Membrane filters

The membrane filter of WaterShield consists of a bundle of hollow fibre membranes on our exclusive Ceramic patent in a tube. The space between the membranes and the tube is hermetically sealed with epoxy resin or optimized glue for drinking water.

Because the membranes need a low pressure drop for operation, the filter can be made very compact. That makes him ideally suited to the point of use.

Filtration Techniques:

WaterShield filtration employs two techniques:

In the ‘Dead End’ filtration technique (see Figure 1), the water flows from the outside to the inside. The filtered particles and bacteria remain in the porous membrane wall. Those affected the accumulated to be slowly. When the flow rate (Pressure flow) decreases, the filter must be replaced.

At the ‘Dead End’ filtration technique (see Fig. 1), the water flows from the outside inwards. The filtered particles and bacteria remain in the porous membrane wall. Which slips thereby slowly close. When the flow rate (flow rate) decreases, the filter must be replaced.

This technique we apply mainly in the Legionella Safe showers, in-line filters and faucet filters.

In the “Forward Flush Technique (see Figure 2), the membrane is streamed from the inside. The filtered particles, bacteria and viruses are kept on the inside. With this technique, it is possible to reverse the flow so that the filtered, pure water rinses the inside of the Membrane. The dirt is removed at the bottom.


Purification Standards:

The WaterShield membrane filters meets the highest standards purification. The Ultra-filtration membranes meet even the highest standards in the world. These are the U.S. EPA criteria for micro-biological water purifiers, nl> 6 log (99.9999%) for bacteria and> 4 log(99.9%) for viruses. (See also: The Importance of Safe Water).

Filter life:

There are wide and unpredictable variations in the nature and concentration of micro particles in water. As a result, the service life of a filter depends on local conditions, and the water may or may not be present by pre-filtration.

Figure 1 – Filtration at the end where it is needed.
Filtration at the end where it is needed
Figure 2 – forward flush Filtration

Forward flush Filtration

Membrane technology

WaterShield uses a super efficient

  • Hollow Fiber by a unique blend of polymer and mineral components extremely hydrophilic and highly porous, including a consistent pore size in the separating layer. Thus a high flow rate guaranteed at a low pressure drop at both micro-and Ultrafiltration.

This Membrane added benefit of low energy filtration, this all leads to end result of low energy cost.

The capillary membranes WaterShield have the following properties:

  • Asymmetric Microporous Structure.
  • Internally smooth texture, 1mm diameter.
  • High flow at low pressure.
  • Very consistent pore structure:
  • Microfiltration 0.1 to 0.15 µM (microns max)
  • Ultrafiltration from 0.01 to 0.02 µM (microns max)
  • High porosity (85%).
  • Permanently hydrophilic, with an inert surface, and which substances do not adsorb to the membrane is easy to clean.
  • Resistant to internal and external pressure between 1.5 to 25 Bars.
  • Resistant to disinfection with chlorine.
Capillary (hollow fiber) membrane
Capillary (hollow fiber) membrane
Cross section of a capillary (hollow fiber) membrane (156x)
Cross section of a capillary membrane
Exterior of a capillary (hollow fiber) membrane (5000x)
Exterior of a capillary membrane

Membrane technology General information

General Information

Membranes according to their filtration properties are classified into 4 categories:

  1. Microfiltration, range from 0.1 to 1 micron (1 micron (µM) = 1/1000 mm)
  2. Ultrafiltration, range from 0.001 to 0.1 microns
  3. Nanofiltration, range from 0.0001 to 0.001 micron (0.001 micron = 1 nanometer(nm))
  4. Reverse Osmosis, range

As the pores become smaller, there is more pressure at the filtration process in motion. Also the surface properties of the membrane play a major role. When a hydrophobic (water-repellent) surface will be more pressure than with a hydrophilic(water-attracting) surface.

Micro-filtration and ultra-filtration filter particles from the water. Nanofiltration and Reverse Osmosis change the chemical or ionic composition of the water, such as for example the removal of minerals.

Filtration Spectrum:

Filtration Spectrum

Compliance with the Medical devices regulations

Compliance with the existing regulations

The fabrication of the filters is based on the standard requirements of ISO 13485:2003 Medical devices, maintaining quality. The Regulatory requirements are according to Directive 93/42/EEC concerning medical devices.

All the components of the products are selected in accordance with the recommendations of the Food and Drug Administration (FDA), according to the legal code for products that come into contact with foodstuffs. The products are Class Ⅰ medical devices and are marked CE follow the requirements of the regulations. The ABS plastic material that is used to meet the requirements of European Pharmacy – Issue 5, Chapter 3.2.2 “Packaging and plastic closures for pharmaceutical use US-USP VI” – and the material is tested for biological reactivity. The hollow fibres of the micro-filters are selected based on the quality and guarantees ACS & NSF61 & in process of obtaining CE- Medical (see link attach), NSF 42, 53, 401 & 177 certificates standers

The products WS2013PRO & WS2014PRO are individually tested to the good state of the membrane and the water resistance of the device to be ensure. The filters contain a bacterial component which resists the spreading of micro-organisms on the surface of the product; the risk of subsequent contamination reduces by 99%.

The product does not contain latex!

Materials & Agreements
  • Hollow fiber : material Polysulfone used in ours membranes with ACS & NSF61 agreements
  • Ceramic: in process of obtaining CE- Medical, NSF 42, 53, 401 (Filtration) & 177 (Shower Filters) certificates standers
Resin & Glue material for potting Medical grade & optimized glue for drinking water used in ours membranes with ACS & NSF61 agreements