Compounders smell success in packaging The use of fragrances and deodorants in plastics compounds is on the increase with key applications in packaging in particular. Jennifer Markarian reports on some of the applications already on the market and describes some of the difficulties encountered in their incorporation in plastic compounds.

March / April 2006

Fragrances and deodorants for plastics are used in a variety of applications and are playing a growing role in marketing food and beverage packaging and in consumer products for the home. Fragrance-containing plastic applications are growing globally, say industry experts.

Consumers are looking for more scent in their homes, notes Andrew Kindfuller, vice-president of global innovation and new ventures for International Flavors & Fragrances Inc. (IFF), a leading global flavour and fragrance supplier. In addition to more traditional methods of releasing fragrance into an environment such as sachets, candles and sprays, fragrances are now increasingly being embedded in consumer goods such as laundry baskets, storage containers, and sink stoppers, for example, notes Mr. Kindfuller. In industrial applications, such as scents for hotels, offices and public areas, fragrances are being encapsulated in both polymers and fibres. Home fragrance diffuser systems that have historically used liquids or gels are moving towards use of fragrance encapsulated in solid polymer instead, says Sandra Albee, marketing manager at fragrance concentrate producer Aromatic Fusion, Inc.

Packaging is a major outlet for plastics with fragrances. (Photo: © Getty Images)

 

Fragrances delivered in various plastic parts are being used in stores to create a mood, such as chocolate chip cookie fragrance being used in a kitchen store. Controlled fragrance diffusion systems are also being used in amusement park attractions for an 'extra-sensory' experience. In other applications, fragrances are used to scent toys, games and novelties, such as floral fragrances in plastic stakes used to support flower stems, notes Robert Axelrod, vice-president of sales, technology, and marketing at Polyvel Inc., which offers Polyscent™ pellet or powder concentrates. Other plastic applications include sachets filled with scented plastic beads and room air fresheners.

A relatively new and growing area for fragrances is use as a novel marketing tool for bringing products to the consumers' attention, particularly in food and beverage packaging. For example, AddMaster recently developed a chocolate fragrance masterbatch for use in polyethylene packaging of chocolate-flavoured milk-based drinks that is intended to create an 'in-store awareness' of the product. "Smell is the only one of the five senses capable of triggering a true impulse reaction because it is the only sense processed in the brain's limbic lobe, the section of the brain where emotion, hunger and impulses are processed and where memories and experiences of pleasure are stored. Nothing rivals the sense of smell for making an immediate impression about a product's flavour and freshness," explains ScentSational Technologies, which develops and licences olfaction packaging technologies. ScentSational has patents surrounding the effects of scented packaging and patents pending in relation to using food grade flavours in polymers and their subsequent effect on the aroma and taste of foods and beverages. ScentSational's CompelAroma™ Encapsulated Aroma Release® technology involves adding specially engineered food grade flavours within the structure of plastic packaging components to enhance the aroma profile of a product, says the company. In most cases, ScentSational licences its technology directly to brand owners, and then works with flavour and fragrance companies, compounders and packaging vendors to incorporate the technology into end-use applications. "Leading flavour and fragrance suppliers Givaudan and Firmenich, as well as others, utilize our proprietary flavour and fragrance formulation guidelines to create flavours and fragrances which are specific to the application," says Steven Landau, ScentSational Technologies CTO.

Scent can be incorporated into plastics. Photos: AddMaster

"We are getting tremendous interest from brand owners for improving aroma, taste and shelf-life. CompelAroma puts back some of the flavours lost during food processing or that are unable to be added during processing, such as fresh-cut basil. CompelAroma in package walls or liners can significantly increase the length of time that a package such as coffee remains on the shelf because a desirable aroma is maintained. This is a way for brand owners to reduce costs but maintain product quality. Brand owners are very focused on the bottom line. We look for cost-effective ways to add aroma, which sometimes involves redesigning the package," explains Mr. Landau. ScentSational has developed technology to add fragrance and flavour to closures or closure liners for beverage containers. "It is especially beneficial for single serve beverages that are consumed directly from the bottle. This is because approximately 90% of what a person tastes is a result of their sense of smell. With CompelAroma, the headspace of the bottle is filled with very aromatic top note aromas that provide a greatly improved consumer experience," says Mr. Landau. ScentSational is working with packaging company Crown Holdings, Inc. to encapsulate aroma and flavour in liners and closures for Arizona Beverage Company's ready-to-drink teas.

CompelAroma also works well with beer, flavoured malt beverages, and flavoured distilled beverages. "CompelAroma enables light and low carbohydrate brands to offer a more full-bodied beer aroma and taste experience without modifications to existing formulations. It can also add the aroma and taste of citrus and fruit flavours without these distinct flavours being lost in other ingredients," explains the company. IFF is developing technology to actually impart a flavour from a polymer to a previously unflavoured food or beverage, says Mr. Kindfuller. For example, plain potato chips (crisps) could be transformed into different flavoured chips using flavours imbedded in a polymer sheet or package. Flavouring frozen food lids is another possibility.

Besides adding marketing appeal to food and beverage packaging, fragrances are being used in point-of-sale displays, white-goods showroom displays and personal care packaging. AddMaster has developed a baby lotion fragrance masterbatch for a company that manufactures point-of-sale display stands. In point-of-sale displays for fine fragrances, bottle tops and sampling devices are used to give an exact rendition of the fragrance, rather than actually spraying the perfume. This is particularly useful in European markets where spraying perfumes are regulated or prohibited, says Ms. Albee.

Photo: © Getty Images

 

A new and growing market area is adding fragrance to closures of shampoo, laundry detergents, and other cleaning, health and beauty products in which consumers want to sample a product's scent, but manufacturers want to avoid product tampering, say industry experts. ScentSational has developed patent pending technology for this application.

Fragrances are also being used to mask unpleasant odours in applications such as garbage bags or household chemical containers. In trash bags, citronella fragrance both masks odour and keeps insects away, notes Joseph Serbaroli, strategic business manager at Ampacet. Fragrances such as cedar can be used after renovating computer rooms or offices to mask the odour remaining from materials in wire and cable and other new plastics, adds Mr. Serbaroli. In PVC, fragrances are used to cover the smell of sulphur based stabilizers, says Dr. Axelrod. In pharmaceuticals and neutraceuticals, pleasant odours can be used either in a container wall or in a desiccant canister for masking unpleasant odours of medicines or vitamins. For example, Süd-Chemie Performance Packaging is licencing ScentSational's CompelAroma for use in Süd-Chemie's Aroma-Can® dessicant canisters. The canisters release scents such as orange or lemon to mask odours from packaged products such as fish oil tablets or herbal supplements. Süd-Chemie will soon be offering CompelAroma® in stoppers, tubes, packets, bags and other scented packaging configurations, says ScentSational.

Suppliers are seeing an increased interest in deodorants that can be used to absorb volatile organic compounds such as malodours or unwanted vapours from plastic articles, rather than simply masking them with a pleasant scent. Deodorants consist of dispersions of microporous inorganic materials in a polymer carrier. Inorganic materials with specific ranges of pore sizes are selected, depending on the type of vapour to be absorbed, explains David Wells, sales manager at speciality compounder AddMaster (UK) Limited, which supplies ScentMaster fragrance and odour neutralizer masterbatches. Deodorants are typically used in articles containing recycled polymer or polymer with residual monomer content. In some food packaging films, deodorants can be used to remove odours and gases that can lead to food spoilage. AddMaster notes that the company has had success in combining deodorants with silver-based antibacterial additives, to give products that absorb malodours as well as inhibiting growth of the bacteria Pseudomonas aeruginosa, which is a primary producer of malodours from the breakdown of organic materials. Wells Plastics also provides combinations of antimicrobials with fragrance systems, typically for hospital or healthcare applications. "Inorganic antimicrobial systems are used in conjunction with fragrances by Wells Plastics, because organic antimicrobials solubilized by the fragrance tend to migrate from the polymer at a much faster rate, often during the extrusion process", notes Carl Birch, sales and marketing director at speciality additive masterbatch producer Wells Plastics. Deodorants are also used in combination with fragrances, he adds.

Compounding of fragrances
One of the greatest challenges for incorporating fragrances into plastics is that typical polymer processing temperatures may cause fragrance components to flash off or may change the fragrance profile. Due to processing temperature concerns, fragrances are better suited to olefins rather than higher temperature plastics such as nylon or PET, notes Dr. Axelrod. Fragrances can also be put into some biodegradable plastics, he adds. Fragrances are typically incorporated into masterbatches or concentrates for later addition during extrusion or moulding of the plastic part.
Several suppliers of fragrance concentrates and compounds use proprietary or patented compounding processes to incorporate fragrances into a masterbatch without deteriorating the quality of the fragrance. "Due to the low temperature processing utilized in the unique production process of our ScentMaster fragrance masterbatches, the heat history of the products is not compromised, thus protecting the top notes of fragrances while allowing for optimum performance in the final application. Normal polymer processing temperatures can typically be used by the customer," claims AddMaster's Mr. Wells. While standard resin processing temperatures can be used, holding process temperatures to the low end will minimize fragrance loss during processing, recommends Polyvel. The formulation must be designed to both survive plastics processing temperatures and to be long lasting in the end product. "Factors such as the compatibility of the fragrance with the base, the choice of polymer carrier and residence time in the extruder affect how well the fragrance stays in the polymer matrix to be released slowly over time," says Wells Plastics' Mr. Birch. IFF supplies PolyIFF® fragrance loaded pellets for use either in a sachet or as a concentrate for plastics processing. "PolyIFF® pellets hold fragrance longer due to our patented compounding method," says Mr. Kindfuller. IFF plastic processing experts can help plastics processors optimize their process so that the fragrance remains intact. Possible solutions are to add the fragrance concentrate later in the process or to use lower residence times or lower temperatures, notes Mr. Kindfuller. Compounders, fragrance suppliers and plastics processors often work together in three-way development to develop a fragrance formulation that meets both processing and end-use needs, adds Dr. Axelrod. The development process includes optimizing the diluent or carrier for the fragrance and looking for possible discoloration interactions with other additives. Encapsulating fragrance to optimize performance is a very sensitive process, cautions ScentSational's Mr. Landau. ScentSational's CompelAroma™ Encapsulated Aroma Release® technology was commercialized in 2003 after several years of research and development in developing proprietary fragrances formulations, solvent systems and methods of encapsulating the fragrance in the polymer. The proprietary technology includes methods of producing fragrance concentrates as well as adding fragrances directly to moulding or extrusion processes, he notes.

Photo: © Getty Images

 

Aromatic Fusion Inc., which began commercial production in 2004, uses a patent-pending, minimal heat, multiphase dispersion compounding process to create fragrance infused polymer concentrates or direct-use compounds in proprietary polymer matrices. In the pressurized, ambient temperature Aromatic Fusion process, temperatures increase by 5-10°C at the most, so that no fragrance is lost due to flash off or burn off and there is no colour shift due to heat exposure. Products from this no-heat process are in demand for fine fragrance sampling in particular, as well as other applications, says Ms. Albee. "Heat takes out the high and low notes of a fragrance, which is what distinguishes a perfume," she explains. Loading levels from 5-70% are possible, depending on the resin, fragrance and application, notes Ms. Albee. Addition of fragrance lowers the melting point of the mixture by 10-20°C, thus reducing the moulding or extruding temperature needed, she adds.

Fragrances can also be added via microporous resin concentrates such as Accurel® MP and XP from Membrana/Accurel Systems. "Microporous structures act like tiny sponges with the ability to absorb several times their own weight of liquid additive. When liquids or meltable solids are mixed with the porous polymer, the micron-size voids in the polymer are filled by capillary absorption. Since the mixing is done at room temperature, it is especially suitable for thermally sensitive additives. When loaded with additive up to 75% by weight, the system remains dry and free-flowing," explains Claudia Gramann, marketing manager at Membrana's Accurel Systems.

Processors should be educated about processing fragrances and be prepared to expect their release during the manufacturing process, cautions Mr. Kindfuller. In some cases different air handling systems may be warranted.

Contacts:

AddMaster
Tel: +44 1785 225 656
Website: http:// www.addmaster.co.uk

Ampacet
Tel: +1 914 332 7329
Website: http://www.ampacet.com

Aromatic Fusion Inc.
Tel: +1 215 244 1830
Website: http://www.aromaticfusion.com

International Flavors & Fragrances Inc.
Tel: +1 212 708 7278
Website: http://www.iff.com

Membrana/Accurel Systems
Tel: +49 6022 812 434
Website: http://www.membrana.de

Polyvel Inc.
Tel: +1 609 567 0080
Website:http:// www.polyvel.com

ScentSational
Tel: +1 215 886 7777
Website: http://www.scentt.com

Wells Plastics Ltd.
Tel: +44 1785 817 421
Website: http://www.wellsplastics.co