Reliable welding of the belt profiles and conveyor belts is imperative to ensure process reliability in the application.
That is why BEHAbelt offers an extensive range of specially developed welding tools. On this page we provide information about the different joining techniques, show tutorial videos, answer frequently asked questions and give product advices.
Of course, our technical team is at your disposal at +49 7684 907 170.

Connection methods for belt profiles

Regardless of whether you are using unreinforced belts or ­reinforced belts, we distinguish the following connection methods: butt and overlap welding.

Two connection methods can be used on profiles with ­reinforcement. Butt welding to reduce elongation without changing the belt strength. Overlap welding to reduce elongation and increase the belt strength.

Stoßschweißung ohne Zugträger

Butt welding
without reinforcement

(Standard)

Stoßschweißung mit Zugträger

Butt welding
with reinforcement

Butt welding to reduce elongation without changing the belt tensile force.

Überlappverschweißung Riemenprofil mit Zugträger

Overlap welding
with reinforcement

Overlap welding to reduce elongation and increase the belt tensile force.

Stoßverschweißung Sonderprofil Corn Belt

Butt welding

Belt without reinforcement (here: orange special profile “Corn Belt“)

Überlappverschweißung transluzenter Keilriemen mit Zugträger

Overlap welding

Belt with reinforcement (here: Sapphire blue V-belt with reinforcement polyester

Welding types for conveyor belts

Elastic monolithic PU conveyor belts from BEHAbelt offer new possibilities for endless joining due to the full PU belt construction. Due to the belt design without traction-layer, a connection by finger welding is no longer necessary, as the monolithic belt is a homogeneous belt design in itself – even in the joining area.
A preferably homogeneous design of the joint is a quality criterion both functionally and with regard to the elastic elongation behaviour of the monolithic strip.
In principle, this potentially “inhomogeneous“ area should be as narrow as possible, since the relatively large pretensioning force applied to monolithic tapes of 0.5…4% inhomogeneity in the belt is very quickly visible in the tensioned state.

Stoßverschweißung bei monolithischen Bändern
Butt welding with hot paddle at elastic monolithic belt

Butt welding

with paddle welding tool

Überlappverschweißung bei monolithischen Bändern
Overlap welding with hot press at elastic monolithic belt

Overlap welding

with hot press

Fingerverschweißung bei elastischen monolithischen Bändern
Finger splice with hot press at elastic monolithic belt

Finger joint

with hot press

Elektrodenverschweißung bei monolithischen Bändern
Finger splice with hot press at elastic monolithic belt

Electrode welding

with hot air

Overview of the different welding tools/categories

Below you will find a list of representative welding tools for the respective categories friction welding machines, welding paddles, hot presses, guide clamps, scissors and useful accessories. Of course, you will also receive corresponding spare parts, such as paddles, adapters or batteries.

Reibschweißmaschine RS02 AKKU

Friction welding machine RS02

Unique tool that enables fast butt welding of PU profiles with high repeatability.

Paddle welding tool EErgo 60 & 90

Specially developed paddle welder for butt splices with ergonomic shape and very fast heat-up time.

Heißpresse HP01 zum profiessionellen Überlappverschweißen

Hot press HP01

Professional hot press with external temperature control for overlap welding.

Welding unit HS400&800

Compact, transportable welding unit for butt welding of elastic conveyor belts.

FZ01 Vario Guide clamp

Guide clamp FZ01 Vario

Handy guide clamp with interchangeable locking jaws for different belt profiles.

SH01 Belt cutter

Cutting device SH01

Useful accessory for exact preparation of belt ends for overlap welding.

AS04 Schere / Scissors zum Zuschneiden der Riemenenden für die Verschweißung

Scissors AS04

Robust scissors with angle stop for cutting the belt ends for welding.

Overlap welding set

Overlap welding set FZ03/1

Manual welding unit for overlap welding of belt profiles by means of Z-welding paddle.

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Videos explaining the welding techniques

In the videos listed below, we show you in detail how professional welds are e.g. with round belts or bands. You are also welcome to visit our YouTube channel here or subscribe. We always post our latest videos here.

Butt welding of a round belt with friction welding machine RS02

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Butt welding of a conveyor belt with the HS400 welding unit

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Butt welding of a V-belt with the paddle welder EErgo

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Overlap welding of a reinforced V-belt with the HP01 hot press

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Frequently asked questions about welding technology for PU and TPE

Below we answer important technical topics on the welding of belt profiles and belts. If you miss a topic or have questions about an area, the technical team is very happy to hear from you (+49 7686 907 170 or info@behabelt.com).

General topics on welding technology

What are the correct temperatures for welding PU (polyurethane) and TPE (polyester)?
Temperaturangaben zum Verschweißen von PU und TPE

To ensure that the welded joint on the belt is carried out reliably, we recommend the following temperatures: For PU (polyurethane) 285°C (approx. 275…295°C) or 545°F (approx. 527…563°F) and for TPE (polyester) 235°C (approx. 225…250°C) or 455°F (approx. 437…482°F).
In general, it is recommended that the belt to be welded is at least at room temperature.
Too high temperatures “burn” the welding material, too “low” do not produce the sufficient fusibility.

How do you weld a belt in a small installation space?

The battery-powered friction welding machine is particularly suitable for this. This cordless machine requires no heating time and the guide clamp is already integrated. This makes handling in confined spaces much easier and the welding is done within seconds.
Alternatively, manual welding can also be carried out with guide clamp and a hot paddle welder.

Is the weld as strong as the rest of the belt?

If the welding is done correctly (e.g. temperature, contact pressure, holding time, cooling time), the splice is almost as strong as the rest of the belt. Often, the belt tends to break at a different point if the load is too high.

Is an angled weld better than a transverse weld at 90°?

No, this makes no difference with non-reinforced belt profiles. In addition, the execution of an angled weld on profiles would be very difficult.

Are there other ways of joining the belts apart from welding the belt profiles?
Gedrehte Rundriemen verbunden mit einem Metallhaken
Einpressen des Nippels in einen Hohlrundriemen

Yes, and they are mechanical connections. In general, however, these are intended more as a quick bridging option in the event of a belt break. BEHAbelt offers so-called twisted round belts or hook belts. These are twisted and connected with a metal hook.
The other alternative is the hollow round belt. Here the inside of the round belt is hollow. A nipple is placed inside, which holds both belt ends together.

Things to know about butt welding

Which belt profiles are butt welded?
Stoßschweißung bei grün gerautem Rundriemen

Generally, butt welding is sufficient for belt profiles without reinforcement. It is irrelevant whether the belt profile is a round belt or a V-belt, for example.
Butt welding can also be carried out on belt profiles with reinforcement, but it must be noted that the reinforcement itself cannot be welded (aramid, polyester or steel). Only the patented glass fibre PU reinforcement from BEHAbelt can be welded.

How do I perform butt welds with a welding paddle on reinforced and non-reinforced belt profiles?

In principle, the welding process can be roughly divided into four steps:

  1. Prepare the belt profile (for non-reinforced belt profiles the plane 90° cut is sufficient; for reinforced profiles the reinforcement should be drilled out after the plane 90° cut).
  2. Clamp the belt profile in the guide unit (e.g. guide clamp FZ01 Vario). This aligns the ends to be welded correctly.
  3. The actual welding process: The hot paddle welder is lifted between the two belt ends. Then the guide unit is pressed together so that the belt ends are heated and melted on the welding plate. After the welding seam is visible, the clamp is opened, the plate is removed and the clamp is pressed together again and locked in place.
  4. After the welding process and the cooling time, the welding seam is cut off all around using a side cutter. In addition, the remains of the bead could also be ground off.

You can find instructions for butt welding with BEHAbelt EErgo paddle welder here as a video.

Accordion Panel

The fundamental difference between these two processes is the type of welding:
In paddle welding, a Teflon plate is heated up to the desired temperature. Once this temperature is reached, welding of PU or TPE can begin.
With the friction welding machine, the heat or melting of the belt ends made of PU (TPE not possible) is achieved by means of friction. This saves the heating time and due to the automatics (0-position, contact pressure, frequency of friction) the repeatability is also given.
The welding paddle always comes with a separate guide clamp, which makes the field of the different profiles to be welded very variable. In principle, any profile can be welded thanks to individually exchangeable inserts for the guide clamp. Flat belt strips up to a width of 80mm are also possible.
On the RS02 friction welding machine, the clamping jaws can also be exchanged; however, due to the design of the machine, the bandwidth is somewhat more limited than with the separate guide jaws for welding paddle (geometries for RS02: round belts 6-20, V-belts: 6×4 – 22×14, in addition, various special profiles such as ridge top V-belts, twin V-belts, T-profiles and also, for example, square or U-profiles).
As the welded profile requires a cooling time for further processing, it must remain in the friction welding machine, contrary to the use of a welding paddle, as the guide unit is integrated there. Thus, for series welding in larger quantities, the welding paddle is the better choice. There, the welded belt remains in the guide clamp and additional belts can be joined quickly with additional guide clamps.
Finally, the purchase price is another factor in the decision-making process. The RS02 friction welding machine or RS02 AKKU cost considerably more than the combination of welding paddle and guide clamp.

Does the reinforcement have to be drilled out before welding?
Ausbohren des Zugträgers in einem Rundriemen
Rundriemen mit ausgebohrtem Zugträger

Since the reinforcements (aramid, polyester, steel) themselves cannot be welded, the belt should be drilled out to improve the connection. This prevents the two reinforcements from lying against each other without a connection and instead fills this area with PU, which itself can be completely welded.
You can find detailed instructions for this step here.

How do I perform butt welds with a friction welding machine on reinforced and non-reinforced belt profiles?
Reibschweissmaschine RS02 verschweisst roten Rundriemen

In principle, the welding process can be roughly divided into four steps:

  1. Prepare the belt profile (for non-reinforced belt profiles the plane 90° cut is sufficient; for reinforced profiles the reinforcement should be drilled out after the plane 90° cut).
  2. Clamp the belt profile into the BEHAbelt RS02 friction welding machine.
  3. The friction welding machine does not need any heating time, as the heat and the melting process are generated by friction. After starting the machine, the two belt ends move together with the automatically correct contact pressure and are welded by friction in seconds.
  4. After the welding process and the cooling time, the weld seam is cut off all around with a side cutter. In addition, the remains of the bead could also be ground off.

You can find instructions for butt welding with the BEHAbelt RS02 friction welding machine here as a video.

Things to know about overlap welding

For which belt profiles is an overlap welding carried out?
Überlappverschweißung transluzenter Keilriemen mit Zugträger

For belt profiles with reinforcement, the overlap welding offers an increase in tensile force. Belt profiles with reinforcement are used in applications that require a higher tensile force. The reinforcement (e.g. aramid, polyester, steel) itself cannot be welded.

In which cases is overlap welding necessary?

In general, the following two parameters should be taken into consideration when making a decision:

The belt length and the weight to be conveyed.

The following two recommendations apply to the belt length:
Belt length < belt diameter x 1000 => none
Belt length > belt diameter x 1000 => recommended

Example: Round belt 12mm x 1000 = 12000mm = 12m
(Note: For V-belts, the height is given as the diameter).

The conveying weight can be matched with the respective Fmax value (butt / overlap) of the belt profile.
Example:
PU V-belt with the following Fmax values (butt 15.4kg, overlap 30.0kg).
Conveyor weight is 21.0kg.
Thus, the overlap welding would be mandatory because the weight load would be too high for the pure butt welding.

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Do you have questions about welding technology?
Our technical team will be happy to advise you.

“Every belt is only as strong as its splice”. As there are many different ways of welding, we are happy to help you with our decades of experience. We look forward to your request.

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