General Preperation or requirement of garment & textile physical & mechanical testing lab area.

Handling of Test Specimens

Caution must be taken when handling fabrics to be tested, especially knitwear and stretch fabrics, as undue stresses and strains can be applied when preparing a specimen prior to test.

Preparation Area

A suitable sized preparation table should be used such that a full width of fabric can be spread out with zero tensions. This area must be wiped clean and free from any possible causes of contamination.

The table must also be of appropriate height for the technicians to comfortably work at.

Drying

Wet specimens must not be dried in the air-conditioned laboratory. This will cause variations in temperature and humidity.

Measuring Rulers

These must be calibrated metal rulers, free from any imperfections and graduated in mm.

A selection of rulers should be available e.g. from 150mm to 2 metres

Markers

Indelible markers should be used.

Scissors

Sharp scissors should always be used with care.

GENERAL REQUIREMENTS FOR A CONTROLLED ENVIRONMENT

Equipment and Ancillary Items

Conditioning unit capable of maintaining an atmosphere of 65 % +/- 2% RH and 20 °+/-2°C

Contractors supplying conditioning units that operate merely to cool the atmosphere for a more comfortable working environment are not acceptable.

Requirements

Testing must not be undertaken if the conditions are not within the tolerance (65% +/-2% RH and 20°C +/- 2°C)

The conditioning unit must be serviced and maintained in accordance with the manufacturers requirements.

The conditioned laboratory must be constructed so as to minimise fluctuations in temperature and humidity. This may require the walls and ceiling to be insulated.
Windows must be secondary double glazed to avoid draughts and have curtains or blinds to prevent heat from sunlight. Dividing partitions that do not reach the ceiling are not acceptable.

The room should be fitted with an air lock to reduce fluctuations in the conditions when the doors are opened. The air lock must consist of 2 doors. The doors must be self-closing so that they cannot stay open. Notices should be placed on the doors warning, “Please close the door”

The entrance and exit to the room must be through the same door, or air lock.

Only personnel carrying out testing should be in the room.

Only tests that do not produce moisture can be carried out in the conditioned laboratory, i.e. drying of stability squares is not permitted.

Heat producing equipment must also be kept to a minimum such as ovens. However a hot plate is acceptable.

All of these points help to minimise the cost of running the conditioning unit.

Room Size

So that the conditions can be controlled to within the specification, the conditioning unit needs to be relative to the size of the room.

The minimum size for a conditioned laboratory is 2.0m x 2.5m.

Monitoring the Conditions using a Thermohygrograph chart recorder

The conditions must be maintained and monitored.  If the unit malfunctions or is switched off or the conditions go out of tolerance, testing cannot continue until the correct conditions have stabilised.

A Thermohygrograph chart recorder must be fitted into the conditioned room to monitor the fluctuations in humidity and temperature.

The Thermohygrograph chart recorder must be sited in an area of the laboratory that is free from vibration or any other possible causes for the pens to unnecessarily fluctuate, thereby giving a false reading.

The Thermohygrograph chart recorder should be calibrated

Monitoring the Conditions using a hygrometer

In addition to the chart recorder, weekly checks must be carried out using either a whirling digital or Assman hygrometer. These readings will monitor any fluctuations in temperature or humidity in different areas of the air-conditioned laboratory and also verify that the chart recorder is within the specified tolerances.

It is necessary to take other readings in the room to ensure that the conditions are consistent throughout.  Other suitable locations are next to pieces of testing equipment and the conditioning racks.

Records should be kept of both the weekly chart recorder graphs and hygrometer readings.

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