ATH

ATH (aluminium tri hydrate, chemical formula Al(OH)₃) is a side stream of the aluminium production, characterised by:

 

• High purity
• High whiteness
• Relatively low density of 2.4g/cm³ compared to other mineral fillers, which are typically at 2.7g/cm³
• Medium Mohs hardness of 3
• Decomposition around 180°C, releasing water.

 

Basic properties

Property	Value	Unit
Moisture	< 0.4	[%]
pH	9	[-]
Hardness (Mohs)	3	[-]
Refractive index	1.57	[-]
Electrical conductivity	60	[µS/cm]
L.O.I.	34.5	[%]
Density	2.4	[kg/ dm3]

 

 

 

Product overview:

Product	Grade	D50 [µm]	D97 [µm]	OA [g/ 100 g]	L*
Portafill	A7	2.4	6.5	27	98.5
	A10	3.8	10	27	98.4
	A25	7.3	24	21	97.0
	A40	11.5	36	20	96.5
	A25/10	13	35	18	98

 

Production locations Portaflame SG, Portafill A

 

 

Application

ATH will provide:

• Chemical resistance: due to its inert nature, ATH will provide good chemical resistance compared to conventional fillers.
• Gloss control: with the availability of ultrafine ground ATH (Portafill A7) and a product with an optimised particle size distribution (Portafill A25/10), it is possible to apply coatings with a broad range of gloss levels.
• Increasing extruder output: the optimised particle size distribution of Portafill A25/10 provides better free-flowing properties. As a result, the material is easier to dose into the extruder, so the residence time inside the extruder can be optimised.
• UV resistance: being insensitive to UV radiation, ATH will reduce the coating’s degradation.
• Water spotting resistance: powder coatings formulated with ATH show less tendency for water spotting then similar coatings formulated with barium sulphate.