11 - Is there a hard and fast definition of dosing accuracy?

mo explains: “Dosing accuracy” can be defined in many ways, depending on the application

Translucent injection-moulded components call for very high dosing accuracy. This makes disc dosing a good choice for this application.

Generally, the term “dosing accuracy” is used to describe how accurately a dosing unit achieves the target mass or volume. In other words, it describes the discrepancy between the required and actual mass or volume. However, you have to keep in mind that official values are typically determined in a laboratory environment, and usually only apply to specific materials. This means these figures reflect the dosing unit’s best-possible performance under optimal conditions – so you may not be able to achieve these results for your application.

For most applications, consistent dosing is crucial for achieving uniform results. Dosing tolerance also plays an important role – and must reflect the final product’s requirement profile. Dosing tolerance is defined as the greatest allowable deviation from the target values for the metered flow, the metered mass or volume, or the ratio of ingredients as required by the recipe.

Dosing unit 2 is more precise and has a narrower tolerance range. This allows it to operate at a lower setting, saving additive.

The final result depends on the material type and its properties, the dosing mechanism and dosing device, and environmental considerations. Numerous external environmental factors can have a large or small impact on dosing accuracy and results. This makes it practically impossible to calculate a universally applicable value independent of the surrounding conditions. When choosing and installing equipment, it is important to factor in parameters such as vibration, frequency of material changeovers, irregularities in material consistency, or how broad the different material throughput rates are.

Dosage accuracy can be determined by collecting samples of metered materials over a defined timeframe. Once there are a sufficient number of samples, statistical tools can be used to analyse dosing consistency, and to identify any errors. The overarching goal is to ensure good results via precise dosing. However, you should keep in mind that if dosing consistency is lacking, you can still achieve unsatisfactory results – even if the dosing is highly precise.

Choosing and installing dosing equipment sounds very complicated to you? Visit www.motan.com for help.

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