Polyamide is used in a diverse range of applications including automotive, electrical, construction, household and machinery as well as thin films and powder coatings. This Engineering Plastic and is well regarded for its exceptional hardness, good impact strength and abrasion resistance.

Stabilization

Polyamide 6 and Polyamide 66
In color critical applications, the use of Ciba® IRGANOX® 1098, Ciba® IRGANOX® B 1171 and Ciba® IRGANOX® 245 offers excellent processing as well as light and long-term thermal stability.   

Ciba® CHIMASSORB® 119 or Ciba® TINUVIN® 770 alone or in combination with Ciba® TINUVIN® 234 provide superior light stability to polyamides. Ciba® CHIMASSORB® 119 is recommended for challenging conditions, where high temperatures are applied on processing equipment with a vacuum degassing zone.

Polyamide 11 and Polyamide 12
The use of Ciba® IRGANOX® 245, Ciba® IRGANOX® 1098 or Ciba® IRGANOX® 1010 and Ciba® IRGAFOS® 168 as processing and long term thermal stabilizers provides excellent performance.   
For enhancing UV protection, Ciba® TINUVIN® 770 or Ciba® CHIMASSORB® 119 in combination with a UV-absorber such as Ciba® TINUVIN® 234 or Ciba® TINUVIN® 312 is highly recommended. Ciba® TINUVIN® 312 offers excellent initial color to Polyamide 11 or Polyamide 12 applications.

Coloration

Polyamides are hydrophilic and therefore, require pre-drying prior to processing. The colorants and additives that are to be included in formulations for PA should also have low or no contact with moisture. Colorants can be easily dispersed in polyamides with correct processing conditions and equipment. However, polyamides exhibit a very narrow melting range, and if this is exceeded the melt viscosity of the polymer may rapidly become too low. Thus, the shear forces required for complete dispersion to occur may be lacking. This group of polymers are probably the single most difficult class of polymers to color. Therefore, it is always advisable to consult colorant manufacturers with regard to selection and fastness properties of the relevant products.

Recommended colorants are mostly part of our Ciba® ORACET® range of polymer soluble colorants for Engineering Plastics, and some organic pigments of the Ciba® CROMOPHTAL® range of high performance pigments show potential use, all offering required heat stability.

For further information, please contact us.