EVA is the industrial standard material for photovoltaic cell encapsulation with more than 25 years experience.
The EVA encapsulant provides physical isolation of the solar cell and the circuit components as well as structural support and positioning of the solar cell circuit (see graphic below).
In order to get the necessary structural stability the EVA film has to be crosslinked by peroxides during the lamination process. This crosslinking process is significantly improved by using TAC or TAICROS® as crosslinking additives in the EVA film providing the following advantages:
- Reduction of cure time/cost savings
- Increased gel content/crosslinking degree
- Improved transparency
- Improved color stability due to shorter cure times
The chemical background for the improvements achieved by TAC or TAICROS® as coagents is a multiplication of potential crosslinking points, when TAC or TAICROS® is grafted on the polymer in the first reaction step. By this the crosslinking efficiency of the peroxide is improved even though some of the TAC or TAICROS® homopolymerizes.
As a consequence a part of the peroxide can be replaced by TAC or TAICROS® in order to reach a certain crosslinking degree, whereby the formation of volatile or even toxic byproducts from the peroxide is reduced. By this also the amount of unreacted peroxide can be reduced, which is advantageous for color stability.
For more information please contact our technical team.