08/10/2025 By CNCBUL UK EDITOR Off

Technical Evaluation Guide: How to Identify a Quality Used, Secondhand, Pre-Owned, Surplus FERMAKSAN High Frequency PVC Welding Machine Table 14 Meters made in Türkiye

1) Key Specifications & Benchmark Expectations

Before visiting, obtain from seller the original specs or datasheet for the specific 14 m table model: electrode length, power rating, frequency, table dimensions, drive / motion type, welding head design, electrode gap, pressure system, etc.

Typical features you should benchmark:

Welding length: ~14 meters electrode / upper bar travel
HF generator power rating: e.g. in the tens to hundreds of kVA, frequency ~27.12 MHz or a standard HF plastic welding frequency
Electrode gap / maximum stroke: the maximum opening distance between upper electrode and table for clamping thickness + margin
Table dimensions / table bed structure: the width, support rails, rigidity
Drive / motion system: linear rails, ball screws, servo/stepper drives for longitudinal motion
Pressure / pressing system: hydraulic or pneumatic pressing, platen / electrode force control
Cooling / dielectric / electrode cooling / water circuits
Control system & interface: PLC / HMI, control logic for motion, dwell, welding timing

Use these spec values as your target reference. Any deviations should be understood relative to original design or modifications.

2) Document & Record Checklist (Before Arrival)

Request the following from the seller:

Original specification sheet / datasheet (electrode length, power, frequency, motion parameters)
Serial number, manufacture year, model designation
Maintenance / service logs (generator servicing, electrode maintenance, drive repairs)
Calibration / test records (weld quality, alignment, electrode gap consistency)
Electrical schematics, wiring diagrams, control logic (PLC / motion interface)
Spare parts list (oscillator tubes, electrode bars, motion components)
Alarm / fault history logs
Any modification / retrofit records (generator upgrades, motion system changes)

These documents help you judge how much the machine may deviate and identify non-original parts.

3) Visual & Static Inspection (Power Off)

Walk around and visually inspect all major parts:

Bed / frame / table support structure: check for weld repairs, cracks, sagging, fatigue, corrosion in long spans
Tables / rails / guide systems: inspect alignment, wear on rails or bed supports, signs of binding or deformation
Upper electrode bar / platen / pressing head: look for surface wear, corrosion, bending, damage in electrode surfaces or holder
Electrode guides / insulating supports: check for wear, cracking, insulator damage, misalignment
Drive trains (ball screws, linear guides, couplings) over the full 14 m: inspect for visible wear, backlash, play
Hydraulic / pneumatic press components: cylinders, hoses, seals—check for leakage or past repair evidence
Cooling / water circuits / plumbing: hoses, pipes, connections, valves for leaks, corrosion, brittle lines
Electrical cabinets / enclosures: open panels, inspect wiring, signs of overheating, corrosion, modifications, cleanliness
Motion cable carriers, drag chains, flexible conduit: inspect for wear, broken links, fatigued insulation
Safety covers / guards / interlocks: confirm guards are present, doors function, interlock switches in place

Photograph any anomalies, repairs, or evidence of previous impacts.

4) Installation & Alignment Checks

If the machine is already mounted or partially installed:

Confirm that the table is level over its full length—check for rolls or twist using precision levels or straightedge
Inspect anchoring or foundation mounting to ensure the machine is not subject to bending or stress
Using a reference rail or straight edge, check longitudinal alignment of the electrode / motion direction
Check that the electrode bar / platen slides or moves uniformly along its full length without binding
Place a dial indicator at multiple points along the electrode length; test for parallelism to table surface / bed

5) Power-Up & Motion / Functional Tests

With power and safety measures active:

Warm up the motion system via jogging the electrode carriage or welding head for ~20–30 minutes
Home / reference return sequence: check repeatability of home positions, no limit errors
Drive test: move the electrode carriage full 14 m at different speeds (slow, mid, fast), watch and listen for binding, jerkiness, or motor strain
Press / pressing head motion: test the upper electrode elevator / press downward stroke, check smoothness and consistency
Generator output simulation (if safe to energize): test the HF generator without load or with test material to see stable output and no spark misfires
Timing / dwell test: run a mock welding cycle to verify correct dwell time, electrode contact, motion timeline
Electrical / controls: test PLC / HMI inputs, outputs, interlocks, emergency stops, parameter setting, alarm panels
Cooling / water circuits: run coolant / electrode cooling water flow, check for leaks or pressure drops
Pressure system: pressurize hydraulic / pneumatic press, monitor pressure stability, no leaks

6) Weld Accuracy, Uniformity & Reproducibility Tests

This is the core component for HF PVC welding:

Place standard test sheets or PVC material and perform test welds over full electrode length (long seams). Inspect weld uniformity—consistency of weld bead, seam strength, visual appearance
Weld seam quality across length: inspect that weld is continuous, no cold joints, dropouts, or weak spots
Electrical / HF current uniformity: use measurement probes to check that generator current / power is stable and uniform across electrode length
Electrode gap stability: test initial gap and check whether drift occurs over repeated passes
Pressure uniformity: ensure pressure is consistent along the electrode length (press force control)
Thermal consistency: after extended welding, verify that the electrode / platen temperature remains within acceptable bounds—no thermal warping
Cycle repeatability: repeat the same weld program multiple times and measure consistency in weld quality, bead dimensions, power draw

7) High-Frequency Generator & RF Components Checks

Inspect the generator power module, tank circuit, oscillation tube (if used), capacitors, matching network for obvious wear, discoloration, or overheating
Verify RF cable / transmission lines / connectors between generator and electrode – no corrosion, cracks, loose fittings
If applicable, examine the arc suppressor / spark protection tube for condition and functionality
Test the generator under dummy load (or calibration standard) to verify stable output, correct frequency (e.g. 27.12 MHz) and no drift
Monitor the generator’s current draw and voltage during test cycles for anomalies
Check cooling of generator / RF modules: fans, heatsinks, coolant jackets (if applicable)
Inspect matching networks, inductors, capacitors, tuning circuits for loose parts or signs of arcing

8) Lubrication, Cooling, Water & Auxiliary Systems

Cooling / water systems: flow rate, pressure, no leaks, cleanliness of coolant, check for contamination
Electrode / platen cooling circuits: ensure water or coolant flow to electrode holders, no blockages
Hydraulic / pneumatic systems: check pressurization, leakage, actuator response
Filtration / water filtration / strainers / traps: ensure filters are clean, no clogged lines
Cabinet & component cooling: ensure that enclosures, fans, ventilation are working, no overheating
Lubricant systems (for motion carriage): confirm grease / oil delivery to rails, screws, check blocked lines, dry spots

9) Common Wear, Failure Modes & Red Flags

Electrode bar bend, warping, or deformation
Nonuniform motion / binding in long carriage travel
Generator component failure (capacitors, tubes, matching network)
RF line leakage, breakdown, connector faults
Pressing head misalignment or press actuator wear / leaks
Thermal drift or heating causing electrode misalignment
Motion drive backlash or looseness over long span
Cooling / water leakage damaging insulating or structural components
Control electronics failure, PLC faults, parameter corruption
Cable harness fatigue, connector corrosion

If multiple of these appear, the machine risk is high.

10) Acceptance Criteria & Benchmark Targets

Use these sample tolerance guidelines (adjust based on datasheet):

Parameter	Target / Acceptable Tolerance
Electrode carriage positioning repeatability	± 0.1 mm (for 14 m motion)
Motion smoothness / no binding	Fully smooth travel, no vibration
Press stroke repeatability	Very tight repeatability each cycle
Weld seam quality consistency	Visually uniform along full length + mechanical test
Generator frequency stability	± < 0.5 % from nominal
Generator output stability	No major fluctuations during cycle
Electrode gap drift over cycle	Minimal drift (< 0.1 mm)
Thermal stability over extended use	Minimal drift or deformation
Cooling / water pressure drop	Within spec, no major drop
Motion drive current stability	Smooth current traces, no spikes