The difference between PUR and PIR

- Nov 20, 2020-

On the surface, the degree of delicacy of the bubbles is different.

Essentially, the chemical composition is different.

In terms of use, the fire level is different. PIR can reach B1 level, while PUR cannot reach such a high fire level.

The details difference as below

PUR and PIR refer to the chemical composition of rigid polyurethane foam. Both PUR and PIR can be used as the core material and various rigid or flexible materials as the surface material to be compounded by various processing methods.


PUR composite board refers to the polyurethane rigid foam as the core material. Generally, the formulation system of polyether polyol, lower isocyanate index and flame retardant is adopted. The foam skeleton structure is composed of urethane segments. It can only be used below 100 degrees Celsius.


PIR composite board refers to the polyurethane rigid foam as the core material, which generally uses polyester polyol, high isocyanate index (over 250), and uses no or less flame retardant formula system. The foam skeleton structure is made of urethane The product is composed of the chain segment and the urethane modified isocyanurate segment together, and the product can be used below 150 degrees Celsius.


   The so-called PIR polyurethane cold storage board means that the combustion grade of polyurethane sandwich board reaches B1 level. When it comes to fire rating, we have to mention the old standard GB8624-1997. This is the earliest standard for building fire protection materials. This is described in the standard: Class A: non-combustible materials (such as rock wool, stone, etc.) Class B1: non-combustible materials (such as polyurethane, polystyrene) Class B2: combustible materials (polyurethane, polystyrene) Class B3: flammable materials (Extruded polystyrene, polyurethane, etc.)


   Polyurethane is found in B1, B2, and B3 grade materials. Back to the topic, polyurethane cold storage board, as a very good insulation material, has been widely used in the construction of cold storage in our production and life. Polyurethane materials are organic materials, and only inorganic materials can achieve Class A non-combustibility. Therefore, the highest combustion level of polyurethane materials can reach B1 level. What we usually call PIR polyurethane cold storage board does not add a large amount of flame retardant to the polyurethane raw materials, but uses a special formula system, which is different from the traditional PUR system.