Bluing is a common problem in rubber products like rubber hose and rubber sheet. The bluing will not affect the capacity of use, but it’s a serious problem for high appearance requirement products like toy and shoes. Worse more, it will cause rejection and return.
Then what cause bluing in rubber products? As an expert in rubber and plastic industry, we OrientFlex analyzes the reasons as follow.
The oil has been oxidized before feeding mixing rubber, then the vulcanized rubber turns blue. Besides, feed too much aromatic hydrocarbon softening oil cause the rubber products turn blue.
When produce carbon black, the macromolecule aromatic hydrocarbon has not burned enough, so it will turn blue after feeding rubber.
Feed much anti-aging agent will also cause rubber products turn blue. While additives like PEG, SA and 4010NA can make rubber products turn blue.
When feed additives that easy to bluing, if the mixing temperature is too high, it will cause the vulcanized rubber turn blue.
Uneven rubber mixing
Uneven of disperse cause some of the additives have high concentration, then cause erupt phenomenon.
Incomplete miscibility of paraffin oil in the carbon black
The more use of carbon black, the smaller the oil adsorption will be. The smaller the structuredness is, the easier the coloring will be.
Lack of vulcanize or less vulcanizing agent cause blooming and then cause coloring.
Know the reasons cause bluing, let’s learn the solution
1. Test the carbon black match or change carbon black brand. The test method is boil the carbon black and look if there is oil when it cooling and sediment.
2. Reduce the use of oil. Besides, naphthenic oil is more better than paraffin oil in color control.
3. Change the distribution of feed material.
4. Improve the vulcanize technology and avoid the blooming
5. Improve the process technology and increase the dispersity
From this article we learn the reasons cause bluing and how to solve such problem. OrientFlex is a professional plastic and rubber products supplier. If you have any questions about the products or production technology, we will offer you the best solution. Contact us and get more information.