What is batch coding and why is it so important?

5 minutes

Simply speaking, batch coding is the process in which an identifiable code, usually made up of both letters and numbers, is applied to a product and/or it’s packaging. It’s a code that will be given to a group of identical products that were all produced at the same time, on the same date, at the same location, using the same ingredients etc.

So, a consumer could pick up two of the exact same tins of soup from the Supermarket, with the same ingredients, produced in the same way but if they were made on a different day, or on a different line for example, they would carry different batch codes.

The importance of batch codes

Traceability is crucial to protect and reassure consumers and to comply with legal requirements. Therefore, applying batch numbers is a mandatory part of the manufacturing process for all companies producing goods destined to be sold to consumers.

The batch code allows the individual product and it’s history to be fully traced throughout the supply chain. This traceability is vital, for if there was an issue raised with a particular item, the unique code can be traced right back to the source. All products with the same batch code can then be recalled and removed from sale.

What is a batch coding machine?

A batch coding machine is the equipment that applies the batch codes, and often other variable information, such as date or LOT codes directly onto products and/or their packaging. This can be a printer (sometimes referred to as a coder) integrated onto a production line, or a dedicated off-line system that both feeds and prints onto the packaging before it is filled.

Aluminium foil lid coding for dairy products - best before and batch code
A glass pill bottle with white variable information printed on the bottom.
Pet food sleeve printed with batch number using best before date

Different types of coding technology for printing batch codes

Depending on the application, there are various technologies that can be used to apply batch codes onto packaging, each with their particular strengths and weaknesses. Here’s a quick summary of the most popular technologies:

Continuous Inkjet (CIJ) – A non-contact print technology with very good adhesion to most packaging materials. Ideal for high-speed production and printing on curved surfaces, i.e. the bottom of a can.

Thermal inkjet (TIJ) – A non-contact print technology that delivers high-resolution, high-speed coding. The compact units are mess and maintenance-free and require minimal downtime, due to their interchangeable ink cartridges.

Laser coders – An environmentally friendly non-contact technology, laser coders work by etching or vaporising the surface layer of the material, leaving an inerasable mark.

Thermal Transfer Overprinting (TTO) – A contact print technology, Thermal transfer is ideal for applications that require a large amount of information to be printed, typically onto flexible film, label stock and medical paper (Tyvek®).

Hot Foil coding – A contact print technology, hot foil is reliable, economical, and low maintenance, making it ideal for printing use by dates, lot numbers, batch codes and expiry dates. It is also versatile in that it can print metallic codes – something other technologies cannot do.

Things to consider when choosing a batch coding solution

There are several factors to take into consideration when selecting a batch coding machine. These are:

  • Substrate to be printed onto – is it porous/non-porous? Some technologies are better suited when it comes to producing long-lasting prints onto glossy surfaces.
  • Shape of the product – contact printers need to be touching the surface they are printing on to in order to make a print, whereas non-contact printers eject ink onto the substrate from a distance. If you’ve got a flat product, you could use either, but if it’s curved, you will need a non-contact printer.
  • Budget – It’s important to not only factor in the initial purchase price of the system itself, but the ongoing cost of running it in terms of consumables, downtime and maintenance.
  • Print quality required – How important is the print quality? Does it just need to be legible? Or, does it need to be clear and discreet so that it doesn’t affect the overall look and feel of the packaging?
  • Colour of print needed – The range of colours available varies depending on the technology, so if anything other than a standard black print is needed, it’s important to mention this early on.
  • Integration – Do you need a solution that can be seamlessly integrated into your existing line? What equipment does the new printer need to work with?
  • Speed of the production line – The coder needs to be able to keep up with the speed of the production line in order to prevent delays or bottlenecks.
  • Production environment – Does the coding machine need to be able to withstand harsh environments or contend with regular wash-downs?
  • Environmental impact – with an increasing pressure to make processes more sustainable, it’s good to understand the waste produced by the different technologies and the chemicals and energy required to use them.

Ask our experts

Deciding on the best way to batch code your products isn’t easy. Our team of coding experts at Rotech have over 25 years of hands-on experience working with manufacturers to deliver the best solution in terms of efficiency, capability and cost. Get in touch today to discuss your batch coding requirements.