To make color masterbatches, it is generally necessary to add some antioxidant systems and lubricants, but not too much. Under the action of high shear, the absence of oxygen resistant system protection in the masterbatch will cause the color to turn yellow, and the masterbatch will also degrade. At the same time, the performance of the material will be reduced, and it will not be able to be granulated by stretching.
One of the main uses of antioxidants is to prevent color change and oxidative decomposition. However, due to the high price of antioxidants, considering factors such as cost, whether and how much antioxidants are added to the color masterbatch mainly depends on the processing needs of downstream customers and the products in which the color masterbatch is applied. If the product is used outdoors, in addition to adding UV stabilizers, antioxidants should also be added; If the customer has requirements for anti-aging, the anti oxygen system of color masterbatch should also be made into concentrated type.
In short, without special requirements and guaranteed performance, in order to increase the profit margin of the enterprise, antioxidants in the color masterbatch can be omitted in principle. However, antioxidants should still be added to the color masterbatch used for engineering plastics such as PA and ABS, and there are also many weather resistant color masterbatches used for engineering plastics. In addition, it is generally necessary to add some antioxidants to fiber grade color masterbatches.
When using modified ASA masterbatch for surface co extrusion, after polishing, there will be many small pits like small pits, which are very small and occasionally appear. The severity of processing with different equipment is inconsistent. What is the reason for this? Is there a solution?
The reasons for the problem are as follows:
Possible blending issues, such as uneven mixing and poor dispersion; Poor compatibility, etc.
Provide the following solutions to this problem:
Thoroughly dry the material;
Adjust the appropriate co extrusion temperature;
The extruded ASA layer should not be too thin;
The operation method of extrusion should be correct;
Avoid the influence of floating calcium.
How to test the density of color masterbatch? There are many methods in the industry, and the results obtained by different methods vary greatly. Is there a good and correct testing method that can quickly measure the density of color masterbatches?
The precise testing method for the density of color masterbatch is as follows:
The density bottle method is used for measurement, which has high requirements for operation and cannot have bubbles. The testing temperature also has a certain impact on the density;
Using a density gradient meter for accurate measurement and simple operation;
It is measured with an electronic hydrometer suitable for solids, also known as an electronic gravity balance, which is based on Archimedes’ law and can be accurate to four digits.
I want to achieve PP color masterbatch with a carbon black content of over 40%, which is prone to breakage and high pollution. Please provide guidance on the process or formula.
From the perspective of process, the causes and solutions are as follows:
Due to the difficulty in dispersing carbon black, it is difficult to prepare color masterbatches using an ordinary twin screw extrusion mechanism with a carbon black content of over 30%. Two granulation methods can be used and carbon black can be added in batches;
The dry method of making carbon black masterbatch is indeed very dirty. If conditions permit, it is best to use an internal mixer to make it, and the carbon black content can reach 50%;
Alternatively, hot cutting can be considered to eliminate the issue of broken bars.
The methods to solve problems from a formula perspective include:
Using high flowability base materials;
Mix polymer dispersant with ordinary dispersant;
Consider using black slurry for production, as there will be much less dust.
