Conditioning polyamide

Polyamide moulded are manufactured in a dry state (share of water < 0.2%) and are therefore dry and brittle after production. The properties of polyamide moulds must therefore be enhanced with regard to impact strength, firmness and rigidity prior to use.

If dry polyamide is exposed to a controlled moist environment, the polymer structure may retain water molecules due to the high polarity of the groups of carboxylic acid amides. This process is referred to as conditioning, is reversible and is performed based on a state of equilibrium. The polyamide products require specific moisture to achieve satisfactory mechanical properties.

Polyamide products are frequently conditioned to a state of equilibrium, which corresponds to a climate of 23℃ and 50% relative humidity. The water absorption is about 3% depending on the type of polyamide or share of amide groups. The process we use, however, extremely accelerates the water absorption and the state of equilibrium is achieved much faster without the unwanted loss in product quality through water stains and discolouration.

1. Is there also an alternative to the water bath conditioning?

WEISSHAAR conditioning chambers offer excellent and proven procedures. The dry and sensitive polyamide parts are stored in the climatic chamber. In contrast to water bath conditioning, they can be gently conditioned in a predictable and reproducible manner to the desired equilibrium moisture content.

2. Are there conditioning chambers especially designed for the quantity and types of polyamide?

Our conditioning chambers for polyamides are precisely designed and manufactured to satisfy the demands of the respective conditioning task.

3. How is a conditioning chamber designed?

The isolation cell consists of foamed polyurethane with a vapour-tight, chrome-nickel steel sheet on the inside. The cell is sufficiently secure and isolated, prevents condensation and is designed for large number of batches.

4. How are the necessary climate values generated for the conditioning process?

Any desired climate value can be reliably achieved within strict tolerances using the optimised air supply system and the integrated steam humidification system. The steam generator is only pressurised with softened or demineralised water. The generated steam is therefore free of minerals as well as odourless and prevents lime deposits on the moulded polyamide parts.

5. Can the conditioning also be interrupted in a targeted manner and can the chamber be promptly reloaded?

In addition to a heater for the high climate values, our polyamide chambers are fitted on request with equipment to interrupt the moisture process in a targeted manner after the conditioning period. This allows the conditioning chamber to be reloaded for an optimum number of batches.

6. How easy is it to operate and document batches?

WEISSHAAR conditioning chambers feature a high-performance programmable logic controller with a connected control panel. The control panel allows users to conveniently enter all process data, such as the temperature and humidity. Furthermore, it also possible to create graphic and numeric documentation of all product batches. This also ensures a constant and controllable high product quality for different batches.