How we work
An overview of the processes.
Production
How we work
An overview of the processes.
Production
Step 01
Moulding of the model
In order to create the positive wax model, a negative mould must first be created. This is made from several layers of silicone applied with a brush. If the original is not to be cut up, the mould is created in several sections so that there are no undercuts. Plaster support shells are created as an outer skin to keep the silicone in shape. These are reinforced with iron depending on the size of the model.
In order to create the positive wax model, a negative mould must first be created. This is made from several layers of silicone applied with a brush. If the original is not to be cut up, the mould is created in several sections so that there are no undercuts. Plaster support shells are created as an outer skin to keep the silicone in shape. These are reinforced with iron depending on the size of the model.
Procedures
Block silicone
Application silicone
Cast silicone
Silicone mold for wax injection
Bodycast
Block silicone
The simplest option is the block mould. This is used for models without openings and with small undercuts.
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UseFor single use and small moulded parts.
Application silicone
When creating an application silicone mould, the mould is built up with several layers of silicone to a material thickness of at least 4 mm and created using pins, silicone keys and a shell mould.
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UseFor short-term use and large moulded parts.
Cast silicone
For the cast silicone mould, the mould is first created by placing a clay cover mould in the space between the formwork mould and the model.
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UseFor long-term use.
Silicone mold for wax injection
The wax injection silicone mould is created by inserting the model piece into a box mould.
Depending on the volume of the model, it is usually also necessary to create a core mould.
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UseFor use with overlays (plastic with core insert) larger than approx. 10 pieces and small moulded pieces.
Bodycast
For the moulding on the living object, body parts are moulded directly using silicone and support shells.
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UseFor single use only.
Step 02
Create a wax blank
A wax blank must be created for each casting. The first layers are always applied by hand with a brush. All silicone molded parts are then joined together and poured with hot wax. During cooling, a wall thickness is created which also represents the later casting thickness in the metal. The excess wax is poured out again to create a cavity.
The wax retouching is carried out by the caster or the artist himself. The dividing seams are neutralized and any air bubbles etc. are sealed. It is also possible to make small corrections to the surface compared to the model.
A wax blank must be created for each casting. The first layers are always applied by hand with a brush. All silicone molded parts are then joined together and poured with hot wax. During cooling, a wall thickness is created which also represents the later casting thickness in the metal. The excess wax is poured out again to create a cavity.
The wax retouching is carried out by the caster or the artist himself. The dividing seams are neutralized and any air bubbles etc. are sealed. It is also possible to make small corrections to the surface compared to the model.
Procedures
Wax injection silicon mold
Wax injection silicon mold
The wax is injected into the existing cavity between the silicone and the core after the plaster fireclay core has been inserted.
Step 03
Lost wax process
In the lost wax process, the wax model is covered with the ceramic moulding material, melted in the oven and then burnt out. The hot metal is poured into the resulting cavity. The casting shell is then removed and the work of art is exposed.
In the lost wax process, the wax model is covered with the ceramic moulding material, melted in the oven and then burnt out. The hot metal is poured into the resulting cavity. The casting shell is then removed and the work of art is exposed.
Procedures
Fireclay plaster casting
Ceramic casting
Vacuum casting
Fireclay plaster casting
The hollow wax model is covered with plaster chamotte.
The resulting fireclay mould is then fired in the oven at approx. 600°C for up to 7 days. The molten bronze can only then be poured into the mould at once.
After the metal has solidified, the fireclay mould is knocked off the bronze casting blank after 1 - 2 days and carefully removed with the water jet system at over 200 bar without leaving any residue and without damaging the surface.
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UseFor single use and small moulded parts.
Ceramic casting
For special casting blocks smaller than 90 cm, the object for casting is produced using the ceramic shell moulding process.
In this process, the wax model is dipped 4-6 times in ceramic mass and dried.
The wax that is still in the mould is melted out using hot steam.
The ceramic mould is then fired in the oven.
The 1200 C° hot liquid bronze is then poured into the thin-walled ceramic bowl.
After solidification, the bowl is knocked off and the moulded work of art is fully exposed with the help of the water jet system.
Vacuum casting
The vacuum flask moulding technique is used for intricately detailed models. The wax model is placed in a stainless steel cylinder and covered with plaster-bonded moulding compound under vacuum. Once the compound has set, the model is melted out in the kiln and the still-warm mould is placed in a casting container with negative pressure. The molten metal is poured in and the cavities are filled precisely with the help of the negative pressure. After cooling, the casting is carefully washed out of the stainless steel cylinder.
Step 04
Sand casting process
Sand casting is a proven technique for reliefs, inscriptions, coats of arms and small sculptures without undercuts.
Sand casting is a proven technique for reliefs, inscriptions, coats of arms and small sculptures without undercuts.
Procedures
Hand moulds
Furan resin
Moulds through moulding system
Hand moulds
The mould former cuts the model from plasticine, wax, plaster or wood to the correct shape and then places it in moulding boxes in which the negative is removed in moulding sand.
He cuts the inlets, sprue funnels and ventilation ducts into the sand moulds.
The moulding boxes are then reassembled and the hot bronze can be poured in. After solidification, the mould is broken. In the sand casting process, this is also referred to as the lost mould process.
Furan resin
We also produce castings in our hand moulding facility using cold resin (no-bake) binder systems. This process is a self-hardening binder process consisting of sand, binder and activator. This enables us to produce moulds and cores without mechanical compaction. Due to the high strength that is created during hardening, the cores and moulds are easy to work by hand. This is a classic universal process for the production of various castings.
In contrast to automated machine moulding, the workpiece to be moulded is produced by hand
using simple tools such as lancets, trowels, sand hooks and grinding stones.
The moulding material, which is usually sand, is compacted by hand.
Sprue and runners as well as gates and their dimensions are set according to the drawing or individually by hand.
Das ermöglicht uns komplexe Modelle abzuformen.
Moulds through moulding system
The fastest casting process using our moulding plant is suitable for the production of castings with a batch size of more than 50 pieces.
In the first step, bronze bars are melted together with circular material.
The pattern plates for the lower and upper box are fed into the moulding machine and serve as moulding dies. The cavity for the metal is formed by moulding the lower and upper boxes in parallel in the moulding sand. The lower and upper boxes are joined together fully automatically. The casting of the moulding boxes with liquid bronze (1200 °C) at 30-second intervals is portioned via a fully automatic casting process. The solidified casting can be removed from the moulding sand after approx. 8 minutes. The still hot castings (250 °C) are suspended from the steel hanger. The castings are blasted with stainless steel granulate in the steel cabin for desanding and cleaning. The castings are separated from the sprue system by hand and the sprue system is then melted down again as recycled material.
Step 05
Chasing
Chasing is a very important step in the production of a bronze. The individual cast parts are welded together, parting seams are removed, holes caused by the casting process are sealed in order to remove the fireclay core, and then finished with specially manufactured tools such as punches and chisels.
Artistic understanding is required for this work. The artists' ideas are realised in the best possible way. The surfaces of the works can range from cast-grey, ground, brushed to polished, each with its own unique character.
Chasing is a very important step in the production of a bronze. The individual cast parts are welded together, parting seams are removed, holes caused by the casting process are sealed in order to remove the fireclay core, and then finished with specially manufactured tools such as punches and chisels.
Artistic understanding is required for this work. The artists' ideas are realised in the best possible way. The surfaces of the works can range from cast-grey, ground, brushed to polished, each with its own unique character.
Procedures
Raw casting unmachined
Ground
Blasted
Raw casting unmachined
In all lost wax casting processes, the raw casting is freed from the moulding materials and the core material after casting in the water jet system.
Ground
The ground cast surface is machined in various grit sizes, increasing (60, 80, 120,...) completely or partially according to customer requirements.
Blasted
Various blasting materials are available for surface finishing: Lapping, sand, slag, glass beads or rubber. Which blasting media is used depends on the desired final surface/patina.
Step 06
Patina
Patination is the final step in the realisation of an artistic work. The patiniser anticipates the natural process of oxidation. Depending on the influence to which the copper alloy is exposed, the bronze changes colour over time. In direct cooperation, the artist's idea of the colour nuances of the patination must be precisely matched and implemented. Strassacker has a unique variety of traditional formulas for patination solutions at its disposal.
Patination is the final step in the realisation of an artistic work. The patiniser anticipates the natural process of oxidation. Depending on the influence to which the copper alloy is exposed, the bronze changes colour over time. In direct cooperation, the artist's idea of the colour nuances of the patination must be precisely matched and implemented. Strassacker has a unique variety of traditional formulas for patination solutions at its disposal.
Procedures
Bronze light brown polished
Bronze light brown blasted
Bronze brown / light green polished
Bronze cast wax patina, polished
Cast aluminium, mirror polished
Nickel silver
Bronze cast wax cast patina
Bronze cast white pigment
Bronze cast black pigment patina
Bronze cast dark brown patina
Bronze cast nut patina
Bronze cast welded
ECO-Cast
Bronze cast fire patina white
Bronze cast patina red with pigment
Bronze cast fire patina
Bronze cast green pigment patina
Bronze cast green patina
Bronze cast patina blue with pigment
Bronze cast blue pigment patina
Step 07
Assembly
We will transport your work for you, if necessary in co-operation with a specialist company.
We will be happy to carry out the assembly on site for you so that the work can be set up safely and professionally on site.
We will transport your work for you, if necessary in co-operation with a specialist company.
We will be happy to carry out the assembly on site for you so that the work can be set up safely and professionally on site.
