Dough Molding Compound
Dough Moding Compound (DMC) / Bulk Molding Compounds (BMC) are used in compression, transfer and injection molding processes. DMC/BMC are available in bulk bags as well as slug form. The mixing operation can be done in a number of ways. Premix employs three methods for combining glass with paste, a continuous screw mixer, a sigma blade mixer and a plough blade mixer. The process chosen is dependent upon specific product properties, product form and volume.
DMC/BMC is a thermoset plastic made up of a polymer resin, various inert fillers, fiber reinforcement, catalysts, stabilizers, and pigments that form a viscous, ‘play-dough like’ compound for molding. DMC/BMC is, like SMC, a polymeric composite material, which consists primarily of a thermosetting resin, mineral fillers and glass fibre reinforcement. The resin used is generally unsaturated polyester (UP) or vinyl-ester (VE). Additional ingredients such as thermoplastic components, catalysts, inhibitors, mould release agents, thickeners and colour pigments are used to enhance the performance and moulding process of the final product.
Bulk molding compound (BMC)/Dough Moulding Compound (DMC) is very similar to sheet molding compound (SMC) in composition. However, instead of the sheet form, DMC/BMC is made in the form of a thick rope, typically 25–50 mm in diameter. The fiber length in DMC/BMC/ DMC/BMC is usually in the range of 6–12 mm, which is smaller than the fiber length used in SMC. DMC/BMC is highly filled and reinforced with short fibers. Glass reinforcement ranges between 5% to 30% . The fiber weight fraction is also lower than that in SMC. For these two reasons, mechanical properties of DMC/BMC composites, such as tensile strength and tensile modulus, are lower than those of SMC composites. The mean fatigue strength (at 106 cycles) of a DMC/BMC/ DMC containing 15% by weight of 6.35 mm long chopped E-glass roving is reported as 17 MPa compared to its tensile strength of 28.7 MPa. This fatigue strength is also lower than the fatigue strength of SMC. and with glass length typically between 1/8" to 1/2".
Depending on the end-use application, compounds are formulated to achieve tight dimensional control, flame resistance, high dielectric strength, corrosion, and stain resistance and color stability. Its excellent flow characteristics make DMC/BMC well suited to a wide variety of applications requiring precision in detail and dimensions. The material is available in a wide variety of colors.
Versatile Molding of DMC/BMC
DMC/BMC can be moulded both in injection or compression process for large-scale production of medium-size or small complex parts.
DMC/BMC applications are wide-ranging in the Transportation & Automotive, Electrical & Energy, Building & Construction, Industrial, Service, Sanitary, Domestic and Medical markets.
BMC(Bulk Moulding Compound)/DMC (Dough Moulding Compound) can be moulded both in injection or compression process for large-scale production of medium-size or small complex parts.
DMC/BMC: Advanced Composite Material
DMC/DMC/BMC is, like SMC, a polymeric composite material, which consists primarily of a thermosetting resin, mineral fillers and glass fibre reinforcement. The resin used is generally unsaturated polyester (UP) or vinyl-ester (VE). Additional ingredients such as thermoplastic components, catalysts, inhibitors, mould release agents, thickeners and colour pigments are used to enhance the performance and moulding process of the final product.
Understanding DMC Production
Thermosets such as Bulk molding compound (BMC) / Dough moulding compound (DMC) polyesters and vinyl esters offers a high strength material with excellent dielectric strength characteristics. Aside from electrical and physical strength, thermosets are highly resistant to corrosion and chemicals, and are not affected negatively when exposed to outdoor conditions such as high UV exposure, snow, or rain. End users can rely on thermoset materials to create enclosures that remain strong from the day they are installed to the end of its product life cycle.
Characterized by its doughy texture, Bulk molding compound (BMC)/ Dough Moulding Compound (DMC) consists of polyester resin, glass fibre and various mineral Fillers. Using DMC/BMCin the compression moulding process we can produce high-volumes of small complex parts with optimal electrical and corrosion resistant properties. The fire-retardant nature of the compound makes it ideal for use in the electrical or lighting industry.
The decision on whether to injection mould or compression mould will be based on the part to be manufactured.
DMC (Dough Moulding Compound) consists of a dough-like mixture of resin, fibre reinforcement and filler to which pigments and other materials may be added. The reinforcement used may be glass, cellulose, cotton or other fibrous material. Manufacture is usually carried out in a high shear z-blade mixer, after which the compound is often extruded into rope form. To achieve a dry moulding compound a high filler loading is used. DMC usually refers to a compound based on isophthalic polyester resin, formulated to give improved moulding quality.
Polyester DMC is frequently made from conventional orthophthalic polyester resins although other resins may be used for specific applications moulding compounds are also available based on phenolic, epoxy, diallylphthalate and other resin system.
DMC / BMC/DMC Product Overview
Our PRAZASTINAV DMC / BMC/DMC products are adaptable to your specific needs. We design formulations according to your requirements.
Markets: – T&A – Transport & Automotive II E&E: – Electrical & Energy II B&C: – Building & construction II OTH: – Other
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| Acoustic |
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Better acoustic damping properties |
| Antistatic |
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Conductive materials with antistatic properties for explosion proof parts |
| Arc Resistance |
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Applications requiring arc resistance |
| Chemical |
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Increased chemical resistance to most chemical agents |
| Class A |
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Excellent surface quality for painted reflector headlamps |
| Dielectric |
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Materials with specific di- electrical properties |
| Finish |
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Special appearance effects: granite, marble, stone, etc. |
| Flame Resistant |
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Formulations designed to meet your required flame Retardancy. UL “Yellow Cards” available. |
| Flow |
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Better flow properties during the moulding process to fill intricate parts |
| Food Contact |
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Food contact applications |
| High Temperature |
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High temperature stability for applications requiring high service temperature |
| Hydrolysis |
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Increased hydrolysis resistance |
| Low Density |
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Reducing the weight of the parts |
| Low Emission |
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Low emission of volatile organic components |
| Low Shrink |
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Parts requiring precise tolerances for mounting of various components |
| Low Profile |
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Parts requiring very precise tolerances for mounting of various components |
| Low Pressure |
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Applications requiring moulding at low press tonnage |
| Low Smoke Emission |
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Formulations designed to meet low smoke emission requirements |
| Paintable |
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Materials adapted to all painting processes |
| Reactive |
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High reactivity to improve cycle time |
| Resistance |
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Applications requiring high mechanical performance |
| Surface |
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Applications requiring excellent surface quality |
| Unidirectional |
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High strength with unidirectional reinforcement to strengthen especially the fibre direction |
| UV stable |
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Enhanced UV resistance |
| Other |
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Tell us your required key property and we will design the specific formulation to meet it |