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Pigment Preparation Advantages and Benefits for Plastic Application

An effective and clean way for plastic coloring

In the past decades, Precise has been engaged in the research and production of colorants, include organic pigments, solvent dyes, masterbatch and pigment preparation. Clean and easy-to-use is always the users’ expectation in this industry. With the increase of environmental protection policy globally, as well as more and more young people's requirements for a good working environment, we can predict that producers’ willingness to use more environmental-friendly colorants will be continuously increasing. Our company also put forward the targeted concept, that is to provide such clean and easy to use colorant, so as to strive for the first position of Chinese pigment preparation manufacturer. At the same time, we want to reshape the image of "Made in China".

As we know, China is one of the biggest original countries of pigments and dyes. The total annual yield of China’s domestic pigments is about 170,000 to 190,000 tons, accounting for about 45% of the global pigment production. Moreover, China also has more new capacity   coming in the next 3-5 years, which will reach 280,000 to 290,000 tons as a yearly amount.  Regarding color masterbatch in China, that is also raising up with an annual growth rate about 12%. Now the annual capacity of color masterbatch in China is over 1.7 million tons. However, it is so regret that China’s color masterbatch doesn’t occupy corresponding market share in exporting market, because masterbatch enterprises rarely go out even some of them have tremendous production capacity. Both Price and quality of their masterbatch limits.

According to the using tradition and price factors, we know that most of the masterbatch manufacturers are still using powder pigments, so what are the advantages and defects of powder pigments? We can find out in below figure.

 

Characteristic

Original Powder

Pigment Preparation

Liquid Masterbatch

Color Masterbatch

Compounding

Dispersibility (spot)

△-○

Dispersibility (rhyolitic)

△-○

△-●

Fluff/Dust

x

Pollution

x

△-○

Metering

x - △

No need

Processability

△-○

Influence to physical property

△-○

△-○

Storage stability

△-○

Storage cost

x

General application

△-○

x

△-○

x

Cost on coloring

△-○

x-△

x

Dosage

0.5-1%

0.5-5%

1-1.5%

2-10%

No need

Shape

Powder

Pellet

Liquid

Granule

Granule

●=excellent  ○=good  △=moderate  x=not good

For the application which demands high dispersion, it is necessary to pre-disperse the powder pigment first, for example, ‘squeezing water phase’ is known as one of the traditional pre-disperse paths of organic pigment. Using this technique, manufacturers start from the pigment filter cake stage, followed with grinding, phase conversion, solvent treatment, drying and a series of processes to complete the pre-dispersion process. Polyolefin carriers such as Polyethylene wax are used as dispersing agent, so ball milling time is also very long. But the key is to add the fluidization agent in the process of heat transfer. Different products need to add corresponding fluidization agent according to their chemical structural. For example, double azo pigment needs to use the quaternary ammonium salt or metal (aluminum salts) and Salt Lake-pigments used for an acetyl amino benzene sulfuric acid, sodium hydroxide, etc. Also adjust pH and stir at any time. The process is cumbersome, and output is severely affected. For production enterprises, this is very deadly, will seriously affect the timeliness of delivery and product promotion and expansion speed.

Shapes of Preperse series

As the alternative of powdery pigment, pigment preparation has outstanding advantages. Its high dispersibility and dust-free characteristic meet the trend of production technology & environment protection for contemporary enterprises.

However, the traditional pigment preparation hasn’t made great progress during the past years. What are the reasons for such standstill?

The first reason is, although the traditional pigment preparations improve the capacity of dispersibility, the cost is high but not good cost-performance. In addition, there is more than 50% dispersing agent (e.g., wax) in the traditional pigment preparations, which means their application in severe requirements are limited. Moreover, some products are limited by their genetic characters, so their capacity of dispersibility are improved slightly and the coloristic performance are barely satisfactory.

With the emergence of ‘Preperse’ series pigment preparations from PNM, we find a way to work out the above three problems. There are more than 70% pigment content in whole Preperse’ series. Furthermore, the Preperse-S series has more outstanding dispersibility which launched for polypropylene, polyester, nylon and other special applications.

Improving the pigment content means the increase of effective constituent, and the proportion of dispersants such as wax in the product is correspondingly reduced. With more effective constituent inside, our cost is closer to powdery pigment. Therefore, the cost is transparency and makes the main parameters for our price making.

Meanwhile, less wax means less migration and lower possibility of structure & mechanical property’s changing. In other words, our ‘Preperse’ series improve the dispersibility with less cost.

As we know, better dispersibility brings more benefit, such good visual effect with better brilliance, stronger strength etc. Users can obtain extra profit by using less pigment but ideal color strength.

Besides, good dispersibility also shows unique value during the production. For example, Pigment Yellow 180, the performance of this pigment can meet the requirements of PP fiber, however it needs repeated pelletizing to achieve corresponding dispersibility for severe requirements. Theoretically, pigments dispersibility depend on their 'gene' —— even we know that the upper limit of Pigment Yellow 180 can fulfil our request for the application, but we must put in more shear force and dispersing agent to achieve the target.

Pigment under microscope x160

Outstanding pigment dispersibility under x160 microscope

pigment dispersion under microscope

Defective pigment dispersibility under x160 microscope

Thus, we know that the top dispersibility is not easy to approach but request extra effort and cost. Extra input such as repeating pelletizing, is wasteful for producer on production efficiency and opportunity.

Our Preperse series is fully considering the above practical problems. In order to raise up the dispersibility, we take ‘fast and easy dispersing’ as the core concepts of product design. With the goal for full dispersibility by one time pelletizing, we made strict quality control index: All Preperse-S series is complying with filament requirements by one time pelletizing and FPV must be lower than 1, under the condition of 1400 meshes, 60g pigment through the FPV machine (40% pigment loading masterbatch dilute to 8%).

In most cases, making masterbatch through one-time pelletizing is not enough to approach an acceptable FPV performance for strict applications, such as filament, thin film etc. The 'Preperse' series is one of the ideal solutions for this limitation. Benefit from the pre-disperse performance and excellent dispersibility, 'Preperse' pigment preparation contribute to make high pigment content mono masterbatch which obtain a pigment percentage from 40% to 50%. Even some 'ungifted' pigments which can't well dispersed genetically also work out high pigment content mono masterbatch. For example, Pigment Violet 23, known as the most difficult-dispersible pigment, we generate Preperse Violet RL which contains 70% pigment value and makes fully 40% mono masterbatch, with a FPV at 0.146 bar/g (see in below picture). 

 

PV23-pigment-preparation 1
PV23-pigment-preparation 2

Besides, our Preperse series can get good colorant effect without high shear force equipment. For example, 'Preperse' pigment preparation can be used as replacement of pigment and mono masterbatch when making masterbatch or terminal product which directly by single screw extruder. 

For masterbatch producers, they can remove the current process of making mono masterbatch or SPC but firsthand do color matching. By this way, users save more time and benefit by higher efficiency.