Design trends in colour and effects push plastics forward Adding colour and special effects to plastics continues to expand their role and potential applications. Jennifer Markarian reports on how design and fashion trends are shaping the market.

May / June 2006

Colour and special effects are used to grab the consumer's attention and are integral parts of product marketing and package design. Colour has value as part of the branding process, notes Larry Nitardy, marketing manager for PolyOne's colour and additive masterbatch group. Design trends depend on the end-use market and whether the product is short term, such as packaging, medium term, such as automotive, or longer term, such as business machine housings, appliances and construction products. Fashion is a leading indicator for short term colour applications. Trends in colours and effects tend to become more conservative as they move from short to long term products, with bolder colours being used in shorter term products. While there really are no truly new colours, 'new' or 'trendy' colours are those appearing in applications in which they have not been used before, such as feminine colour shades being used in automotive applications, notes Pat Verlodt, president of consultancy Color Services and Associates, Inc. "We are proactive and try to predict how fashion trends will move into packaging and more durable goods before designers come to us with requests," notes Kathryn Brannon, marketing manager for plastics at the Shepherd Color Company. Designers work to attract their target audience by interpreting what consumers will respond to, explains Mr. Nitardy.

Coloured bottles (Photo: PolyOne Corporation)

 

Designers do have an influence on trends, but resin and additive prices also affect what is produced. "For example, when oil prices go up, polypropylene (PP) prices go up and PET becomes more attractive. PET typically uses transparent colours because PET is clear while PP is more opaque, so we see a trend towards transparent colours," comments Craig Sibol, U.S. director of sales for business line plastics in the coating effects segment at Ciba Specialty Chemicals.

In the packaging market, colours and effects are continually changing due to the ongoing need to have a package stand out on the shelf. "Change and innovation have become a driving force behind consumer sales. Time-compressed consumers with shorter attention spans have resulted in shorter trend cycles. Having six to 12 months to refine the aesthetics of a package is a luxury of the past. We are seeing plastic packaging changes implemented in three months or less," says Linda Carroll, market development manager at Ampacet Corporation.

Bright chromatics, deep hues, and bright chromatic translucents are currently popular, notes Mr. Nitardy. Lustre and richness are obtained through the use of pearlescent, reflective, and colour shift effect pigments, explains Bill Blasius, director of technology in North America for Clariant Masterbatches. "We are starting to see use of these effects in more applications, such as personal care packaging," he adds. Effects are even moving into more durable goods such as plastic houseware containers and sporting goods, agrees Dr. Brannon. Designers use effects to meet their desire for more and unique options. Special effects offer design flexibility because the appearance can be changed with particle size, loading level, part thickness, and by combining with colour, says Dr. Brannon. "One of the most technically challenging requests we've seen has been the desire for 'chrome' or liquid metal effects within a polymer structure," says Ms. Carroll. A true mirrored effect is currently obtained by using vacuum deposition to metallize the surface. A combination of pearlescent materials and mould surface polish can yield a high gloss surface, but further development is needed to obtain a mirrored effect, says Ms. Carroll.

New Lustre+ sample plaques from GE Plastics.

 

Globalization plays a role in colour and effect trends. Large, global consumer products companies are in some cases using the same brand and packaging colour design worldwide to gain economies of scale. However, regional differences remain and companies are not putting brand marketing ahead of cultural traditions, says Mr. Nitardy. For example, yogurt containers in the U.S. are only pastel or white, but are bright colours like yellow or red in Latin America. There are some regional differences in expectations for colour durability in exterior applications, notes Dr. Brannon. Newer markets like China seem to have less demanding requirements for colour durability, but this will probably change relatively quickly with experience in using plastics over time, she adds. "The emerging markets in Brazil, Russia, India and China are having an enormous impact on our world economy. We are just beginning to recognize creative designs from these countries and their affects on other regions," notes Ms. Carroll.

Colour matching and design services
Colour matching, or choosing a pigment system that is acceptable to the customer, is an important step in the colouring process. Several pigment and masterbatch suppliers offer colour matching services to their customers. For example, in GE's 'Color-on-the-spot' service, a customer comes with an idea and leaves with a final colour choice in a sample part. Clariant Masterbatches' ColorWorks Design & Technology Centers provide mould flow analysis, rapid prototyping, and colour and resin recommendations to help customers optimize their colour specifications and adjust their targets to obtain the best value. Ciba Color Services is an independent group within Ciba that helps clients with colour matching and formulation, using Ciba® Colibri™ colour matching software and ColorViz colour visualization and 3D rendering software.

The trend towards reduced inventory results in the need for faster turnaround of colour matches. "Speed to market is key. One tool to accomplish this is the use of colour selection rather than colour development. Customers can select an initial colour from PolyOne's wide library of electronic colour files. The more precise the idea of a colour is initially, the faster the speed to market will be," explains Mr. Nitardy. "The idea of colour selection rather than colour matching is a paradigm shift, but it serves the customer's main objective, which is to gain market share," he adds. Some see a trend toward increased use of colour matching software and tools that allow users to connect via the internet. This virtual colour depiction can reduce the number of iterations between the designer and the colour laboratory, but designers still want to see the colour in the end product, agree industry experts.

Matching colours in different substrates, such as multiple plastic types, leather, paint, and textiles, continues to be a challenge, particularly in automotive markets but also in appliances and furniture. "Involving the colour experts early in the design process increases the speed to market," says Mr. Nitardy. "When working with different materials, the colour provider needs to understand the limitations of colour systems, work closely with the end-user, and find the best compromise for everyone," notes Mr. Blasius. "Designers should think about colour very early in the design process so that there is time to adjust requirements. For example, designers should be aware that some colorants and special effects can change physical properties. Also, since multiple textures and fluorescence cannot be computer matched or measured accurately with standard systems, success still depends on the human component - an experienced effects specialist and a good light box," adds Mr. Blasius.

Viba’s Opaline white masterbatch is used for polycarbonate applications.

 

Colour software is also beginning to be used for quality control (QC). "As effects and colours get more complicated and difficult to reproduce, the need for colour matching software becomes more important for brand management. Using the internet and internal databases to link sites and suppliers provides real time QC management of colour, thus reducing costs and product supply chain issues that may be colour related," explains Randy Snavely, NAFTA business manager for Ciba Color Services. With proper calibration, colour specifications can be communicated to many different global locations. GE conducted a Six Sigma program to globalize its databases, and each site calibrates its spectrophotometers monthly, says Marc Ros, European product leader for GE's Lexan product group.

New products and services meet needs for improved processing
Dispersion requirements continue to increase, driven partly by increasing use of thinner sheet and film in packaging. Processors also want to reduce costs by using the least amount of colour possible, which requires pigments that are both highly dispersible and exhibit high colour intensity at low concentrations. In addition, shorter cycle times at higher temperatures require pigments with high heat resistance. Clariant Pigments & Additives Division introduced several new PV Fast organic pigments with high heat resistance and colour strength. Viba introduced monopigment microgranule masterbatches for improved colour homogenization in transparent applications, notes the company.

With the trend towards higher output in PVC profile production, quick release of colour in the extruder is important, says Eric Dudas, global industry manager for building & construction at Holland Colours. Holland Colours introduced new Holcoprill Profile rheologically neutral products designed for rapid dispersion in PVC profile production.
In PET beverage bottle moulding, improved dispersion can yield especially large cost savings because the production volumes are so large. New PETek™ Micro-Bead colour concentrates from Teknor Apex's Teknor Color Company have improved dispersion in PET due to the bead form and the carrier's compatibility with PET. The improved dispersion reduces swirl, haze and other defects. In addition, the bead form eliminates the handling problems of conventional wax-based and liquid PET colorants, says the company.

Various test methods, including extrusion of a pigmented film, are used to evaluate dispersion. While Filter-Pressure Values (FPV) have been commonly used in both Europe and North America as a dispersion measure for more than a decade, the European Committee for Standardization recently published a standard test method, EN 13900-5, to determine FPV and make results from different suppliers easier to compare. This test method uses the pressure build-up on a metal wire filter as a measure of filter blockage to quantify the ease of dispersion of pigments or the dispersion quality of pigment concentrates. Although the standard method is European, it is being more frequently requested in North America, say industry experts. Ciba offers a line of filter-tested organic pigments in which the particle size is controlled to meet EN 13900-5.

A key challenge in using special effects is that effects tend to create knit or flow lines in moulded parts. Reducing flow lines is important for aesthetics in any application, but is especially critical in the drive to replace secondary painting operations for automotive exteriors. Several effect products that claim to reduce flow lines have been introduced recently. PolyOne's PlastOne™ flow modifier helps to both overcome dullness and to reduce knit lines created by special effects. Ferro's new Nimex low flow line, durable, metallic colour masterbatches are targeted for paint replacement options. Shepherd Color's StarLight® line of silver coated glass flakes, which give a glittery or lustrous effect, was first commercialized about three years ago. "StarLight has unique processing advantages because the glass substrate gives the particles rigidity so they do not break down, and the silver coating makes the particles less abrasive in the extruder. Knit lines are reportedly unapparent or less apparent compared to other reflective effects, probably due to the rigidity of the glass substrate," explains Dr. Brannon. Engelhard Corporation introduced Firemist® Turquoise special effect pigment last year. The effect pigment uses thin borosilicate flakes, smooth surface, and large particle-size distribution to achieve high reflectivity, shimmer, and multi-colour effects, with negligible flow lines, says the company. GE recently added Cycoloy EF resin, an engineered product with filler, to its Visualfx special effects resin product line. The new product gives a metallic look with improved flow line performance through a combination of resin and additive formulation, says Mr. Ros.
There is a continuing trend towards low customer inventories, small lot sizes, rapid colour changeovers, and improved processing efficiency. GE recently implemented new compounding technology for producing small batches of custom colour. GE's Customer Xpress service can deliver colour masterbatch within six days of order placement, meeting customers' desire to maintain low inventories, says Mr. Ros. The service is currently available in Europe, but will soon be implemented in the U.S. and China. Ampacet introduced SmartColor™ Masterbatches, which limit colour build-up in plastic extrusion and moulding equipment. "The decreased build-up shortens the purge time needed when switching colours as much as 60 percent, which helps processors reduce a major source of lost productivity. This can cut the amount of resin needed in purging as much as 50 percent, significantly reducing scrap generation," says Doug Brownfield, strategic business manager at Ampacet. Clariant Pigments & Additives Division recently launched the DrizPearls® range of pigments that have a new handling form. DrizPearls® are free-flowing, non-dusting, pre-wetted organic pigments that offer cleaner material handling and faster colour changes, among other benefits. Clariant also introduced new Licocene® wax grades for use as masterbatch carriers. The new grades allow pigment loadings up to 65 percent and are easily dispersible, says the company.

Coloured pellets from Ampacet Corporation. A selection of colours from Holland Colours. Photo: Holland Colours.

Meeting regulatory requirements
Regulatory compliance continues to be important for colour compounders, who must test their raw materials for restricted materials such as additives or pigments containing heavy metals, including cadmium or lead. For packaging applications and any European applications, colour compounders must ensure their masterbatches do not contain organo-tins, which are sometimes used as polymer stabilizers or pigment catalysts, notes Mr. Blasius. The changeover from lead stabilized to calcium-zinc stabilized PVC formulations in Europe has presented challenges for formulating PVC colorants, notes Mr. Dudas. While lead formulations were somewhat standard, there are many variations and continuing changes in mixed metal, calcium-zinc stabilizer formulations, he explains. There is an increasing trend towards heavy-metal-free colour not only in Europe but also in the U.S., say industry experts. There is also increasing demand in the U.S. for pigments with FDA approval. Ciba recently introduced the Xymara™ line of FDA-cleared special effect pigments and gained FDA clearance for Ciba® Cromophtal® Yellow 3GNP. Clariant Masterbatches introduced a palette of colours prescreened for USP class 6 to help customers take some of the risk out of developing products for the medical device market, says Mr. Blasius.

New technologies bring multiple functions to colours
Adding multiple functions to colours is a growing way to meet customer needs and add more value. For example, in its new Lexan DMX resins, GE combined its scratch resistant polycarbonate technology with rich colours such as piano black that are normally very sensitive to scratching. Engelhard Synergy™ pigments optimize both organic and inorganic pigments for improved properties and reduced cost by 'rightfitting' - giving customers the properties that they need but removing those not needed, says the company.

Recent developments in pigments and dyes have been based on understanding how colours absorb, reflect, or transmit different portions of the light spectrum. Functional dyes and pigments manage light for applications such as transmitting certain wavelengths of light through greenhouse film to improve plant growth, or reducing heat build up in dark-coloured exterior plastics. Infrared reflecting pigments reduce heat build-up in dark coloured plastic parts, which helps prevent degradation and reduce warping.

Shepherd Color offers Arctic® inorganic pigments that reflect infrared energy, and recently introduced a new blue-shade black, Arctic Black 10P922. "Arctic pigments are well known in the PVC siding and building products markets, and have more recently been used in other applications such as lawn furniture and playground equipment," notes Dr. Brannon. Users should note that some materials may appear to be the same colour but have different infrared reflectance properties, cautions Dr. Brannon. For example, adding carbon black, which is a strong absorber, to a formulation will reduce its IR reflectance. Other IR reflecting pigments include Ferro's Cool Colors™ and Eclipse™ black pigments.

Coloured pellets from PolyOne Corporation.

 

In PET packaging, ColorChem's new UVaplast UV absorbing dyes are used to protect the package contents. ColorChem's Amaplast IR absorbing dyes speed processing on PET bottling lines by absorbing IR light from the quartz heaters used to preheat PET performs. "The PET packaging market is an innovative area that is growing worldwide and is actively looking at new developments. In this industry, incremental improvements in efficiency can add significantly to the bottom line," says Tom Shakely, product manager at ColorChem International Corporation. There is a trend in PET bottles towards combining colour with additives such as UV protectants and odour scavengers, says Mr. Nitardy, noting that PolyOne's SmartBatch™ concentrates combine colour and additives in one pellet.

Contacts:

Ampacet Corporation
Website: http://www.ampacet.com

Ciba Specialty Chemicals
Tel: +1 302 992 5600
Website: http://www.cibasc.com/plastics

Clariant Masterbatches Division
Tel: +1 508 829 6321
Website: http://www.clariant.masterbatches.com

Clariant Pigments & Additives Division
Tel: +49 6151 875534 or
+1 401 823 2421
Website: http://www.pa.clariant.com

Color Services & Assoc. Inc.
Tel: +1 815 653 7800

ColorChem International Corporation
Tel: +1 770 993 5500
Website: http://www.colorchem.com

Engelhard Corporation
Tel: +1 732 205 5901
Website: http://www.engelhard.com

Ferro Corporation
Tel: +1 419 682 3311
Website: http://www.ferro.com

GE Plastics
Website: http://www.geplastics.com

Holland Colours
Tel: +31 55 366 3143
Website: http://www.hollandcolours.com

PolyOne Corporation
Tel: +1 216 589 4018
Website: http://www.polyone.com

Shepherd Color Company
Tel: +32 16 46 88 88 or +1 513 874 0714
Website: http://www.shepherdcolor.com

Teknor Color Company
Tel: +1 401 725 8000
Website: http://www.teknorapex.com

Viba S.p.A.
Tel: +39 0331 687 491
Website: http://www.vibagroup.com