Puraflex

Puraflex Hydrocarbon Barrier

  • Multilayered hydrocarbon & chemical resistant barrier membrane
  • Independently tested to ISO 15105-2
  • Independently tested for chemical resistance to carboxylic acids, heterocyclics, inorganics, organics, total petroleum hydrocarbons (TPHs), halogenated hydrocarbons & turpenes
  • Compliant to BS 8485:2015 and Ciria C748
  • CE Marking
  • High tear and puncture resistance
  • Available in rolls for joining on site
  • Prefabricated panels option for specified footprints
  • Also acts as a damp proof membrane
  Puraflex
Weight 440gsm
Thickness 440mu
Gas permeability Benzene 3846mg/m2/day
Toluene 3763mg/m2/day
Ethyl Benzene 494mg/m2/day
Xylene 767mg/m2/day
Acetone <0.0001mg/m2/day
Methane 0.120cm3/m2/day/bar
CO2 1.958cm3/m2/day/atm
Tensile strength MD 53N/mm
XD 48N/mm
Colour Black/Yellow
Standard size 2.1 x 50m

 

Ciria-CE-IsoqarPuraflex Hydrocarbon & Chemical Barrier is a co-extruded multilayer barrier membrane with unrivalled resistance to a wide range of pollutants including hydrocarbons, VOCs (volatile organic compounds), industrial chemicals, toxic waste and natural and radioactive gases. The membrane's chemical resistance is confirmed by comprehensive test data, and the unique Puraflex Permeation Modeller software can be used to calculate the permeation rates of site-specific chemicals.

The composite membrane comprises protective polymeric layers on both sides of a chemical resistant inner core.

Industrial Textiles & Plastics Ltd is ISOQAR Quality Assured and certified to ISO 9001 and Puraflex Hydrocarbon & Chemical Resistant Barrier has CE Marking. The membrane has been independently tested to ISO 15105-2 and is compliant to both Ciria C748 and BS 8485:2015. 

Puraflex is supplied as rolls for joining on site as standard.

ITP's Geomembranes Team provides technical support and customer-specific service. Contact them on +44(0)1347 825201 or email powerbase@itpltd.com.

See Tech Base for more information about Compliance and Certification.


 

Application

Puraflex Hydrocarbon & Chemical Resistant Barrier provides effective protection on contaminated land and brownfield site developments against a wide range of pollutants including hydrocarbons, industrial chemicals, toxic waste, and natural and radioactive gases. Other applications include environmental protection, secondary containment, and water resource and groundwater protection.

Puraflex is suitable for sites requiring NHBC Green, Amber 1 and Amber 2, and Red gas protection measures.

Installation

Typically, an impermeable barrier is designed in the foundations of the building over a high permeable ventilation layer. Hazardous gases and VOCs migrate up through the soil and collect under the membrane in a sump from where they are vented and safely dispersed into the atmosphere. The principal function of the gas barrier membrane is to prevent harmful gases from entering the building through cracks, construction joints and service openings in the floor slab. The membrane should cover the whole plan area of the structure to all external faces in order to seal the ground slab as well as any cavity walls and voids in hollow concrete block work.

Typical use is for covered installations with a low level of mechanical constraints and no risk of puncture or abrasion.

Puraflex can be joined on site with hot-air/hot-wedge welding.

Certification and Compliance

Alongside CIRIA and the British Standards Institute, ITP contributed to the latest standards. Within CIRIA C748 Guidance on the use of plastic membranes as VOC vapour barriers, more comprehensive and specific requirements are demanded.

Puraflex vs HDPE/LDPE

BTEX chemicals (benzene, toluene, ethylbenzene, xylenes) are found in contaminated land sites, a legacy of an industrial past. Hydrocarbons and their derivatives have been identified as carcinogenic and a serious threat to human health. In the past HDPE and LDPE type membranes were considered sufficiently resistant to hydrocarbons; in ISO14414 and ISO14415 these homogenous single-layered membranes give sufficient durability to pass. However, this is only a residual strength test and no measure of permeability.

Typically, an impermeable barrier is designed in the foundations of the building over a highly permeable ventilation layer. Hazardous gases and VOCs migrate up through the soil and collect under the membrane in a sump from where they are vented and safely dispersed into the atmosphere. The principal function of the gas barrier membrane is to prevent harmful gases from entering the building through cracks, construction joints and service openings in the floor slab. The membrane should cover the whole plan area of the structure to all external faces in order to seal the ground slab as well as any cavity walls and voids in hollow concrete block work.

Alongside CIRIA and the British Standards Institute, ITP contributed to the latest standards. Within CIRIA C748 Guidance on the use of plastic membranes as VOC vapour barriers, more comprehensive and specific requirements are demanded.

Any membrane now claiming to be used as a "Hydrocarbon resistant barrier" must show the listed chemicals and their permeation rates on the data sheet, and the permeation rates must be to the latest ISO15105-2 permeation test.

Puraflex was developed in line with all the above criteria.The multilayered structure consists of several resistant layers and a VOC resistant core. This exclusive technology vastly improves the resistance level by several orders of magnitude to make Puraflex the most resistant membrane currently available on the market.

Puraflex vs HDPE Permeation Rates Chart

CE Marking is required for many products. It shows that

  • the manufacturer has checked that these products meet EU safety, health or environmental requirements
  • is an indicator of a product’s compliance with EU legislation
  • allows the free movement of products within the European market

BS 8485:2015 is the code of practice for the design of protective measures for methane and carbon dioxide ground gases for new buildings.


 

The unique Puraflex Permeation Modeller (PPM) software App enables you to:

  • Upload Soil Analysis chemical concentration values - the programme recognises chemical names, synonyms and/or CAS No
  • Enter project-specific variables:  soil temperatures, partition coefficients, soil ensities, etc
  • Output permeation results for incorporating directly into risk assessment software models (eg CLEA)

Puraflex Permeation Modeller is provided free of charge to qualified environmental scientists and design engineers.

To register for access to the Puraflex Permeation Modeller App, email the Puraflex Technical Department.


 
 
ITP Ltd