Colour and effects have long been used to differentiate products and help them stand out on the store shelf. Now they are increasingly being used to do this in more applications. For example, even brand owners of utilitarian products such as toothbrushes and heart-rate monitors are using current trend colours often combined with transparent or reflective materials to make their products stand out. Carolynn Sedgwick, business manager for the North American packaging segment at Clariant Masterbatches, explains the use of colour and effects as a marketing tool, “Designers use colour, effects, and combinations of the two to communicate a product’s message. For example, a luxury product is currently conveyed with pearlescents, and a new, innovative technology may use a current fashion colour to strengthen the ‘state of the art’ message.” Global brand consistency, and a corresponding global colour supply consistency, is a major concern in packaging, consumer goods, and even industrial goods, adds David Stonecipher, director of marketing for North American colour and additives at PolyOne. Colour and effects suppliers are seeking to please their customers with expanded trend and design services and new colours and effects. Other key concerns for all stages of the supply chain include improving environmental impact, ensuring regulatory compliance, and keeping costs down.

Colour trend and design services

Several pigment and additive suppliers have added to their colour trend and colour design services. For example, PolyOne recently opened two colour design centres in Europe that will serve customers in packaging and other markets. Expanded services from Ciba seek to help designers create and explore new uses of colour and effects, says Chris Wells, NAFTA head of marketing for plastics at Ciba. Ciba’s Xymara^™ website (www.xymara.com) helps designers visualize their colour and effect ideas, while Ciba’s Colour Trend Vision design package provides global and regional colour trend forecasts and information, design tools, and consulting services. Clariant, which has long participated in industry colour trend initiatives, began publishing its own trend analysis with ColourForward 2007. “We look at cultural influences and trends globally and interpret how these relate to colour. We also plot thousands of Clariant colour matches completed over the last 12 months, analyze how our customers’ colour choices have shifted, and estimate where we see colours going in the near future. Our first two years of analysis have validated these methods,” says Ms. Sedgwick, noting that ColourForward 2009 is targeted for publication in February. Clariant’s seventh ColourWorks^™ design and technology centre opened in Italy in 2006. ColourWorks helps companies, typically large brand owners, bring colour into early design stages and accelerate new product launches through services such as colour consultation, 3D colour simulation, mould simulation, and on-site moulding, says the company. Mould flow analysis simulates how a colour will impact processing so that manufacturing roadblocks can be reduced. For example, simulation predicts where flow lines may occur and how tooling design can be altered to reduce flow lines. Clariant says these services are some examples of its new 360° Service^™ concept, which officially defines Clariant as service-focused rather than product-focused.

New colour and effects technologies

In packaging, use of clear resins tinted with colours and effects is on the rise, corresponding to PET’s growing use. Designers are excited by the new colours and effects that can help differentiate their clear products or packages, say concentrate suppliers. For example, Teknor’s ColorMorph^™ concentrates yield distinct colour shifts as the viewing angle changes, such as gold to red or transparent to opaque. Ampacet’s Blue Edge^™ effect creates a blue hue around a bottle’s edge without reducing translucency. PolyOne’s OnColor PicoTint^™ liquid colour for clear engineering resins can be used in packaging or applications like appliances, electronics, and automobile taillights. PicoTint maintains high clarity through a patentpending, fully-compatible carrier that extends shelf-life and improves distribution, says the company. A metallic look is in demand for personal care and other packaging, says Teknor Color Company, which recently introduced MetaLustre^™ colour concentrates. The concentrates are available in multiple formulations designed to deliver an identical hue in different resins, so that packaging manufacturers can maintain their brand identity in all the resins they use. Achieving a highly reflective, chrome metal look in plastics has been an ongoing challenge for effects developers. Pearlescent technology offers a high gloss effect, but not a true mirrored effect. Ampacet says they have met this challenge with new LiquidMetal^™ colours that can bring an opaque, reflective metal-look to PET and other polymers. One new PET application is replacing aluminium cans in the energy drink market. Other potential PET applications for LiquidMetal include personal care and car-care products, notes Douglas Brownfield, business manager at Ampacet. These new masterbatches use Ampacet’s new Formula X^™ PET technology, which eliminates the need to pre-dry PET colours, reduces processing problems associated with typical carriers, and improves colour dispersion. Ampacet has introduced POP^™ High Gloss Colors, designed to enhance gloss in Nova’s MMWHDPE for producing high-gloss HDPE packaging that can compete with PET.

Infrared-reflective functional colours

Dark-coloured pigments that reflect infrared sunlight and reduce heat build-up have been gaining interest and growing in use. While light colours are known to reflect infrared (IR) light, dark colours range from non-reflective to highly reflective. Carbon blacks, for example, absorb IR energy. CICPs (complex inorganic colour pigments) are inherently IR reflective, and formulation can accentuate this effect, explains Kathryn Brannon, marketing manager for plastics at the Shepherd Color Company, which offers Artic ^® infrared-reflective pigments. Reducing heat build-up helps products stay more comfortably cool and reduces warping in vinyl siding and profiles. Reflective surfaces save energy by reducing cooling costs. For example, reflective roofing significantly reduces buildings’ cooling load, and even reduces urban temperatures and associated smog, explains Dr. Brannon. Requirements for energy reduction are a key driver for use of these pigments, agrees Thierry Chevrier, director of performance chemicals for BASF in North America, which recently introduced a Sicopal ^® NIR-reflecting black pigment that reduces solar heating of dark black, structural components for the building and automotive industries. Exterior wood-plastic composites (WPC) can also benefit from IR-reflective technology. PolyOne’s new OnColor^™ WPC masterbatch line, which includes some products with IR-reflecting colorants, features weatherable colorants that, combined with other additives, reduce colour fading of WPC, says Mr. Stonecipher.

Environmentally-friendly colours and effects

Interest in environmentally-friendly products continues to grow, particularly in North America and Europe where environmental legislation, environmental scorecards from stores such as WalMart, and public sentiment are driving initiatives. Consumer goods and packaging manufacturers are seeking a ‘greener’ image through use of bio-based resins and colorants, increased use of postconsumer recycle (PCR), and continued downgauging and light-weighting. While bio-based resins such as PLA (polylactic acid) and starch-based resins have been slow to take off, growth is expected in the next few years as capacity increases, comments Mr. Stonecipher. Several masterbatch suppliers have introduced bio-based resin carriers for their colour and additive masterbatches. For example, PolyOne’s OnColor^™ Bio pigment masterbatches are designed for use with biopolymers. Teknor Color Company also has a line of colour concentrates for an assortment of bioresins, including PLA. Clariant has gone one step further with Renol^® -natur colour masterbatches containing colours made from natural, sustainable resources such as orange from the turmeric plant and green from chlorophyll. While conventional pigments do not degrade and would remain after composting, Renol colorants are biodegradable. Although current standards for compostability allow a non-degradable residue, many Clariant customers want to avoid any non-degradable materials. Some customers are using Renolcolorants even in conventional polymers as a way to show an environmental commitment, explains Ms. Sedgwick. Another way to improve a company’s environmental footprint is to use PCR in a package or part. However, using PCR at high levels typically causes variability and adds a greyish cast to colours. Clariant’s new Enigma ‘Environmental Impact’ colours are designed to mask variability and greyness, producing a bright colour in 100% PCR. Clariant has showcased three of these colours and says they can work with customers early in the design process to develop others. Ampacet’s BlueEdge additive effect can be used to counteract yellowness due to increased recycled content in PET, notes Mr. Brownfield.

Regulatory compliance for colours

In the European Union (EU), ensuring that colours are in compliance with regulations for a given application is becoming increasingly complex. Suppliers say REACH (Registration, Evaluation, Authorisation and Restrictions of Chemicals) will not affect their ability to supply customers, but will require increased communication in planning changes in formulas and other supply chain decisions. EU regulations such as RoHS (Restriction on Hazardous Substances) and WEEE (Waste Electrical and Electronic Equipment Directive) restrict heavy metals, which may be found in some inorganic pigments. “Because regulations are complex and vary by country and application, the better question is not whether a pigment is ‘heavymetal- free’ but whether it is compliant with a specific regulation in a given application,” cautions Dr. Brannon. “We see increasing demand for RoHS-compliant products, especially in PVC, which seems to be the last area where heavy-metal based colours are being eliminated,” comments Bob Trinklein, colour technology manager at Teknor Color Company, which recently expanded its RoHS-compliant concentrates for use with low-smoke PVC wire and cable compounds. Heavy metal pigments, such as those containing lead chromate or cadmium, are being replaced with organic pigments, non heavy-metal inorganics, or blends of the two.

While traditionally inorganic pigments have had better heat stability, lightfastness, and weatherfastness than organic pigments, organic pigments can be redesigned with these properties, making them an effective alternative to heavy-metal containing inorganic pigments. “Improvements in dispersion, heat, light and migration resistance provide more robust formulas, aiding in reproducibility and performance,” says Scott Heitzman at Sun Chemical, which recently introduced improved versions of several organic pigments. He adds: “While a few areas still exist where improved lightfastness and heat stability is needed, the biggest hurdle is gaining acceptance for the value-in-use of organic pigments. They are typically higher cost by weight, but their stronger colour means they can be used at lower loadings. They are not drop-ins; users have to adjust their formulas.” Ciba recently launched Ciba ^® Oracet ^® Orange ES, which has full food contact clearance for use in PET, and Ciba ^® Cromophtal ^® Yellow 4GV. The company says this is thew first pigment that can replace heavy-metal-based yellow pigments in outdoor HDPE applications and that has also received FDA food contact clearance in all use conditions. Ciba sees a continued need for lower dusting forms of colorants and other additives to reduce workplace dust, particularly since the U.S. Occupational Safety and Health Administration (OSHA) initiated a programme in which inspectors will target dust explosion hazards. Ciba offers several pigment dispersions in low dusting forms targeted at different polymer types.

Keeping costs down

Saving costs, at all stages of the supply chain, continues to be an issue. Carrying fewer numbers of pigments or reformulating to lower-cost materials are some ways used to control costs, notes Dr. Brannon. BASF says their Synergy ^® pigment line helps formulators control costs by meeting an application’s specific requirements using synergistic properties of organic and inorganic pigments. Also, pigments with improved processing allow concentrate producers to compound more efficiently. Higher pigment loadings in colour concentrates are one way to keep costs down for concentrate users, who can use less concentrate to obtain the same pigment loading in the final part. While 4% loading of colour concentrate in the final mixture (25:1 let-down ratio) was standard in the past, 2% loading is common today, with 1% or even lower possible, say industry experts. Improved pigment dispersion characteristics aid concentrate producers in obtaining higher loadings. The balance between surface treatments, pigment particle size and shape is key to improving dispersion, says Mr. Heitzman, noting that Suns’ Palomar ^® Pigment Blue 60, Fanchon ^® Pigment Yellow 110 and 150, Fastogen ^® Super Red 254 have improved dispersion. Concentrate producers can also use a pre-dispersion, whether made in-house or purchased from the pigment supplier, to get dispersion in a concentrate with higher loadings. Some caution that higher loadings are not automatically the most cost-efficient choice. The limiting factor is often obtaining adequate distribution in the plastic processor’s equipment. In addition, feeders must allow accurate dosing of lower masterbatch levels. “A higher let-down ratio has increased measurement error. Sometimes this leads to operators over-dosing to compensate,” cautions Tony Gaukroger at ColourTone Masterbatch.

While some concentrate users look for higher let-down ratios, others find costefficiency in combining one or more functional additives, such as UV stabilizers or processing aids, into the colorant masterbatch. Processors should look at their equipment capabilities for metering and mixing as well as their product range in order to choose a cost-effective option, notes Clariant’s Ms. Sedgwick. PolyOne also sees increasing demand for their OnColour SmartBatch^™ combination colour and additive masterbatches, notes the company. For masterbatch producers, lower-cost pigments from non-traditional sources such as Asia and India are becoming an acceptable alternative. “High quality pigments, comparable to Western products, are available as long as you find the responsible, quality-conscious suppliers,” says Mr. Trinklein. Traditional pigment suppliers have responded to this competition by being more costcompetitive and developing innovative, value-added products, say industry experts. Ms. Sedgwick adds: “As colorant supply expands globally, it is very important to have an extensive knowledge of product safety legislation around the world as well as industry-specific and company-specific standards. At Clariant Masterbatch, our Product Safety network is made up of experts that cover legislative requirements from over 30 countries, and we take supply chain product stewardship very seriously.”