The circular economy, electromobility and the continuing corona pandemic are influencing color selection for plastics. Kunststoffe asked colorant manufacturers about the resulting color trends. We also wanted to know what effects the increased use of recyclates is having and the extent to which manufacturers are affected by the present supply bottlenecks.

16:9

Trend Report on the Coloration of Plastics

Masterbatches

Kunststoff Werkstoffe

Additive

Farbstoffe und Pigmente

Streifinger, Florian

Recycling

Umweltmanagement

Farbkonzentrate (Batches)

Farbstoffe

Kunststoff

Bauwesen

Baustoffe

Kunststoff-Recycling

Kunststoffverarbeitung: Verfahren

Kunststoff-Aufbereitung

Farben, flüssig

Colored Mood Enhancers

Plastics processors have a wide range of colors at their disposal to color their products. Choosing the right color can ultimately be the key to success. But colors are just as subject to trends as materials and designs. Kunststoffe asked manufacturers of pigments, masterbatches, and colorants which colors would be particularly popular in the coming year.

Colors inspired by nature will also be very much in demand in2021. They give products a more sustainable appearance

Pigmente

Pigmente, bunt

Kunststoffe

Photonik

Optik

Effektpigmente

What Will Be the Color of 2021?

Colors can turn plastics products into real eye-catchers. Kunststoffe asked colorant manufacturers to predict which colors will be trending in the coming year.

Trend Report on the Coloring of Plastics

Garish or Necessarily Plain?

A trade show highlight of masterbatch manufacturer Lifocolor will be its biodegradable plant-based color concentrates. These are claimed to enable a closed-loop system for biodegradable plastics.

When it comes to long-term closed-loop recycling, it is not only the plastics that matter, but also the colorants employed. Lifocolor has developed masterbatches specifically for coloring recycled materials.

Messe K-Kunststoffmesse

kunststoffe-international.com

kunststoffe.de

Biokunststoffe

Biodegradable Plant-Based Colors

Besides compounds modified for special applications and lightweight components, sustainable materials are also becoming an increasingly important focus. In the additives sector, too, recyclates, the circular economy, and reprocessing are now playing a key role.

Not only Polymers but also Additives and Masterbatches Must Be Sustainable

Zubehör / Hilfsmittel Wärmebehandlung

Wärmebehandlung

Compound

Thermoplaste

PVC-Additive

Andere Werkstoffe

Werkstoffe für additive Verfahren

Vernetzungsmittel

Compoundeure

Dienstleistungen

Handel

PVC-weich (Compounds)

Verarbeitungshilfsmittel, allgemein

Flammhemmende Mittel, allgemein

Betriebsausrüstung / Betriebsmittel

Verarbeitungshilfmittel

Filamente für additive Verfahren

Flammschutzmittel

Gleitmittel für Kunststoff

Attention to Detail

Two new inorganic yellow pigments based on iron oxide and zinc oxide respectively are designed for coloration in a temperature range of between 220 and 260 °C.

The yellow pigments are used for all common polymer materials as well as for engineering thermoplastics even at the highest production temperatures

Hochleistungskunststoffe

Yellow for High Temperatures

Sustainable development is the focus of the Israeli company Tosaf’s trade show presence. The company presents functional, color and combined masterbatches for processing by extrusion and injection molding. These will include color masterbatches for recyclates with a special focus on post-consumer plastics as well as biodegradable masterbatches.

Special masterbatches can be used for permanent orange coloring of high-voltage components in electric vehicles

Elektromobilität

Mobilität

Messe Fakuma

Kunststoff-Rezyklat

Masterbatches for Current Trends

At Fakuma, Granula presents masterbatches specially tailored to more sustainable plastic products. For this purpose, the company has developed grades with biological pigments and degradable additives for injection molding and extrusion.

The masterbatches are used, e. g., for pigmenting the lids of to-go cups 

Bio- and PCR-Based Masterbatches

Automated Color Measurement for Bulk Materials

With the measuring system, color analysis measurements are possible inline, online and atline. This allows for quick intervention during production.

With automated color measurement, it is possible to check the color of pellets during production. 

Farbmessgeräte

Messtechnik

Optische Mess- und Prüftechnik

Messgeräte für Farbe

Qualitätssicherung

Qualitätssicherung Kunststoff

Inline, Online, Atline But Not Offline

To be able to manufacture products from 100 % recycled post-consumer materials (PCR), Avient has developed appropriate colorant and additive masterbatches with PCR matrix.

Especially for packaging, post-consumer recycled percentages of 100 % are increasingly in demand

Verpackungsmaterial

Logistik

Standardkunststoffe

Additiv-Batches

100 Percent Made from Recycling Material

A metallic look and decorative design using lasers have been very popular for some time. To meet this demand, Rowa Masterbatch includes optimized raw materials in its portfolio.

Metallic surfaces are very popular right now for personal care products and packaging. The fact that they can also be laser-marked without any loss of quality is ensured by a specially developed masterbatch. 

Laserbeschriftung in Farben

Oberflächentechnik

Laserbearbeitungen

Laserbeschriftung

Laser without Color Loss

Grafe’s color experts not only had a very special presentation but also a good cause in mind for this year’s color preview. A bold and informative campaign has been developed in cooperation with a youth initiative. Colors are becoming more natural in pastel hues with a disco revival of pink, purple, and gold in 2020.

Fig. 1. Managing Director Matthias Grafe (left) and Roman Malessa, Secretary General & spokesperson for Youth Against Aids, wanted to send a message with the color preview

Grafe Trend Colors Are Presented together with the “Youth Against Aids” Association

Einfärben

Educational Design

A new process developed by the Fraunhofer Institute for Building Physics IBP is able to isolate carbon black ash recovered from old tires – allowing both the carbon black and the minerals from the ash to be reused.

Top, primary product from left to right: raw rCB, clean rCB (96+), pearlized clean rCB (96+). Bottom, secondary products recovered from the ash, from left to right: liquid sodium silicate or “water glass”, precipitated SiO2, precipitated ZnSO4

Technik Trend

Kreislaufwirtschaft

Carbon Black Recycled from Car Tires

Effect pigments can be used to injection mold thermoplastic parts with a shiny metallic surface. However, non-uniform pigment orientation can lead to optical defects. Suitable simulation methodology enables defects to be predicted and prevented.

There is huge demand for automobiles that have metallic finishes. Plastic parts are often painted or electroplated for this purpose. Metallic effect pigments constitute an alternative. Audi and PEG are working on a simulation process for these pigments with a view to ruling out surface defects. 

Simulating Surface Defects in Parts Using Effect Pigments

Simulation

Software

Effective Prediction

Milliken introduced an orange colorant for electric vehicles. It is said to be very color-stable even at high temperatures.

The colorant offers excellent thermal stability up to 300 °C or more.

Orange Colorant for Engineering Plastics

How Plastics Processors Find the Most Suitable Colorants for High-Performance Polymers

Colored plastics are not just a marketing gimmick, but fulfill important functions with technical components. In particular, they warn of hazards and permit the fast and direct identification of components. However, when coloring such plastic components, the processors are faced with several difficulties. For example, the colorants used must exhibit long-term resistance to high temperatures and must not impair the polymer’s mechanical properties. Therefore, when selecting the colorant, compounders and processors must observe several important points.

Because they exhibit better mechanical properties as well as higher resistance to chemicals and heat, high-performance plastics meet higher demands than standard and technical plastics. Due to these characteristics, the application range for high-performance thermoplastics has increased considerably in the past years. Typical examples are found all around battery electrics. Because of the increasing importance of electromobility – where products with long service life and high dimensional stability under heat are required – they play a far more important role. Similarly, digitalization requires very demanding solutions for high-efficiency electronic components.

Common to many of the application areas is that on the one hand, the plastics used must meet the demands for resistance to high thermal loads, and on the other they must ensure a wide color range, in particular for bright colors. Because in many cases, good distinguishability is essential, e. g. for high-voltage cables and connecting elements in hybrid and electric vehicles, which must be marked with orange colors. Moreover, the color must exhibit safety-relevant features clearly, also after long periods of use or high continuous operating temperatures. For example, important markings like on emergency Off switches must not bleach out. That is why colorants with particularly high temperature resistance are necessary to ensure that the component retains its color and function also under thermal loading. By selecting suitable colorants, also brilliant colors such as RAL 1021 rape yellow, RAL 2010 signal orange, RAL 3000 flame red, RAL 4006 traffic purple, RAL 5015 sky blue, and RAL 6018 yellow green are possible.

Finding the Most Suitable Masterbatch Jointly

Consequently, the coloring of high-performance plastics is a particular challenge. Apart from high expertise, close and trusting cooperation between masterbatch producers and customers is also required. These customers include processors, such as injection molders or extruders, as well as compounders. The differences in cooperation consist mainly in that compounders have original recipe expertise and therefore detailed know-how that is not readily available for processors. Moreover, the processor is primarily concerned with the respective component requirements.

For both sides, however, an open dialog with the masterbatch producer is an essential prerequisite for optimum results. Only if detailed information is available about the polymer or compound to be colored, and the requirements for the component, are masterbatch producers such as Rowa Masterbatch able to develop a customized color masterbatch. Therefore, a confidentiality agreement is a basic requirement for cooperation in most cases.

Various criteria for colorant selection must be carefully examined:

Processing temperature of the polymer or compound: for masterbatch producers, this is an important criterion for correct colorant selection. The temperature resistance of the colorants used should be at least 10 °C above the processing temperature. Moreover, the colorant must be suitable for the polymer. Particularly with polymers that have only been on the market for a few years, adequate information from the colorant producers is not always available. Therefore, comprehensive suitability tests by the masterbatch producer are necessary.

Demands on the final product: detailed requirement profiles must always be prepared. Typical requirements are:

<ul><li>high resistance to light and weather,</li><li>high continuous operating temperatures,</li><li>approval for contact with foodstuffs (e. g. EU 10/2011, FDA),</li><li>product standards (e. g. test and delivery regulations of the automotive industry, UL and VDE specifications, standards in the building sector, etc.).</li></ul>

Observing Reflectance Curves  and Additives

Particularly in automobile manufacturing and in the decorative field, good agreement between the reflectance curves of color sample and reproduction is decisive. This prevents the occurrence of metamerism under different kinds of light (light source D65 = daylight, light source F2/F11 = fluorescent lamp light, or light source A = incandescent lamp light).

Many compounds contain functional additives such as filling and reinforcing substances, flame retardants, stabilizers, anti-friction agents, etc. During colorant selection, it is important to ensure that there are no interactions between the colorants used and these additives.

Also the decomposition products sometimes occurring in low concentrations in polymers during processing must be taken into account. For example, acid recipe constituents and/or acid decomposition products can cause the generation of hydrogen sulfide with zinc sulfide pigments (e. g. white pigment, P. W. 7), ultramarine pigments (e. g. blue pigment, P. B. 29) and cerium sulfide pigments (e. g. red-orange pigment, P. O. 78).

What is more, colorants can have a significant effect of the mechanical properties of the final product. Organic pigments like copper phthalocyanine pigments (e. g. green or blue pigment), which exhibit high dispersion hardnesses, can lead to a significant reduction of breaking strength, breaking elongation, and impact resistance. Although high shear forces are introduced by efficient twin-screw extruders with high processing lengths during the production of corresponding masterbatches, the complete dispersion of all pigment agglomerates cannot be ensured in all cases. Usually, inorganic pigments are easier to disperse, but they exhibit higher hardness (Table 1). Usually, the Mohs hardness scale is used [1]. With glass fiber-reinforced compounds of the same Mohs hardness, the inorganic pigments used have a negative influence on the mechanical properties due to damaged fibers.

The requirements mentioned above clearly limit the selection of colorants for technical plastics and high-temperature polymers. Therefore, the suitability of colorants available on the market must be tested and entered in a color recipe system. Moreover, in spite of the same color index, many colorants are not exchangeable 1 : 1. Consequently, for a producer of polymer-specific masterbatches, who claims to color all polymers available on the market, this means several hundred colorants.

In addition, new colorants keep coming. Of particular interest for high-performance polymers are newly developed products, if they exhibit very good heat resistance as well as good light and weather resistance. Particularly in the past years, new inorganic pigments and more temperature-stable colorants for high-performance polymers have been introduced to the market. Some of these colorants are color-stable with processing temperatures up to 380 °C. If necessary, masterbatches containing these colorants can ensure good covering also with thin wall thicknesses. Hereby, the mechanical properties of glass fiber-reinforced compounds are maintained to a high extent.

In many cases, compromises are necessary when coloring high-performance polymers. Hereby, it must be decided whether an optimum metamerism-free color reproduction or good mechanical properties of the final product has higher priority. All of these points underline the relevance of careful and exact preparation, including a detailed information exchange between the processor or compounder and the manufacturer. Rowa Masterbatch is highly experienced in this field and – with the help of an extensive portfolio of colorants and additives – has created the basis for the development of precisely matched recipes for highly demanding applications in the field of high-performance and engineering plastics. The company offers its customers comprehensive consultation for coloring high-performance polymers (see Box).

[1] Martin Bastian, Einfärben von Kunststoffen, Hanser Verlag 2010, pp. 104/105)

ROWA Masterbatch GmbH  

https://www.rowa-masterbatch.de

Ausgabenartikel

For color matching, large DIN A5 test panels (210 x 148 x 4 mm, shot weight about 135 g) are produced on a 200-ton injection molder

A co-rotating twin-screw extruder with coupled strand pelletizer is used for masterbatch production

 Individual inscription of colored panels is possible with the digital flat bed printing technology

The customer’s sample is inspected visually in the Color Competence Center, and the feasibility of the requirements investigated

The colorist responsible for color development evaluates the color by means of injection molded sample platelets

Table 1. Mohs hardness of different inorganic pigments

KU 7-21_Rowa - Hauptartikel

In its Color Competence Center (CCC), Rowa has bundled the consultation offers of its company divisions for masterbatches in granulate form (Rowa Masterbatch), finished colored plastics (Romira), liquid colors (Rowasol) and finely dispersed pigment preparations (Rowa Lack). There, in cooperation with customers, the company’s color experts develop specific solutions for the respective application area. Thanks to this in-house expertise, all products can be adapted flexibly. In this way, customers obtain a product that provides the best color and consistency for their production and application. The developed products are precisely reproducible. Different color systems such as RAL, NCS, and Pantone are available from the CCC. By means of modern data communication, customers can obtain a color match also without a visual sample, so that the requested color match can be started quickly, and a customized color concentrate or compound can be made available.