In the process of using color masterbatch, the biggest difficulty is how to properly add it to the material. The two main factors are the carrier resin used to produce color masterbatch and its molecular weight, which can not be determined by the company purchasing color masterbatch.

Qingdao Sainuo polyethylene wax for color masterbatch has high molecular weight, high viscosity, Both lubrication and dispersion; the dispersion performance is equivalent to BASF A wax and Honeywell AC6A.

The addition amount of color masterbatch in the final resin is generally 2% - 5%. If the color masterbatch is mixed and added correctly, the content of carrier resin in the final mixture accounts for 1% - 3% or more. In this way, it has become the largest additive in the additive series. Therefore, some details should be paid attention to when selecting the carrier resin. For example, users' requirements for color, color stability, environment and the role of color masterbatch in final products make the formula of Color Masterbatch more and more complex.pe wax

Generally, the same resin as the product resin is selected as the carrier for the color masterbatch, and the compatibility between them is the best. However, in complex cases, the fluidity of the carrier and the pigment dispersion and mixing distribution after selecting this carrier should also be considered. Only through the unified balance of these complex characteristics can the most appropriate color masterbatch formula be obtained.

Specifically, the five principles of carrier selection in color masterbatch formula are compatibility, fluidity, processability, high viscosity and applicability.

1. Compatibility

The so-called compatibility refers to the ability of two substances to accommodate each other. According to the principle of similar compatibility, the structure of Color Masterbatch carrier resin and colored resin is the same or similar. Its compatibility is good. Under normal circumstances, the color masterbatch carrier resin and the matrix resin of the product should choose the same type of polymer, in order to ensure good chemical compatibility between the carrier resin and the matrix resin.

2. Fluidity

The so-called fluidity is that the fluidity of the color masterbatch carrier resin itself is good, and the melt flow rate of the carrier is higher than that of the colored resin. If the same polymer as the plastic to be colored is used as the carrier, its molecular weight should be lower than that of the colored plastic (that is, the melt flow rate of the carrier is greater than that of the plastic to be colored). In this way, it is easier for the color masterbatch with high melt flow rate to flow ideally in the coloring screw, and it is easier to disperse in a large amount of resin.

However, this method often has disadvantages. After all, the relationship between melt index and molecular weight can not be ignored at any time. In the final analysis, the molecular weight determines the performance of the resin, and the carrier resin with high melt flow rate may lead to the decline of product performance in the final processing and molding, especially the coloring of engineering plastics. If a carrier resin with a molecular weight similar to that of the resin to be colored is selected, an appropriate amount of lubricant can be used to improve the fluidity of the overall color masterbatch, that is, to improve the melt index of the color masterbatch; Otherwise, the low molecular weight resin is easy to degrade, which will seriously affect the appearance of the product.

However, sometimes, in some colored products, it is clearly required that dispersant is not allowed to be added to the color masterbatch. At this time, it is more important to select appropriate carrier resin.

3. High viscosity

High resin viscosity and good fluidity may be a pair of contradictions, but if the melt viscosity of the carrier resin is high, the shear viscosity of the system is also high, and the greater the shear force transmitted from the molten resin to the pigment particles, which is conducive to the dispersion of the pigment particles. Therefore, how to unify the contradiction needs to be comprehensively considered in the choice of carrier.

For example, the molecular structure of conventional LLDPE is characterized by its linear main chain, with only a small amount or no long branched chain, but it contains short branched chain, and there is no long branched chain, which makes the crystallinity of the polymer high. Under the same molecular weight, the melt viscosity of LLDPE with linear structure is higher than that of LDPE with non-linear structure. At the same melt flow rate, the melt viscosity of LDPE is also significantly lower than that of LLDPE. Therefore, it is not surprising to choose or partially use high melt flow rate linear low density polyethylene (LLDPE) as the carrier of polyolefin color masterbatch.

4. Processability

The so-called processability refers to meeting the needs of production process. Many practical experience and statistical results show that the final dispersion performance obtained by using powdered resin is better than using granular resin. An obvious difference is that the powdered resin can quickly complete the melting process in the equipment due to its small particle size, that is, the pigment particles can be infiltrated earlier and enter the wetting and dispersion process. At the same time, the mixing uniformity between powders is also very high, which also effectively improves the wetting speed.

In order to improve the quality of Color Masterbatch, the manufacturer of Color Masterbatch needs to consider the morphological differences of different carrier resins in the formulation. However, not all resin products in the market are supplied with powdered materials. At the same time, the color masterbatch manufacturer shall provide its own grinding equipment and, if necessary, grind some or all of the resin used for the production of Color Masterbatch, so as to improve and ensure the quality of products.

5. Applicability

Applicability means that the carrier needs to meet the production needs of customers and the needs of products, and can not affect the surface and internal quality of products. When the color masterbatch is used for coloring plastics, it shall not affect the mechanical properties of plastic products due to the improper use of the carrier. For example, when selecting color masterbatch for degradable plastic products, it is necessary to avoid using masterbatch with non degradable material as carrier, so as to prevent influence on the determination of the properties of degradable products.

For example, the color masterbatch of PPR tube adopts LLDPE as the carrier resin, which has good compatibility with PPR, but the high melt index of LLDPE means that the molecular weight is too low to withstand hot water pressure; HDPE carrier resin has good compatibility with PPR, but the heat resistance time is very short.

This problem also needs to be paid attention to for non spraying plastic resin. The more transparent the resin is, the better the silver effect of the product is. For example, with the same silver addition, the effect of transparent ABS is more bright than that of PP. In addition, it is also required that the fluidity of the carrier and materials is high, and the thermal stability and volatile matter are low. Too high melt viscosity will also be detrimental to the movement of metal pigments and affect the dispersion. Too low melt viscosity has weak shear performance, and the dispersion and distribution of pigments will become worse.

In a word, when designing the formula of Color Masterbatch, it is necessary to fully consider the performance of the target matrix resin and select the appropriate carrier resin. Color Masterbatch manufacturers can design different color masterbatch carrier formulas according to the processing process of products, such as injection molding or extrusion, the flow of matrix resin, the final use conditions of products, etc.

Qingdao Sainuo Chemical Co., Ltd. We are a manufacturer for PE wax, PP wax, OPE wax, EVA wax, PEMA, EBS,Zinc/Calcium Stearate…. Our products have passed the REACH, ROHS, PAHS, FDA testing. Sainuo rest assured wax, welcome your inquiry!

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