An In-Depth Engineering Guide for Cable Manufacturers

Overheating in a cable making machine is one of those issues that can silently sabotage a production line. At first, it may appear as a subtle rise in motor temperature or a small smell of burnt insulation. But left unchecked, it can escalate into strand deformation, insulation degradation, premature wear on bearings, or even complete downtime. For high-speed production lines producing PVC-sheathed, foamed, or high-voltage cables, overheating is more than an inconvenience—it is a threat to quality, efficiency, and cost control.

In this technical guide, we explore why overheating occurs, how to diagnose the root causes, and practical solutions for preventing it. Insights are drawn from field data, engineering studies, and experiences from Dongguan Dongxin (DOSING) Automation Technology Co., Ltd., a company with decades of expertise in high-precision cable making equipment.

1. Understanding the Consequences of Overheating

Before solving the problem, it’s crucial to recognize its impact:

• Insulation quality degradation: PVC or PE can discolor, soften, or even bubble.

• Conductor oxidation: High temperatures accelerate copper or aluminum oxidation.

• Bearing and motor damage: Overheating drastically shortens bearing life and can burn out servo motors.

• Energy inefficiency: Hot components consume more electricity, increasing operational costs.

• Production downtime: Replacing damaged parts can halt the line for hours or even days.

Overheating isn’t just a technical issue; it’s a cost and reliability issue. Modern factories often quantify the cost of a single overheating incident in lost material, labor, and opportunity—sometimes tens of thousands of dollars per day.

2. How a Cable Making Machine Generates Heat

A cable making machine involves multiple heat-generating elements:

2.1 Extruder Motor & Screw

Extrusion motors and screws generate heat through:

• Friction between the screw and barrel

• High shear rates in viscous polymer melts

• Poor lubrication or worn screw surfaces

An extruder running at maximum throughput without proper cooling is a common hotspot.

2.2 Crosshead & Die

The crosshead shapes insulation but also retains heat:

• Die restriction increases polymer shear, generating thermal energy

• Misaligned crossheads create friction zones

• Tooling wear can increase local temperatures

2.3 Gearboxes and Rotating Elements

Stranding gears, take-up motors, and bobbin shafts convert torque into rotation:

• Worn or misaligned gears generate extra friction

• Bearings may heat due to inadequate lubrication

• High RPM amplifies heat production exponentially

2.4 Cooling Systems & Quench Troughs

Ironically, insufficient or uneven cooling can worsen overheating:

• Water flow inconsistencies lead to polymer hotspots

• Over-reliance on air cooling may fail in high-speed lines

2.5 Environmental Factors

Ambient temperature, ventilation, and line proximity to other heat sources also matter.

3. Diagnosing Overheating in the Cable Making Machine

A systematic approach prevents guessing:

3.1 Monitor Key Temperature Points

Install or check thermocouples at:

• Extruder barrel zones

• Crosshead surface

• Motor housing

• Gearbox

• Bearings

Sudden spikes or gradual rise patterns reveal root sources.

3.2 Analyze Torque and Load Curves

Overheating often accompanies increased motor torque:

• Compare motor load against production speed

• Detect overload zones during thick or high-viscosity cable runs

3.3 Inspect Mechanical Wear

Friction caused by worn parts is a hidden heat source:

• Screws and barrels: signs of scoring or wear

• Bearings: check for play or lubrication issues

• Gears: measure backlash and uneven wear

3.4 Check Cooling System Functionality

• Water pressure and flow uniformity

• Trough alignment and level

• Cleanliness and descaling of cooling channels

3.5 Evaluate Polymer Quality

Some overheating issues originate from the raw material:

• High-viscosity batches increase shear heat

• Contaminants cause melt friction

• Incompatible formulations may be heat-sensitive

4. Practical Solutions to Fix Overheating

4.1 Optimize Extruder Operation

• Reduce screw speed slightly during high-load runs

• Ensure barrel zones maintain uniform temperatures

• Replace or recondition worn screws and barrels

• Upgrade motors if running at maximum capacity continuously

4.2 Improve Crosshead & Die Efficiency

• Re-align the crosshead to reduce friction

• Regularly polish and maintain die surfaces

• Install temperature sensors on critical zones for real-time monitoring

4.3 Maintain Gearboxes & Bearings

• Replace worn gears or bearings

• Use high-temperature rated lubricants

• Check gearbox alignment and coupling tension

• Implement scheduled thermal checks

4.4 Enhance Cooling Systems

• Ensure water flow is even across all zones

• Consider adding secondary quench or heat-exchange loops

• Insulate exposed hot zones where appropriate

4.5 Modern Automation Solutions

Advanced cable lines, including those from Dongguan Dongxin (DOSING) Automation Technology Co., Ltd., integrate:

• PLC-controlled temperature management

• Closed-loop feedback systems for motor and extruder load

• Real-time alarm systems to prevent thermal overload

Automation ensures overheating is detected and mitigated before it affects production.

4.6 Operational Best Practices

• Avoid sudden changes in line speed or polymer viscosity

• Maintain ambient shop temperature and ventilation

• Train operators to recognize early warning signs (smell, color change, vibration)

• Use preventive maintenance schedules for bearings, gears, and motors

5. Preventive Maintenance to Avoid Recurring Overheating

The best-performing lines never wait for a failure to appear:

Daily Checks

• Motor, screw, and crosshead temperatures

• Trough and water flow

• Visual check for smoke or discoloration

Weekly Checks

• Bearings and gears

• Lubrication levels

• Thermal imaging scan for hotspots

Monthly / Quarterly

• Screw, barrel, and die inspection

• Motor and gearbox overhaul

• PLC and sensor calibration

Consistent preventive maintenance is far cheaper than emergency downtime.

6. Why Fixing Overheating Matters Today

Modern cable specifications demand:

• Consistent insulation thickness

• High-speed stranding without defects

• Low scrap and reduced rework

• High safety and electrical performance standards

Overheating directly compromises these goals. Factories that proactively address thermal management enjoy:

• Longer equipment lifespan

• Stable production output

• Reduced energy consumption

• Better product quality and customer satisfaction

Companies investing in advanced thermal control and monitoring, like DOSING, demonstrate measurable reductions in downtime and scrap—sometimes by 30–50%.

Conclusion: Overheating Is a Systemic Issue Requiring Systemic Solutions

A cable making machine overheating problem rarely has a single cause. It involves:

• Mechanical wear and alignment

• Motor and screw load

• Friction in die and crosshead

• Cooling efficiency

• Material properties and line operation

By systematically monitoring, diagnosing, and addressing each of these areas—and integrating modern PLC and automation systems—manufacturers can prevent overheating, maintain line efficiency, and deliver consistent high-quality cables.

For cable plants, mastering thermal stability is no longer optional. It’s a competitive advantage, enabling safer, faster, and more reliable production while extending the lifespan of high-value machinery. With careful engineering, proactive maintenance, and intelligent monitoring, overheating stops being a threat and becomes a controlled, manageable factor in everyday cable production.