Why Does the Wire Get Stuck?

The hot wire gets stuck when it hits something it cannot melt away. The most common problem is foreign bodies in the material: EPS blocks often contain recycled content – and therefore sometimes wood, metal wire or other contaminants. The cutting wire hits the foreign body, gets stuck and in the worst case breaks. There are also further causes such as Neopor graphite or temperature too low.

The Most Common Causes

Foreign Bodies in EPS – The Main Problem

EPS blocks are often partly made from recycled material. This is not fundamentally a problem – but recycled content occasionally contains foreign bodies: pieces of wood, metal wire, plastic parts or other contaminants from the original material. The cutting wire hits this foreign body, cannot melt it away, gets stuck and in the worst case breaks. This is a problem for both the wire and the cutting job. Anyone with frequent wire breakage from foreign bodies should first talk to the material supplier. Quality can often be improved or a switch to EPS without recycled content can be made.

EPS block with visible foreign bodies – wood and contaminants in the cut

Neopor: A Special Challenge

Neopor is EPS with graphite content. The graphite gives the material its characteristic grey colour – and makes it a challenge in hot wire cutting. During cutting, graphite deposits on the hot wire and cools it down. The melting power of the wire drops – it gets stuck or breaks. With long cutting times on a single wire this problem is particularly pronounced. For Neopor processing we recommend multi-wire machines such as the CUT4000S or CUT5000S. Shorter cutting times per wire significantly reduce graphite deposits.

Neopor block with visible graphite particles – grey colour

Solution: Increase Temperature and Adjust Speed

When the wire gets stuck: first check the material – are there foreign bodies in the block? With foreign bodies, talk to the material supplier – quality can often be improved or a switch to EPS without recycled content can be made. For other causes: gradually increase temperature until the cutting gap is approx. 2 mm. If that does not help, additionally reduce cutting speed. With Neopor always work at lower speed than with standard EPS.

Frequently Asked Questions

Why does my hot wire keep breaking?

Frequent wire breakage often indicates foreign bodies in the EPS material – recycled content brings wood, wire or contaminants. Further causes: Neopor graphite, temperature too low or damp material. Check material for foreign bodies, increase temperature.

Can foreign bodies in EPS damage the wire?

Yes. EPS blocks with recycled content sometimes contain pieces of wood, metal wire or other contaminants. The cutting wire hits the foreign body, cannot melt it away and gets stuck – or breaks. Solution: first talk to the material supplier – quality can often be improved or a switch to EPS without recycled content can be made.

Why does the wire get stuck when cutting Neopor?

Neopor contains graphite that deposits on the hot wire during cutting and cools it down. Melting power drops and the wire gets stuck. For Neopor we recommend multi-wire machines – shorter cutting times reduce graphite deposits.

Can damp material cause the wire to get stuck?

Yes. Damp areas in EPS blocks have locally increased resistance. The wire encounters more resistance than expected and can get stuck. Allow fresh blocks sufficient drying time before cutting.

Solve Wire Problems

Maschinenberatung

Frequent wire breakage or wire getting stuck costs time and material. We help with root cause analysis.

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