years, without compromising on quality.
Possible harm to foam mattresses
Recently, it has been widely believed that foam rubber is harmful to health, because the material emits harmful fumes. Despite the use of PPU for several decades, the debate about the appropriateness of its use has not subsided.
It is known that foam rubber is made from fully synthetic components. As a result, substances with a characteristic odor are released. But they quickly erode and do no harm to the body.
However, brands issued in violation of technology and the most budget, often continue to exude a smell throughout the entire service life. Vapors are compared with the substance released during combustion. But their concentration is so small that there is no need to talk about harm to humans.
Conclusion
Foam rubber is widely used in furniture production. On average, there are usually medium-density brands that are suitable for the manufacture of children's furniture or backboards. The density of the foam rubber for the sofa should be above 30 kg / m 3 , but these types are produced directly for industrial purposes.
PUFs are often used in the manufacture of mattresses. Now this material is the most common. This is facilitated by the positive characteristics that polyurethane foam has:
- affordable price;
- it does not fade on its own (burns only with the support of another source);
- vapor tightness;
- low thermal conductivity;
- moisture resistance;
- simplicity in leaving;
- convenience of transportation.
However, when choosing a foam mattress, it is necessary to take into account the presence of a block of springs. Nevertheless, despite the increased density, the material is quite soft. Therefore, in the manufacture of furniture, additional devices are used to ensure sufficient rigidity. This can be a coconut coir, independent springs and other inventions that improve the properties of foam rubber.
Despite disputes about the dangers and benefits of foam rubber, its properties are invaluable and allow you to produce things quite soft and at the same time resilient.