Next, let's talk about the molded products of EPP and EPS materials. How to distinguish them?
1. The ingredients are different (intuitively, the names are different first)
1. EPS (English full name: Expandable Polystyrene), Chinese name: expandable polystyrene, also known as Styrofoam.
2. EPP (English full name: Expanded polypropylene), Chinese name: foamable polypropylene.
Second, the production process is slightly different
Note: (1) When the EPS raw material is purchased, it is a crystalline particle, which needs to be pre-expanded into foam particles;
(2) When molding, EPS requires a small steam pressure, about 0.4-1.0; the steam input time and cooling time are relatively much lower than EPP;
(3) When drying, the temperature requirement is also lower than that of EPP, about 50-60 degrees, and the time is about 4 hours;
2. EPP molding process
Note: (1) EPP raw materials are different from EPS. The raw materials purchased from EPP are already foamed foamed particles, but the foamed particles need to be loaded (or pre-pressed). Due to the difference in the density of the foamed particles , the required pressure is about 2-4 pressure, and the time is about 15 hours;
(2) When forming, EPP requires a high steam pressure, about 3+/-1 pressure, and the steam input time and cooling time are relatively much higher than EPS;
(3) When drying and shaping, the temperature requirement is also higher than that of EPP, about 80+/-5 degrees is enough, the time is about: 6-8 hours, and then natural cooling for 2-4 hours (related to the temperature difference between the outside and inside , the temperature difference is large, the time is longer; the temperature difference is small, the time is short);
If you want to know other differences, let's listen to the next chapter to break it down!