Candidate Support Pack - Scottish Qualifications Authority

For polyester and polyester cotton blended items, the moisture retention will be
significantly lower as polyester does not absorb moisture the same way that cotton or
woollen items will. However, a certain amount of moisture will be held in the weave
between the fibres which will add to the moisture retention level.
Because the amount of moisture retention in a polyester cotton blended article will vary
according to the amount of cotton present, it is necessary to determine what is the
correct moisture retention levels on these types of items for your laundry. The
machinery will have been set up to process the work at a given level based on the
normal moisture retention achieved from the washroom. So it may be necessary to take
several loads of polyester cotton blended items and calculate the average moisture
retention so this can be recorded and used as the benchmark criteria for all future
testing.
It is also well worth while co-ordinating any moisture retention tests with the tumbler
operators as they will also be checking the evaporation rates from the tumble dryers, ie
how efficiently the tumblers are working and how long it takes to evaporate the moisture
from the items tumbled dry. Whilst you are doing your moisture retention test, the
tumbler operator can also do their tumbler evaporation rate tests.
Other reasons for production losses in CTWs
The CTW wash line is probably the most expensive equipment in the laundry and
effectively controls the production output for the rest of the laundry. It is therefore
essential that if the machine is designed to produce a given volume of work in a fixed
time period, that you, the CTW operator, ensure that these production targets are
achieved.
The following are the principal reasons, over and above the production losses, obtained
from not correctly setting the membrane press:
Sequencing the work through the CTW
The CTW line normally has:
• An overhead rail system comprising a number of dedicated lines or rails with different
classifications on each rail line. This is normally pre-programmed into the
computerised system and it is essential you know which classifications are on each
line. Alternatively, there will be a segmented conveyor where each classification is
manually unloaded from a trolley onto the CTW load/feed conveyor.
• The CTW washing machine.
• A double or single stage membrane press.
• A bank of tumble dryers which are automatically loaded from a shuttle conveyor from
the membrane press and automatically discharged at the end of the pre-programmed
cycle time.
GC8N 22 — Laundry Operations Level 2 5.69