thermocouple
thermocouple
The thermocouple works by producing a difference in potentials (measured in mV), which could be interpreted as a temperature,and they are the preferred temperature sensor for plastic extrusion, injection molding, blow molding applications.
The thermocouples most commonly used in HR systems are Fe-CuNi and NiCr-Ni, Fe-CuNi is called J thermocouple,which provides a linear characteristic between 200°C and 350 °. NiCr-Ni is called K type.
- Compared with type K, type J has a smaller temperature range and has a shorter service life at higher temperatures. Equivalent to K-type in terms of cost and reliability.
- K type thermocouple is cheap, accurate, and provides a broad temperature range. Due to its relative radiation hardness, type K is usually found in nuclear applications. The maximum continuous temperature is about 1100°C.
A wire thermocouple may be bent, and provides freedom of choice of the place where it is set. This thermocouple is also used in nozzles.
Thermocouple Diameter
Φ1.0mm, Φ1.5mm, Φ1.6mm, Φ2.0mm
Length
Customized
An angled thermocouple, set in a hole on the front surface of the manifold
Term
Φ4.0*12mm
Mounting hole
M4
Thickness
8.0mm
An angled thermocouple, set in a hole on the front surface of the manifold
Term
Φ4.0*12mm
Mounting hole
M4
Thickness
1.0mm
A ring type thermocouple often used on manifold
Term
Φ14mm
Mounting hole
M4
Thmocouple diameter
Φ1.5mm
A ring type thermocouple often used on manifold
Inside diameter
Φ5.5mm
Outside diameter
Φ14mm
Thickness
2.0mm
A ring type thermocouple often used on manifold
Inside diameter
Φ6.0mm
Outside diameter
Φ19mm
Thickness
3.0mm
Frequently Asked Questions
Corrugated flexible heater is bendable into all shapes, So does Hasteco tubular heater, A bending tool as bending aid is also available from Hasteco, Hasteco also provide preformed tubular heater, customers only need to provide a one-to-one drawing.
- While coil heaters and cable heaters look much the same on the appearance, there are important performance difference on the inside. The “coil” in coil heater refers to a spiraled resistance wire inside the coil heater, compared to a straight resistance wire on a cable heater
- The spiraled wire allows a higher watt density to be carried on the surface of the heater, In most nozzle heating applications, performance improvement is obtained by removing heat from the center and compensating for heat loss at the head and tip of the nozzle
- By carrying more watt density, a coil heater allows engineers to focus more heat where there is heat loss and reduce the rise in temperature in the center. This reduces cycle time, improves quality, and extends the range of plastics that can be run on a hot runner system.
- Hasteco Pressed in Brass coil heater delivers the benefits of an even heater transfer over the whole length of the nozzle because Copper has good thermal conductivity
- Press in brass coil Heater provides faster response and longer thermocouple life than traditional “cast in brass” designs due to the elimination of Molten brass temperature and air bubbles during the casting process.
- It can be done,but we do not recommend this for several reasons, first, the coil heater should actually be undersized or smaller diameter than the tool.
- Then it should be twisted in to remain very tight. Finally, when we wind the coil heaters to the required diameter they are pressed to that to help eliminate some of the spring effect.
- Apressed on sheath is brazed to the heater and sized to a slip fit tolerance. A pushed on sheath is essentially a slip on cover for the coil heater
- Hasteco recommends a pressed on sheath for best performance, thermal transfer and energy effiency.
- The range of profiles can be confusing at times, the options of height for coil heaters is important to ensure sufficient clearance of the net OD of the heater compared to the bore ID for nozzle performance
- As a rule the wider a heater,the more watt density can be applied per linear inch. Narrower widths allow for higher precision of distributing wattage across the nozzle body
- As manifold designs increasingly call for closer drops, the mini coil has emerged as a “small space claim” alternative to help designers meet objectives. Round coil heaters, the original nozzle heaters, are now primarily used for form in groove applications
- effiency.
