Frequently Asked Questions.
Can COREBON induction heating systems be used for heating of moulds made of steel?
Yes, induction heating works very efficient for steel moulds
Can COREBON induction heating systems be used for heating of moulds made of aluminium?
Yes, either directly, or more efficiently, through an added layer of steel with thermal contact
Can COREBON induction heating systems be used for heating of moulds made of carbon fiber composite?
Yes, heating of carbon fiber based moulds is a very cost effective solution for e.g. vacuum forming
Can COREBON induction heating systems be used for heating of carbon fiber blanks?
Yes, in-situ heating using induction is very efficient
Does the lay-up of carbon fiber affect the implementation of COREBON heating technology?
The layup is the single most important factor, followed by the fiber volume fraction. The induction heating system is very flexible and can generally be adapted to the particular parameters.
Is the COREBON heating technology compatible with applied pressure during curing?
What are the min and max blank thicknesses recommended for heating using COREBON technology?
The thinnest is one layer spread-tow weave, less then 0.1 mm. Thin UD fibers in one direction are very difficult to heat efficiently by induction, while thicker UD fiber parts work fine. Larger size and lower electrical conductivity of the blank give the deeper penetration of the heat, so typically 20 mm is no problem.
What is the repetability level of heating results using COREBON heating technology
With proper temperature measurement, very good repetability is obtained. Large variation in electrical properties, in particular within the layup is a challenge, but can usually be detected and compensated by the system.
What are the figures regarding energy savings?
It depends on the application, for certain applications energy savings exceed 95 %
What are the power supply requirements for the heating and cooling systems?
It depends on the application, how much power is needed. See the answer below.
What is the power supply required to run the inverter?
Each frequency inverter need a 3 phase 380-480Vac, 32A supply.
What is the max output power of the inverter?
Typically 15kW, depending on loadcase
What is the frequency range for an inverter?
16 kHz – 1.04 MHz, software limited.
What are the requirements for cooling of inverters and moulds?
Cooling of the frequency inverters shall be done with a closed circuit cooling system to avoid residues, for example a chiller unit. For cooling of the mold we strongly recommend a closed cooling system both to avoid residues but also for environmental reasons.
Are all inverters the same, or do they vary depending on the power needed?
The basics setup of the frequency inverters is the same but each different type of load need to be matched with the correct transformer setup. A workhead consisting of several different setups can be bought as an accessory for manual or automatic load matching.
What is the ramp up speed vs tool size?
Assuming one frequency inverter of 15 kW, the heat rate is 33 °C/s for 1 kg of steel, 17 °C/s for aluminium and 14 °C/s for CFRP. The less material, the quicker heating.
What is the fastest temperature ramp up?
No particular limit.
What is the slowest temperature ramp up?
No particular limit.
What are the limits cooling rates?
Depends on the integrated cooling. For certain processes, support heat if needed to keep the desired cooling rate. Corebon offers optimization of cooling systems to meet target cooling rates.
Is it possible to stabilize to a required temperature?
The frequency inverter has a RS-485 port for communication with accessories, such as thermocouple receiver or pyrometer, as well as three general 4-20mA ports for temperature surveillance. The frequency inverter can control the output using load temperature, power or current as feedback. A PLC can be used for temperature control by sending current or power setpoints to the inverter through RS-485.
What is the percentage of homogeneity achievable on a blank?
It depends on the particular application, layup, ramp speeds etc. It is often a trade-off between development time, uniformity and speed. Very good homogenity can be obtained if required.
What is the highest temperature reached by COREBON induction heating?
The induction heating technique has no upper temperature limit. Usually, the max temperature in an application is limited by the materials of the inductor, mold, heated piece or other.
Which regulations does COREBON equipment comply with?
We comply our equipment according to IEC61010 (electrical safety for the frequency inverter), EN55011 (EMC induction heating system) and EN60519 (General safety induction heating system). Electrical safety of the frequency inverter (IEC61010) is tested by a CB (Certified Body) testhouse. General equipment is designed according to 60519 and tested at an EMC lab while customized systems are verified in-house. Systems may also be certified by a CB test house on request. The presense of electro-magnetic fields around the inductor can be simulated and verified by measurements.
What are the inverter safety functions?
The inverter is equipped with a number of safety functions and turns off automatically if a failure occurs. Protection functions include overvoltage, overcurrent, brownout, internal over temperature as well as minimum flow and over temperature of the cooling water.
How is the system software updated?
Simple updates of the PLC system can be done by an on-site engineer after instructions from COREBON. Software updates of the frequency inverter, or updates of the PLC where hardware readjustment and testing is needed will be done by COREBON’s personell travelling on site.
How is the frequency inverter handled and maintained?
The frequency inverter must never be opened by anyone except for by COREBON specially trained people. Normally these units do not need to be opened outside of the factory, or possibly during testing and tuning of a new inductor setup, generally performed at COREBON by COREBON personnel. Inside the enclosure of the inverter, stored voltage in capacitors might be lethal also after disconnecting the unit from the grid.
What are the hazards related to the induction coils voltage?
The induction coils are galvanically isolated from the grid, reducing the risk of electric shock, nevertheless, in any induction heating application the cables and coils must be protected from physical contact, as high voltage is present during operation.
What are the hazards related to the induction coils electro-magnetic field?
Emission limits after integration of the induction heating equipment are ensured by measurements and/or simulations on each new setup, performed by COREBON or approved company. The system operator is responsible for the overall system compliance to the legal guidelines at the workplace.
Does the induction heating system affect pacemakers?
Sensitive equipment, including people with pacemakers must be kept at a safe distance from the induction heating equipment during operation. The distance considered safe will be determined and marked according to the regulations in EN60519.