Ash and Moisture Applications for Plastic and Composites

Automation of moisture and ash analysis with the prepASH provides efficiency, quality and security into the laboratory. Plastic is the common term for a wide range of synthetic or semi synthetic organic amorphous solid materials suitable for the manufacture of industrial products. Plastics are typically polymers of high molecular weight, and may contain other substances to improve performance and/or reduce costs. Polymers are often blended with inorganic fillers, mainly to enhance the mechanical properties of the plastic (e.g. fibreglass) or dyeing (white colour: Titanoecid). Plastics can contain small organic molecules (polymer plasticiser, internal lubricants) and Carbon (carbon fibre). An ash test is used to determine the total thermal stable filler content. It cannot identify individual percentages in multi-filled materials without additional test procedures being performed.

Case Study: Fibreglass

Fibreglass is used as a reinforcing agent for many polymer products. The resulting composite material, correctly known as fibre-reinforced polymer (FRP) or glass-reinforced plastic (GRP), is called “fibreglass” in popular usage. As with many other composite materials, the two materials act together, each overcoming the deficiencies of the other. Whereas plastic resins are strong in compressive loading and relatively weak in tensile strength, the glass fibres are very strong in tension but have no strength against compression. By combining the two materials, GRP becomes a material that resists both compressive and tensile forces well. The two materials may be used uniformly or the glass may be specifically placed in those portions of the structure that will experience tensile loads. The fibreglass content of the plastic can easily be determined by ashing. The polymer is burned or decomposed at high temperatures whereas the glass resists heat and is measured as the residual ash.

GF20: 20 % fibreglass, GF30: 30% fibreglass

Ashing to determine the plastic content of fibreglass

Applications Available from Precisa:

  • prepASH 008 PP GF Recyclable Materials
  • prepASH 3006 PVC
  • prepASH 0708 Polyamide 6 filled with talcum powder
  • prepASH 0709 Polypropylene filled with talcum powder
  • prepASH 0710 Polypropylene filled with glass fibre
  • prepASH 0711 Polypropylene filled with calcium carbonate
  • prepASH 6001 Rubber compound

prepASH – optimal solution for ash analysis in plastics

Reduced time and effort: prepASH is a fully automatic drying and ashing machine. This removes the requirement for multiple weighings, removal of hot material and reduces the time spent as there is no requirement for cooling post analysis in a desiccator. Working in groups of similar samples in a single run increases efficiency and optimises analysis time.

Improved safety and efficiency: No more exposure to extremely hot areas and or open flames. With the prepASH, analysis can be automated in time slots where the laboratory is empty or occasionally used such as nighttime runs.

Improve the quality of your results by up to 20%: In the case where ash determination has to be re-analysed because of faulty/undefined results, the automated nature of the prepASH reduces the need for rework of samples.

Detailed analysis reports: Due to the permanent recording of measurements during the entire process and the automatic saving of the final results, all data can be retrieved at any time.

Determining the ash content of plastic

Standard Method with ovenvs.prepASH
Burning off of crucibles for constant weight beforePossibility to pre-define a ”burning off” crucibles
Tare of crucible one by oneAUTOMATIC PROCEDURE
Addition of sampleDry MatterSampling
Weighing + documentation of each crucibleAUTOMATIC + sample addition by operator
Samples in drying oven + STARTSTART PROGRAM
Removing samples from oven + cool downResults (moisture)
Back weighing samples, calculation (moisture)
Pre-ashing with rapid incinerator or hot plateResults (ash)
Samples in muffle furnace for Ash contentAsh
Remove samples + cooling down in desiccator
Calculation and documentation (ash)
Back weighing for stable results (repeat?)

Download Application Note

You can download the complete application note as a pdf: Ash and Moisture Applications for Plastic and Composites

Series 340 | TGA

If you would like to find out more about TGA Analysis we have a excellent range of Thermogravimetric Analysers that could accommodate your ash analysis needs on our website. Please don’t hesitate to get in touch, someone from our team will be happy to assist you.

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