GB/T 39368-2020.Leather-Physical and mechanical tests-Determination of flex resistance : Vamp flex m...
GB/T 39368-2020 皮革 物理和机械试验耐折牢度的测定:鞋面弯曲法
GB/T 39368-2020.Leather-Physical and mechanical tests-Determination of flex resistance : Vamp flex m...