Weights and measures – are you compliant?

Published on Friday 03 August 2018 (1:09pm)

One of the most important requirements of process manufacturing is ensuring that packaging contents are accurate and compliant with local weights and measures legislation.

Current UK legislation defines packaged goods as products that are sold sealed, between 5 grams and 25 kilograms or 5 millilitres and 25 litres and are of the same weight or volume as other products of the same type.

What does it all mean?

There are two accepted ways to pack your products – the minimum system and the average system. In the minimum system, your products should be packed so that they contain at least the quantity displayed on the label. The packages can contain more than the label says, but not less. Using the average system, your products can be packed to an average measurement that is displayed on the label.

Reducing or (eliminating) underweight packs is therefore a vital part of the process. Equally as important is reducing overweight packs as either will result in product giveaway or waste; a long-term cost to you and your bottom line.

The most effective solution is to install a checkweigher in your production line. This will ensure your compliance with legislation – and your weight control/quality control.

Packaging must be checked to make sure a random sample is packed to meet a set of rules known as the ‘three packers’ rules’.

These rules state that:

  1. The contents of the packages shall not be less on average than the nominal quantity. With a checkweighers installed, you can carry out a checkweigher test to ensure average weight is enabled and correct. Pass the first product below target – this should reject. An inline checkweigher will automatically monitor this and reject any product dropping the batch average below the target weight. A check on your filling system can reduce this happening and decrease giveaway as well. If you rely on Static Scale sampling alone – you may be missing this and could be giving more product away.
  2. The proportion of packages which are short of the stated quantity by a defined amount (Tolerable Negative Error or TNE) should be less than a specified level -Product Weight = 90g, TNE 1 = 4.5g. For the best accuracy, you should use a checkweigher that has a display value of 0.1g or lower (0.05g).
  3. No package should be short by more than twice the TNE. With a checkweigher installed this is easy because it is rejected and recorded as an underweight reject, as long as it is accurate enough. However, if you are only using a static scale, its difficult because it is only a sample.

The average system generally applies to most goods that are pre-packed in pre-determined quantities, by weight or volume, including food stuffs and non-foodstuffs.

Its aim is to provide you, the manufacturer, with a defined regulatory framework for the automatic filling of packages. A degree of variation in the content of the packages is an accepted part of the process, but the aim of the average system is to define acceptable tolerances for that variation, so that your customers and end users may buy with the confidence that they are protected against short weight or measure, while businesses are protected against unfair competition.

To demonstrate your compliance with the three rules, you are placed under a duty either to measure the content of each package, or to check the contents by sampling. Where you choose to measure each package, there is no requirement under the Regulations for records to be made. However, if records are not made, your compliance with the packers’ rules can be assured only by checking that each package contains at least the stated quantity (that is, by packing to the minimum system).

Telling the world

So, you have checked your products’ packaging using a checkweigher in your line. But, how do you demonstrate to your customers and consumers that the product complies?

You can place the E-mark on your packaging as a declaration by the packer that the contents comply with the average system Directives (Directive 75/106/EEC and Directive 76/211/EEC).

In essence, the E-mark is a measurement passport throughout the European Economic Area (EEA), ensuring free access, so far as weights and measurement requirements are concerned, to all EEA markets.

To qualify for E-marking the package must:

  • Have been packed in conformity with the three packers’ rules
  • Have a nominal quantity between 5g or ml and 10kg or L (inclusive)

And you must keep production records that prove compliance.

There is no requirement for your packages to be labelled with the E-mark, it is entirely optional. But whether you are producing to the average system or the minimum system, Yamato checkweighers can help you, particularly in the food processing sector.

Yamato I and J series checkweighers are designed specifically for the High-End Food Industry. They comply to the IP67 Standard for the ingress of water and contaminants and can comply with IP69K with additional motor seals only upgrade. They feature full stainless-steel construction and are fully polished for improved hygiene. They are also fully supermarket compliant.

Yamato machines are compliant with the CE-Mark, the Machinery Directive in relation to local UK safety compliance with machine guarding and risk assessments.

The Yamato I series Checkweigher is also fully Measuring Instrument Directive (MID) compliant. MID compliance is an option and requires initial verification if the only source of the average weight measurement is the Checkweigher. If it is not, then an offline type approved static scale must be used.

The bottom line is quite simple. A Yamato checkweigher in your production line puts you in control of compliance. If you install a checkweigher in your line you can comply with health and safety, accuracy and national weights and measures standards – putting you at a competitive advantage.

Can you afford not to?