Os extrusores de dupla hélice são equipamentos essenciais em indústrias como plásticos, alimentos e produtos químicos. A qualidade e o custo de seus componentes de reposição afetam diretamente a eficiência da produção, a qualidade do produto e os custos de operação e manutenção. Este relatório classifica os principais componentes de reposição por módulos funcionais essenciais, detalha suas faixas de preços de mercado e fornece recomendações de vida útil correspondentes, baseadas em padrões da indústria, propriedades do material e condições de aplicação, com o objetivo de fornecer referências para as decisões de aquisição da empresa e o planejamento de manutenção.
I. Componentes principais de transmissão e transporte
1. Parafusos e tambores
Análise de preços: As the core components of the extruder, the prices of screws and barrels are significantly affected by material, specifications (diameter, length-diameter ratio), and manufacturing processes, with large differences in market prices. The unit price of a common nitrided steel (38CrMoAlA) screw and barrel set is approximately 828 – 2760 US dollars; bimetallic materials (such as centrifugally cast wear-resistant alloys and powder metallurgy alloys) have higher prices due to their excellent wear and corrosion resistance. The quotation for an 80/156 model bimetallic conical screw and barrel set is 4350 – 4500 US dollars, and the bimetallic screw and barrel specially used for nylon and chemical fiber can even reach more than 2070 US dollars per set; the unit price of modular segmented screw elements is lower, with a single segment element about 1.1 – 2 US dollars per millimeter, and discounts are available for bulk purchases of more than 500 millimeters.
Recomendações de vida útil: The service life is closely related to materials, processed materials, and working conditions. The service life of ordinary nitrided steel screws and barrels is about 6 – 12 months when processing ordinary plastics (such as PP and PE); when processing materials containing fillers such as glass fiber and calcium powder, the service life is shortened to 3 – 6 months. Bimetallic screws and barrels have significantly improved wear resistance, and their service life can reach 12 – 24 months when processing high-filler materials, which is 2 – 3 times that of ordinary nitrided steel. The service life of parallel twin screws is usually longer than that of conical twin screws; the guaranteed service life of the former is mostly more than 6 months, and that of the latter is about 3 months. According to industry standard JB/T 11686 – 2013, when the radial unilateral wear of the screw reaches 2mm, it should be replaced in a timely manner.
2. Elementos de parafuso e blocos de amassamento
Análise de preços: Screw elements (conveying blocks, shear blocks, transition blocks, etc.) adopt a modular design, and their prices are measured by material and specification. The unit price of commonly used 6542 high-speed steel elements is about 0.62 US dollars per piece (domestic), and the unit price of imported or special alloy materials is about 1.5 – 2.8 US dollars per piece; when purchasing more than 100 pieces in bulk, the unit price can be reduced to less than 1.1 US dollars per millimeter.
Recomendações de vida útil: The service life of screw elements made of 6542 high-speed steel or nitrided steel is about 4 – 8 months under normal working conditions; when processing high-wear materials, the service life is about 2 – 4 months. Elements adopting bimetallic spray welding technology can have their service life extended to 8 – 12 months. When the radial unilateral wear of the major diameter of the kneading disc reaches 2mm, it will affect the uniformity of material mixing and needs to be replaced.
II. Componentes de proteção resistentes ao desgaste
1. Bushing (câmara de expansão)
Análise de preços: The main materials of bushings are nitrided steel and nickel-based alloys. The unit price of ordinary nitrided steel bushings is about 41.4 – 69 US dollars; nickel-based tungsten carbide bushings have higher prices due to their excellent wear and corrosion resistance, with a single set quoted at 2800 – 3000 US dollars.
Recomendações de vida útil: The service life of ordinary nitrided steel bushings is about 3 – 6 months, with a short maintenance cycle; the service life of nickel-based alloy bushings can reach more than 12 months, and the wear amount is less than 50μm after 1000 hours of operation, which is 2 – 3 times that of ordinary nitrided steel, and the comprehensive maintenance cost can be reduced by 30%. According to industry standards, when the radial unilateral wear of the inner hole of the bushing reaches 2mm, it should be replaced.
III. Componentes do Sistema de Transmissão
1. Caixa de velocidades e acessórios internos
Análise de preços: The gearbox is a precision transmission component, and the overall replacement price is relatively high. The unit price of ordinary models is about 1800 – 3800 US dollars; the unit prices of internal accessories such as gears and bearings are lower, the unit price of gears is about 24.84 – 27.6 US dollars per piece, and the unit price of main bearings is about 16 – 21 US dollars per piece.
Recomendações de vida útil: Under normal lubrication and maintenance conditions, the overall service life of the gearbox is about 5 – 8 years; the service life of internal main bearings and gears is about 15000 hours (about 1.7 years). When the gearbox has abnormal noise, increased vibration, or wear and damage to gears and bearings, it is necessary to inspect, repair or replace components in a timely manner.
2. Cinto de sincronização e roda dentada
Análise de preços: The unit price of a timing belt is about 6.9 – 27.6 US dollars per piece, the price of pulleys varies by specification, about 0.78 – 4.56 US dollars per piece, and discounts are available for bulk purchases of more than 5 pieces.
Recomendações de vida útil: The service life of timing belts and pulleys is about 1 – 2 years, which is greatly affected by operating speed and load. When the timing belt cracks, the tooth surface is severely worn, or the pulley is worn or deformed, it should be replaced in a timely manner to avoid affecting transmission accuracy.
IV. Componentes de aquecimento e controle de temperatura
1. Aquecedor (fio de aquecimento, barra de aquecimento)
Análise de preços: The unit price of a cast aluminum heating coil is about 6.9 – 13.8 US dollars per piece, and the unit price of a head heating rod is about 2.76 – 6.9 US dollars per piece; the price of imported high-temperature resistant heating elements is higher, about 5 – 10 US dollars per piece.
Recomendações de vida útil: The service life of conventional heating elements is about 6 – 12 months, and may be shortened to 3 – 6 months under high-temperature and high-humidity working conditions. When the heating efficiency decreases, the surface is damaged, or there is an open circuit, it should be replaced in a timely manner to avoid affecting the plasticization effect of materials.
V. Componentes de alimentação e descarga
1. Componentes do sistema de alimentação (rosca de alimentação, alimentador lateral)
Análise de preços: The unit price of a hollow feeding screw is about 41.4 – 82.8 US dollars per piece, the overall quotation of a side feeder set is about 1791 US dollars, and the price of a feeding screw set specially used in the food industry is about 500 – 700 US dollars.
Recomendações de vida útil: The service life of the feeding screw is about 6 – 12 months, and about 3 – 6 months when processing materials with high viscosity or impurities. The overall service life of the side feeder is about 3 – 5 years, and the internal transmission components need to be regularly maintained.
2. Placa de matriz e componentes de troca de tela
Análise de preços: The unit price of a discharge die plate is about 27.6 – 69 US dollars per piece, the unit price of a screen changing orifice plate is about 13.8 – 41.4 US dollars per piece, and the price of a die plate specially used for food extruders is higher, about 200 – 500 US dollars per set.
Recomendações de vida útil: The service life of the die plate is more than 400 hours under normal working conditions, and shortened to 200 – 300 hours when processing high-wear materials. According to industry standards, when the diameter of the die plate hole is worn to 1.2 times the original size, or qualified products cannot be processed, it should be replaced. Screen changing components are wearing parts, and it is recommended to check them every 1 – 2 months and replace them as needed.
VI. Componentes de vedação e auxiliares
1. Vedação de óleo, anel de vedação
Análise de preços: The unit price of the input/output oil seal of the transmission box is about 2.76 – 6.9 US dollars per piece, the unit price of the O-ring of the vacuum component is about 0.69 – 2.76 US dollars per piece, and the cost is lower for bulk purchases.
Recomendações de vida útil: The service life of oil seals and O-rings is about 6 – 12 months, which is greatly affected by temperature, pressure, and material corrosion. When oil leakage or air leakage occurs, they should be replaced in a timely manner.
2. Fuso, relé de estado sólido
Análise de preços: The unit price of a fuse is about 0.28 – 0.69 US dollars per piece, the unit price of a solid state relay is about 13.8 – 41.4 US dollars per piece, and the unit price of imported brand temperature control instruments such as Omron (Japan) is about 69 – 138 US dollars per piece.
Recomendações de vida útil: Fuses are disposable protective components and should be directly replaced after failure; the service life of solid state relays and temperature control instruments is about 2 – 3 years, and their accuracy needs to be regularly calibrated, and they should be replaced in a timely manner when failures occur.
VII. Fatores de influência chave e recomendações de otimização
1. Seleção de materiais: Quando se processam materiais de alto desgaste que contenham fibra de vidro, pó de cálcio, etc., devem ser preferidos materiais resistentes ao desgaste, como ligas bimetálicas e de níquel. Embora o custo inicial de compra seja elevado, pode prolongar significativamente a vida útil e reduzir o custo de manutenção global; quando se processam materiais comuns, os materiais de aço nitrurados podem atender às necessidades com um desempenho mais elevado em relação ao custo.
2. Controle das condições de trabalho: evite a operação a longo prazo com temperatura elevada e sobrecarga, e reduza o teor de impurezas nos materiais, o que pode reduzir o desgaste das peças de reposição e prolongar a vida útil. Por exemplo, o controle da temperatura do material na área de alimentação pode reduzir o desgaste mecânico dos materiais sólidos na parede interna do tambor.
3. Manutenção: Adicione regularmente óleo lubrificante aos componentes de transmissão, como caixas de engrenagens e rolamentos, inspecione os elementos de aquecimento e as juntas, e resolva tempestivamente os pequenos defeitos, o que pode evitar a falha prematura das peças de reposição.
