Dyeing
Atmospheric dyeing machinery
Atmospheric dyeing machinery should have:
- hot parts guarded or lagged;
- steam injection nozzles of a noise-reduced design;
- open vessels - valves and other controls located in a safe position (no risks from overflowing or boiling liquor);
- buckets with lids used to prevent spillages;
- adequate drainage provided;
- pits and gullies guarded, fenced and clearly marked;
- where liquor preparation plants are in separate rooms 0 arrangements made for lone worker emergency contact;
- access limited where winding-on or batching of operations takes place at speed; and
- where 'A' Frames are used - precautions in place to stop them falling over.
Screen printing machines
Screen printing machines should have:
- all traps and shearing areas guarded or safe by design;
- platforms or walkways available on wide rotary or flat printing machines; and
- system in place to prevent access during screen preparation where lasers, ultra violet or other special light sources are used.
High temperature dyeing machines
High temperature dyeing machines (HTDMs) are considered to be machines with an operating temperature of 100C or more. Additionally, if the temperature exceeds 110C, the chamber of the dyeing machines falls within the scope of the Pressure Systems Safety Regulations (PSSR) 2000.
HSE Guidance provides advice on safeguarding standards, safe operating procedures, maintenance and users duties under PSSR.
Recently, HSE's Textiles Sector Group identified that injuries were continuing to occur at HTDMs. In particular, there were a number of incidents associated with the failure to maintain the safety devices at the door locking mechanisms. A visit programme was therefore undertaken to look into this problem.
Several instances were found of serious defects in the safety devices at multi-bolted and quick opening doors. In the main these had been damaged or defeated by misuse. HSE inspectors issued prohibition notices on some of the machines, while with others repairs were carried out immediately to allow the machines to be used. The majority of these defects should have been identified and brought to the attention of appropriate people by the operators of the plant. A properly implemented preventive maintenance scheme should also identify such defects before a potentially dangerous situation could arise.
The findings of this investigation were disappointing in that the level of compliance with legislation and guidance together with the condition of the plant and the effectiveness of maintenance itself was poor.
As a result, efforts are now being made through publicity to raise awareness of the standards in PM4 within in the dyeing industry.
High pressure dyeing machines should have:
- suitable safety valve;
- correct pressure gauge;
- safe working pressure and corresponding temperature marked clearly;
- supply pipe fitted with a suitable reducing valve or similar automatic device;
- thermal locks fitted and maintained regularly both on main and sample machine;
- extra precautions taken if hydrogen peroxide is used;
- safety devices and gauges simple to read and understand and easily accessible;
- where machines are inter-connected - non-return valve fitted in each line;
- multi-bolted door machines - device fitted to break the seal;
- quick-opening doors - safety devices fitted;
- hot parts guarded or lagged;
- ventilation sufficient to remove steam quickly and effectively;
- winching, winding or automatic feeds - emergency stop button fitted to allow instant access for employees;
- access to equipment and machinery well maintained and regularly cleaned eg steps, platforms, rails, gantries;
- where batching, winding and automatic feeds are in use - documented safe system of work followed that reduces the likelihood of entanglement;
- safe systems of work in place to protect employees from trapped pockets of super-heated water; and
- high-pressure dyeing machines subject to written scheme of examination.
Check the British Standards that apply to dyeing machinery.