DIN EN ISO 22007 Thermal Conductivity Testing of Plastic Storage Plastics

The DIN EN ISO 22007 standard provides a comprehensive framework for testing the thermal conductivity of plastic materials used in storage and container applications. This method is particularly critical for ensuring that containers and packaging meet stringent safety, performance, and regulatory requirements. The standard applies to a wide range of thermoplastics and thermosetting plastics that are commonly utilized in storage environments.

The primary objective of this testing procedure is to determine the thermal conductivity (k) of plastic materials under specific conditions. Thermal conductivity is defined as the amount of heat transmitted per unit area through a material per unit time for every one degree temperature difference across its thickness. This parameter is crucial for ensuring that storage containers do not compromise product integrity or safety due to excessive heat transfer.

The DIN EN ISO 22007 method involves precise measurement techniques using calorimetric equipment, which can either be steady-state or transient in nature. Steady-state methods measure the thermal resistance of a specimen while it is at equilibrium with its surroundings, while transient methods involve changes over time to observe heat flow. The choice between these approaches depends on factors such as material properties and desired precision.

Preparation of specimens for testing is critical to ensure accurate results. Specimens should be cut from the edge or center of a larger sample, depending on the specific requirements outlined in the standard. It’s important that the samples are free from defects, cracks, or other anomalies that could affect their thermal properties. Samples must also undergo conditioning to eliminate any residual stresses and ensure uniformity.

The testing process itself involves placing the specimen into a controlled environment where temperature and humidity levels are carefully monitored and maintained within specified ranges. The sample is then exposed to heat from one side while the other side remains at a lower temperature, creating a thermal gradient across its thickness. By measuring the rate of heat transfer through the sample, the thermal conductivity can be calculated.

Once testing has been completed, detailed reports are generated that include all relevant data points such as specimen dimensions, environmental conditions during testing, and final thermal conductivity values. These reports serve not only as documentation but also provide valuable insights for quality control teams and R&D departments.

DIN EN ISO 22007 is widely accepted across Europe and beyond, ensuring consistent application and interpretation of results throughout different regions. Compliance with this standard helps manufacturers meet international standards set by regulatory bodies like the European Committee for Standardization (CEN).

Frequently Asked Questions

What is the difference between steady-state and transient methods in thermal conductivity testing?

Steady-state methods measure heat flow through a material once it has reached equilibrium, providing consistent results but potentially slower. Transient methods observe changes over time, offering faster results though with possible variations due to initial conditions.

Why is specimen preparation so important in thermal conductivity testing?

Properly prepared specimens ensure accurate representation of the material's properties. Imperfections or inconsistencies can lead to erroneous readings, thus compromising both the reliability and validity of test results.

Which regulatory bodies recognize DIN EN ISO 22007?

DIN EN ISO 22007 is recognized by numerous international organizations including CEN, and it is widely accepted across Europe. Its acceptance extends to other regions where compliance with European standards is required.

Can you explain the role of environmental control during thermal conductivity testing?

Environmental control ensures that external factors like temperature and humidity do not interfere with the accuracy of the test. This allows for precise measurement of the material's intrinsic thermal properties.

What kind of equipment is typically used in DIN EN ISO 22007 testing?

Calorimetric devices are commonly employed for both steady-state and transient tests. These instruments provide precise measurement capabilities necessary to accurately determine thermal conductivity.

How often should specimens be conditioned before testing?

Specimens should undergo conditioning as per the requirements specified in DIN EN ISO 22007. This ensures that any residual stresses are minimized, leading to more accurate and reliable test results.

What information is included in a thermal conductivity report?

Reports typically include specimen dimensions, environmental conditions during testing, and the calculated thermal conductivity values. They also provide additional insights useful for quality assurance and R&D purposes.

Are there any specific materials that this standard does not apply to?

DIN EN ISO 22007 is primarily focused on thermoplastic and thermosetting plastics used in storage applications. It may not cover other types of materials such as metals or composites, which have different testing protocols.

Materials included: Thermoplastics and thermosetting plastics for storage containers
Not applicable to: Metals, composites, or non-plastic materials used in similar applications