Every packet coding

Legislation and consumer pressure have resulted in very widespread application of every packet coding in the biscuit industry. All packaged food products should be coded to ensure that they are likely to be in satisfactory and safe condition when they are bought and consumed. For perishable foods where there is a potential for food poisoning "Sell by" coding is used but for other foods, like biscuits, where deterioration is not dangerous "Best before" marking is usually adopted. In some countries it is also necessary to show the date of manufacture of the product. In this way consumers are protected from the possibility of purchasing packets that contain substandard biscuits.

Most biscuits are wrapped in plastic films that are formed into packs from reels. It is normally impossible to include a "Best before" coding onto the film at the time that it is printed because the time when it will be used is uncertain. Thus techniques have to be used that print the code as the pack is made and this can mean very high speed movement of the film on the wrapping machine. Of all the possible methods the only practical one for biscuits is hot foil printing. This involves the setting of a small die assembly with the desired information, and placing it in an apparatus that heats it and presses it against a film with transferable material, usually plastic "ink", which is pressed against the wrapping film at the correct place. In the early days of this technique more problems arose from this printing device than for all other adjustable points on the wrapping machine. Thankfully the hot foil printers are now much more reliable. Their good performance needs constant vigilance as it may be an offence to supply biscuits with no coding or illegible coding.