What is bottle induction sealing machine?How it works?

What is bottle induction sealing machine?How it works?

2021-08-12 10:40:05

What is bottle induction sealing machine?How it works?

Have you ever google what induction sealing is and how to use it for your product line?

And if you want to apply this technology for a reliable packaging solution,here is an induction sealing machine for your products.

Today' guide leads you through all aspectsof inudction sealing machine:

From basic defintion,working principle,application,etc.

Let's get started:

What's Induction Sealing Machine?


Induction sealing is the process of bonding thermoplastic materials by induction heating. This involves controlled heating an electrically conducting object (usually aluminum foil) by electromagnetic induction, through heat generated in the object by eddy currents.

Induction sealing is used in many types of manufacturing. In packaging it is used for package fabrication such as forming tubes from flexible materials, attaching plastic closures to package forms, etc. Probably the most common use of induction sealing is cap sealing, a non-contact method of heating an inner seal to hermetically seal the top of plastic and glass containers. This sealing process takes place after the container has been filled and capped.

Sealing process

The closure is supplied to the bottler with an aluminum foil layer liner already inserted. Although there are various liners to choose from, a typical induction liner is multi-layered. The top layer is a paper pulp that is generally spot-glued to the cap. The next layer is wax that is used to bond a layer of aluminum foil to the pulp. The bottom layer is a polymer film laminated to the foil. After the cap or closure is applied, the container passes under an induction coil, which emits an oscillating electromagnetic field. As the container passes under the induction coil (sealing head) the conductive aluminum foil liner begins to heat due to eddy currents. The heat melts the wax, which is absorbed into the pulp backing and releases the foil from the cap. The polymer film also heats and flows onto the lip of the container. When cooled, the polymer creates a bond with the container resulting in a hermetically sealed product. Neither the container nor its contents are negatively affected, and the heat generated does not harm the contents.

Filling bottling line,Capper,Sealer,Labeler,Packaging machinery

It is possible to overheat the foil causing damage to the seal layer and to any protective barriers. This could result in faulty seals, even weeks after the initial sealing process, so proper sizing of the induction sealing is vital to determine the exact system necessary to run a particular product.

Sealing can be done with either a hand held unit or on a conveyor system.

A more recent development (which suits a small number of applications better) allows for induction sealing to be used to apply a foil seal to a container without the need for a closure. In this case, foil is supplied pre-cut or in a reel. Where supplied in a reel, it is die cut and transferred onto the container neck. When the foil is in place, it is pressed down by the seal head, the induction cycle is activated and the seal is bonded to the container. This process is known as direct application or sometimes "capless" induction sealing.

Choosing the Right Container, Cap & Liner Materials

Selecting the best induction liner for your product is dependent on several factors, such as the container's material and application.

Filling bottling line,Capper,Sealer,Labeler,Packaging machinery

Induction liners are available in one-piece or two-piece construction. The one-piece type consists of a foam-backed or paper-backed foil laminate. After the sealing process, the entire liner will be completely removed from the cap.

A two-piece liner has an additional wax layer and pulp board layer. The induction heating process will melt the wax, which is absorbed into the pulp board, releasing it from the foil liner. The pulp board layer remains inside the cap for improved resealing after the foil liner has been removed.

Plastic containers with continuous thread plastic caps produce the most consistent seal with the least challenges. Some glass containers may need to be treated in order to properly accept an induction seal. Sealing with metal caps is possible, but can pose several problems. As the induction system heats the foil liner, it also heats the metal cap, which can remain hot for a while. This can become a safety hazard and could also melt the threads if used on plastic containers.

Induction sealers are suitable for all the containers such as:

  • HDPE Bottles

  • HDPE Jars

  • LDPE Bottles

  • PET Bottles

  • PolyPropylene (PP) Jars

  • PolyPropylene (PP) Bottles

  • Glass Bottles (Plastic cap is mandatory)

Filling bottling line,Capper,Sealer,Labeler,Packaging machinery

Induction sealers are suitable for all the caps such as:

Filling bottling line,Capper,Sealer,Labeler,Packaging machinery

Benefits of Induction Sealing Machine:

There are a variety of reasons companies choose to use induction sealing:

  • Tamper evidence

  • Leak prevention

  • Freshness Retention

  • Protection against package pilferage

  • Sustainability

  • Production Speed


Tamper evidence

With the U.S. Food and Drug Administration (FDA) regulations concerning tamper-resistant packaging, pharmaceutical packagers must find ways to comply as outlined in Sec. 450.500 Tamper-Resistant Packaging Requirements for Certain over-the-counter (OTC) Human Drug Products (CPG 7132a.17).

Induction sealing systems meet or exceed these government regulations. As stated in section 6 of Packaging Systems:

“…6. CONTAINER MOUTH INNER SEALS. Paper, thermal plastic, plastic film, foil, or a combination thereof, is sealed to the mouth of a container (e.g., bottle) under the cap. The seal must be torn or broken to open the container and remove the product. The seal cannot be removed and reapplied without leaving visible evidence of entry. Seals applied by heat induction to plastic containers appear to offer a higher degree of tamper-resistance than those that depend on an adhesive to create the bond…

Leak prevention/protection

A common application for flat sealing heads are to seal containers in the food and beverage industry to prevent leaks and extend shelf life.

Some shipping companies require liquid chemical products to be sealed prior to shipping to prevent hazardous chemicals from spilling on other shipments.



Induction sealing keeps unwanted pollutants from seeping into food products, and may assist in extending shelf life of certain products.

Pilferage protection

Induction-sealed containers help prevent the product from being broken into by leaving a noticeable residue on plastic containers from the liner itself. Pharmaceutical companies purchase liners that will purposely leave liner film/foil residue on bottles. Food companies that use induction seals do not want the liner residue as it could potentially interfere with the product itself upon dispensing. They, in turn, put a notice on the product that it has been induction-sealed for their protection; letting the consumer know it was sealed upon leaving the factory and they should check for an intact seal before using.


In some applications, induction sealing can be considered to contribute towards sustainability goals by allowing lower bottle weights as the pack relies on the presence of an induction foil seal for its security, rather than a mechanically strong bottle neck and closure.


Production Speed

Some manufacturers have produced devices which can monitor the magnetic field strength present at the induction head (either directly or indirectly via such mechanisms as pick up coils), dynamically predicting the heating effect in the foil. Such devices provide quantifiable data post-weld in a production environment where uniformity - particularly in parameters such as foil peel-off strength, is important. Analysers may be portable or designed to work in conjunction with conveyor belt systems.

High speed power analysis techniques (Voltage and Current measurement in near real time) can be used to intercept power delivery from mains to generator or generator to head in order to calculate energy delivered to the foil and the statistical profile of that process. As the thermal capacity of the foil is typically static, such information as true power, apparent power and power factor may be used to predict foil heating with good relevance to final weld parameters and in a dynamic manner.

Many other derivative parameters may be calculated for each weld, yielding confidence in a production environment that is notably more difficult to achieve in conduction transfer systems, where analysis, if present is generally post-weld as relatively large thermal mass of heating and conduction elements combined impair rapid temperature change. Inductive heating with quantitative feedback such as that provided by power analysis techniques further allows for the possibility of dynamic adjustments in energy delivery profile to the target. This opens the possibility of feed-forward systems where the induction generator properties are adjusted in near real-time as the heating process proceeds, allowing for a specific heating profile track and subsequent compliance feedback - something that is not generally practical for conduction heating processes.

Types of Induction Sealing Machines

You must know all the types of induction sealing machines to know what type will be the most beneficial to you.

1.Automatic continuous type bottle induction sealing machine

he continuous induction sealer type is very suitable for conducting an uninterrupted capping operation of non-metallic bottlenecks containers.

Due to that kind of non-stop operation, the sealer is compatible with dealing in large scale input and output.

Filling bottling line,Capper,Sealer,Labeler,Packaging machinery

Continuous induction sealing machine

Advantages of continuous induction sealing machine include:

  • Suitable for handling a vast bulk of sealing containers

  • Guarantee large scale output

  • Faster capping and sealing

  • Constant operation

  • Wide range of applications in several industries (including pharmaceutical, chemical, food and cosmetic)

  • Available in various designs for sealing a wide range of bottleneck diameter

On the other side of the spectrum, the sealer suffers from a few limitations such as; not applicable with metallic bottlenecks or non-threaded caps.

The following are the distinct parts of the equipment: speed conveyors, induction head, air cooler/ regulator, wheels, control panel.

Identifying a continuous induction sealing machine is simple and straightforward.

All you have to do is to confirm some of the following features:

  • It applies the electromagnetic induction principle

  • Achieves a higher level of production

  • Adjustable and motor fitted induction head

  • Easy variable speed conveyors

  • Production of instant heat that melts the aluminum foil.

  • The equipment conforms to quality compliance such as GMP standard, FDA regulation conformity.

  • Stainless steel material structure.

  • Seals and caps a range of bottlenecks diameters and accommodate a wide range of container heights.

  • It employs a printing embodiment on the caps with product details, brand or even factory logo, etc.

  • The sealer consumes little power as low as 2.0 KW.

2.Manual/Portable Induction Sealer Machine

The manual electromagnetic induction sealer is almost an entirely manually driven piece of equipment.

It is suitable for customers or users who deal with small scale input and likewise need a low output.

Filling bottling line,Capper,Sealer,Labeler,Packaging machinery

Manual induction sealer machine

Even though it’s a manual type it has several benefits including:

  • Relatively low initial buying price

  • Sealing time ranging between 0.2 to 2 seconds depending on both the bottle material as well as machine type

  • Moderate consumption of power

  • Suitable for small forgery

  • Ideal for serving numerous different industries ( Pharmaceuticals, food, chemical, and oil)

  • Considerable production speed, and output some have got an approximate production of up to 360 containers every hour

Apart from that, the machine suffers from the following disadvantages:

  • Unsuitable with extensive manufacturing

  • Seals an only limited range of bottle sizes

  • Doesn’t seal or cap metallic bottlenecks

The main parts include cable, digital/ manual up/ down timer, control panel, heating plate (sealing surface).

Some of the main parts of the manual induction sealer machine include the following:

  • Sizeable heating plate/ surface which has an adjustable height for sealing a wide variety of plastic bottles.

  • Occupies very little space, they’re small in dimensions thus enabling the user quickly and optionally mount it onto a tabletop or counter.

  • Small weight, some weigh as low as 6kg.

  • Portable due to lightweight.

  • User-friendly.

  • Some have got a backup power storage/ battery. Therefore, it isn’t entirely dependent on electricity such that it operates even during a power outage.

  • Requires customizable outer material, either plastic, stainless steel.

  • Equipment consumes little power and low voltage.

3.Desktop Induction sealing machine

Filling bottling line,Capper,Sealer,Labeler,Packaging machinery

Automatic continuous electromagnetic induction sealer aluminum foil cap sealing machine for food chemical medicine bottles


Driven type:Electric

Product material: stainless steel body

Sealing bottle diameter: 15-60mm

Bottle height:20-280mm

Motor power: 220v/50Hz  1800w

Sealing speed: 20-50 pieces/minute

Conveying speed: 0-12.5m/minute

Bottle height: 20-280mm

Product size: 900*450*500cm


Automatic aluminum foil sealing machine is an automatic fast aluminum foil sealing machine in the electromagnetic induction aluminum foil sealing machine series. The power of the switching power supply can be manually adjusted, and the digital display temperature meter, AC speed regulating motor performance and stable delivery are configured. With infinitely variable speed system, with intelligent sensor switch, intelligent delivery of products, automatic detection and diagnosis, full air cooling, four sections are suitable.

Component of sealing machines and how it works

Though the induction sealing machines have various designs and parts for different types, the main two components, the power supply and the sealing head, are the same. Without these two parts, the machine can never work.The sealing head has a plastic-covered coiled conductor inside that emits an electromagnetic current once the main power supply heats up the inductive coil. When a container fitted with an induction lined cap passes through this current, the inner-seal foil gets heated, melting down the foil’s outer polymer coating, resulting in bonds with the container’s mouth. You must check them very closely to understand the work efficiency and quality of the machine.

  • Main power supply

The power rating of a sealer is very important as it indicates the machine’s work efficiency and suitability for your use. It also determines the production rate of the machine. The small or manual ones do not need a very high-power supply. 1KW is enough for them. But for the continuous or automatic ones need nearly 6KW or more power rating to work properly.

  • Sealing head

Check the type and size of the sealing head. It may be small or large. Check what type of sealing the machine can perform too. Also, check the coil’s material and quality in the sealing head as it ensures the quality of sealing. A two-piece liner has an extra layer of wax and pulpboard that melts down during the sealing process and remains within the pulpboard to make resealing better once the foil liner is pulled out. Plastic containers containing plastic thread caps are the easiest to perform sealing on, while glass and metal are the toughest.

  • Sealing type

Choosing the right power supply strength will depend on the size of your closure and the speed at which the production line will operate. The sealing head design depends on the application. The two most common designs are a flat sealing head or a tunnel head.

Flat Sealing HeadWidely disperses the electromagnetic field.Flat Sealing Head

Filling bottling line,Capper,Sealer,Labeler,Packaging machinery


Able to seal a large area

Accommodates various cap sizes without exchanging sealing head


Less concentrated field can cause in inconsistent seals if container is not properly centered

Filling bottling line,Capper,Sealer,Labeler,Packaging machinery

Tunnel Sealing HeadConcentrated magnetic field on sides and above cap.


Uniform field, which results in a more consistent seal

Deeper field allows for sealing thicker closures (ex. child resistant caps) or closures with recessed liners (ex. spout caps, push/pull caps)


Cannot accommodate a broad range of neck finishes

Variety of products application by induction sealing machine:






Cosmetics, health & beauty

Automotive petroleum products


Agricultural and ag chem.

Animal care and medicines

Sporting goods supplies

Children’s toys (clays, bubbles, etc.)



Home remodeling products

Musical instrument supplies (cleaners, resins, lubricants, polishes)


Personal pleasure products

Hunting / fishing aids

Computer aids/ inks

Laundry detergent /products

Manufacturing shop supplies

School supply products

Inks, dyes, carbon products….


Common Induction Sealing Problems and Solutions

Like other pieces of types of equipment, the induction sealing machine isn’t short of faults and troubles, especially during the sealing operation.

We shall, therefore, seek to identify the problems, state their potential causes, and find their solutions in this segment.

Here are the likely problems often reported by the machine users and the several various ways to troubleshoot them.

Machine Fails to Operate Even after Pressing the Hand Inductive Head Button?

Likely causes: Faulty button switch

Solution: Consider replacing the switch.

Likely cause: Power plug poorly connected.

Solution: Unplug and securely reconnect the plug.

Likely cause: Inductive head possibly damaged

Solution: Substitute the inductive head with an efficient one.

Work Indicator doesn’t Light though the Power Supply Connection is Correct, and the Power Switch is ON.

Possible cause: Defective fuse

Solution: Replace with a new fuse.

Possible cause: Incorrect power plug connection

Solution: Unplug and reconnect the power plug securely.

Machine Doesn’t Seal the Containers Even Though the Work Signal Indicator is Operational.

Possible effect: Short heating period of the inductive head.

Solution: Regulate, and if possible, prolong the heating time under the application.

Possible effect: Damaged inductive head

Way out: Substitute the inductive head with an efficient one.

Likely effect: Inconsistent inductive film materials and sealing objects.

Way out: Select a consistent inductive material with that of the sealing objects.

Sealing Film often Folds and Melts

Likely effect: Long periods of inductive heating.

Possible solution: Shorten the period of heating appropriately.

Both the Spacer and the Film are in Contact or not Entirely Separated.

Likely effect: Either too long or too short a period of inductive heating.

A possible way out: Modify the heating period appropriately.

Cardboard Liner Burnt

Possible cause: conveyor moving too slow, or maybe excess power.

Solution: set the conveyor speed properly and adjust the power input.

Caps Too Tight and not Easily Removable

Possible cause: inadequate sealing power.

Possible solution: properly adjust the power input.

Possible effect: the coil set excessively high.

Way out: adjust the height of the coil appropriately.

Varying Seal Results

Likely effect: inconsistent bottle lips, burrs, etc.

Possible solution: confirm whether all the caps are evenly torqued and not fully cocked before undergoing sealing.

Inadequate Sealing Power

Likely cause: the metal guide rails very close to the sealing head.

Possible solution: ensure that the guide rails which are under the sealing head aren’t metallic.


Metallic materials affect the electromagnetic field.


Read the article carefully and understand what qualities need to be checked before buying an induction sealing machine. Be wise and choose only the best machines for yourself to get the best results.

Important Point: People often get confused that induction sealer, induction sealing machine, induction wad sealing machine, induction bottle cap sealer and induction foil sealing machine etc are different machines, but these are the same terms or synonyms.

So! Don’t get confused, we are here to help you.