In October this year, one of customer reported that the our direct roving E310-4400tex had fuzzy, and the surface of pultruded products was not smooth. We checked the company's production records and tested the samples of the batch and found that the quality of this batch of products was qualified. Through the communication with customers, the customer had two producing line, old one and the new one. We found that the products of the old production line of customers are good, and the products of the new production line which started to be produced in September this year would have the bad appearance. Through our engineers' on-the-spot investigation, we found the reason: the edge of the mould entrance of the new product line is too sharp, which will scratch the surface of the yarn, break a small number of filament glass fiber, and cause bad effects on the surface of the product. We suggest the customer to improve the mold entrance and solve the problem successfully.