Packaging Technology and Engineering. Dipak Kumar Sarker

these innovations. Surprisingly, given its cost, after the 1970s glass packaging began to be used ubiquitously for the protection of high‐ and low‐value products and to aid the visibility of pack contents. It continues to demonstrate a wide variety of uses today and remains a form of packaging that can be recycled; in the modern era this is an important consideration.

      Metal packaging, used in antiquity in the form of gold, silver, and pewter boxes as well as strong alloys such as bronze and brass for coverings and to protect many products, is finding new uses in modern packaging technology. Tin – an essential part of tin‐plated steel, the basis of almost all food cans – became a viable surface treatment following the production of tin in sheet form in Bohemia from 1200. Later, at the beginning of the 1300s, metal cans were first used to store food. These cans were different from those of the modern era but remained an unwritten ‘secret’ until the 1600s. William Underwood aided in the further development of the food can by the development of an improved process for fabricating steel plate. The notions of food cans and of canning were pushed to the forefront of public awareness in 1809 when Napoleon Bonaparte offered a reward of 12 000 French Francs (∼£1000), a huge prize in that period, to any inventor who could develop a method to protect army food supplies during envisioned military excursions and campaigns. The opportunity was seized by Nicolas Appert, a confectioner from Paris (portrayed in Figure 6.4), who presented a selection of pasteurised lidded glass jars, following on from initial investigations. He found that a steel can covered with a fine layer of tin was able to preserve food post heating in an aseptic process and without the can container rusting in the damp. A year later Englishman Peter Durand patented the familiar‐shaped cylindrical can with his coated tinplate as an invention. This development spawned a host of subsequent modifications and adaptations. The first printed box was made in the USA in 1866 but went on to be used for containment of many types of product. Fast‐forwarding to 1910, the tin box was found in commercial environments ubiquitously until the point when aluminium in a suitable form became available. The aluminium foil box was developed in the early part of 1950, and in 1959 the first aluminium can‐based food became available.

      In the nineteenth century sharp objects combined with hammers were used to open metal packaging and tin cans, which was a highly unsatisfactory state of affairs. Later on and at least until the middle of the twentieth century, the ‘pig‐stick’ tin can opener – a brutal spear‐looking object, based on a steel spike and sliding blade – was used to open food products. The routine use of the pig‐stick device and the sharp serrated edge it created resulted in many hand injuries. The pivoting can opener was developed by E.J. Warner in 1858, followed by the ‘church key’ of 1892. The pivoting can opener was improved on in 1925 by the Star Can Opener Company, and yet further improved in the now familiar pliers‐form Bunker‐type modern can opener first developed in 1931 by the Bunker Clancy Company. Electric can openers were developed in the late 1950s and the side can opener was developed in the 1980s. Packaging with tear‐open lids was first developed in 1966 and has become increasingly evident in use over the last five decades.

Paper, which is still used universally in the present times, is the oldest conveniently reshaped packaging material available. In ancient Egypt in 5000 BCE, papyrus – a material based on marsh reeds – was used to wrap foods and hold objects together. Many millennia later in China, mulberry tree bark, reconstituted as paper, was used in the first and second centuries BCE to pack food. Paper‐making methodologies and techniques improved during the subsequent 15 centuries. These high‐quality papers and products and technological know‐how were then transferred to the Middle East. From there paper‐making techniques reached Europe, and then from Western Europe they reached England in 1310 and subsequently America in 1609. In 1817 the first commercial cardboard box was produced in England, almost 200 years after being made in a basic and simplistic form in China. The corrugated form of cardboard was invented in the 1850s, gradually replacing wooden boxes in the trade and transportation of goods such as fruit to the point at which, today wooden boxes are barely seen for food products. Selected examples of continuing wooden box or crate use do persist but these are relatively rare. The twentieth century has been the most prominent period for universal paper and cardboard use with the added advantage of recyclability and biodegradability. This is an important consideration since, in the UK in 2013 alone, approximately 750 000 tonnes of household waste, rich in plastic and paperboard materials, went for landfill disposal.

1.2 Survey of Packaging Use

      Consumers demand convenience from their packaging, so packages can have features that add convenience in distribution, handling, stacking, display, sale, opening, reclosing, use, and reuse. Packaging materials are used for a host of commercial product‐containment purposes. These traverse informatics and IT, such as CD or USB stick packaging, through to the diverse range of degradable (e.g. cooked meat) and non‐degradable (e.g. retorted canned fish) foods and also the protective and containing roles of packaging used for over‐the‐counter and prescription‐only medicines, surgical aids, or emergency medicines, and to safeguard the consumer against accidental consumption or contamination. Everything from furniture to garden centre compost and on to mobile phone devices is enveloped in an informative and protective sheath of packaging. In this book, topics centre on foods, medicines, and medical devices but these still account for only approximately 45–50% of global packaging use. Packaging accounts for about one‐third of the use of all polymeric materials and is by far the single biggest use of the materials. Medicine bottles and closures alone, for example, account for about one‐third of pharmaceutical packaging use.

A definition of the meaning of packaging indicates that packaging fulfils at least five roles. The first of these is the socioeconomic role of packaging; since the packaging has a value of its own this is not simply attributable to the contents being of significant value. Consequently, a good definition suggests that packaging is a precious material that protects the product within, allows the product to reach the customer in the most hygienic and safest form, and makes it easier to transport and store the product after delivery. The socioeconomic influences on packaging form are technological, political, sociocultural, availability (being at hand), ecological, economic, and demographic. Packaging has often been referred to as originating as a consequence of these socioeconomic influences, as the ‘silent salesman’, and both has managed to enter the commercial sphere and is used as a vehicle in the marketing arena in the form of the ‘8P's’ or ‘holy octet’ concept. The holy octet involves the product itself as well as aspects of pricing, placement, promotion, participant involvement, physical form, process of use, and finally a notion of personal targeting, all obtained from the idea of a malleable marketing mix to appeal to the customer [2]. The other four criteria that define packaging cover the basic functions of any packaging, which can be effectively summarised as relating to the provision of a description (information, salesmanship, and promotion) of the product, very important containment, equally important protection for storage capability, and the ability to be successfully transported or shipped across the globe.

      The reasons for adherence to packaging use are manifold but are based on the ability of the materials to reduce wastage and, in doing so, because of scarcity or perishable status, reduce the product cost. A crude estimate suggests that 30–50% of ‘thrown food’ and medicinal products are disposed of because of inadequate storage; therefore, extending shelf life by a means that requires passive storage without energy consumption consequently saves energy (need for freezing/refrigeration/cooling). The pack itself also has a very important mechanical role in that it reduces damage while presenting the product in an aesthetically pleasing form. For a number of products that require a guarantee of microbial security, the pack also serves as a means to avoid pack tampering (see Chapter 8). At the same time the pack must provide information (safety, nutrition, dosage strength, mode of operation) to the customer and, therefore, aid selection or choice‐making. When well designed, a package can provide convenience, as in the case of ring‐pull or easy‐opening closures, and may in the presentation of an easily recognisable form aid the marketing of goods. However, the complexity and sheer number of layers of packaging in composite materials combined with the non‐biodegradable nature of some forms of packaging (plastic, laminated paper, glass) have contributed enormously to concerns raised