Flexibility: comprehensive film performance

Flexibility is the comprehensive performance of a film when subjected to external forces, including factors such as resilience, plasticity, adhesion, etc. This performance indicator reflects the adaptability and durability of the film in actual use. In this article, we will explore the concept of flexibility, testing methods, and its application in the Coating industry.

Definition of flexibility

Flexibility is the performance of the film when subjected to external forces, which can usually be divided into the following aspects:

Resilience

Whether the film can return to its original state under the action of external force, that is, whether it has resilience. This includes the tensile and compressive performance of the film.

Plasticity

Whether the film will be permanently deformed under the action of external force, that is, whether it has plasticity. The flexibility test also includes the plasticity performance of the film.

Adhesion

Whether the film can be firmly attached to the substrate, i.e. adhesion. The flexibility test also examines the interface between the film and the substrate.

Impact resistance

Flexibility An indicator used in testing to assess the ability of a film to withstand rapid deformation. Impact resistance is usually related to the flexibility of the film.

Postformability

Whether the film can maintain its flexibility and performance in subsequent processing, such as applications in the coil coating industry and the can industry.

Flexibility test method

Flexibility is usually measured by bending a film template. These test methods involve bending the film with the substrate and seeing if the paint film will break or stretch. Here are some commonly used flexibility test instruments and methods:

Shaft rod tester

Using steel shafts of different diameters, bend the painted sample on the shafts to see if the film is damaged after bending. The minimum shaft diameter indicates the flexibility of the film.

Cylindrical mandrel Bending tester

Use cylindrical mandrel to bend the film. This method is suitable for thinner panels, and flexibility is evaluated by observing whether the paint film is cracked or disbonded.

Cone deflection tester

A cone is used to flex the film template to observe the minimum diameter that causes the film to break. This instrument is suitable for the whole plate test and eliminates the influence of the human body on the temperature increase of the test plate.

Cupping test machine

Observe whether cracking or peeling of the paint film is caused by pushing the spherical punch against the back of the painted panel. The minimum press-in depth indicates the flexibility of the film.

T-bend test

For coil coatings, the sample is folded in half to observe whether it is cracked, and then continuously tested, usually marked as 0T, 1T, 2T, etc., indicating the flexibility of the film.

The choice of these test methods depends on the type of film, application and test criteria. Each method has its scope and advantages.

Application of flexibility

Flexibility testing has a wide range of applications in the Coatings industry:

Quality control: Manufacturers can use flexibility testing to ensure their film products have the required durability and adaptability in actual use.

Coating selection: Manufacturers can choose the type and formulation of Coating suitable for different applications based on the results of the flexibility test.

Post-formability evaluation: The flexibility test can also be used to evaluate the performance of the film during subsequent processing, such as in the coil coating and molding industries.

Development and Improvement: By understanding flexibility, manufacturers can better develop and improve Coating formulations to meet different performance requirements.

In conclusion, flexibility is one of the important performances of film, which directly affects the mass and usability of Coating products. Through flexibility testing, manufacturers can ensure that their products perform well in a variety of applications and meet customer needs. The choice of flexibility testing method should be based on specific circumstances and standard requirements to ensure the accuracy and comparability of test results.