... is three times longer than any other kind of fusing machine belt. Advantages of PTFE coated seamless belt: Stable running, ... long service life. Disadvantages: High prices.2, Jointed fusing machine belt: usually with black color, jointed with F46 film. Advantages ... service life of usually 3 months.3, double-layer fusing machine belt: Advantages: High strength, long service life, without deviation. ...