From Screening Systems
Star screens can be used when processing high-moisture compost, decomposed bark, mulch, peat etc. Depending on your product, star screens can help to emiminate binding inherent in high-moisture materials. With stars mounted on closely-spaced parallel shafts, material is conveyed upwards when the shafts rotate. The star points separate the fines from the larger material. The fines pass through the stars and the overs are conveyed past the end of the screener.