What are the applications of polyurethane foam in furniture?

1 Sofas and seats, back cushions

In the past, sofas, seats, and back cushions were mainly made of cotton, latex foam, and steel springs. Since flexible PU foam entered the market, it has quickly become widely used in the furniture industry due to its low cost, light weight, and excellent performance, comparable to latex foam. Block-type flexible PU foam is the ideal material for upholstered furniture. Polyether-based and polyester-based flexible PU foam, along with high-resilience foam of various densities, fully meet the specific requirements of durability and comfort. The material must match the final application. Foam used for seat cushions should have a density of no less than 35kg/m³, while backrests and armrests should use foam with a density above 28kg/m³. In the cushion manufacturing industry, flexible PU foam composites with traditional materials play a significant role.

In recent years, there has been an increasing trend of using flexible PU foam as the sole cushion material in seating. Various high-quality all-foam seat cushions are made from foam combinations of appropriate grades. These all-foam cushions use composite materials or polyester-based PU foam with higher compression hardness as support and edge reinforcement, while the surface layer uses standard polyether-based flexible PU foam or high resilience foam with excellent recovery and comfort.

2 Mattresses and pillows

Most bed products can be made using polyurethane foam. Flexible PU foam is widely used in mattresses, pillows, lumbar cushions, and headboards. Ultra-soft PU foam is used in mattress toppers, quilts, and bedcovers, while rigid PU foam can be carved into decorative bed frames.

2.1 Mattresses

Traditional mattress materials included cotton, latex, springs, and jute. Since flexible PU foam was commercialized in the 1950s, it quickly became the preferred cushioning material. Its advantages over latex and springs include lighter weight, excellent breathability, good heat and moisture transfer, and biocompatibility—making it particularly suitable for mattresses. Mattress manufacturing is simple: just wrap a rectangular foam block 10–15cm thick. To enhance comfort, foam layers or wool fiber materials may be added. Foam density and hardness must match the intended use: children’s mattresses use softer foam, while adult mattresses use firmer foam—but neither should be too low in density. If the foam is too light, it softens quickly in use, leading to sagging and reduced breathability. A minimum density of 32kg/m³ is required to ensure durability.

Moreover, flexible PU foam features high load strength, good flexibility, resistance to dust, mold, and insects, no odor, light weight (1/4 the weight of a spring mattress), and lower cost—only 40% the price of latex and 63% of spring mattresses for the same size. These mattresses are not only favored in households but are especially suitable for hospital use due to their strength, durability, resilience, softness, comfort, and ability to be disinfected. Flame-retardant, low-smoke high-resilience flexible PU foam mattresses are also gaining popularity for their safety and comfort.

Some flexible PU foam medical support pads have obtained patents.

Recently, composite processes combining foams with different properties have been used in mattress production. For example, high-density, firm foam blocks can be layered with soft, high-resilience PU foam on both sides. Such composites exhibit ideal stress-strain behavior with excellent comfort and durability. Some mattresses are designed with two usable sides, each using foam of different hardness. Perforated foam mattresses also improve stress-strain characteristics by adding air chambers, enhancing breathability and thermal transfer. Flexible PU foam is also used in innerspring mattresses, where pre-formed steel springs are wrapped in PU foam. These resemble composite foam mattresses and typically show linear compression behavior.

Additionally, there are foldable mattresses that double as sofas—serving as sofas during the day and mattresses at night. These flexible PU foam pads are especially popular among families with limited space.

2.2 Pillows

Pillow cores traditionally used kapok and cattail down. Molded flexible PU foam pillows are lightweight, elastic, affordable, and can be customized to suit individual preferences—even offering dual-hardness options for couples.

Innovative types of flexible PU foam pillows have emerged, including travel pillows, cervical care pillows, music sleep pillows, slow rebound pillows, and aromatherapy pillows made by adding medicinal fragrances to the foam formula. The cervical care pillow is ergonomically designed according to the neck’s natural curve, aligning with the head and neck to massage and regulate nerves—helping to prevent and treat cervical spine problems, and has been patented. A foreign-made music sleep pillow uses breathable flexible PU foam and includes a built-in stereo system that plays relaxing nature sounds, helping users fall asleep peacefully.

3 Quilts and comforters

Comforters are expected to be lightweight, warm, and tear-resistant. Ultra-soft flexible PU foam meets all these requirements and is an excellent material for comforters—warm, light, and extremely comfortable.

4 Imitation wood furniture

Polyurethane structural foam is a type of sculptable synthetic material developed in the mid-1970s. Due to its high rigidity, mechanical strength, simple molding process, high production efficiency, and attractive product appearance, it has gained wide popularity and has rapidly developed in recent years both domestically and internationally. It is especially prevalent in the furniture industry, interior decoration, and the electrical and computer sectors. Structural foam materials can be divided into three categories by density: decorative synthetic materials with a product density ≤400 kg/m³; structural synthetic wood materials with a density of 400–600 kg/m³; and reinforced structural materials with a density ≥600 kg/m³.

In summary, structural foam can be used in the following areas:

①As a high-end material for carved decorative items, such as frames for oil paintings and photographs, interior decorative moldings for hotels and auditoriums, artistic reliefs, and Roman columns.

②As components for furniture or building materials, such as tables, chairs, window frames, vanities, wash stands, coat racks, vents, door frames, food storage containers, and bathroom fixtures.

In addition, structural foam can be used to produce office supplies, electrical housings, and recreational equipment.

Due to its versatility, it can replace high-grade wood, and is therefore often referred to as polyurethane synthetic wood. From a physical and mechanical performance perspective, polyurethane structural foam is considered the best-performing type among all synthetic wood materials made from polymers, and its properties can be adjusted by changing its density.

To summarize, structural foam materials offer four main advantages:

①Excellent repeat molding performance. Not only can it be molded into precise product shapes, but it can also replicate realistic wood grain and other patterns with a pleasant texture.

②The look and feel are close to wood. It can be planed, sawed, drilled, and sculpted.

③Molds can be made from silicone rubber, epoxy resin, aluminum, steel, or plastic, offering a wide range of cost options.

④Simple molding process, high efficiency, and high yield rate.