What Is Polyurethane?

Polyurethane is the abbreviation of polyurethane polymer, commonly referred to as PU. It is a widely used polymer material with a broad range of industrial applications.

Polyurethane materials offer good elasticity, softness, abrasion resistance, cushioning, and processability. By adjusting the raw material formulation and manufacturing process, polyurethane products can be produced with different densities, hardness levels, resilience properties, and cell structures. As a result, polyurethane is widely used in furniture, automotive interiors, packaging, construction, sporting goods, as well as footwear materials and insole manufacturing.

In the footwear industry, polyurethane materials, especially PU Foam (Polyurethane Foam), are commonly used for insole cushioning layers, shoe upper padding, tongue foam, collar padding, and other cushioning components in footwear.

What Is Polyurethane Foam?

Polyurethane foam, also known as PU Foam / Polyurethane Foam, is a porous foam material produced by foaming polyurethane materials.

Depending on the raw material formulation, density, hardness, cell structure, and manufacturing process, polyurethane foam can be produced with different properties, including:

• Conventional flexible PU foam

• High resilience foam

• Slow-rebound memory foam

• High-density foam

• Polyether-based PU foam

• Polyester-based PU foam

• Functional PU foam

Different types of PU foam offer different levels of softness, resilience, support, breathability, and cushioning performance, allowing the appropriate material to be selected according to specific product requirements.

What Is Foam?

Foam generally refers to a soft, porous material containing a large number of small cells or pores.

Common foam materials used in industrial applications include polyurethane foam, EVA foam, polyethylene foam, and other polymer foam materials.

Among them, polyurethane foam is lightweight, soft, easy to process, and highly customizable in terms of physical properties, making it widely used in the footwear industry.

By adjusting the density, hardness, cell structure, and resilience of the material, PU foam can meet different requirements for comfort, support, and cushioning in footwear and insole products.

High Resilience Polyurethane Foam

High Resilience Foam, commonly referred to as HR Foam, is a type of polyurethane foam with good elasticity and recovery performance.

HR foam typically features a relatively open-cell structure. When compressed, it provides effective cushioning and support, and after the pressure is released, the material can quickly return to its original shape.

By adjusting the polyurethane formulation and processing conditions, HR foam can be customized in terms of:

• Density

• Hardness

• Thickness

• Color

• Resilience

• Support

• Cell structure

This allows the material to meet the performance requirements of different applications.

Features of High Resilience Polyurethane Foam

1. Good Resilience

High resilience PU foam can quickly recover its original shape after compression, making it suitable for products that are repeatedly subjected to pressure.

2. Good Cushioning Performance

The material can help absorb and distribute impact forces, making it suitable for insoles, sports footwear, casual shoes, and other footwear products requiring cushioning.

3. Good Support

While maintaining a soft and comfortable feel, HR foam can also provide a certain level of support, helping insoles achieve a balance between comfort and stability.

4. Soft and Comfortable

High resilience PU foam provides a soft feel and can be used as a cushioning or comfort layer in insoles to improve overall wearing comfort.

5. Easy to Process

PU foam can be processed through slicing, cutting, die cutting, lamination, bonding, punching, and heat pressing. It can also be combined with mesh fabric, EVA, latex, textiles, and other footwear materials.

6. Customizable Properties

Depending on the requirements of different insole and footwear products, the density, hardness, thickness, color, and resilience of the material can be customized.

Applications of Polyurethane Foam in Footwear Materials

Polyurethane foam is one of the commonly used cushioning materials in footwear manufacturing and can be applied to:

• Insole cushioning layers

• Sports insoles

• Casual insoles

• Work shoe insoles

• Shoe tongue padding

• Shoe collar padding

• Shoe upper lining

• Heel cushioning components

• Laminated footwear materials

• Other cushioning and shock-absorbing components

In insole manufacturing in particular, PU foam can be laminated with EVA, mesh fabric, latex, memory foam, and other functional materials to achieve different levels of softness, cushioning, breathability, and support according to the insole structure.

For example:

High Resilience PU Foam + Mesh Fabric
This combination can be used to create insole materials with a soft feel and good breathability.

PU Foam + EVA
This combination integrates the soft cushioning properties of PU foam with the structural support and resilience of EVA.

PU Foam + Functional Fabric
This combination can be used to develop different types of comfort insoles and functional insoles.

Other Applications of High Resilience Polyurethane Foam

In addition to footwear materials and insoles, high resilience PU foam is also widely used in:

• Sofas

• Mattresses

• Automotive seats and interiors

• Protective packaging materials

• Sports protective products

• Furniture cushions

• Various industrial cushioning products

Since the properties of polyurethane foam can be adjusted through formulation and manufacturing processes, suitable density, hardness, and resilience levels can be selected according to the requirements of footwear, furniture, automotive, and other industrial applications.