The starting points for most of the plastic products used today are polypropylene and naphtha-derived polyethene. These polymers are used in many applications ranging from toys to clothing. By adding different substrates to the base material during manufacture, specific properties of the polymer, for example texture, flammability, workability and color can be controlled. These properties can relate to legislated behaviors, for example fire-resistance, to how easy the material is to work with during manufacture, or to appearance.
Titanium oxide, for example, is a white pigment that is widely used. It helps make the color look bright and is especially useful because it adds opacity and whiteness. Magnesium, calcium and zinc stearates are used as lubricants to help reduce friction between the polymer and the other additives and this makes the process easier.
The amount of additive is controlled tightly because overuse can be expensive but there needs to be enough to ensure that the material has the desired properties. It is important to monitor the amount of additive in the mix during manufacture and one of the best ways of doing this is with XRD analysis.
Fast, Accurate Measurement with XRF Equipment
X-ray fluorescence (XRF) is an established technique for detecting contaminants, gauging how much of a given compound is present within a sample and for measuring elemental composition. The test is entirely non-destructive, so none of the precious production materials are wasted, and can measure liquid of solid samples.
The technique can accurately detect very low amounts of material (parts per million). This means that it is ideal for checking the amount of additive within polymer-based production.
A range of XRF analyzers that help make quality control simpler is available from Hitachi High-Tech. They can detect a broad variety, including magnesium, calcium, zinc and titanium. The polymer granules, fibers or discs are put into the sample cup and this is then put into the instrument and a button pressed. The measurement takes about a minute and results can be displayed in a simple pass or fail format on the screen.
Results are stored within the equipment and they can be directly transmitted to the cloud-based data management solution, ExTOPE connect. This makes it very easy to store and trace results for quality records and is also beneficial if certificates of analysis are required with shipments. The analyzers can be used equally effectively along the production environment or in a lab and their rugged design is built for minimum downtime.
Using XRF to Meet Legislation
It is also possible to screen materials for regulated substances with XRF. For example, it is possible to prove that halogenated flame-retardant applications have been checked against REACH guidelines. The RoHS regulations currently state that both PBDEs and PBBs must be below 1000 parts per million. XRF can be used to measure bromine content and identify whether you are within or outside these levels.
Additionally, this technique can be used to detect heavy metals, for example chromium, mercury, cadmium and lead. This helps customers to meet the current packaging legislation.
The range of XRF analyzers from Hitachi can be used at different stages throughout the manufacturing process to make sure that the correct amount of additive is being used and that the product is compliant with current legislation.
This information has been sourced, reviewed and adapted from materials provided by Hitachi High-Tech Analytical Science.
For more information on this source, please visit Hitachi High-Tech Analytical Science.