Cobot welding covers require a visual check before every shift, a detailed spatter and pinhole inspection every week, and a frame, fastening and roller inspection every month. This routine prevents hot spatter, ultraviolet radiation and welding debris from reaching personnel, robot joints, dress packs and nearby equipment.
Cobot welding cover inspection intervals
The inspection frequency depends on exposure rather than calendar time alone. A two-shift cell produces twice the exposure hours of a comparable single-shift installation, so maintenance records must include operating hours or weld cycles.
| Interval | Components | Inspection task | Required action |
|---|---|---|---|
| Before each shift | Curtains, blankets, robot covers and enclosure panels | Check position, tears, open seams, burn marks and obstructed sight lines | Stop operation where the protective boundary is incomplete |
| Weekly | Welding-facing surfaces, overlaps, fasteners and cable openings | Remove loose spatter and inspect for pinholes, hardening and gaps | Repair only with a manufacturer-approved system |
| Monthly | Frames, tracks, rollers, hooks, screens and anchor points | Check alignment, free movement, wear, corrosion and loose fixings | Adjust or replace defective hardware |
| After a collision or weld fault | Entire protective assembly | Inspect impact points, torch area and hidden surfaces | Record findings before restarting production |
| At replacement threshold | Affected component | Confirm loss of containment or material integrity | Fit the specified replacement and update the asset record |
The risk assessment sets shorter intervals where the process has high deposition rates, confined torch access or frequent changeovers. The maintenance plan must identify the person authorised to release the cell after a failed inspection.
Step-by-step inspection and maintenance procedure
Follow the same sequence on every inspection so defects are not missed. Use the cell manufacturer's isolation procedure before entering the guarded area or placing any body part within the robot's operating space.
1. Stop the welding cycle. Park the cobot in its defined maintenance position and allow hot workpieces and torch components to cool.
2. Isolate hazardous energy. Apply the documented electrical, pneumatic, gas and stored-energy isolation procedure. Verify isolation before touching covers near the robot, torch or positioner.
3. Inspect from outside the cell. Check that curtains overlap by the specified amount, fixed panels remain seated and viewing areas provide an unobstructed line of sight.
4. Examine the welding-facing surface. Look for spatter accumulation, scorch marks, cuts, abrasion, hardened folds and local discolouration. Mark each defect so its position appears in the inspection record.
5. Check for pinholes. Place a low-power inspection lamp behind an opaque flexible cover and examine the opposite face in a darkened area. Do not use the welding arc as an inspection light.
6. Inspect seams and openings. Check stitched joints, hems, hook-and-loop closures, cable penetrations and overlaps. Confirm that robot movement does not pull a closure open at maximum reach.
7. Check attachments and hardware. Examine hooks, magnets, eyelets, clips, rails, rollers and frame fixings. Move sliding curtains through their full travel and confirm that they remain on the track.
8. Clean by material type. Apply the approved method listed below and prevent debris from entering cobot joints, fans, connectors or EOAT.
9. Assess against replacement triggers. Replace any component that no longer contains spatter, blocks the specified optical radiation or stays in its designed position.
10. Restore and test. Remove tools, restore energy and run the cell at reduced speed under the site's validated restart procedure. Confirm full robot travel does not contact or stretch the cover.
11. Record the work. Enter the inspection date, asset ID, defects, photographs, corrective action, replacement part and responsible person's name.
For selection criteria covering exposure, access and material construction, use the cobot welding cover guide.
Cleaning methods for each cover material
PVC welding curtains
Remove loose dust with a soft brush or low-suction industrial vacuum. Wash the curtain using lukewarm water and a manufacturer-approved neutral detergent, then rinse and dry it with a lint-free cloth.
Do not use solvent cleaners, abrasive pads or metal scrapers because they scratch the surface and attack plasticisers. Replace a viewing curtain when cleaning no longer restores the visibility required for safe observation.
Glass fibre welding blankets
Use low-suction vacuuming to remove loose particulate without breaking fibres. Do not shake, fold aggressively or use compressed air because these actions release contamination and damage the weave.
Follow the supplier's instructions before applying water or detergent because coated and uncoated glass fibre products have different cleaning limits. Remove a blanket from service when fibres are exposed, the coating flakes or the weave opens.
Kevlar robot and dress-pack covers
Brush off cool, loose spatter using a soft non-metallic brush. Clean the cover only with the detergent, temperature and washing method stated by its manufacturer.
Inspect high-flex zones around joints, cable bends and wrist assemblies after cleaning. Refitting must preserve the cobot's full reach and prevent loose fabric from catching the torch, fixture or workpiece.
Replacement triggers for covers and enclosures
Replace a cover immediately when it has a through-hole, open seam, split eyelet or burn-through. Replacement is also required when embrittlement, shrinkage or distortion prevents the part from maintaining its specified overlap.
Persistent spatter that makes a curtain too heavy to hang correctly is a functional failure. A cloudy viewing panel that prevents operators from seeing the process is also unserviceable, even when no hole exists.
Replace bent frames, seized rollers and damaged tracks when adjustment does not restore alignment and free movement. Do not patch safety-critical material with unverified tape, sheet or adhesive because the repair lacks documented resistance to flame, heat and optical radiation.
The cover remains one part of the wider cobot welding cell risk-control system. Replacement material must match the specification established by the cell risk assessment and supplier documentation.
How cover condition affects the complete welding cell
A welding enclosure controls hazards beyond visible sparks. Its material, geometry and overlap support containment of spatter and optical radiation while protecting cobot cabling, connectors, joint seals and nearby production assets.
The cover does not replace the cell risk assessment or other protective measures. Welding fumes require local exhaust ventilation, hazardous robot movement requires validated safeguarding, and hot components require controlled handling procedures.
PUWER requires work equipment to remain in an efficient state, in efficient working order and in good repair. A planned inspection regime provides evidence that the business checks deterioration before it defeats a protective measure.
Maintenance changes can affect the original conformity assessment. A different curtain grade, altered frame opening or relocated panel can change exposure and access conditions, so the responsible engineer must assess the modification before production restarts.
PUWER inspection records
Record each cover as an identifiable asset or as a defined component of the welding cell. The record must connect the inspection result to the correct cell, location and date.
Include the inspector's name, operating hours or weld cycles, observed defects, photographs and corrective actions. Add the replacement material's part number, batch or serial reference where one exists.
Keep failed parts quarantined until the fault has been reviewed where recurring damage indicates a process problem. Repeated burns in one position often identify torch alignment errors, unsuitable cover clearance or an unmanaged spatter path.
Inspection records do not create compliance on their own. They demonstrate that the maintenance system finds defects, assigns actions and verifies completion.
Downtime cost of a failed welding cover
Calculate direct downtime cost as stopped production hours multiplied by the cell's contribution per production hour, then add labour, replacement parts, expedited delivery and restart validation. A cell losing £350 of contribution per hour during a four-hour stop creates £1,400 of lost contribution before repair costs.
A planned 20-minute curtain replacement during scheduled maintenance has a different cost from an unplanned failure during a staffed shift. Stocking the specified curtain, blanket, fasteners and rollers removes procurement lead time from the recovery period.
Cover damage can also contaminate cobot components or halt adjacent work. The cost record must separate the failed cover from consequential damage so recurring losses remain visible.
Frequently asked questions
Can a pinhole in a welding curtain be repaired?
A repair is acceptable only when the curtain manufacturer supplies or approves a repair system for that material and defect. Replace the curtain when the repair lacks documented flame, heat and optical-radiation performance.
How often must a cobot welding cover be replaced?
There is no universal calendar life. Replace it when inspection identifies perforation, open seams, embrittlement, loss of visibility, failed attachments or an inability to retain the designed position.
Can compressed air remove welding spatter from a cover?
Do not use compressed air on glass fibre blankets or where it disperses hazardous dust into the workplace. Use a soft brush or suitable low-suction vacuum after the material has cooled.
Does a welding cover make the cobot cell collaborative?
No. Collaborative operation depends on the application risk assessment, robot mode, tooling, workpiece, speed, force, access and validated protective measures.
What spare parts belong at the cell?
Hold the specified curtain or blanket, approved fasteners, rollers and attachment hardware where procurement time exceeds the site's downtime tolerance. Store flexible materials clean, dry and away from ultraviolet light, heat and sharp edges.
