The most important thing for trays used in lithium battery cells is accurate sizing. Only the ones with precise dimensions can meet the requirements of modern automated production. To achieve precise processing dimensions, it requires the machine to be accurate, and engineers must also be familiar with the characteristics of the material. After all, EVA foam is not metal, and when processing it, you cannot fix the material with a normal jig. Conventional processing methods will never achieve precise dimensions.
Our experience currently meets the tolerance requirement of +/-0.1mm. It fully satisfies the precision requirements of trays for battery core cell transportation and testing, and can be widely applied to the fixture requirements of other automated production. Moreover, the shock-absorbing and compressive buffering characteristics of EVA foam can further meet the fixture requirements of other similar products.
Some people might ask, wasn’t the POM (polyacetal pom) trays working well too? Why change it to EVA foam?
First, POM trays cannot be used directly because the material itself is very hard. Before use, a layer of softer EVA foam needs to be applied inside to protect the products and prevent scratches and bumps.
Furthermore, the density of steel materials is very high, resulting in a substantial self-weight and requiring more energy consumption during actual production. In contrast, EVA foam effectively addresses this issue. Due to the characteristics of foam, its internally stable microcellular structure makes the trays extremely lightweight. With conventional sizes, one person can easily handle a dozen or more pallets with hands, which is unimaginable for other materials.
Some people are still concerned about the flatness of trays made from EVA foam material, which involves the processing equipment and technology. However, one thing is clear: if the flatness is insufficient, the precision cannot be controlled. In other words, with our precision requirements, this issue can be completely disregarded.
As for other issues such as burrs or dust, these are even more basic requirements. We have always required that all products must be free of burrs and dust before being put into storage.
Some may be concerned that the edges of products appear extremely rough after manual trimming of burrs, which could greatly affect the appearance of tray products. This issue does not exist with us. The products we process have no burrs before leaving the machine. Manual work mainly serves to inspect and ensure that the trays have been properly processed.