First, the dispersion should be high
Black masterbatches are produced using carbon black. Raw carbon black is a very difficult and dirty mixture. It is dusty, light and fluffy. Unless large-scale treatments are used, it will stain machines and workers and make the work environment dirty. Because of this, casters generally choose a resin carrier, that is, black masterbatch, to complete the pre-dispersion of carbon black. This resin carrier is clean, free flowing and easy to use. In addition, carbon black has the property of being difficult to disperse in addition to being dirty. If the raw carbon black is melted directly during injection molding, the coloring effect will be very poor. Non-dispersed carbon black streaks and speckled areas will clearly appear if they are leaned against less colored areas. Standard injection molding machines cannot effectively disperse carbon black.
这个规律lt dispersion property of carbon black also plagues color masterbatch manufacturers. High-load black masterbatch produced using single or double screw extruder has very poor dispersion. When the end user mixes or molds these black masterbatches, its performance is only slightly better than carbon black, but the effect is also unsatisfactory. To achieve a stable, high dispersion, a high level of shear blender must be used to blend carbon black, such as a mixture of FCM or BANBURY. With sufficient strength, these mixers can completely mix carbon black and base resin. The type of carbon black used also affects color dispersion. The smaller the carbon black particles, the more difficult dispersion becomes.
Second, the coverage should be strong
The second factor that determines the quality of black masterbatches is coverage. This factor is particularly important for masterbatches used in waste or recycled polymers. In these cases, the role of black is to cover other colour. Large particle carbon black has poor coloring ability, and it is not easy to cover all other colors in the lower layer. As a result, the final product has only deviated colors. In the melting process, the ability to correctly select a carbon black with high coloring ability to cover the existing color is the so-called covering power.
Third, better liquidity
The third factor that determines the quality of black masterbatches is rheology and fluidity. If a masterbatch itself has good dispersion, but it cannot flow into the material to be molded, the production effect is not ideal. Generally, the primer resin used to produce masterbatches has a high rheology. In order to save costs, some masterbatch manufacturers use recycled materials, waste or recycled materials as resin carriers. The flowability of the masterbatch produced in this way will be significantly reduced. If the rheology is not good, the mold union will have trouble in the cycle time and appearance treatment. It is worth noting that if the dispersion and rheology are not high, some end users will make up by increasing the dilution ratio, but this approach will only increase the use cost of the masterbatch. Masterbatches with the smallest dilution ratio can produce uniform, good dispersion black.
第四,兼容性应该大
Compatibility is the fourth factor that determines the quality of black masterbatches. If the masterbatch is produced using chips or recycled materials, it may contain contaminants or other non-meltable polymers. This will cause some unpredictable and difficult to restrain the trouble, wasting the time and raw materials of the end consumer. At this time, a primer resin can be selected to produce high-quality masterbatches, and the masterbatches have good compatibility during the melting process. High-quality masterbatches can be produced using LLDPE, LDPE, HDPE, PP, PS, SAN, PA and other materials. If engineering grade and strict physical properties have been specified, then special polymer masterbatches can be obtained. Several major international masterbatch manufacturers are conducting research to produce so-called "global universal" masterbatches. These masterbatches can be widely used with other raw materials, have good fluidity, and can be flexibly applied.
Five, stability must be consistent
In today's internationalized economy, it is absolutely necessary for internatio客户高要求必要部分lity of masterbatches and the stability of raw materials. This is also the fifth factor that determines the quality of black masterbatches. A major manifestation of stability is a smooth carbon black ratio. If the percentage of carbon black is fluctuating, the number of masterbatches to be melted is not the same, and it is not possible to produce products of the same color tone. Some final producers report that the dilution ratios required by chemical manufacturers usually vary by 5-8%, depending on how much material the masterbatch manufacturer has invested in manufacturing. Obviously this is unacceptable. Of course, other factors such as the fluidity and dispersion of the injected melt should be consistent with the amount of each batch.
Six, light and dark
The final factor that determines the quality of the black masterbatch is the lightness and darkness of the color. There are various types of carbon black on the market that can be used to color masterbatches, but the colors and prices of each type are also very different. Large particle carbon black has lower coloration and different background color than small particle carbon black. Large particle masterbatches are suitable for the production of films such as garbage bags, but are not suitable for the production of aesthetically important products, such as television signs or places that require UV protection such as agricultural films or external pipes. For these products, the only small carbon black that is more expensive is used. In addition, low transparency is also a characteristic of small particle carbon black.
Classification and application scope of ordinary carbon black
SRF carbon black is generally used in the production of garbage bags that do not require strong tinting power, high coverage or UV protection. The color tends to be gray-blue, cheap, and relatively easy to disperse, so small manufacturers of masterbatch that are only equipped with single or double-screw extruders will choose this carbon black. The particle size of HAF carbon black is half that of SRF carbon black particles, but the coloring intensity is twice that. It is brown-red, and its ultraviolet protection ability is obviously stronger than SRF carbon black, and the cost is lower than P carbon black. It has good coverage and can be applied in many ways. P carbon black is suitable for UV protection applications and in the food industry. It is red and blue. JET carbon black has the most satisfactory color shades, with a deep, glossy black. It has the smallest particles but is not easily dispersive. only those manufacturers equipped with high-efficiency shear mixers can achieve consistent dispersion when using JET carbon black. It is also the most expensive of ordinary carbon blacks. The cost comparison shows that the more expensive color masterbatch can economically get better production effect than the cheaper color masterbatch.