Molecular sieves

Molecular sieves are synthetically produced zeolites with a regular crystalline structure – and thus a uniform pore diameter. Small molecules get trapped in the pores and are held there; large molecules flow past outside. One needs molecular sieves with a pore width of 4 Å in order to retain water.

Molecular sieves are used for particularly rapid flash drying or to maintain objects (products and goods) with an air humidity of almost 0% RH. Unlike bentonite and silica gel, however, they take up 16 - 22 per cent of their weight in water vapour regardless of the particular relative humidity.

Regeneration of molecular sieves is possible repeatedly at 250 - 350°C. Whereby it is necessary to ensure slow heating – otherwise the molecular sieve ages too quickly or is completely destroyed.

Pack Designs:

We supply molecular sieves in every pack size, according to customer requirements:

  • in polyethylene (thickness = 200 microns),
  • in aluminium composite film, and
  • in tin cans.



ORANGE ® dry pearls

ORANGE® dry pearls are the only desiccant with a humidity indicator free of heavy metals. This desiccant replaces blue gel. ORANGE® dry pearls permit a reliable monitoring of the drying process. Thanks to an indicator, the dry pearls change colour from orange to colourless when they have taken up about 6% of water by weight. Water, however, is still adsorbed after this point has been reached. The total adsorption capacity is not affected by the colour indicator. ORANGE® dry pearls can be regenerated from 130°C - 160°C. There is then a colour change back from colourless to orange and the product is fully functional again.

Main areas of use:

  • In the inspection windows of drying systems
  • In transformer dehumidifiers
  • In laboratories
  • In pharmaceutical packages

Typical properties:

  • High adsorption capability
  • Low abrasion, high mechanical strength and thus long service life
  • Ideal flow conditions in bulk bed due to pearl shape
  • Uniform regular change of colour in proportion to water uptake
  • Excellent regeneration properties


Pack designs:

We supply ORANGE® dry pearls in every pack size, according to customer requirements:

  • in polyethylene (thickness = 200 microns),
  • in aluminium, and
  • in composite film in tin cans


Technical data: 

  • Grain size: 2.0 - 5.0 mm² BET surface area: approx. 750 m²/g
  • Pore volume: approx. 0.40 ml/g
  • Vibrated bulk density: approx. 0.8 kg/l
  • Fracture strength: over 200 N
  • Abrasion (acc. to Mil-D) below 0.05% by weight


Chemical Composition:

  • SiO2: approx. 97% by weight
  • AI2O3: approx. 2.9% by weight
  • Organic colour indicator: approx. 0.1% by weight