Rapid Drying

Rapid Drying

How can the rapid drying of a combination of cellulose nitrate solution with short-chain alkyd resin in the preparation of nitro-putty fillers be reduced?

The drying of such a combination can be freely adjusted to be fast or slow. However the method of doing this depends on the composition. Without knowing the composition only the following recommendations can be given. Drying will b slowed by:
  • a) using a weakly-reactive alkyd resin.
  • b) substitution of a part of the alkyd resin by plasticizer.
  • c) use of siccative mixture which is only weakly active (eg. no cobalt).
  • d) having no low-boiling materials in the solvent mixture; on the contrary it should contain a high proportion of high-boiling materials.
  • e) concurrent use of a soft resin such as carbamide resin or SAIB (sucrose acetate isobutyrate).
The filler can also affect hardening. Use of a filler which forms fibres or platelets can be useful in retarding drying. There is also the question of whether the putty, whilst slow to harden is ultimately required to be very hard or whether it must remain somewhat soft and flexible. This is very dependent on the filler.




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