BMC Eletric Motors Mechanical Strength

BMC molding (DMC) material is the abbreviation of Bulk (Dough) moldingcompounds, that is, mass molding compound. Domestic often known as unsaturated polyester molding compound. The main raw material from the GF (chopped glass fiber), UP (unsaturated resin), MD (filler) and a variety of additives are fully mixed from the mass-like prepreg. BMC molding materials in the 1960s in the former West Germany and the United Kingdom, first applied, and then in the 1970s and 80s, respectively, in the United States and Japan have been a greater development. Because BMC Eletric Motors molding compound has excellent electrical properties, mechanical properties, heat resistance, chemical resistance, but also to adapt to a variety of molding process, to meet the performance requirements of various products, so more and more User's favorite.

The bimetallic molding compound (BMC Eletric Motors) is a thermosetting plastic in which various inert fillers, fiber reinforcements, catalysts, stabilizers and pigments are mixed to form an adhesive "mortar" for compression molding or injection molding, Composites. The bimetallic molding (BMC molding) is highly filled and reinforced by short fibers, and the glass fiber reinforcements comprise between 10% and 30% and are typically between 1/32 and 1/2 inch (12.5 mm) in length.

According to the different final application areas, the preparation of composite materials can be precisely controlled size, good flame resistance and resistance to electric marks, with high dielectric strength, corrosion resistance and stain resistance, excellent mechanical properties, low shrinkage Color stability. The molded polymer (BMC molding) has excellent flow characteristics and excellent insulation and flame retardancy, and is suitable for a wide range of applications where details and dimensions are required. The material has 75 colors to choose from, can withstand powder coating or water-based paint.

Nature: chopped glass fiber and unsaturated polyester paste mixed with the group of prepreg. It is suitable for molding by molding, transfer molding, injection molding and so on. The obtained products have good mechanical properties, high dimensional stability, good surface finish, water resistance, oil resistance, excellent corrosion resistance and good heat resistance and electrical properties. Arc resistance can reach about 190s. According to the formula dubbed resin paste, the main component with the sheet molding compound, filler increased, generally without thickener, and then resin slurry and chopped glass fiber (length of about 3 ~ 25mm) fully mixed in the system. Mainly used in electrical appliances, electrical, radio, instrumentation, machinery manufacturing, chemical equipment, construction, transportation, defense and other departments.

⒈ general performance: BMC Eletric Motors (DMC) the proportion of large, between 1.3-2.1; product appearance bright, feel good, hard and heavy feeling; with fire will produce a lot of fumes, and styrene smell; Some varieties of BMC Eletric Motors (DMC) flame retardant, but some varieties and easy to burn, burning after leaving inorganic substances.

Dimensional stability: BMC molding (DMC) has a linear expansion coefficient of (1.3-3.5) x 10-5K-1, which is smaller than the average thermoplastics, thus making BMC molding (DMC) has high dimensional stability and Dimensional accuracy. The effect of temperature on the dimensional stability of BMC Eletric Motors (DMC) is very small, but the effect of humidity is more serious, BMC Eletric Motors will expand after moisture absorption. BMC Eletric Motors (DMC) linear expansion coefficient and steel, aluminum is very close, so it can be combined.

⒊ mechanical strength: BMC Eletric Motors (DMC) tensile, bending, impact strength and other properties than thermoplastic, creep resistance than thermoplastic.

⒋ water and solvent: BMC Eletric Motors (DMC) for water, ethanol, aliphatic hydrocarbons, oils, oils have good corrosion resistance, but not ketone, chlorinated hydrocarbons, aromatic hydrocarbons, acid and so on. BMC Eletric Motors (DMC) water absorption is low, soaking a day after the insulation performance is still very good.

⒌ heat resistance: BMC Eletric Motors (DMC) heat resistance than the general engineering plastics are good, heat distortion temperature HDT 200-280 ℃, long-term use at 130 ℃ temperature.

⒍ Aging resistance: BMC Eletric Motors (DMC) anti-aging performance is very good, in the room available 15-20 years, outdoor exposure 10 years after its strength retention rate of 60% or more.

⒎ electrical properties: BMC Eletric Motors (DMC) arc resistance of the most prominent, can reach about 190 seconds.

⒏ low odor: BMC Eletric Motors (DMC) used in the styrene cross-linking agent in the curing will remain 0.1% residual, heating will be issued odor. Therefore, BMC molding (DMC) for food utensils (such as microwave utensils) should be used without residual styrene monomer type UP resin.

(1) Summary

The base resin, the low shrinkage agent, the curing agent, the filler, the internal release agent and the glass fiber are mixed into a colloid as a molding compound. Can be molded, injection manufacturing composite materials due to non-heating stage, so the filler content can be higher than the SMC. Glass fiber length - as 6-12mm, sometimes to meet the high mechanical properties used to 25mm; to meet the requirements of forming liquidity, with 3mm. Glass fiber content is usually 15% to 20%; for high-performance products, used 25%. BMC molding glass fiber content is lower than the SMC, can add more filler, so the cost is low.

(2) raw materials

Resin unsaturated polyester resin, vinyl ester, phenolic, melamine and other resins.

Fiberglass BMC Molded Glass Fiber Twistless Roving.

Fill calcium carbonate, aluminum hydroxide and so on.

(3) advantages

① molding cycle is short, can be molded, can also be injected, suitable for mass production.

② can add a lot of filler, to meet the flame retardant, dimensional stability requirements, low cost.

③ complex products can be the overall shape, insert, holes, Taiwan, tendons, grooves, etc. can also be shaped.

④ Compared with the usual thermoplastics, the product heat resistance, insulation, elastic modulus and other properties to be higher.

⑤ on the skills of workers is not high, easy to achieve automation, saving labor.

⑥ product size is accurate.

⑦ good operating environment.

(4) shortcomings

① only suitable for the production of small size, strength requirements are not high (generally BMC molding material strength is about 30% lower than SMC) products.

② injection machine prices higher.

(5) Typical products

Electrical components (front light, rear door, loudspeaker shell, etc.), the meter housing (the insulator, the switch 29, the meter box, the circuit breaker shell, the terminal, all kinds of household or business mechanical and electrical products shell) , Audio equipment shell.

(6) BMC Eletric Motors molding method