SIZE MATTERS Comfort, safety and productivity are partly a function of garment size and ﬁ t. A full range of coverall sizes is absolute necessity since there is a clear correlation between ﬁ t and function when it comes to protective coveralls. For example, by comparison, a single size of footwear or gloves cannot be expected to ﬁ t an entire workforce. Garments that are either too big or too small introduce unnecessary risks. Loose, non- breathable fabrics will contribute to a bellows effect
potentially causing unwanted air exchanges between the worker and his/her surrounding environment and will be easy to snag, awkward to wear and potentially restrict the wearer s vision. On the other hand, tight body-hugging coveralls will tend to expose the body s extremities, will be dangerously stressed during bending and stretching movements, will signiﬁ cantly impede movement and be very uncomfortable to wear.
The Tyvek® barrier fabric from DuPont™ uses a proprietary non-woven fabric structure to provide a protective fabric that actually allows moisture vapour to pass through.
The material is formed from High Density Polyethylene (HDPE), with diameters as low as 1/150th of a human hair, which are spunbonded into a tough, light, homogeneous fabric with inherent vapour breatheability characteristics on account of its microscopic lattice structure.
This inherent ability to evacuate body moisture results in greatly improved wearer comfort in many Type 4,5 and 6 applications.
HUMIDITY BETWEEN UNDERWEAR AND GARMENT
0 0.5 1 1.5 2
Phase 1 Acclimatization phase
Phase 2 Sweating phase
N=5 garments tested Source: Independent Institute.
Tyvek® Microporous SMS
With their open structure, SMS coverall removes better the humidity than Microporous Film, by far. Tyvek® meets quite good performances during sweating. Microporous Film is the material that takes the longest time to remove humidity.
ANNEXE 6: COMFORT CONSIDERATIONS
GARMENT CUT Be aware that low-cost coveralls will often skimp on the cut to reduce fabric usage and this can have unacceptable consequences. Over-tight garments will pinch and pull, the fabric will be unduly stressed, they will be uncomfortable to wear, they might restrict
movement and the seams can be stretched and break or open up and lose their efﬁ cacy. It is not only comfort and efﬁ ciency that is at stake, the worker s health and safety will be unnecessarily put on the line.
Figure 12. Humidity between underwear and garment (by family).
Annexe 6 69