Durante el procesamiento, los termoplásticos se mezclan en un extrusor y se desgasifican en la sección de tornillo del extrusor. Se usa un vacío para extraer los componentes gaseosos y de vapor de la fundición. Todas las sustancias de bajo peso molecular se extrae para obtener termoplástico de calidad óptima con una superficie suave, más resistente, mejores propiedades aislantes y un menor tasa de desgasificación.

Solutions for Plastic Extrusion

Imagen del icono Vectra SX

Bombas y compresores de vacío de anillo líquido VECTRA SX

La línea Vectra SX, diseñada desde el principio para cubrir las generalizadas necesidades de la industria de procesos, incorpora cinco modelos a la serie Vectra de Nash en el rango de 1 ½ a 10 HP a 60 Hz (0,75 a 5,5 kW a 50 Hz); eso proporciona la solución correcta para requisitos de bombas de vacío de capacidad reducida.

Aprende Más

vectra-xl-liquid-ring-pump-compressor

Bombas y compresores de vacío de anillo líquido Vectra XL

La NASH Vectra se diseñó alrededor de una plataforma modular con las técnicas más avanzadas de diseño asistido por computadora, como el modelado de sólidos en 3D y el análisis por elementos finitos (FEA). La plataforma modular ofrece la ventaja de dos versiones con numerosas piezas comunes.

Aprende Más

NASH Vectra SX For Plastic Extrusion

Vacuum Process For Plastic Extrusion
 

Nash Pumps For Barrel Venting

Plastic extrusion begins with plastic chips, beads or pellets - often referred to as resin. The resin, along with additives such as colorants and UV inhibitors, is fed from a hopper into the barrel of the extruder.

The resin is pushed by the screw extruder towards the barrel where it is heated at around 400°F (200­°C) to a molten state. As the material nears the end of the screw, the melt is unpressurized, and Nash vacuum pumps are used to vent the trapped gases. The gases need to be vented because they could create voids and other imperfections in the finished product. 

Crosshead For Plastic Extrusion

Once the melted plastic leaves the barrel, it travels through a screen pack and removes any contaminants. The screens are reinforced by breaker plates, which are thick metal pucks with many holes. The plates can withstand the high pressure at that stage of the process, which can exceed 5,000 psi. They also serve to create backpressure in the barrel, which is required for uniform melting and proper mixing of the resin and it converts the "rotational memory" of the material to "longitudinal memory," adding strength. 

 

Nash Pumps For Calibration & Vacuum

Once through the breaker plate, the plastic - still in its molten state - enters the die, which gives it the final profile. The extrudate is then cooled and solidified as it is pulled through a water tank. In a tube or pipe extrusion line, a sealed water bath has a carefully controlled vacuum applied to keep the molten tube or pipe from collapsing. 

Nash liquid ring vacuum pumps are ideal for this application because they handle intermittent and continuous streams of water without damage or loss of vacuum level and are tolerant of plastic resin carryover. 
 
Vectra SX Water Handling Pumps For Calibration Tables
The Vectra SX eliminates the need for traditional arrangements of separate air and water removal pumps.

The Liquid Ring Advantage

Nash is a leading global provider of engineered vacuum solutions and has supported the growing plastic extrusion industry for several decades. The NASH Vectra is rugged in construction with lower water consumption and associated utility costs. The Vectra is the ideal solution and supports customer’s specific demands and offers:

  • Efficient design for lower operating costs
  • No flooded starts and improved reliability due to horizontal connection
  • One moving part for long term reliability
  • Quiet operation for an improved and safe work environment
  • Stainless steel rotor and stainless steel lined body for better long-term operation and erosion resistant

NASH liquid ring vacuum pumps are tested prior to installation. Thus, ensuring top quality and avoiding operational downtime. Nash is the leading global manufacturer of highly-engineered vacuum products.

Backed by over 110 years’ experience, NASH certified experts provide aftermarket support with maintenance, service, parts, and repair. Service centers are globally located to protect your vacuum system investment and provide quality, reliable and efficient solutions.