High Frequency Induction Cap Sealing

High Frequency Induction Cap Sealing With IGBT heating units

Objective To heat an aluminum foil inside a plastic shampoo cap forĀ sealing
Material 2.0ā€ diameter, plastic flip top cap, with a 0.9ā€ diameterĀ aluminum foil seal
Temperature 250 – 300 ĀŗF (120 ā€“ 150 Ā°C)
Frequency 225 kHz
Equipment DW-UHF-7.5 kW, induction heating system, equipped with aĀ remote heat station containing two 1.5 Ī¼F capacitors (totalĀ capacitance 0.75 Ī¼F).
An induction heating coil designed and developed specificallyĀ for this application.
Process A three-turn two-position helical coil is used to heat theĀ aluminum foil in a tunnel style assembly. Product (containers)
passes easily under the induction coil. The assembly is locatedĀ such that the entire perimeter of the aluminum foil is heated
uniformly. The container and cap is placed under the coil andĀ RF power delivered for 0.12 seconds. The aluminum foil heats
and seals to the plastic of the cap.
Results/Benefits This induction heating configuration fulfills the process
requirements and:
ā€¢ uses a simple, economical coil design
ā€¢ increases throughput with a dual-position coil
ā€¢ delivers quality, consistent seals
ā€¢ offers a repeatable process, well-suited for automation

induction cap sealing

Heating Aluminum Foil For Cap Sealing

InductionĀ Heating Aluminum Foil For Cap Sealing with IGBT inductive heater

Objective An induction heater is used to heat a polymer laminatedĀ aluminum foil in 0.5 to 2.0 seconds. The heat produced in theĀ aluminum foil melts the polymer that bonds to the neck of aĀ plastic container.
Material Aluminum foil, polyethylene, polypropylene, polyvinylchloride,Ā polystyrene, polyethylene terephthalate, styrene acrylonitrile
Temperature 300 – 400 (ĀŗF), 149 – 204 (ĀŗC)
Frequency 50 to 200 kHz
Equipment DAWEIĀ solid-state induction powerĀ supplies operating between 1 & 10 kW at frequencies of 50-Ā 200 kHz. These units operate with remote sealing heads whichĀ allows the main power cabinet of the equipment to be locatedĀ away from the immediate production area. Distances of up toĀ 100 meters are possible. The microprocessor is used to control
and protect the system and ensures that the optimal operatingĀ frequency is maintained at all times and that each container
receives the same amount of heat energy from cycle to cycle.
Process Two different types of aluminum foil laminates are available forĀ this application. The first assembly includes backing
board/reseal, a wax layer, aluminum foil, and a heatseal filmĀ for supported systems (Figure 1). The second assemblyĀ includes a high temperature film, aluminum foil, and a heatsealĀ film for unsupported systems (Figure 2). The procedure is to fitĀ the foil membrane into the cap and to fit the cap to theĀ container after the product is filled.
Results For the aluminum foil assembly as shown in Figure 1, heatĀ induced in the metallic foil by the induction coil almost
instantaneously melts the polymer coating and the neck of theĀ container forming a hermetic seal between the heat seal film
and the rim of the container. The heat also melts the waxĀ between the aluminum foil and the back board. The wax is
absorbed into the back board. This results in an air tight bondĀ between the aluminum foil/membrane and the rim of the
container, the back board is released and remains in the cap.

Process (contā€™d) In the case of unsupported membranes in Figure 2, one side ofĀ the aluminum foil is coated with a heat sealable polymer filmĀ and this face that will be in contact with and sealed to theĀ container. The other side of the foil that will be in contact withĀ the cap has a higher melting-point film that prevents adhesionĀ of the aluminum to the cap allowing the end user to unscrewĀ the cap. Unsupported membranes are typically used where theĀ end user pierces the tamper evident membrane prior toĀ dispensing the product.Ā The aluminum foil acts as a vapor barrier preserving theĀ freshness of the product and prevents it from drying.

induction heating aluminum foil cap sealing

Shrink Fit Steel Gear onto Shaft

Shrink Fit Steel Gear onto Shaft With High Frequency Induction Heating Units

Objective Heat the bore of a hardened spur steel gear to shrink fit onto aĀ gear motor shaft. This is part of a chair for the disabled.
Material Steel gear 2.5ā€ (63.5mm) OD, .75ā€ (19mm) ID x .625ā€ (16mm)Ā thick, temperature indicating paint
Temperature 400 ĀŗF (204 ĀŗC)
Frequency 300 kHz
Equipment ā€¢ DW-UHF-3.2 kW induction heating system, equipped with aĀ remote workhead containing two 0.66 Ī¼F capacitors for aĀ total of 1.32 Ī¼F
ā€¢ An induction heating coil designed and developedĀ specifically for this application.
Process A four turn helical internal coil is used to heat the gear bore.
The coil is inserted into the gear bore and power is applied forĀ 90 seconds to reach the required 400 ĀŗF (204 ĀŗC) and expand
the gear bore. The gear is then placed on the shaft andĀ allowed to cool, creating the shrink fit between the gear and
the shaft.
Results/Benefits Induction heating provides:
ā€¢ No pre-heat cycle, heat is available on demand
ā€¢ Energy efficient, heats only the part, not the atmosphereĀ around it
ā€¢ Controlled, even distribution of heating
ā€¢ Faster production times

Shrink Fit Steel Gear onto Shaft

Induction Shrink Fitting Carbide Ring

Induction Shrink Fitting Carbide Ring With IGBT Induction Heating Units

Objective Shrink fitting a carbide ring into a steel valve seat
Material Steel valve seat 6ā€ (152.4mm) OD with 3ā€ (76.2mm) ID hole &Ā .75ā€ (19mm) thick, carbide ring
Temperature 500 ĀŗF ( 260 ĀŗC)
Frequency 85 kHz
Equipment ā€¢DW-HF-15kW induction heating system, equipped with aĀ remote workhead containing two 0.50 Ī¼F capacitors for aĀ total of 0.25 Ī¼F
ā€¢ An induction heating coil designed and developedĀ specifically for this application.
Process A three turn helical coil is used to heat the steel valve seat.
The steel valve seat is placed in the coil and heated for 50Ā seconds to enlarge the center hole & drop the carbide ring in
for the shrink fitting process.
Results/Benefits Induction heating provides:
ā€¢ Accurate and repeatable results
ā€¢ Ease of integration into existing production lines
ā€¢ Energy efficient, only heats the part, not the atmosphereĀ around it
ā€¢ Hands-free heating that involves no operator skill forĀ manufacturing
ā€¢ Even distribution of heating

shrink fitting carbide ring

 

Induction Shrink Fit Aluminum Shaft

Induction Shrink Fit Aluminum Shaft with IGBT induction heating systems

Objective Heat aluminum impeller blades to 200 ĀŗF (93 ĀŗC) and shrink fitĀ onto a shaft.
Material Aluminum impeller blades with a .28ā€ (7.109mm) bore,Ā aluminum shaft
Temperature 200 ĀŗF (93 ĀŗC)
Frequency 255 kHz
Equipment ā€¢ DW-UHF-6W induction heating system, equipped with aĀ remote workhead containing one 1.0Ī¼F capacitor.
ā€¢ An induction heating coil designed and developedĀ specifically for this application.
Process A split two turn helical coil is used to evenly heat the openingĀ on the impeller blade. The impeller blade is heated for 20Ā seconds to reach the 200 ĀŗF (93 ĀŗC). The impeller blades areĀ then removed from the coil & slipped over the shaft toĀ complete the shrink fitting application.
Results/Benefits Induction heating provides:
ā€¢ Repeatable results
ā€¢ Reduced cycle time, lower consumables cost
ā€¢ Even distribution of heating

Shrink Fit Aluminum

 

 

 

 

 

 

 

 
Shrink Fit Aluminum with induction

Inductioin Shrink Fitting Aluminum Pulley

Inductioin Shrink Fitting Aluminum Pulley With IGBT Heating Units

Objective Heat aluminum pulley for insertion of an inner bearing for theĀ automotive industry
Material Aluminum pulley 2.3ā€ (60mm) OD x 1.6ā€ (40mm) ID x 1ā€Ā (27mm) high and inner bearing 0.7ā€ (17.8mm) high x 1.6ā€Ā (40mm) dia
Temperature 464 ĀŗF (240 ĀŗC)
Frequency 283 kHz
Equipment ā€¢ DW-UHF-4.5kW induction heating system, equipped with aĀ remote workhead containing two 0.33Ī¼F capacitors for aĀ total of 0.66Ī¼F
ā€¢ An induction heating coil designed and developedĀ specifically for this application.
Process A three turn helical coil is used to heat the aluminum pulley.
The pulley is heated to 464 ĀŗF (240 ĀŗC) in 20 seconds toĀ expand the inner diameter and then the inner bearing isĀ inserted to form the completed part.
Results/Benefits Induction heating provides:
ā€¢ Defined and controlled heat pattern
ā€¢ Process easily integrated into automated system
ā€¢ Even distribution of heating

shrink fitting aluminum bearing

 

Shrink Fitting Assemble Connecting Rods

Induction Shrink Fitting Assemble Connecting Rods With IGBT Heating Units

Objective Assemble connecting rods with a more accurate control of theĀ heat
Material Rod has an OD of .9125ā€ (23.18mm), knuckle has an ID ofĀ .9125ā€ (23.18mm) with an interference of .0001ā€ (.0025mm).Ā Knuckle assembly is forged steel
Temperature 400 ĀŗF (204 ĀŗC)
Frequency 210 kHz
Equipment ā€¢ DW-UHF-Ā 3.5 kW induction heating system, equipped with aĀ remote workhead containing two 1.0Ī¼F capacitors for aĀ total of 0.5 Ī¼F
ā€¢ An induction heating coil, designed and developedĀ specifically for this application.
Process A six turn helical coil is used to heat the connecting rod for 13Ā seconds. The coil is perpendicular to the axis of the bore toĀ promote even heating around the circumference. TheĀ connecting rod is then assembled with the piston for shrinkĀ fitting.
Results/Benefits Induction heating provides:
ā€¢ More accurate control of heat vs a flame burner. Only heatsĀ knuckle, not the whole part.
ā€¢ Lower temperature used to prevent discoloring.
ā€¢ Increased productivity due to repeatability & ease ofĀ operation. A foot pedal & timer is used.
ā€¢ No product contamination.

 

Shrink Fitting Assemble Connecting Rods

 

 

 

 

 

Induction Shrink Fitting Assemble Connecting Rods

Induction Shrink Fitting Assemblies

Induction Shrink Fitting Assemblies

Objective To use induction to prepare cast iron assemblies for shrink fitĀ assembly
Material Customer supplied cast iron rocker arms of varying sizes
Temperature 450 ĀŗF (232 Ā°C)
Process Time 20 seconds
Frequency 148 kHz
Equipment DW-UHF-5.0 kW, 150-400 kHz solid state induction heatingĀ system, equipped with a remote heat station containing oneĀ 1.0Ī¼F capacitor
An induction heating coil designed and developed specificallyĀ for this application.
Process A four-turn helical coil heats the ring at one end of theĀ assembly. The coil is designed to concentrate the field towardsĀ the center of the assembly where the thermal mass is greatest.
Across the heated ring, the coil presents a lighter field.Ā After heating, a pin is place within the ring and the assembly isĀ water quenched.
The heat time varies from part to part but is less than 20Ā seconds.
Results/Benefits Induction heating satisfies the needs of this process for:
ā€¢ rapid part heating
ā€¢ flexibility for parts of differing geometries
ā€¢ individual, series part heating, suitable for automation
ā€¢ a clean source of heat
ā€¢ even heat distribution

Induction Shrink Fitting Assemblies

Heating Shrink Fitting Camshaft Gear

Induction Heating Shrink Fitting Camshaft Gear with IGBT Induction Heater

Objective: Heating a camshaft gear with a bore size of 1.630″ to shrink fit over aĀ steel shaft that has a diameter of 1.632″. A temperature of 5000F is requiredĀ for the gear to expand 0.002″ in order to slip over the shaft. Production isĀ presently done at a rate of 15-20 gears per 24 hour shift by heating the gear
on a hot plate. The hot plate heating cycle lasts for approximately 45 minutes.
The customer would like to explore the options available in terms of heatingĀ times and machine size.
Material: Steel Camshaft Gear measuring 7″ in diameter, 1″ thick, with a bore sizeĀ of 1.630″.
Temperature: 5000F
Application: A unique three (3) turn helical coil along with the various DAWEIĀ solid state induction power supplies were used to achieve the followingĀ results:
–Ā 5000F was reached in three (3) minutes while using the DW-HFĀ 5, 5 kW output solid state induction power supply.
–Ā 5000F was reached in five (5), eight (8), and ten (10) minutes using theĀ DW-HF-3, 5Ā kW output solid state induction power supply.
–Ā Even heating was observed as a result of the unique three (3) turn helicalĀ induction coil.
Equipment: DW-HF-35Ā andĀ DW-HF-55 kW output solid stateĀ induction power supplies respectively, including remote heat stations and aĀ unique three turn helical coil made from 3/16″ copper tubing and having a 4.4″Ā inside diameter.
Frequency: 62 kHz

Shrink Fitting Camshaft Gear

Induction Shrink Fitting For Inserts

Induction Shrink Fitting For Inserts with IGBT Shrink fitting Heater

Objective: To heat an aluminum fuel pump housing measuring 8″ x 4 1/2″ x 3 1/2″ toĀ 3750F, allowing steel parts to be inserted. Presently the housings are heatedĀ for over one hour in a convection oven. The areas that are to have steel partsĀ inserted measure 1.5″ and 0.6875″ in diameter. In addition, the insertionĀ process lasts for a little over one minute, so 3750F should be maintained for a
period of time to complete the process.
Material: Aluminum Pump Housing measuring 8″ x 4 1/2″ x 3 1/2″
Steel insertion parts.
Temperature: 3750F
Application: By using the DW-HF-Ā 25, 25 kW output solid state induction powerĀ supply the following results were achieved.
– 3750F was reached in one (1) minute to allow for insertion.
–Ā 20 housings were successfully heated using a five (5) turn right angleĀ pancake coil.
Equipment: Ameritherm SP 25, 25 kW output solid state induction power supply includingĀ one (1) remote heat station containing four (4) capacitors totalling 1.0 Ī¼F, and Ā a five (5) turn right angle pancake coil made from 3/16″ copper tube.
Frequency: 80 kHz

shrink fitting for inserts

 

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