1 Contents Fundamental Guidelines – Suggestions Basic Tips Materials Tools & Techniques History of Synthetic Resins History of 3D Scanners History of 3D Printers Modeling - Molding - Casting & Replication Materials Synthetic Resins Modeling, Molding and Replication Resins Admixtures, Fillers and Reinforcement Materials for Resins Aggregates and Fillers for Resins Reinforcement of Resins With Glass Fabrics Processing of Resins Usual Technical Processing Instructions from Manufacturers Resin Pigments Mold-Releasing Agents for Resins – Application Procedures Silicone Elastomers or Silicone Rubbers Condensation and Addition-Curing Silicone Compared Modeling Modeling Classical Modeling Transfer of the Points to the Clay Manikin From Model to Mold Plaster Waste Mold Steps of Multiple-Piece Mold Making Molding Processes of Multiple-Piece Molds Molding a Live Model - Body Silicones & Alginate Rubber Molding by Immersion in Alginate Rubber Making Mold by Casting Alginate Rubber Molding with Body or Skin Silicone 1 5 6 7 9 14 15 17 17 18 19 20 24 26 27 29 32 35 34 37 39 40 42 44 45 47 48 58 59 60 63 Contents
2 3D Modeling 3D scanning Techniques of Three-Dimensional Scanning Contactless 3D Scanners Structured White Light 3D Scanners Refection or Emission Scanning Process of 3D Models Software for 3D Processing File Export File Types Slicing Software 3D Printers Terminology of 3D Technology Scanning - Processing - Printing 3D Modeling Processes in Detail Scanning Using a Laptop or Desktop Using the Smartphone App for 3D Scanning 3D Scanning and Editing on a Smartphone Computer Surface Scan Processing Full Body Model Scan Processing with Slicing Software Print with SLA Printer Post-Processing From 3D Printing Model to Final Artwork Digital to Plaster Model Transfer Procedures Mold Making through 3D Technology Multiple-Part Mold through 3D Printing Molding Silicone Rubber Molding Rubber Molding by Casting and Laminating Technique Rapid, Easy, and Cost-Efective Silicone Molding The Various Modes of Rapid, Easy and Cheap Application Manufacture of Keys for Silicone Relief Molding with Moldable Silicone Putty Combination of Moldable Putty and Brush Application 75 76 77 78 79 79 80 81 82 83 85 86 90 91 92 93 94 98 96 99 101 103 104 105 107 111 113 115 117 117 118 119 120 118 121
3 Relief Molding by Brush Application Silicone Combination of Brush Application Silicone with Plaster Multiple-Part Mold Creating a Relief Mold by Silicone Pouring Creating a Two-Part Mold by Silicone Pouring Internal Mold for Reproducing a "Hollow" Copy Two-Part Silicone Mold by Brush Application Double Sided Mold with Addition-Curing Silicone The Internal Mold Making Molding & Casting with Synthetic Resins Acrylic Resin - Applications Processing Acrylic Resin Mother Mold Making with Acrylic Resin Mold Making with Acrylic Resin From the Flexible Model to the Rigid Mold Replication by Lamination of Acrylic Resin Placement of Pin Support Application of Acrylic Resin - Bronze Replication by Casting Acrylic Resin Polyurethane Resin - Applications Polyurethane Types Molding with Polyurethane Polyurethane Preparation Molding of a Relief Model with Elastomer PU Molding with PU Elastomer and Reinforcement Materials Mold with a Combination of Flexible and Rigid Polyurethane Master Mold by Casting of Rigid Polyurethane Polyurethane, Replication by Casting Replication of a Hollow or a Solid Object Making Solid Core with Expandable Polyurethane Molded PU with Ready Solid Core Hollow Core Making with Acrylic Resin PU Rubber Lamination (Brush Application) Expandable Flexible Polyurethane Foam Mold Making by Casting Rigid Polyurethane 123 125 128 129 137 139 143 154 167 168 172 169 174 178 181 183 188 191 192 194 194 195 197 199 200 206 210 213 214 217 218 223
4 Epoxy Resin - Applications The Processing of Epoxy Resins Epoxy Resin and Moisture Casting Clear Epoxy with Fillers Epoxy by Brush Application The Polishing of Resins Transparent Resins - Liquid Glass or Crystal Clear Cast Liquid Glass Casting Crystal Clear Epoxy Resin in a Double-Sided Mold Creating Transparency with Liquid Glass Creating Transparency with Sandpapers Polyester Resin – Applications Transparent Polyester Resin Mother Mold Making with Polyester Replication by Laminated Polyester Application of Polyester by Casting Lifelike Silicone Figure Making a Lifelike Silicone Figure Casting Silicone in a Rigid Mold Core Making for a Lifelike Silicone Figure Core Making Using Expanding Polyurethane Molding Silicone SFX having Ready PU Core Core Filling with Expandable Polyurethane Foam Making a Lifelike Figure by Casting Silicone Materials, Tools, and Simulation Aids Διαδικασίες Προσομοίωσης (Life-Like Casting) Procedures for Life-Like Silicone Casting Analytical Procedures for Silicone Coloring The Hair Addition Procedure Silicone Mask Making Applications with Latex Rubber Application of Latex by Immersion Latex Brush Application (Lamination) - Mask Making Safety Bibliography 229 230 232 233 235 237 240 241 243 252 254 257 258 259 261 267 269 271 272 276 280 281 285 289 291 292 295 299 300 301 305 306 308 315 320
7 Materials Tools & Techniques History of Modern Materials & Methods Modelling, Molding & Replication Modern Materials - (Silicones - Synthetic Resins) Modelling, Molding & Replication Modeling Tools and Techniques through 3D Technology
18 Modeling, Molding and Casting Resins 1. Latex: Latex is commonly used in casting as a mold-making material or rubber replica. It is a rubber-based component with a new formulation based on natural rubber, making it completely odorless. This formulation contains no ammonia but uses an odorless potassium hydroxide. 2. Polyvinyl Chloride (PVC): PVC is a hard, lightweight thermoplastic material known for its resistance to acids and bases. By adding plasticizers, PVC can be made softer and more flexible. Vinamold®, a flexible and durable vinyl-based casting compound, is a thermoplastic PVC resin used primarily in refinishing. I t can be melted and poured over the original pattern and has the ability to be re-molded multiple times, making it a cost-effective casting material. 3. Silicone Resins: Silicone resins have a partly organic nature with a polymer backbone structure composed of alternating silicon and oxygen atoms, unlike traditional carbon-based organic polymers. Silicone resins have varying physical forms (liquid, gel, elastic, or solid) and properties depending on factors such as molecular weight, structure, and substituent groups (R = alkyl, aryl, H, OH, alkoxy). 4. Acrylic Resins: Acrylic resins are widely used in manufacturing and are petroleum-based thermoplastics. They are available in different forms, such as hydrocarbon-based solvents (solvent acrylics) or waterbased emulsions or dispersions. Acrylic resins can be supplied as 100% solids and are used in various applications. 5. Polyester Resins: Polyester resins are thermosetting polymers that are versatile and relatively inexpensive. These resins are based on monoesters and are created by adding a catalyst to form a tough and durable material. Polyester resins can be dyed and molded into molds, taking on the desired shape. 6. Epoxy Resins: Epoxy resins can be homopolymerized or copolymerized with multifunctional cross-linking agents or curing agents. As the reaction proceeds, larger molecules with high branching structures and cross-linking are formed. The curing rate of epoxy resins is influenced by factors such as temperature, functionality, and physical form. 7. Polyurethane Resins: Polyurethane resins are formed by combining isocyanate resins and prepolymers with low or high molecular weight polyols. Strict stoichiometric ratios are necessary to control polymerization, resulting in varying degrees of cross-linking and physical properties. Catalysts and inhibitors play a significant role in influencing the rate of polymerization and final properties of polyurethane resins.
19 The factors that affect the function of filler when mixed with a resin are as follows. Contamination of the resin due to moisture in the filler. Several of the admixtures tend to absorb moisture. Moisture causes bubbles and, especially in polyurethanes, foams and even expands. Elimination of moisture can be achieved by heating the filler at 60°C (150°F). Particle weight of the filler. Light fillers tend to float in the resin and rise to the opening of your mold, while heavy fillers tend to sink into the resin and appear on the surface of the cast after curing. It is important to mix the filler well with the resin to minimize this problem. Otherwise, the castings may harden in places with more resin and less filler and vice versa. This create a weak or brittle casting. Particle size of the filler. The larger the particle size, the weaker (more brittle) the cured plastic will become. This is because there is less resin holding each individual particle together. Smaller particle sizes generally yield a more durable part. Pre-mixed filler. Adding filler to a resin in which we have already mixed both components (part A + part B) limits how well the resin mixes. Quantity of filler. The amount of filler we add to the resin mixture (A + B) is up to us. Increase in viscosity. The viscosity of the resin/filler mixture increase in proportion to the amount of filler added. The more viscous the resin/filler mixture, the greater the chance of bubble trapping. Working time and curing time. Stirring and casting life and removal time can be lengthened depending on the amount of filler added. Appearance. The final appearance of the cast is proportional to the amount of filler added. Particularly interesting results are obtained by mixing fillers with transparent resins called "liquid glass". Admixtures, Fillers and Reinforcement Materials for Resins Synthetic resins are molded either as such or as blends with additives. These additives are admixtures, fillers, and reinforcement materials. The use of resins in their pure form without additives is done in order to fully exploit their properties and because the final product they give us is completely satisfactory. Proper mixing with fillers improves their basic properties to meet our requirements. Adding fillers is usually done to: ��Reduce costs; ��Reduce or increase weight; ��Change the viscosity so that the processing method can be changed, e.g., make it suitable for lamination casting; ��Improve the material’s mechanical properties with reinforcing materials, e.g., glass fibers; Achieve a specific external appearance, e.g., imitation marble.
24 Reinforcement of Resins With Glass Fabrics Although glass fibers have been produced for centuries, the oldest patent was granted in the United States in 1880 to the Prussian inventor Hermann Hammesfahr (1845–1914). Mass production of glass strands was accidentally discovered in 1932 when Games Slayter , a researcher at Owens-Illinois, directed a stream of molten glass into a jet of compressed air and produced fibers (patented for this production method in 1933). The method was adapted by Owens Corning to produce the patented "Fiberglas" in 1936. The glass reinforcements used for fiberglass are available in different physical forms: micro-spheres, chopped or woven. The fibers can be laid randomly, flattened into a sheet (chopped strand mat) or woven into a fabric, roving fabric-cloth or woven roving. The fiberglass manufacturing process is called pultrusion. The process of making fiberglass suitable for reinforcement is done in large furnaces where silica sand, limestone, kaolin clay, dolomite and other minerals are gradually melted until a liquid is formed. It is then extruded through rings, which are bundles of very small orifices (usually 5—25 μm in diameter). These filaments are then coated with a chemical solution. The individual filaments are now grouped together in large numbers to form the glass fabric. The term 'reinforcement products' is very general it covers all products which can be impregnated with resins and can form a structural component of a structure in order to give it superior technical characteristics, e.g. tensile strength, compressive strength, etc. Chopped Fibers Chopped fibers can be used in all constructions, but are most commonly used in castings to give strength or mixed into resins to thicken them as putty or glue so that the mixture can eventually be used in welds or fillers. Fiberglass - Chopped Strand Mat Fiberglass consists of thin fibers of short glass, which are evenly distributed in all directions on the surface of the fabric and glued together. The glass fabric is impregnated with all types of resins (polyesters) except epoxy resins
37 Modeling Classical Modeling through Molding by Manikin Modeling by Molding with Silicone Body from live model Modeling and Molding via 3D Technology
42 Transfer of the Points to the Clay Manikin For the clay model, measurement starts in reverse, from the coordinates we have marked on the ground (on the millimeter paper). The process starts with the construction of the armatures. The armatures are made of iron rods and sticks tied with wire (fg. 1). The structure is held together by the metal corner attached to the easel. From here on, the eye, hand, and ruler work. With the ruler, we fnd the distances of the points in space based on the coordinates as we have recorded them.
45 Plaster Waste Mold To prevent the plaster from adhering to the iron armature, surround its perimeter with clay. Apply a clay water mold release onto side edge of the plaster. Initiate the process of making the second part of the same half of the mold by coating it with plaster, starting with a brush. Continue, as it sets, by applying plaster by hand. Flatten the plaster with a spatula. The model will be divided into two halves by the construction of a dividing wall, i.e. a frame - fence or shim, approximately in the middle of the model which we define as "seam". After molding the first half, we peel off the fence and move on to molding the other half. The fence or shim can be made of clay, plasticine or metal slats. We start by cutting sheets of clay to make the shim of the manikin. Mark the seam with a knife. We nail the clay sheets with hard wire. Alternatively, we can divide the model with thin metal blades. Proceed with the molding process, taking advantage of the progressive setting property of plaster. Apply the plaster initially with a brush to prevent bubbles and ensure optimal capturing. The frst coat can also be applied by hand, splattering onto the model, called the “back hand fick”. Use a spatula to fatten the plaster of the frst part of the mold. We proceed to the enchantment taking advantage of the property of the progressive setting of the plaster. We first apply the plaster with a brush to avoid bubbles and for the best possible impression. Alternatively, the first pass can be done by hand, by splattering the model. Use a spatula to smooth the side edge of the first part of the mold.
48 Keys are fashioned from plaster or Styrofoam combined with plaster. Finish the partition using a rasp. Release the mold with two successive applications of soapy water on both the mother mold and the model. Making Metal Eye Hooks: Metal eye hooks are crafted to secure the mold pieces within the mother mold, preventing them from dislodging during mold rotations, whether opening or closing. They are easily fashioned using sturdy wire and pliers. Start by creating a loop at the wire's center, then twist the wire ends in opposite directions. These eye hooks are inserted by pressing them into the plaster just before it sets. Easily and swiftly divide the model by creating a dividing wall or shim with Styrofoam and plaster. The dividing wall or shim can be crafted from plaster, plasterboard, or Plasticine, supported around the perimeter by plaster or any other suitable building material, depending on available time and materials. Molding Processes of Multiple-Piece Molds
49 Begin by applying fuid plaster with a brush to ensure a bubble-free casting. As the plaster progressively sets, switch to using a spatula for application. Insert the eye hook just before the plaster begins to set. Use a spatula for the fnal smoothing of the plaster. Once the plaster has solidifed, use a rasp to fatten its exterior. Gently tap the mold piece with a hammer to dislodge it. Ensure proper contact layering between the mold pieces. Realign the mold piece with soapy water. Apply two coats of soapy water for mold releasing. Repeat the same procedures for the second mold piece, starting with brushing and then using a spatula before placing the eye hook.
58 Alginate Rubber Mold The typical composition of alginate elastomer (by mass) consists of: - Sodium alginate: 14% - Calcium sulfate (CaSO4): 10% - Sodium phosphate: 1% - Diatomaceous earth: 75% Here's a breakdown of each component: 1. Sodium alginate: This is a natural polysaccharide produced by various algae, serving as the primary component of the alginate elastomer. 2. Calcium sulfate: Also known as gypsum, calcium sulfate is a common salt found in nature, mainly derived from the evapo-ration of seawater. It can exist in various forms, including calcium sulfate dihydrate (CaSO4·2H2O), anhydrite (CaSO4), and alabaster hemihydrate (CaSO4·1/2H2O). In the alginate elastomer, calcium sulfate contributes to its structural integrity. 3. Sodium phosphate: This compound is added to the alginate mixture to aid in the setting process and improve its performance characteristics. 4. Diatomaceous earth: This mineral of plant origin is ground into a fne powder and has a high silicon dioxide content, typically over 90%. It is derived from the accumu-lated remains of fossilized phytoplankton (diatoms) and serves as a fller in the alginate elastomer. There are two main techniques for alginate elastomer molding: 1. **Immersion**: In this method, the gel is poured into a container, and the object is fully immersed in it. Immersion requires a larger amount of mixture and is typically slightly more diluted. It's well-suited for molding small to medium-sized objects. 2. **Coating**: In this technique, a thicker mixture of alginate is spread onto the object, usually with a spatula or by hand, forming an elastomeric layer. This layer can be removed after a few minutes to reveal the molded object. The water-to-powder ratio for immersion casting is approximately 35:100 by weight, which roughly translates to 1 cup of powder per 1 cup of water. For dental alginates, the mixing, processing, and setting times are typically 1 minute for mixing and 1.5–2 minutes for processing and setting. If a mold shell made of gypsum gauze is used, an additional delay of 5–6 minutes for demolding is usually necessary. Alginate body molding requires more time, as it begins setting at 2–3 minutes and reaches fnal setting within 8–10 minutes. These time-frames assume a water temperature of 18°C (64°F). Cold water, such as 5°C (41°F), can cause delays in the setting process, while warmer water accelerates it. When alginate is mixed with water, it often changes color, depending on the manufacturer, ranging from white to various shades of purple, orange, blue, etc. This color transformation serves as a visual cue for the craftsperson to gauge the working time available. The most suitable mold shell for an alginate mold is typically one made of plaster gauze, as its quick setting facilitates the rapid release of the model from the mold. The frst reproduction from the alginate mold is often cast using plaster for easy retouching and serves as the initial model if casting with other materials is desired. Attention: It's important to prepare all the alginate needed in advance during the learning process. If a supplement is required later on, the new alginate may not adhere properly to the previously applied material. Alginate rubber exhibits high viscosity, so when pouring it into frames, be precise to achieve the desired amount and shape. It's crucial to note that alginate is typically intended for a single mold; it breaks down during demolding and can further dehydrate, shrink, and deform within 24 hours. Molding a Live Model with Alginate Rubber and Body Silicones
59 The simplest method of molding with alginate rubber is that of immersion provided that the object to be molded is offered (eg an arm or a leg). We pour the alginate powder into the water in the proportion given by the manufacturer (usually 35 to 50 to 100 by weight). Stir quickly to anticipate the short processing time of the alginate (if we have chosen the 2-3 minute alginate, there is also a slow one with a 9 minute processing time) Dip the object to be molded (hand) into the gel. The final curing takes place in two minutes. With a thin tube we blow air (by mouth or with the compressor) to facilitate the release of the object. We pour plaster into the empty mold as soon as possible, because the alginate shrinks and deforms when it dries. The setting of the plaster is not affected by the humidity of the alginate. Plaster is the most suitable material for reproducing a first model, because the plaster cast is easily retouched and offered as a molding model of a new and more stable mold. Molding by Immersion in Alginate Rubber Alginate is easily crushed with a knife or even by hand. The plaster cast of the hand ready.
66 To minimize discomfort for the model, we don't need to wait for the silicone to fully set, which can take around 10-12 minutes. Instead, we can apply the wet plaster (mother mold) directly onto the silicone at approximately 6-7 minutes after mixing. Gypsum gauze sets quickly, typically within 6-8 minutes. It's crucial to apply a sufcient thickness of 4-5 mm to prevent deformation or smearing until it is completely dry. The mold with the advantages of the material and the disadvantages of its casting method. It provides a fairly good capture of the surface, where it is applied directly, but problematic in some places such as in the nostrils or without imprinting such as in the eyes. Sculptural restoration after casting is inevitable, so we continue the process through an intermediate model from which we will take the final reproduction mold. Creating an intermediate or temporary model through silicone body molding is a straightforward process that doesn't require specialized knowledge. However, the true artistry emerges from transforming this direct cast into a fnished sculpture, which relies heavily on the sculptor's skill and vision. Plaster is the preferred material for modeling due to its ease of manipulation. It can be easily retouched, carved, and flled, especially when still damp. Molding Intermediate Model
70 Silicone application involves laminating layers onto the mold. The frst coat is typically applied with a brush, followed by subsequent coats with a spatula after the initial layer has cured. For the application of the second coat, the process involves weighing, adding a thixotropic agent, mixing, and stirring the silicone and catalyst components. The addition of pigment aids in achieving opacity between the frst and second silicone coatings. The second silicone layer is applied using a spatula. If necessary, a third coat of silicone may also be applied. Fifteen to twenty minutes after the fnal spatula application, the silicone is dabbed with wet Wetex to fatten any spatula traces. The silicone mold remains as a single piece until the mother mold is opened. At that point, it will be surgically cut with a scalpel as needed, minimizing the need for retouching. Separating the model into three parts facilitates easier opening of the mold. The mother mold is created by frst depositing plaster with a brush.
90 Terminology of 3D Technology 3D: Three-dimensional: Can refer to a screen, representation, or medium in three dimensions (X, Y, and Z axes). 3D object: Anything that can be represented in three-dimensional space. Geometric objects are prime examples of three-dimensional objects, whether they are surfaces, curves, points, or polygon meshes. 3D rendering: A fnal stage in three-dimensional modeling that involves fnalizing a model. It includes special efects, color modifcations, texture addition, and lighting. 3D sculpting: The process of creating a threedimensional model through shaping and molding blocks using brushes and other sculpting tools. The process involves pushing, pulling, pinching, and carving. Axis of motion: A line that an object follows when moving in a scene. Axis of rotation: A line around which a threedimensional object rotates in the scene. Backface culling: A technique that checks the orientation of a triangle and removes those facing away from the camera. Beveling: The process of removing sharp edges on a model to give it a realistic appearance and improve its look. Boolean: A mathematical system used to express the relationship between objects. It is used in three-dimensional modeling for adding, subtracting, and performing other operations. Boolean operations: A technique that uses two objects to create another object. The objects must overlap. CAD: An acronym for Computer-Aided Design. It is a system that allows designers to use computers to design models. CAM: Computer-Aided Manufacturing is the creation of physical products from computerdesigned objects. Edges: Formed by two connected vertices, edges are used to defne three-dimensional models. Extrude: Adding a third dimension to a twodimensional shape to create a three-dimensional object. Faces: Formed by a connection of three or more edges. Geometry: These vertex data culminate in the actual three-dimensional model. Lighting: Multi-directional and uniform lighting illuminating a three-dimensional model makes scene rendering much easier. V-Ray and Corona are some of the programs used for lighting. Materials: Includes colors and textures that have been assigned to three-dimensional models to make them more realistic. It encompasses diferent types of properties depending on the rendering function used. Mesh: A three-dimensional model consisting of triangular polygons. The polygons are composed of edges, faces, and vertices that determine the appearance of an object's shape. Node: A container found within a scene. It contains properties such as angle and position. NURMS modeling: A technique that uses a lowpolygon mesh to transform the shape of a smooth surface. It is typically used for smoothing surfaces in programs like AutoCAD and 3ds Max. Polygonal modeling: Three-dimensional modeling of objects using polygons to make rough estimates of surfaces. In polygonal modeling, all vertices, edges, and faces are processed. Rapid prototyping: The entire process of creating a three-dimensional model using threedimensional modeling techniques and printing it using a three-dimensional printer. Render: Generating an image using data stored on a computer. Rig: The process of facilitating animation by adding control points to the model. Scene: Main elements used to contain objects in three-dimensional modeling programs. It includes environment settings and object graphics. Texture: The image applied to a threedimensional object as part of a material. Topology: How polygons are organized and connected. Vertices: A point in three-dimensional space. When multiple vertices are combined with edges, a polygon is formed. WebGL: A JavaScript code used for rendering three-dimensional objects in a web browser.
99 The main diference in this procedure compared to the previous one is that the scanner can be used freely without the use of a tripod. This does not reduce the quality of the scan, as the scanner has an anti-vibration system, and its software provides full guidance. For accurate guidance, ensure that the "Body" option is selected if you are scanning the whole body, or "Face" if you are scanning just the head. The scanner we are using here has the capability to scan objects ranging from 15 cm to 200 cm. Full Body Model Scan Set the options, click "Body," then "Next," and fnally click "New Scan" to start scanning. We start scanning from the head, rotating around a stationary model, and work our way down slowly and steadily to the feet. The scan time is approximately fve minutes. Finally, proceed with transferring the scan data to the computer for processing.
100 Transfer scan from smartphone to computer for processing. We now move on to the process of converting the scan into a 3D model that you can export for 3D printing. The One-Click process performs three tasks using automatic settings: It creates an optimized Point Cloud of all the measured points of the scanned model. - It then joins these points to create a triangular 3D mesh that you can send directly to your 3D printer or edit in additional software. This process can also be done manually. Click the eye icon next to the Point Cloud in the multiproject panel, then shift-click and drag with the left mouse button around any sections you want to remove, and click the delete icon.
103 Print on an SLA Printer We insert the USB to transfer the data to the printer through the STL file. Printing time is proportional to size, complexity, requested print accuracy and printer type. In any case the time is from quite to very long. After the printing process is completed, we open the cover of the printer and take the copy together with its support base. With a spatula we detach it from the support base. We cut the supports of the print. We rinse with water the remains of unpolymerized resin that remained on the object solidified by the ultraviolet laser beam.
104 Post-Processing We place the print product for a few minutes in a UV radiation chamber to give it the fnal hardness of the resin. We start the retouching processes which are related, almost exclusively, to the residues left by the props when they are cut. Retouching is done with sandpapers. We start with a coarsegrained sandpaper and end up with a fne-grained one. We finish the retouching with wet sandpapers to erase the scratches of the dry sandpaper and completely smooth out the last imperfections. The process is again from coarse to fine sandpaper.
115 Molding Negative Mold or Matrix Molding via 3D Technology Rubber Molds Molding with Silicones, Alginates & Elastomeric Polyurethanes Molding with Synthetic Resins Molds made of Acrylic Resin Epoxy resin Polyurethane Polyester
126 The making of the gypsum mold parts from the bottom, progressing upwards and addressing concave regions, known as undercuts, such as those found behind the ears. Once the gypsum has set, it is fattened using a rasp. Key grooves are carved into the gypsum. A mold releasing agent is applied to the initial gypsum parts before commencing with the subsequent mold parts. The molding between the ears can and should be divided into two pieces. This can be achieved in a single motion. After covering the rubber with gypsum, we wait for the onset of the "knife time" and cut it with a knife at the appropriate point. The surface of the plaster parts is fattened using a rasp and applied a mold release soapy-clay water.
129 Making a Two-Part Mold by Silicone Pouring The silicone molding process, whether condensation or addition curing, remains consistent. However, attention must be paid to ensuring that the construction materials of the model and its division do not inhibit the curing process of addition curing silicone. In this chapter, we utilize a plaster intermediate model derived from a 3D model print. A fundamental requirement for molding a model with intricate details is to divide it into as many parts as necessary to ensure easy release after molding. Typically, a minimum of two parts is sufcient. This division is easily executed for the rubber part of the mold due to its fexibility. However, the rigid part, such as the mother mold, may require additional pieces. In complex molds, employing the multiple part mold technique over the rubber part may be necessary. Initially, we seal the pores of the gypsum model with release wax. To achieve the division of a model into two parts, we utilize a dividing wall constructed from clay or plasticine or plaster or Styrofoam or a compination of them. Using plasticine and plaster as a dividing wall ofers an optimal solution. After placing the plasticine around the model and at the height of the dividing seam, we construct a plaster wall to support the plasticine.
146 Cut wires and glue them to the places where there is a fear of air entrapment during the casting of the resin when it comes time to reproduce the replica. When we make a mold we must have calculated from the beginning the material's casting inlet and air release ducts. The wires when removed will act as vent ducts. Here we have a model whose mold during replication will fill from the neck with a high probability of trapping air in the nose and chin. There it needs vent ducts. The most common practice, once the model is ready to be cast, is to close the mother mold and pour the silicone. Obviously, we have correctly calculated the ventilation ducts in advance and sealed the joint (seam) of its two parts when closing. Here we show an additional option, for the case where we cannot make air release ducts and we fear that the rubber may not be channeled into some undercuts, such as the inside of the ears. For these points (undercuts), the best option is to coat them with rubber, before closing the mother mold, Prepare some thickened silicone with thixotropic, to reduce its fluidity, and apply it to the closed points (undercuts) with a brush or a spatula.
147 After applying the silicone to the undercuts, close the mother mold. Seal the seam to avoid leakage when casting the silicone. Weigh the two components of the silicone, mixing them one by one by weight. De-bubble the mixture through a degassing chamber. It is good to pour the silicone in batches, especially if the silicone has a short processing time (pot-life). As the silicone descends from the mold inlet, it rises from the vents. We let it run a little to push out the trapped air and stop the leak by plugging the vent with some plasticine. After the silicone has hardened, cut the air release ducts. Cut off the excess silicone from the inlet pipe.
164 After removing the plaster extensions on the ducts, smooth out by grinding the mother mold with an angle wheel, where hardened fabric protrusions remain. We burn the remains of the fabric that appear after grinding and sandpaper. Open the silicone rubbers of the first half of the doublesided mold and release the model. Opening the silicone rubbers and the second half of the double-sided mold. The model-shell with the inner and outer molds in open. Trim the rubber flashings and chamfer the ducts to facilitate the insertion of the rubber into the mother mold. Opening silicone rubber, if necessary with the help of compressed air.
165 Molding & Casting with Synthetic Resins Acrylic Resins Epoxy Resins Polyurethane Resins Polyester Resins
168 Processing Acrylic Resin Acrylic resin is combined with pigments, fillers, thixotropic agents, and metal powders. Fluidity reduction is achieved by using a thixotropic agent for acrylic resins or by employing fumed silica (such as Aerosil®, Cab-O-Sil®, etc.) or a powder (quartz, talc, etc.). When acrylic is applied through layering, it requires reinforcement with suitable fabric. The fabric should be applied between two overlapping coats with a brush to ensure impregnation and adhesion with the previous layers. Another method of reinforcement involves the use of polypropylene fibers. However, this method is not utilized in both brush application and casting. Acrylic resins can be colored internally with pigments for acrylic resins and with painting powders. Externally, they are painted and patinated using various techniques. An indirect painting method involves coating the walls of the mold with powders such as graphite, bronze, etc., which adhere to the resin during casting and are stabilized by its curing process. There is also a pre-mixed acrylic resin available with bronze, copper, and iron powder, which are susceptible to chemical oxidation (patina). Addition of a thixotropic agent, specifc to acrylic resins or silica fume. The thixotropic agent is necessary to control the viscosity, ensuring that the resin adheres to the mold walls. If desired, we can reinforce the acrylic resin with polypropylene fbers. We place the fbers in the emulsion before adding any powder; this facilitates dissolution. The primary reinforcement of the resin is through its fabric. Fibers are utilized solely when reinforcing areas where fabric cannot be applied. Transfer the components from the large package to smaller buckets. We frst weigh the emulsion and then add the powder, stirring. The mixing ratio by weight is 2 to 2.5 parts powder (mineral), depending on the manufacturer, to one part emulsion (resin).
177 We repeat the processes of making a support base, necessary to support the two halves of the mold on the workbench while casting the replica. We again weld a piece of styrofoam with thick plaster. Embed the styrofoam in the mother mold with acrylic resin - fabric - acrylic resin. Grind the mold around the seam and open the mold. Release the model, mold ready for silicone or latex reproduction.
200 Molding by a Combination of Flexible and Rigid Polyurethane For molding a holographic model that is divided into two parts, we want a mold made of a flexible material such as rubber so that it can be detached easily and without problems from the model, and a shell (mother mold) for the rubber, made of a rigid material to hold it while casting the model reproduction. This can be done by using silicone or polyurethane rubber which is held by a mother mold made of gypsum-sisal fiber or acrylic resin or polyurethane or polyester etc. The plaster mother mold may be the easiest option in terms of construction, but due to its weight and relatively low resistance to stress, it is not the best. Here, we describe the molding process of the rubber part of the mold with elastomeric polyurethane and the mother mold with rigid polyurethane. The molding is done by the method of casting both the rubber and the rigid polyurethane. Elastomer polyurethane is much cheaper and relatively more durable than silicone, so if nonsticky materials such as plaster or low-adhesion materials such as cement are going to be cast in it, it is worth choosing. For cement, a coat of silicone oil is sufcient before each casting. Otherwise the gain in material cost is lost in labor cost, as every new casting of any synthetic resin will require very good insulation with several coats of release wax. When we have a plaster model, as here, the sealing of its pores must be done, definitely before the application of release wax, with an epoxy primer or stone varnish or shellac or with a special sealing varnish (sealer) recommended by some polyurethane manufacturing companies. The application of release wax from the model is done, the first time with successive layers (4-6 per 20 minutes) and then with a repeated layer of wax or silicone oil, before each new casting.
217 Before starting, we carefully read the manufacturer's instructions. We first weigh A (polyol), color it, then weigh B (isocyanate), mix them and stir them very well. Pour the polyurethane into the mold, leaving enough space for the polyurethane foaming elastomer to expand and fll the mold. Restrict the escape of the expanding polyurethane to ensure it better captures the walls of the mold. The end result looks like a sponge covered on the outside by a fleshy skin. Expandable Flexible Polyurethane Foam Expandable Flexible Polyurethane Foam is a twocomponent synthetic resin that is fexible, durable, and easy to use. The casting procedures for this foam are similar to those followed for expandable rigid polyurethane. The mixture (A + B) expands many times its original volume and can be colored by adding pigments. Depending on the manufacturer, there are diferent mixing ratios, processing times, swelling rates, and mechanical properties. Therefore, it is essential to carefully read the manufacturer's instructions before starting. The fexible polyurethane foam we will use here has the following specifcations: - Mixing ratio: 100 A: 34 B by weight - Processing time: 8 - 12 minutes - Gelling time: 15 - 20 minutes - Unmolding time: 15 - 18 hours An incorrect mixing ratio and rough or insufcient stirring can cause future shrinkage of the material and reduce its mechanical properties and strength. Expandable polyurethane foam is suitable both for filling the interior of a replica and for reproducing a flexible replica.
218 Molded PU with Ready Solid Core We take the expanded polyurethane core. We nail thin nails in the seam, in key points, which will act as spacers, so that a gap is left between the core and the mold which will be occupied by the resin that will be cast. Make sure the core is well secured and properly centered in the mold and leaves an even gap from the mold walls. Preparation of polyurethane rubber by known procedures. Weighing, mixing and stirring ingredients. Optional pigment addition. We close the mold carefully so that the nails are caught in the seam when it is tightened and the perimeter gap is not lost. Place the mold in the pressure tank.
271 Lifelike Silicone Figure Simulation of Life with Silicone Silicone prosthetics and SFX Silicones Silicone Coloring & Hair Punching Making Mask with Silicone SFX Latex Mask Making
275 Core Making Using Expanding Polyurethane Here we show molding a like-life fgure with silicone using the lamination casting technique. To fx the silicone internally, we prepared a core with expandable polyurethane in a mold we had made for this purpose. The core could also be made with acrylic or polyester resin, but expandable polyurethane is the easier, faster, lighter and cheaper option. The core can also be made as a parallel work while we wait for the silicone to harden in the other mold. Weigh and mix the two components of the silicone, add a little pigment (and a little focking powder if you have it) and a little thixotropic to control the fuidity and stir. Here we have a rigid acrylic resin mold, suitable for replica reproduction with silicone without the need to apply mold releasing agent. Apply the frst silicone coat with a brush. After the frst silicone coat begins to set, we apply the second one as well. Before placing the core in the mold, we prepare with its thixotropic agent, a little but sufciently thick silicone and with a spatula we make lumps, 6-8 mm in diameter and place it in three or four selected points on both parts of the mold. These bumps will act as spacers which when hardened will hold the core centered in the mold.
281 We remove the Plexiglas lid from the entrance of the casting. Even if it is stuck to the Plexiglas, the foam is very easy to cut. We open the mold, and release the copy. Cut the fashing from the seams. We clean the seam with acetone so that the silicone has good adhesion, which will fll any gaps and smooth the joining of the two parts during retouching. We make some silicone and apply it on the seam to repair the imperfections left by welding and cutting the fashing. Spread the seam allowance with a spatula and smooth it by dabbing the silicone with a wet Wettex®. Our aim is to have the seam completely gone by repeating the process, if necessary, brushing it with a brush of silicone diluted with white spirit and dabbing again.
300 We prepare the colored silicone as mentioned above, dilute it with white spirit as needed to pass through the nozzle of the airbrush, test it on a white paper and start spraying. Dab and dry the paint after each coat. Last spray to homogenize individual colors. We complete the process by powdering the surface which will make the silicone dummy look more natural, Make sure your coloring process is completely done before applying any matte powder. The powder will act as an insulation that will prevent any new coloring. We start the coloring process with an airbrush. Airbrush painting requires patience, because the dilution of the paint and the thinness of the layer, it takes time to start paying of as more sprays, dabbing and waiting for the paint to dry will be needed. This slow process, however, has the advantage of controlled dyeing in terms of the amount of coloring in places, the smoother transition from one tone to another and from one shade to another.
315 Coloring can be done entirely with a brush, but it can be done from the beginning or from one point and then with an airbrush. The procedures for coloring latex are identical to those we described in the relevant chapter for coloring silicone. Completion of coloring.
316 Although the latex has enough elasticity, most of the time it will need to be cut a little, in an inconspicuous place, so that it can be easily removed from the core and even easier to wear as a mask. Before cutting with a scalpel, we make a round hole at the beginning of the cut. This movement prevents continued tearing when using the mask. We remove the mask from the temporary core. Cut the latex with a scalpel where it needs to be to open the eyes, mouth and ears. Testing the mask.
330 About the author Sotas S. Dimitris born in Athens Greece in 1953 Sculptor Graduated from the Athens School of Fine Arts - Member of the Athens School of Fine Arts Teaching as Lecturer (1999 -2013) at the Department of Visual and Applied Arts (TEET) School of Fine Arts, Aristotle University of Thessaloniki (AUTH) Authorship: “Molding, Casting & Replication” Athens 2018 “Modern Technology for Modelling, Molding & Casting” Athens 2024 Professional experience: Sculptor - artisan in the TAPA (Archaeological Resources Fund) 1997 -1999. External collaborator - supplier of metal and plaster museum replicas for TAPA and OPEP 2003 -2010. Production of a brass replica of Poseidon of Artemis. Gift of Ministry of Foreign Afairs (MFA) to the Council of Europe, Strasbourg 1997 and production of a brass replica of the Adolescent of Marathon. Gift of the Ministry of Foreign Afairs to Peru 2001. Collaboration with the Athens Museum (Vouros-Eutaxia) for the production of copies for the salesroom (2005). Founding member and partner of "D. Sotas - P. Desfniotis OE" specializing in the production of copies of frescoes, vases and ceramic moulds. (1984- 1990) Founding member and partner of "MIKROGLYPTIKI OE" specializing in the conservation and setting up of museum exhibits such as: "Byzantine Christian Museum of Athens 2003 -2004. Museum of Marble Technology in Tinos 2005 -2008. Museum of Environment in Stymphalia 2007 -2008 Archaeological Museum of Kos 2012 and 2014. Conservation and restoration of external decorative elements of the house "Tsalopoulou", a neoclassical building in Katerini 2008. Undertaking of a project by the Ephorate of Prehistoric and Classical Antiquities of Kefalonia a) for the dismantling of a serpentine foor in Sami and b) for the dismantling, maintenance and reinstallation of a serpentine foor of a Roman house in Ag. Efmia, Kefalonia. 2008 - 2009 Dismantling, maintenance and repositioning of the marble propylon of the Municipal Theatre of Piraeus2010. Restoration of the "Roman Agora" in Kos 2011. Removal and reproduction of fve concrete sculptures from the Archaeological Museum of Kos for installation in Casa Romana 2012 Placement of exhibits and construction of a pyre reconstruction at the new museum of Eleftherna, Crete. 2014 Video of the author about the book on youtube. Casting resin in vacuum chamber https://www.youtube.com/watch?v=pNLq-O6hsw8 Molding with alginate rubber https://www.youtube.com/watch?v=tjwRvjfjdgk Latex Application – Making mask with latex https://www.youtube.com/watch?v=-iRwDWpJfTs Double-sided silicon RTV |Rubber Mold https://www.youtube.com/watch?v=7ooYDsn9AR8 Molding with Silicon RTV Rubber https://www.youtube.com/watch?v=l--ec29eByM