Functional fillers
Aluminium hydroxide (ATH)
Alumiunium hydroxide belongs to the mineral fillers. The filler aluminium hydroxide is mostly used for the flame-retardant application of coating materials. It is one of the most environmentally friendly flame retardants. The products based on aluminium hydroxide are chemically inert and non-toxic. Aluminium hydroxide is used in UV-curing coating systems because it absorbs very little UV radiation. In addition to its use in UV systems, it is also used in powder coatings, emulsion paints or pasty plasters.
Products
Average grain size (D50)
Product datasheet
Product datasheet
Applications for this product
Barium sulphate (barite)
The WTH-BB series are natural barite. The barite is mined in Turkey and both the mine and WTH GmbH are ISO 9001 certified. The high-purity, white barium sulphate grades are milled in various grain sizes and constant product control in state-of-the-art equipped laboratories as well as applied quality management in all areas guarantee standardised and high product quality.
The application spectrum of our barite grades is versatile: The WTH-BBxx Double EX grades have a high degree of whiteness and a low yellow tint, which enables their use in paints & varnishes, floor coatings, pigment preparations, primers, adhesives and fillers.
Our non-micronised barite grades do not have as high a whiteness and are used when colour requirements are less critical and value is placed on a specific density or grain distribution. Furthermore, the WTH-BB grades are used in sound insulation, brake linings, brake pads, floor coverings, jointing and sealing compounds as well as in plastics, elastomers and rubber.
Products
Average grain size (D50) (max µm)
Brightness (Ry)
BaSO4 content (min %)
Product datasheet
Product datasheet
Applications for this product
Calcium carbonate
Calcium carbonate is a water-insoluble filler and has a high chemical purity. The Addforce GCC and PCC products have good weather and ageing resistance, which allows them to be used in a wide range of technical applications.
The Addforce GCC grades are milled calcium carbonate grades available in various particle sizes. In addition, there are surface-treated types that enable processing in various polymers.
The Addforce PCC grades are surface-treated, ultra-fine and precipitated calcium carbonate grades. They are used as extenders in plastic compounds and improve tensile strength, elongation at break, hardness and welding angle strength in rigid PVC products, among others. The surface treatment increases the compatibility and dispersibility in polymers.
Applications for this product
Hydromagnesite/Huntite
These products are non-toxic functional fillers. They are used untreated as a standard product in thermoplastics, elastomers and plastisols as an extender for TiO2.
The product is a milled natural mixed mineral and is used as a flame retardant filler in polymers processed up to approx. 240°C (such as polyolefins). The flame-retardant effect is based on the splitting off of chemically bound water and carbon dioxide corresponding to the known metal hydroxides (aluminium or magnesium hydroxide).
Applications for this product
Lightweight filler – FilloCell
FilloCell (closed-cell expanded perlite) is one of the chemically inert lightweight fillers based on naturally occurring resources. This low-cost lightweight filler is used for density reduction in adhesives, sealants and thermosets.
The large-volume siblings of FilloCell have already been used for many years in the building sector for thermal and sound insulation purposes, among others.
FilloCell is available in different qualities. Even the non-coated qualities absorb only small amounts of water. The hydrophobic coated grades do not absorb water and are easier to incorporate into organic matrices. For incorporation with high shearing tools, we recommend the “UltraStrong” qualities with an increased wall thickness.
Technical properties of our FilloCell types
Appearance
white powder
Moisture content
max. 1 %
Softening point
ca. 1000 °C
Weight loss (3 h at 920 °C)
max. 1,5 %
Grain size
1 – 150 µm
Grain size (> 150 µm)
max. 1 %
Whiteness
75 – 90 GE Brightness %
Refractive index
1,47
Mohs’ hardness
1 – 2
Coefficient of thermal expansion
4 x 10^6 /K
ph-value
ca. 7
Product
Bulk density
Grain size
max. Grain size
140 / 140 H
130 kg/m³
55 µm
200 µm
150 / 150 H
125 kg/m³
65 µm
200 µm
UST 140 / UST 140 H
250 kg/m³
55 µm
200 µm
Applications for this product
Magnesium silicate hydrate
Highly white, practically (heavy) metal-free talc in various grain sizes for the reinforcement of plastics, especially PP. The pronounced platelet structure and high whiteness enable a significant improvement in the physical properties, surface gloss and whiteness of the finished part. Also available in compacted versions with higher bulk densities.
Applications for this product
Micro hollow glass bubbles
WTH-GlassBubbles are ultra-light, non-metallic, inorganic lightweight fillers. The micro hollow glass bubble construction makes these products ideal for weight savings and ensures an optimal surface. The WTH GlassBubbles are based on borosilicates, which results in good water and chemical resistance of the micro hollow glass bubbles.
Due to their structure, WTH GlassBubbles additionally improve the stiffness as well as casting and moulding. The free-flowing micro hollow glass bubbles are used in underbody protection as well as in the automotive industry as corrosion protection. Due to their hollow structure, WTH GlassBubbles are very versatile and powerful and find a wide range of applications in automotive and aviation, transport and construction industries due to their excellent temperature stability, for adhesives and sealants, coating, paint, varnish and putties.
The different series of WTH GlassBubbles have a density of 0.15-0.6 g/cm3 and a diameter of 2-150 µm.
Applications for this product
Coloured Polyester Chips
Synthetic coloured fillers in various grain sizes in different standard and special colours for the production of “solid surface” artificial stones, polyester concrete (such as granite).
These are chips in various colours and grain sizes based on filled, cross-linked polyester resins (so-called ‘solid colours’).
The various Lithopol granulations produced on the basis of filled and cross-linked polyester resins are used as a component of filler systems such as in the production of kitchen sinks, sanitary ware, panels, SMC parts and all other products that are intended to resemble corresponding natural stones on the outside. Ready mixes for the production of artificial granite are available in various colours and grain sizes under the name Lithopol BL.
Applications for this product
Your contact

Dr. Silke-Nicola Trzaska
Mail: info@wthgmbh.de

Dieter Holst
Mail: info@wthgmbh.de

Tomasz Wojtas
Mail: info@wthgmbh.de