An introduction to Blockchain


Today it is estimated that fraud costs the global food industry over £30 billion each year. Similarly, over the past decade, a series of scandals such as the 2013 horse meat crisis in the UK, and the growth in examples of counterfeit whisky and alcoholic drinks, have damaged consumer confidence in the quality and provenance of the food and drink that they are buying. A BBC investigation this year has identified that more than a fifth of meat samples taken by trading standards across the UK contained traces of DNA from other species.

The demand for traceability and trust throughout the food supply chain has never been greater.

Indeed, 2018’s report by Mintel on Global Food & Drink Trends demonstrates a clear demand for food safety, listing the need for ‘Full Disclosure’ across the supply chain as its first key trend.

Without trust, value chains – particularly those that support global manufacturing – cannot exist. However, that trust has historically been difficult and costly to establish.

What is blockchain?

As defined by the recent FSA project, “A Blockchain is a type of database that takes a number of records and puts them in a block (just like putting them on to a single sheet of paper). Each Block is then ‘chained’ to the next block, using encrypted signature. This allows block chains to be used like a ledger, which can be shared and checked digitally by anyone with the appropriate permission.”

Put another way, blockchain technology is a way of storing and sharing information across a network of users in an open virtual digital space.

The technology allows users to look at all transactions simultaneously and in real-time. In food, for example, a retailer would know with whom his supplier has had dealings. Additionally, since transactions are not stored in any one location and are linked cryptographically, they remain tamperproof. Also, full traceability is provided throughout the supply chain as actions are time stamped and referenced as they occur and by being available for any interested parties to view, this complete visibility provides a further deterrent to any attempt at falsification.

A diagram of the foundations of Blockchain

What are the benefits of blockchain?

By design, every transaction along a supply chain on the blockchain is fully auditable. By inspecting the blockchain, smartphone applications can aggregate and display information to customers in real-time. Thanks to the strong integrity properties of the blockchain, this information can be genuinely trusted.

For consumers, blockchain technology can make a real difference. By reading a simple QR code with a smartphone, data such as, but not limited to, an animal’s date of birth, use of veterinary medicines and location where the livestock was reared can easily be communicated to the consumer. This provides the greater trust demand and empowers individuals to make better-informed purchasing decisions.

The role of coding in blockchain

Creating the infrastructure to set up the blockchain system is a fundamental part of the solution. However, there is also a key requirement to link the digital information to the physical product.

The technologies by which goods and materials are identified and linked with their digital representation on the blockchain, such as serial numbers, barcodes, digital tags like RFID and NFC, and QR codes are therefore crucial in uniquely identifying a physical product with its digital counterpart.

Adding a code to the goods as a unique identifier acts as a reference point and a link to the vast amount of web-based supporting data. The ubiquity of mobile devices means that consumers can readily access this ‘internet of things’, gathering provenance information not just at the generic category level but for the specific item in front of them. The quality of code and ease of accessing the associated information on the product is therefore critical – as is the cost effectiveness of any technology.

Selecting the best coders

RFID and NFC provide a means to automatically identify and track tags attached to objects and goods. The tags contain electronically-stored information which can be passed on to a reader such as a smartphone, to establish communication by bringing them close to each other, however they remain relatively expensive to implement as a technology at an item level.

An alternative is to attach a printed code to goods and there are a range of printing technologies available to apply a physical code linked to the blockchain, each with their own strengths and suitability, depending on the application. Some offer far greater levels of suitability for specific packaging or product compliance.

It is therefore worth considering the main aspects of each technology in some detail, examining their suitability for blockchain applications by taking into account aspects such as product, pack type, factory/coding environment and line speed.

Thermal Transfer

Thermal Transfer Overprinting (TTO) is a contact print process that is able to print high quality codes at excellent resolution across a range of flexible packaging. The process uses thermal energy to transfer ink from a carrier material to the packaging media. Available print areas are relatively large, and the process is very clean and versatile.

The process allows for printing directly onto packaging media and is therefore efficient in terms of process and material costs. Print resolution is typically 300 dpi. Higher resolutions are available, but these are not generally needed in most applications.

TTO is widely favoured but its application reach does have limitations. Due to the contact print nature of the technology, it is only suitable for flexible packaging and linear print speeds are typically restricted to about 800mm\s if printing barcodes.

ICE Zodiac Hawk Thermal Transfer Overprinter

Other technologies

Thermal Inkjet (TIJ)

TIJ is a non-contact process in which liquid ink is “fired” onto the packaging using thermal expansion. The majority of inks are water based and use vaporisation of the water to create the thermal expansion process. These inks must be applied to porous media to give reasonable drying times. Other ink types are available which allow printing onto non-porous media, but these often have longer drying times and may also contain MEK type chemicals.

Thermal Inkjet is a relatively high-speed process, provides good resolution and due to its non-contact nature, is suitable for printing onto rigid media. The print area is limited by the height of the cartridge array – up to 12.7mm per cartridge.

Consequently, multiple heads must be used if greater print heights are needed. For this reason, TIJ is generally limited to use on primary packaging, or small-scale secondary packages.

Cost per print is comparable to TTO, and due to much of the print technology being contained within the disposable print cartridge, reliability levels are extremely high.

Label Print Applicators (LPA)

Print and Apply Labellers print information onto a label which is the applied to the pack. Unlike LCM, this can deal with most secondary pack types (e.g. shrink-wrapped cases, cardboard cases etc.) with high resolution and print quality, typically 300 dpi using thermal transfer technology. The equipment costs are comparable to LCM, although print quality and barcode legibility are usually higher. The technology is very clean, and systems are available which can apply labels to most pack types, on almost all faces of a package.

Large Character Marking (LCM)

LCM or case coders print variable information, including codes and graphics, directly onto secondary packaging such as cardboard boxes, using inkjet array printing, where a vertical array of addressable jets is used to form an image on a package as it passes. The technology allows for non-contact printing directly onto porous packaging, and so is efficient and has good cost per print figures. However, since corrugated cases are usually brown, this limits the contrast which can be achieved; meaning the quality of barcodes is not as high as when using a paper label.

Print area is typically up to 70mm high with good resolution. Multiple heads may be used to increase print areas and allow application of information to different sides of a package.

Continuous Inkjet (CIJ)

CIJ is another non-contact inkjet process. It uses a stream of charged droplets, which are “steered” to create the printed image. It is able to print onto a wide variety of substrates and win a choice of different coloured inks, at very high speeds.

The resolution of CIJ is not as high as other technologies. In addition, the ink contains a solvent which evaporates after contact with the media to provide fast drying, but this increases the cost of the process, and also the system’s complexity.

The print area is limited by the print height which can be achieved, and whilst the technology provides very high printing speeds, these will reduce as the number of lines of print increases.

CIJ has a higher maintenance requirement than TIJ, but a far broader range of substrates may be printed.

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