Plastic Melting and Flammability: Is there any relationship?
Author: Jasmin Hsu
At Würth Elektronik, we often receive questions from customers, such as, why during the customer reflow process, e.g. 245°C, a SMD component will be melting, even though the component supplier’s datasheet shows a flammability grade withstanding 245°C or above.
It is important to understand that these are two different approaches:
The flammability test is used to determine the material’s tendency to either extinguish or spread a flame once the specimen has been ignited. The test set up may usually be found using key words like, “Flammability testing.” These tests are applied from the plastic manufacturer to test lab, according to relevant international standards.
On the component manufacturer site, transforming plastic pellets into SMD components (e.g. frames) involves an injection molding process: pre-heating -> heating or melting of plastic -> injection into the mold -> make in the form of the required shape.
After the injection molding process, the raw plastic undergoes thermal and mechanical stress, which can weaken its original properties. However, this does not mean that an SMD component is melting during the customer reflow process.
There is ongoing discussion about the use of regrind/recycled plastics in manufacturing. Generally, the answer, is “yes,” and if you google, you will find some statement or article about your question. So, if regrind/recycled plastics are allowed, how can quality be ensured during the customer process?
As mentioned, each injection process will weaken the polymers again and again, and the way of controlling the quality of the polymers or the component is the job and duty of the component manufacturer. This involves properly defining the ratio of virgin plastic to regrind/recycled plastic and the maximum number of passes of reground plastics, following industry standards throughout the manufacturing process.
We as Würth Elektronik, a leading manufacturer from Europe, are committed to quality and strict product quality controls to ensure the highest standards.
View the swiches portfolio of Würth Elektronik at Farnell.
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