ALPHA SPECIAL GYPSUMS - FROM FGD GYPSUM TO HEMIHYDRATE
They prove their benefits day to day particularly in the building materials industry, and have been incorporated in Knauf products for decades. Even customers from other sectors have come to appreciate their excellent product properties. With Blaine values of ≥ 1700 to ≥ 2900 cm²/g, compressive strengths up to ≥ 40 N/mm² and degrees of whiteness of over > 80 %, there is something to be found for (almost) every application.
Do you want to know more about gypsum as a raw material? Interesting facts can be found in our material science section .
In use everywhere
We provide alpha hemihydrate for use
- as a filler and binder in building materials
- in moulding gypsum
- in modelling gypsum
- in the ceramics industry
- in the manufacture of roofing tiles
- in the food industry
- in the manufacture of pharmaceuticals
- in the dental industry
OUR RANGE
Gypsums as binders in the building materials industry
Are you looking for a suitable binder or the right filler? We offer you alpha/beta hemihydrates and thermal anhydrite or natural anhydrite manufactured on the basis of FGD gypsum.
Alpha hemihydrate - our allrounder
We manufacture alpha hemihydrate in various qualities with clearly defined property profiles. They differentiate primarily due to the alpha gypsum costume and the fineness of the particulate grading. They are suitable for the most diverse applications in the building materials industry: For building chemical products, filling and jointing compounds, flowing screeds, raised access floor panels, plasters and dry-mix shotcrete.
Alpha Hemihydrate AGLF | Alpha Hemihydrate
Finely ground alpha hemihydrate for use in the construction chemicals industry
Delivery availability: Bulk and Big Bag
Alpha Hemihydrate AGFF | Alpha Hemihydrate
Finely ground alpha hemihydrate for use in the construction chemicals industry
Delivery availability: Bulk and Big Bag
Alpha Hemihydrate AGLM | Alpha Hemihydrate
Medium-fine ground alpha hemihydrate for use in the construction chemicals industry
Delivery availability: Bulk and Big Bag
Alpha Hemihydrate AGMM | Alpha Hemihydrate
Medium-fine ground alpha hemihydrate for use in the construction chemicals industry
Delivery availability: Bulk and Big Bag
Alpha Hemihydrate AGZSW | Alpha Hemihydrate
Very white, finely ground alpha hemihydrate for use in the construction chemicals industry and as a base plaster for the dental industry.
Delivery availability: Bulk, Big Bag and 25 kg bag
Graining: > 0.040 mm to > 0.200 mm
Alpha Hemihydrate FG 100 | Alpha Hemihydrate
Finely ground alpha hemihydrate for use in the construction chemicals industry and as a base plaster for the dental industry.
Delivery availability: Bulk, Big Bag and 25 kg bag
Graining: > 0.040 mm to > 0.200 mm
DENTAL GYPSUMS
Our ultra-white alpha hemihydrate is the cost-effective basis for premium dental gypsum plasters.
The German Institute for Standardization has defined the properties of dental plasters in the DIN EN ISO 6873: Technical values, areas of application, testing and application procedures. It differentiates between 5 types:
Type 1: Impression plaster
Impression plaster is manufactured from Plaster of Paris mixed with setting accelerators, colourings, fillers and flavourings. Its short setting time makes it the optimum material for use as a quick repair material and for articulation.
Type 2: Plaster of Paris
Plaster of Paris is used in pre-casts and for models for the manufacture of function spoons. Furthermore, it is used for plaster castings in the articulator. It is easy to use and is characterized by its smooth surface, a relatively high expansion and a low compressive strength.
Type 3: Dental stone
Dental stone is also easy to work and is abrasion resistant. Its expansion is moderate in comparison to Plaster of Paris. Its areas of application: Capping, bulb embeddings and the manufacture of counter-maxillary models (counterbite models) and situation models.
Furthermore, it is used in plastic prosthodontics and for preparing repair model castings.
Type 4: Die stone
Type 4 gypsum is used for high quality prosthodontics. Its low setting expansion, the smooth pore-free surface and its high compressive and flexural strengths make it an ideal base material for the manufacture of precision models: For saw-cut models, models for model casting, in the fields of implantology, master models for the crown and bridge, inlay and onlay techniques.
Type 5: Die stone
In contrast to type 4 die stone, type 5 die stone has a high expansion capability. It makes it the preferred material for the manufacture of prostheses- and model castings. As the polymer shrinks when drying, the enlarged die stone model will compensate for this polymer contraction.
Alpha Hemihydrate AGZSW | Alpha Hemihydrate
Very white, finely ground alpha hemihydrate for use in the construction chemicals industry and as a base plaster for the dental industry.
Delivery availability: Bulk, Big Bag and 25 kg bag
Graining: > 0.040 mm to > 0.200 mm
Alpha Hemihydrate FG 100 | Alpha Hemihydrate
Finely ground alpha hemihydrate for use in the construction chemicals industry and as a base plaster for the dental industry.
Delivery availability: Bulk, Big Bag and 25 kg bagGraining: > 0.040 mm to > 0.200 mm
Moulding gypsums
Today, gypsum is used for building construction in large quantities – just as it was in antiquity. It is a material that is readily used to manufacture models and forms thanks to its simple processing, high strength and contour retention in craftwork, in industrial applications as well as by artists and sculptors.
Moulding gypsums are products made of calcium sulphate hemihydrate with optional factory additives, where very pure brilliant raw gypsum is used in their manufacture. Physically different hemihydrates are produced depending on the calcination process used: Alpha hemihydrate in the autoclave, or beta hemihydrate in the boiler plant or in the revolving kiln.
Your requirements – our recipe
Knauf special gypsums are matched to suit your requirements. We offer you different grades and qualities of moulding gypsums. You define your specifications – we develop the ideal recipe
Modelling gypsum
Our modelling gypsum is the ideal material for manufacturing castings and mouldings thanks to its very high degrees of whiteness and purity and its extremely fine graining. This ensures that you will always achieve a consistent surface quality. It is also suitable for repair work.
Gypsum for the ceramics industry
Our special gypsums – moulding gypsums, jiggering gypsum and medium pressure casting gypsum are used in the fine ceramics industry as a modelling and casting material in the manufacture of sanitary porcelain, pottery, stoneware and ceramic tableware. They impress our customers with their high levels of mechanical strength.
Gypsum for the manufacture of roofing tiles
In the heavy ceramics industry, as in the manufacture of high-quality clay roof tiles, gypsum moulds maybe a more expensive option, but they guarantee a particularly high product quality. Our KNAUF roofing tile gypsum offers you optimum cost-effectiveness with exceptional results.
Gypsum for the food industry
Our food and foodstuff gypsums are characterized by their high solubility and fine particle size. The can be used as a release and anti-caking agent, as a grinding additive and extender in the manufacture of flour, a booster to increase the sugar yield from sugar beet, as a water hardness regulator and food additive E 516. They are also suitable for the manufacture of feedstuffs, as an extender and as a source of calcium ions.
Gypsum for the pharmaceuticals industry
For the pharmaceuticals industry we produce special gypsums for plaster casts as well as fillers for pharmaceuticals and cosmetics.
