High rebound sponge in our lives everywhere, and silicone oil is an indispensable component of the sponge, it is used to adjust the structure of the bubble pore, to play the role of emulsification, nucleation, reduce surface tension, the dosage is small but vital, how to professionally evaluate it, technical workers have their own methods, how to select a good product, I’ll share some of our experience in evaluating silicone oil.
First, the stability of silicone oil test
1.1 Storage stability test of silicone oil
Storage stability of silicone oil at low temperature
Inject the silicone oil into a 1L glass bottle and put it in the refrigerator for 24 hours to observe whether there is any delamination of the silicone oil. If it is not obvious, take out the silicone oil and the silicone oil at room temperature to do a comparison experiment to see whether the closed pore and vesicle structure of the silicone oil is normal.
1.2 Storage stability of silicone oil in the combination material
The new silicone oil and the original self-used silicone oil were formulated into a combination of polyether with the same formula, and under the same process conditions, foamed to compare the swelling and bubble hole situation, and then the combined polyether was injected into a 1-liter glass bottle, placed in a 60-degree water bath, and then cooled after 6 hours, under the same process conditions, foamed again to compare the swelling and bubble hole situation of the products before and after aging, if there is any abnormality, it means that the If there is any abnormality, it means that the silicone oil is risky to do the combination material.
Second, the activity of silicone oil evaluation
Process conditions: mold temperature 60 degrees, material temperature 25 degrees, same demold time. According to the approximate silicone oil activity given by the manufacturer, the silicone oil characteristics are determined by the closed porosity.
1、Without equipment, the activity of silicone oil can be determined by the amount of porosity opener.
2、It is also possible to determine the activity of silicone oil by the assistance of indentation hardness meter.
3、During the activity evaluation: all factors affecting the degree of closed pore should be considered thoroughly to avoid interference.
Three, the tolerance test of silicone oil
1、Different systems, after reducing the amount of silicone oil, test the molding changes.
2、Mold temperature adaptability test.
3、Flowability test.
4、Under the same closed porosity, compare the product vesicle structure and select the silicone oil with more delicate vesicles to improve the processing tolerance during the actual molding production.
IV. VOC contribution test of silicone oil
1、Testing method: VDA 278
2、To compare with other silicone oil, use the same formula except silicone oil and the same process to make samples, and use VDA 278 to compare the test data.
V. Summary
Combination material manufacturers are more cautious in switching silicone oil, but 3W silicone oil is known and recognized by more and more famous combination material manufacturers with its excellent quality, which I think is inseparable from our strict testing methods.
Translated with www.DeepL.com/Translator (free version)
