PET bottle packaging: Innovate or stagnate

A MULTITUDE of evolving expectations for packaging dictate what today’s bottled products should look like and how they should be made. Each pack option has its own market, environmental and process benefits, but the industry also needs to consider the different needs of retailers. They have to cater to customers who want assurance that the beverage they buy is safely produced; comes in a pack format that is easy and convenient to use; and is packed in the most sustainable format available.

Polyethylene terephthalate or PET as it is commonly known, has become the preferred packaging material since its introduction in the early 1980s due to its appeal.  As an attractive alternative to glass, PET is now outpacing the growth of traditional packaging materials because of its flexibility in form and size, especially in beverages when compared to arch rivals like the beverage can, glass bottle and liquid carton, reports market research firm Euromonitor. To give beverages their individuality and capture the customer’s eye, producers are increasingly turning to PET to create bottles with distinctive shapes, attractive labels, optimal lightweighting and high quality.  The re-closability afforded by the PET bottle for on-the-go convenience is a pertinent, core strength of the format.  

“Innovations in plastic packaging have brought plastics into new areas once dominated by these materials. Replacement of traditional packaging applications and reduced atmospheric emissions are the reasons for the increasing demand for PET,” says Amunugama Nalin, General Manager of BOGE KOMPRESSOREN Asia Pacific.

Amunugama Nalin, General Manager of BOGE KOMPRESSOREN Asia Pacific

With the demand for beverages predicted to double by 2030, manufacturers need to rely on packaging solutions that meet all their production, food safety, profitability, and sustainability goals. Since PET is fully recyclable, cost-effective and keeps beverages fresh and safe, it will continue to propel the beverage packaging market.

“The characteristics of PET offer many design possibilities.  Its transparency and clarity are also key assets, allowing customers to see the bottle’s contents and assess the quality of the beverage,” Mr Amunugama emphasizes.

Light and right weight

For bottlers of both soft drinks and water, these are golden days for shedding weight, with more and more grams of material being carved from necks, sides and bases. Lightweight bottles offer the industry massive untapped potential for reducing raw materials, processing, distribution and energy costs. 

Most manufacturers are already reducing the weight of their PET bottles by designing optimized preforms, converting the bottles to short neck or completely redesigning the bottle shape. They are not only engaged in lightweighting, but also in RightWeighting™ the bottles, in order to find the perfect balance between resource savings and a great consumer experience. However, when it comes to decreasing the quantity of material used and the overall weight of the bottle, design is very important for optimizing the bottle’s performance.

Since the cost of the raw material used to make a PET bottle represents a significant part of the cost of the product (up to 75 percent of the bottle filled, capped and labeled), the trend towards lightweighting also makes financial sense.  Over the last 23 years, the typical weight of PET bottles holding 1.5 liters of still water decreased from 42 to 22.5 grams, while the manufacturing rate increased from 1,000 to 2,250 bottles per hour.  The lightweighting trend is expected to continue, with the typical bottle weight falling below 20 grams. 

Recycle and reuse

PET bottle recycling surpassed the 1.36 billion kg mark in 2014, with PET and high-density polyethylene representing the bulk of the recycled material, according to the Association of Plastic Recyclers and the American Chemistry Council. Taking advantage of the increased availability of recycled materials, major brands like Coca-Cola and Pepsi started using recycled PET (R-PET) for their packaging, thereby increasing their sustainability and reducing their carbon footprint. 

Europe is also making a push to increase recycled content in PET bottles. The European Union is currently funding a US$3 million research project through Polymark.  Launched in 2014, Polymark comprises key stakeholders in the PET value chain, charged with developing new technologies, one of which is to identify and sort polymers, including PET, in the high-value plastics waste stream over three years. PET combines the ability to be used for innovative packaging with the capability to be recycled, and is by far the most recycled plastic material in Europe.  More than 66 billion PET bottles were collected and recycled in 2014, representing 57 percent of all discarded PET bottles sold in Europe. Almost 30 percent of the total amount of recycled PET is already being used to produce new PET bottles.  

Polymark has successfully developed a prototype, flexible, coating-based approach for marking PET bottles. The group used commercially available, near UV-excitable markers with strong fluorescence in the visible region of the electromagnetic spectrum that allowed them to develop high-speed detection technology with minimal UV/ozone generation hazards. The markers are formulated in a water-based, sprayable coating to minimize the use of volatile organic compounds (VOCs) that have associated flammability hazards. 

Polymark recently released preliminary technical results for the development of food-contact approved chemical markers which it hopes will improve identification and sorting of higher value elements, particularly PET, in the plastics waste stream. This will help the recycling industry to more effectively distinguish between food-contact and non-food contact PET while meeting EU regulations on the use of recycled PET for food-contact applications.

Clean, dry compressed air

The beverage industry depends on compressed air, free of any residues, such as particles, moisture or aerosols, for almost everything it does – whether it’s for cleaning, sorting and filling glass bottles or for labelling packaging.  For more than a decade, manufacturers have relied on oil-free compressors as they virtually eliminate compressed-air related food risks during production. For example, compressed air is required to make PET bottles. Any traces of oil in the compressed air can enter the bottles during the PET blowing process and contaminate the end product. This would negatively impact the taste and odour of the end product and even affect consumers’ health.

BOGE, a global leader in compressed air systems has developed a complete package for manufacturing PET bottles. The company’s Flexpet BFPO is a flexible and efficient solution for manufacturers who require totally oil-free compressed air of up to 10 or 40 bar. The innovative combination of oil-free compressing piston compressors (booster) and an oil-free screw compressor renders it totally safe for producing PET beverage bottles, making the Flexpet ideal for other sensitive areas of applications including the food and healthcare industry.

With the help of its K15 booster, BOGE was able to develop and market the entirely oil-free bundle solution for the PET industry.  The old Flexpet system was based on oil-lubricated SRHV boosters that filtered the oil from the air by means of filter technology. Thanks to the innovative push rod system, the booster does not use any oil at all. This means that manufacturers who operate in sensitive sectors will no longer need any expensive compressed air conditioning equipment.

Mr Anumugama explains, “Oil-free compressors may have a higher initial cost but they have lower maintenance costs as they eliminate the need for oil and filter replacements, and they also reduce energy consumption due to pressure drops in the filters.

The Flexpet comes with components for turnkey installation and is specifically designed to meet the requirements of medium-sized companies that operate in the beverage industry.

The Flexpet BFPO from BOGE is part of a complete package for manufacturing PET bottles. Offering a flexible and efficient solution for manufacturers whole require oil free compressed air of up to 10 or 40 bar, it comes with components for turnkey installation.

Breakthrough print technology

The world’s first Direct Print Powered system using Xaar 1002 printheads is in industrial-scale production, all set to print directly onto PET beer bottles at Martens Brouwerij in Belgium.  Martens, the second biggest brewery in Belgium, is an experienced filler of beer in PET bottles. Now in its eighth generation, the company’s own house brands constitute approximately 15 percent of its output, with the 85 percent attributable to private labels, which are distributed in European countries as well as in China, Japan, Hong Kong, among others.

The Direct Print system was developed by KHS GmbH, a leading global manufacturer of filling and packaging systems, and commercialized by NMP Systems GmbH, a KHS subsidiary for innovation businesses. The Direct Print equipment at Martens uses Xaar 1002 GS6 printheads to jet high-resolution (360 dpi physical and 1080 dpi optical) text and images in five colours (CMYK+W) using low-migration LED-cured inks directly onto PET bottles at the production rate of 12,000 bottles per hour.  The modular design system is also available in configurations of 24,000 or 36,000 bottles per hour. 

“Direct printing onto empty PET bottles is breakthrough technology that enables beverage companies to change graphics within minutes instead of weeks,” says Phil Johnson, Managing Director of NMP. “The use of digital technologies for micro marketing in the packaging sector to maximise consumer engagement is accelerating. The ability to create designs and print them directly onto bottles quickly is a powerful marketing tool which will give brands the ability to localize, personalize and customize their products to drive highly-effective promotional campaigns.”

Packaging the future

The food packaging industry remains vibrant and highly competitive, and food manufacturers are always on the lookout for packaging that can provide consumers with increased convenience and longer shelf life at a lower cost. The industry is well aware that consumers want innovation and value novelty. Creating packaging that is sensitive to the environment will begin to take new forms, particularly using plant-based, recycled, and renewable materials.  The packaging industry must innovate or it will stagnate.