HDK® – Pyrogenic Silica
At a Glance
WACKER has manufactured HDK® pyrogenic silica since the 1970s. Due to our integrated production system with its statistical process control and highly efficient reactor dynamics, the pyrogenic silica we produce is exceptionally pure. Under the globally established brand name HDK®, WACKER offers an extensive product portfolio of hydrophilic and hydrophobic HDK® grades and HDK® dispersions. Furthermore, we offer our customers tailored service and practical support. Thus, we work closely with our customers and partners to develop commercial product innovations, and alternative forms of packaging and transport systems. HDK® products from WACKER are used in different industrial applications, where they improve processes and the end product in each case.
HDK® pyrogenic silica improves the performance, stability and handling of your systems and formulations at all phases of production and processing. HDK® is ideal for adjusting the flow properties of liquids and giving powders optimum free-flow. HDK® optimizes processes and products in accumulators, composites (synthetic resins), printing inks, developers, paints, joint sealants, animal feeds, insulating gels, adhesives, foods, lacquers, natural and synthetic rubber, PVC, bulks materials, silicone elastomers and toners, as well as in paper coating, textile impregnation and pharmaceutical applications.
Hydrophilic HDK® grades
Hydrophilic HDK® is manufactured by the hydrolysis of volatile chlorosilanes in an oxyhydrogen flame. In chemical terms, the loose white powder consists of highly pure amorphous silicon dioxide. Hydrophilic silica is wetted by water and can be dispersed in water.
HDK® Hydrophobic Grades
Hydrophobic HDK® is produced by the chemical reaction of hydrophilic HDK® with reactive silanes, e.g. chlorosilanes or hexamethyldisilazane. It has water-repellent properties and is no longer dispersible in water.
Specific HDK® grades
Pyrogenic silica is an essential component of modern toners and developers. For these applications, we manufacture and deliver specific pyrogenic silicas. The product range comprises pyrogenic silica grades of both low and high specific surface area (BET). They are treated so that they can be triboelectrically charged – either positively or negatively. These products are suitable as components of both modern conventional toners and chemical toner formulations.
HDK® pyrogenic silica is a loose, bulky white powder. It has no known health effects, is chemically stable and does not conduct either electricity or heat. The particular feature of all pyrogenic silicas is their large specific surface area – which results from the microscopic particle structure: 50 grams of a typical pyrogenic silica has a surface area that would cover the size of a football field.