The new standard GB/T 26689-2024 freezer foam will be implemented from March 1
2025-02-26
GB/T 26689-2024 "Rigid polyurethane foam for refrigerators and freezers" has been released on August 23, 2024, and will be officially implemented on March 1, 2025, it will replace GB/T 26689-2011.
Old standards are difficult to adapt to development
Before diving into the new standard, let's talk about its predecessor, GB/T 26689-2011. In the past ten years, this standard has indeed provided an important basis for the production and quality control of rigid polyurethane foam for refrigerators and freezers, and has also guaranteed the basic order of the industry. However, with the passage of time, the rapid development of science and technology, new materials, new processes, and new foaming technologies continue to emerge, and the old standard is gradually unable to cope.
In recent years, the production technology of rigid polyurethane foam for refrigerators and freezers is changing with each passing day. Take foaming technology as an example, from the initial simple system, it has developed to cyclopentane + polyether binary foaming system, cyclopentane +LBA/HFC-245fa+ polyether ternary blending foaming system, and even more complex LBA (HFC-245fa) + cyclopentane + low boiling foaming agent + polyether quaternary blending foaming system. And the new cyclopentane + 2210B + polyether ternary blend foaming system. These new foaming technologies have led to significant improvements in product performance, such as better insulation and lower energy consumption.
At the same time, the product structure of refrigerators and freezers has also undergone earth-shaking changes. A variety of new structure refrigerators such as cross split, multi-door, door in the door have been introduced, and thin-wall and ultra-thin-wall refrigerators have gradually become the new favorite of the market. These new structures put forward higher requirements for the properties of rigid polyurethane foams, such as higher compressive strength and better dimensional stability.
In this environment, GB/T 26689-2011 detection methods and product performance indicators have been unable to accurately evaluate and standardize these new products. This not only brings confusion to the production enterprises, do not know how to produce products that meet the market demand according to the old standards; Also let the design unit in the selection of materials and design, lack of accurate standard reference; It is more difficult for consumers to judge the quality of products when choosing products. Therefore, in order to adapt to the development of the industry, the introduction of new standards is imminent.
Interpreting GB/T 26689-2024
Revision point
This revision, a lot of changes. For example, taking into account the increasing use of low-boiling blowing agents in the industry, the new standard adds the term and definition of low-boiling components, referring to the composition of blowing agents with a boiling point below 0 ° C at standard atmospheric pressure (other than CO₂). Products are divided into 3 types according to the type of physical blowing agent used, including class I using cyclopentane as a single blowing agent; The use of mixed blowing agents containing low boiling point components (low boiling point component content > 1%, measured by combined polyols) class II; And the use of other blowing agents class III.
In terms of physical and mechanical properties, the performance index of Class III blowing agent was also increased correspondingly. At the same time, the technical requirements of thermal conductivity, compressive strength, apparent core density and so on have also changed. Take the thermal conductivity test method, the initial thermal conductivity test should be tested within 72h of product production, sampling after 12h of foam product aging, and then using aluminum foil sealed packaging, before sample preparation in the temperature (23±2)℃, relative humidity (50±5)% of the environment after not less than 2h, Test according to GB/T 10295-2008, the average temperature is 10℃, the temperature difference between the hot and cold plates is 15℃ -20 ℃, and the long-term thermal conductivity is tested by the supply and demand parties. "Compressive strength or deformation 10% compressive stress" is changed to "compressive strength or deformation 10% compressive stress, the minimum value in three directions", which requires more detail.
Scope and definition of application
GB/T 26689-2024 is suitable for the rigid polyurethane foam for refrigerators and freezers produced by foaming combined polyols and polyisocyanates as the main raw materials. The terms and definitions here are also very clear, like the low-boiling point components just mentioned, which provide clear standards for relevant companies in the selection and use of blowing agents.
Technical requirements and test methods
The new standard has many requirements for rigid polyurethane foam for refrigerators and freezers, from appearance to physical and mechanical properties to high and low temperature cycle performance and so on. In appearance, in addition to the defects caused by tearing off the skin, the product should be uniform in color, bubble hole, no cracks and other obvious defects. In terms of physical and mechanical properties, there are detailed index requirements for thermal conductivity, compressive strength, dimensional stability, apparent core density, closed-cell rate, water absorption, etc. High and low temperature cycle performance requires that the product should have no deformation, peeling, cracking.
In order to ensure that these requirements can be accurately detected, the corresponding test methods are also given in the standard. For example, in addition to the thermal conductivity test, the sample preparation is carried out according to the 23/50 secondary environmental conditions in GB/T2918, and the sample should be adjusted for no less than 24h in the temperature (23±2)℃ and relative humidity (50±5)%. The appearance is visually visible under natural light; Thermal conductivity, compressive strength and other properties have their own corresponding national standard test methods, especially rigorous and scientific.
Old standards are difficult to adapt to development
Before diving into the new standard, let's talk about its predecessor, GB/T 26689-2011. In the past ten years, this standard has indeed provided an important basis for the production and quality control of rigid polyurethane foam for refrigerators and freezers, and has also guaranteed the basic order of the industry. However, with the passage of time, the rapid development of science and technology, new materials, new processes, and new foaming technologies continue to emerge, and the old standard is gradually unable to cope.
In recent years, the production technology of rigid polyurethane foam for refrigerators and freezers is changing with each passing day. Take foaming technology as an example, from the initial simple system, it has developed to cyclopentane + polyether binary foaming system, cyclopentane +LBA/HFC-245fa+ polyether ternary blending foaming system, and even more complex LBA (HFC-245fa) + cyclopentane + low boiling foaming agent + polyether quaternary blending foaming system. And the new cyclopentane + 2210B + polyether ternary blend foaming system. These new foaming technologies have led to significant improvements in product performance, such as better insulation and lower energy consumption.
At the same time, the product structure of refrigerators and freezers has also undergone earth-shaking changes. A variety of new structure refrigerators such as cross split, multi-door, door in the door have been introduced, and thin-wall and ultra-thin-wall refrigerators have gradually become the new favorite of the market. These new structures put forward higher requirements for the properties of rigid polyurethane foams, such as higher compressive strength and better dimensional stability.
In this environment, GB/T 26689-2011 detection methods and product performance indicators have been unable to accurately evaluate and standardize these new products. This not only brings confusion to the production enterprises, do not know how to produce products that meet the market demand according to the old standards; Also let the design unit in the selection of materials and design, lack of accurate standard reference; It is more difficult for consumers to judge the quality of products when choosing products. Therefore, in order to adapt to the development of the industry, the introduction of new standards is imminent.
Interpreting GB/T 26689-2024
Revision point
This revision, a lot of changes. For example, taking into account the increasing use of low-boiling blowing agents in the industry, the new standard adds the term and definition of low-boiling components, referring to the composition of blowing agents with a boiling point below 0 ° C at standard atmospheric pressure (other than CO₂). Products are divided into 3 types according to the type of physical blowing agent used, including class I using cyclopentane as a single blowing agent; The use of mixed blowing agents containing low boiling point components (low boiling point component content > 1%, measured by combined polyols) class II; And the use of other blowing agents class III.
In terms of physical and mechanical properties, the performance index of Class III blowing agent was also increased correspondingly. At the same time, the technical requirements of thermal conductivity, compressive strength, apparent core density and so on have also changed. Take the thermal conductivity test method, the initial thermal conductivity test should be tested within 72h of product production, sampling after 12h of foam product aging, and then using aluminum foil sealed packaging, before sample preparation in the temperature (23±2)℃, relative humidity (50±5)% of the environment after not less than 2h, Test according to GB/T 10295-2008, the average temperature is 10℃, the temperature difference between the hot and cold plates is 15℃ -20 ℃, and the long-term thermal conductivity is tested by the supply and demand parties. "Compressive strength or deformation 10% compressive stress" is changed to "compressive strength or deformation 10% compressive stress, the minimum value in three directions", which requires more detail.
Scope and definition of application
GB/T 26689-2024 is suitable for the rigid polyurethane foam for refrigerators and freezers produced by foaming combined polyols and polyisocyanates as the main raw materials. The terms and definitions here are also very clear, like the low-boiling point components just mentioned, which provide clear standards for relevant companies in the selection and use of blowing agents.
Technical requirements and test methods
The new standard has many requirements for rigid polyurethane foam for refrigerators and freezers, from appearance to physical and mechanical properties to high and low temperature cycle performance and so on. In appearance, in addition to the defects caused by tearing off the skin, the product should be uniform in color, bubble hole, no cracks and other obvious defects. In terms of physical and mechanical properties, there are detailed index requirements for thermal conductivity, compressive strength, dimensional stability, apparent core density, closed-cell rate, water absorption, etc. High and low temperature cycle performance requires that the product should have no deformation, peeling, cracking.
In order to ensure that these requirements can be accurately detected, the corresponding test methods are also given in the standard. For example, in addition to the thermal conductivity test, the sample preparation is carried out according to the 23/50 secondary environmental conditions in GB/T2918, and the sample should be adjusted for no less than 24h in the temperature (23±2)℃ and relative humidity (50±5)%. The appearance is visually visible under natural light; Thermal conductivity, compressive strength and other properties have their own corresponding national standard test methods, especially rigorous and scientific.
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