PR97® Technical

PR97 logoPR97®‚ is the result of over 20 years intensive research and development resulting in a highly engineered FR textile now used around the world in the harshest working environments. PR97® has set new standards in terms of protection and comfort. PR97® is recognised throughout the world as a leading textile for secondary protection in the molten metal industry due to its superior protective properties: uncompromising safety, natural comfort, cost effectiveness and proven performance. Designed specifically as a very high performance hot materials safety textile, PR97® also offers workers protection against other thermal related hazards.

PR97® is comfortable from new and laundering and wear enhance its comfort. The fabric is far more user friendly than treated cotton, which has a distinctly unappealing feel when new. The protective properties of PR97® are built in to its construction and cannot be laundered out. 

The slightly higher initial costs of garments constructed from PR97® are more than offset by extended lifespans attributable to the fact that the fabric retains its safety features over its entire life. Garments constructed from PR97® are truly multi-functional and can be used from smelter pot-rooms to maintenance areas to boardrooms.

In the aluminium industry, blended fabrics (PR97®), incorporating Lenzing FR® Viscose are in high demand as they have proven their worth in this complex application. Lenzing FR® Viscose has a special ability that makes molten aluminium and cryolite simply shed off the fabric. Because of this property, it has become the market leader in this sector. Another advantage is that garments can be made lighter and more comfortable yet offer greater protection when Lenzing FR® Viscose is incorporated into the fabric's construction.

PR97® Features

PR97®, with a composition of Merino Wool and Lenzing FR® Viscose, is widely employed as the protective fabric of choice throughout the world and has maintained its position as the benchmark standard for the protective textile across all smelter environments. The multi-functionality of PPC constructed from PR97® offers molten metal operatives a complete solution system across the smelter site. PR97® is now endorsed by some of the world's largest smelter corporations as the textile of choice for molten aluminium and cryolite protection and other thermal related hazards.

The Key Features of PR97®: 

  • PR97® is inherently flame resistant. The FR features cannot be laundered out. PR97® will retain its FR properties for the life of the garment.

  • PR97® will shed molten metal splashes, thereby avoiding penetration of hot material and burn injuries to a worker's skin. 

  • PR97® will not melt or stick to the skin. It will not ignite when exposed to electric arc or molten metals. It offers protection against molten aluminium, cryolite, steel, iron, copper, magnesium and nickel, electric arc and convective and radiant heat.

  • PR97® is completely breathable and with no chemical FR treatments, minimises heat stress. PR97® provides a unique wicking (moisture transfer) effect that immediately absorbs moisture thereby aiding the evaporative cooling process.

  • PR97® offers excellent wearer comfort and the highest standards of health and safety in secondary protective work wear. PR97® has excellent mechanical properties such as, tear strength, pilling and abrasion as well as colour fastness, which are important when assessing the life cycle of a garment. PR97® resists exposure to flame without shrinkage ensuring that slightly damaged garments can remain in service.

  • PR97® garments can be home-washed, commercially laundered or dry-cleaned. They can be effectively repaired or mended using patches and other techniques.

Flame Resistance

One important criterion used to determine the flame resistant ability provided by FR textiles is the reported Limiting Oxygen Index (LOI) of the fibre(s) used in the textile's construction. This index is the minimum concentration of oxygen, expressed as a percentage, which will support combustion of the fibre, noting that the oxygen concentration of atmospheric air is 20.95%. PR97® is a blend of Merino Wool and Lenzing FR® and the reported LOI of each fibre is:

  • Merino Wool: 25 to 26

  • Lenzing FR®: 28

  • Result: these fibres do not burn or melt, which means human skin is much safer when next to these fibres.

Limiting Oxygen Indexes of 25 (Merino Wool) and 28 (Lenzing FR®) means that a minimum concentration of 25% and 28% oxygen would be required to maintain the combustion of a Merino Wool and Lenzing FR® sample when each are exposed to a flame in a vertical plane. Since atmospheric air contains 20.95% oxygen, any textile with a greater value of Limiting Oxygen Index can be considered as non-flammable. This property prevents combustion and therefore the propagation of fire to a wider environment. 

PR97® will not melt or stick to the skin. It will not ignite when exposed to electric arc or molten metals. PR97® provides significantly higher protection from first and second-degree burns (molten metal and cryolite splash) than any other product currently in service of equal weight. The fabric will maintain this performance over its entire life span.


Heat stress is a problem often suffered by wearers of fire resistant work wear. This problem is minimised with PR97®, which provides a unique wicking (moisture transfer) effect that absorbs moisture immediately in order to aid the evaporative cooling process. An additional benefit of PR97®'s inherent flame resistance is that the lack of any chemical treatment in its construction maximises air circulation without affecting safety performance.

Care Instructions

PR97® garments can be home-washed, commercially laundered or dry-cleaned. They can be effectively repaired or mended using patches and other techniques.

However to maximise the service life of PR97® garments and ensure the protective properties of PR97® remain intact, it is important to follow these recommended care guidelines.


  • Use a pH-neutral detergent or one approved for use with wool based fabrics by the manufacturer.

  • Do not use excessive amounts of detergents and follow the manufacturer’s guidelines.

  • Never use soaps, bleaches or fabric softeners of any kind.


  • Always wash PR97® garments in cold to warm water only; a maximum of 40° C is recommended.

  • Separate excessively soiled garments from cleaner garments.

  • Do not wash PR97® garments with other types of garments.

  • Excessively soiled garments should be pre-soaked in cold to warm water using a pH-neutral detergent prior to washing.

  • Minimise the number of garments per load, but maximise water levels.

  • Use a gentle wash cycle setting and minimise agitation during rinse and wash cycles.


  • Never dry garments at hot temperatures; a maximum of 60° C is recommended.

  • Do not tumble dry garments for long periods and do not over dry garments in the drying process, as this could result in excessive shrinkage.

  • Do not dry PR97® garments with other types of garments.

  • For best results tunnel drying or line drying in the shade is recommended.


  • Always repair holes or damage to garments prior to washing.

  • If patching over holes, always ensure patches seal tightly to the garment surface. There should be no lifting of patches which could cause catch points for a metal splash.

Note - this information is provided as a recommended guide only. In all instances end users must firstly satisfy themselves that these guidelines are suitable for their intended application and monitor best care practice throughout a PR97® garment’s service life.