The materials

Membrane housings are designed for brackish water demineralisation or seawater desalination.
products have a thermoplastic inliner protecting the fiberglas shell  from the chemical attacks of brackish- or seawater.
Knappe uses plastic resins from the following groups :
1) the polyolefin group ( Polypropylene [PPhomo,PPcopo,PPblock], Polyethylene [HDPA,LDPA] )
2) the styrenic group(PS,HIPS, ABS, SAN, MBS, MABS, PPO(Noryl) , SMMA, SBS, SEBS)
3) PVC
4) Rubber (EPDM)

The basic resins used by Knappe are:
HIPS(high impact polysterene), SMMA(styrene methyl-methacrylate), PPcopo, PVC(polyvinyl-chlorid)
and for Lip/O-rings EPDM
In order to obtain the best properties for the specific parts the plastic has to be modified.
Additives  needs to be compounded with the basic resin.  (for example glass, color, fillers, modifiers,UV absorbers..)

Plastic resins do not withstand  all chemicals.
Please check for compatibility with Your medium used.
  • first our compatibility list
  • second use our service for sampling/probing media -- chemical 

or products do not withstand  to:
Ketones (examples:  acetone, methyl ethyl ketone,formaldehyde...) 
Esters    (examples: ethyl acetate alphatic esthers..)
Ethers    (examples: ethylene oxyde,dioxane..)
halogenated organic composites  (examples:chloroform, methylene chloride, perchlore ethylene..)
Hydrocarbons  (examples:benzene, cyclohexane, gasoline..)

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picture A1

Check for compability

Our downloadable compatibility list presents general information.
Different products can inter-react and the chemical results is often not known/understood or taken in consideration.

In order to have more security we invite You to
 • initiate a practical test.
 • request A1 samples as on picture A1. 
We will provide these A1 samples and You can submit them to Your medium in the best and closest practical conditions.
After sending them back we can test them.

Results will reveal alteration against non exposed samples.