fast curing powder coating

For the fast curing powder coating, the traditional concept that easily achieve rapid curing the purpose of adding curing agent in powder coating formulations can be designed; but over reliance on AIDS will often bring adverse criticism, others such as: flow variation, yellowing discoloration and powder properties such as thermal storage. This paper from the actual construction conditions of low temperature curing and texture plane powder, conventional sand wrinkle powder, powder of thermal transfer film, integrated apparent properties, mechanical properties and thermal stability of the powder storage performance requirements, selection and demonstration of different reaction activity index of polyester effect on the performance, and finally puts forward the overall solution.

Fast curing type polyester in the use of powder coating are often the following aspects of the following help. For example: (1) improve the crosslink density, thereby improving the film hardness, scratch adhesion, impact resistance and other mechanical properties; (2) reduce the curing temperature or shorten the curing time, low temperature curing or fast curing; (3) melting block powder flow, realize the size of the texture and three-dimensional etc. the apparent aspect of control; (4) interference interspersed with slow speed or curing system, to achieve reduction in apparent gloss and leveling. However, the rapid curing of polyester at the same time, the advantages of other disadvantages are slowly revealed. For example: (1) the hot storage stability is poor, the powder coating made of easy agglomeration; (2) the poor performance of flat film flow, easy peel etc.. To this end, a successful fast curing polyester products must be balanced good mechanical properties and leveling performance, thermal storage stability and curing conditions, such as two pairs of contradictory indicators. In order to apply the use of different types of powder coating, fast curing polyester in R & D, production engineering for the focus of the above indicators are different; therefore, the classification is different, the use of features are not the same. The following will introduce the specific types of fast curing polyester and its corresponding use characteristics.

2 Application of fast curing polyester in heat transfer type powder coating

The difficulty of heat transfer type powder coating is the paper tearing problem. The paper effect is good, no prints or impressions, the transfer efficiency is high; no tearing or sticky paper, then prints is obvious, the production efficiency is low. The experimental results show that the main influencing factors of film transfer paper are: (1) the hardness of film, higher hardness, better paper; (2) the degree of curing polyester, curing speed is faster and more completely, the paper better tear; (3) the distribution of molecular weight, molecular weight more and more narrow distribution, is tearing better tear.