A new innovation in resin production is now in full blast..the Shallow Shell Technology. It creates high efficiency ion exchange resins. Under a microscope, “Shallow Shell” resins look very different from other resins because the resins have inert core. Only the outer shell is functionalized which shorten the ion exchange diffusion path. This leads to more efficient ion exchange and regeneration and better handling of iron and organic foulants.

With increasing demand for better performing resin coupled with lower operating costs, shallow shell resins is seen as a solution. These resins enable a more complete regeneration and provide a higher, more efficient utilization of the regenerant, lower leakage, and reduced rinse water requirements. When compared to conventional softening or demineralization resins, regenerant cost are seen to reduce by 20 to 50%, without sacrificing capacity.

Advantages of Shallow Shell Resin:

• Higher Recovered Capacity


• Lower Leakages at All Regenerant Levels


• Better Iron Removal


• Lower Rinse Requirements


• No equipment Modifications Needed


• Excellent For High TDS Waters


• Shorter Regeneration Cycles


• Superior Physical Strength


• More Resistant to Oxidation


• Lower Iron and Organic Fouling

To regenerate ion exchange without the use of commercial salt is highly desirable. For ion exchange water softeners treating brackish water feed to RO plants, such a solution already exists. By using shallow shell softening resin and some engineering, the reject from the RO can be used as “free regenerant” brine to efficiently regenerate this unique resin while adding no extra salt to the environment.

(Shallow Shell Technology)SST resin exhibit much higher regeneration efficiency than standard resin, permitting the use of more dilute brine concentrations and lower salt dosages than recommended for standard resins. Reason to this higher regeneration level is the unique outer shell and inner core structure of the resin bead. Ion exchange takes place only in the shell area with the core being totally inert. The diffusion path for cations is therefore shorter than that for standard resin, divalent cations (e.g. calcium, magnesium, barium, strontium) are not exchanged deep in the core of the beads unlike standard resin in which divalent cations migrate deep into the center of the resin beads. The efficiency of removal of these deeply trapped divalent cations essentially determines how well the resin performs during the next service cycle. With SST resin, the time for the brine to diffuse to the shell-core interface is lower, resulting in more highly regenerated beads.

Pilot studies showed that brine concentrations as low as 1% can be used to regenerate
shallow shell resin.

Resin Longevity: Expected Life Span of Ion Exchange Resins

The operating life of ion exchange resin depends on several factors. Degradation of resin can be attributed to mechanical, osmotic or thermal shock; temperature; dissolved oxygen; and chemical oxidation due to attack of chemical like chlorine.

DI resins usually last for many years. In general, cation resin for water softening and demineralization may last 5 to 10 years. Anion resins last anywhere from 3 to 5 years and are dependent on operational conditions. Some of the resin beads break during the swell cycle when regenerating. Moreover, resin life is partially dependent on the number of regenerations and partially on the quantity of oxidizers passed through the column.

You can prolong the life of your resin provided the following circumstances are met:

- Adequate pre-treatment is in place, i.e. organics and suspended solids are removed and kept to minimum.

- Chlorine content in feed water is zero to undetected (determined through water quality analysis). In the presence of chlorine or any oxidant, ion exchange resins will breakdown prematurely.


- Low levels of iron in feed water. Cation resin removes ferrous iron but removing the iron off of the resin is a difficult which will result in loss of capacity overtime due to iron being embedded into the cation bead.

- There is no sudden and significant increase in raw water quality that would affect the performance of pre-treatment system which will in turn affect the quality of feed water to the ion exchange resin. Ion exchange resin system is designed based on feed water quality, therefore include safety factor in the design to handle occasional “spikes” in feed water quality.


- Operators are aware of the proper operation and maintenance of ion exchange system.

Because many variables and factors are involved, it's difficult to predict the life span of a resin and we can only provide you with what is the expected life span given ideal conditions; in critical applications it’s best to start analyzing and benchmarking the resin at least once per year.