Chart 4-16 the influence of the coating agent’s concentration on the expandable ratio and preservation period
The 6 curves in the picture represent the coating agent’s concentration(W):
1-15%; 2-12%; 3-9%;4-4%; 5-2%;6-blank material
We can learn from chart4-20 and picture4-16 that when the expandable ratio is reduced from 30 times to 22 times, the time that different coating agent costs to coat the EPS particle is quite different because of their different concentration. As the concentration of the coating agent get larger, its effect to extend the preservation period become more evident. The EPS particle coated by 15% concentration liquid ,its preservation period is 6.3 times longer than the blank material’s. For the strengthen of the coating agent concentration, the coat on the EPS particle is tightened and its thickness is added, too. As a result ,the prevention to the foaming agent dissipation is more evident.
- The influence of low- concentration coating agent
If the concentration of the coating agent is too high, it will be harmful to the processing and application, and it will also cause the waste of the raw materials. So, the concentration of the coating agent should be reduced ,and the preservation effect to the EPS particle should be improved.
Put the EPS particle coated by the low-concentration coating agent together with the blank material in the 45 environment, and measure the expandable ratio at different periods. As picture 4-17 shows.
Compared with blank material, the EPS particle coated with 1% coating agent is 1.2 times longer, and the one with 0.5% coating agent is about one time longer, and the one with 0.1%,0.2% is about 0.6 time longer. So we can know that the coating agent liquid with 1% or 0.5% concentration has influence on the EPS particle preservation period and this influnce is not high.Mainly due to the low degree of tolerance, The difference between the concentration of the dense coating formed by the degree of impact,So that the thickness of membrane has little effect on,In order to preserve a view of the impact of EPS was no significant difference.
Because of low concentration (0.125%, 0.062%) EPS of the film deal with the experimental data show that the particles,Treated by their EPS particles compared with the blank material almost identical results.Can consider, Plaster low concentration, EPS will not be able to form a surface layer of the barrier layer to prevent the loss of blowing agent.
EPS coating method used to deal with particles, Can significantly improve the foam EPS ratio, To extend its shelf life, The use of cheap easy to get mixed type of film, In the production process can be re-used.