We consider an anisotropic curvature flow $V= A(mathbf{n})H + B(mathbf{n})$ in a band domain $Omega :=[-1,1]times R$, where $mathbf{n}$, $V$ and $H$ denote the unit normal vector, normal velocity and curvature, respectively, of a graphic curve $Gamma_t$. We consider the case when $A>0>B$ and the curve $Gamma_t$ contacts $partial_pm Omega$ with slopes equaling to $pm 1$ times of its height (which are unbounded when the solution moves to infinity). First, we present the global well-posedness and then, under some symmetric assumptions on $A$ and $B$, we show the uniform interior gradient estimates for the solution. Based on these estimates, we prove that $Gamma_t$ converges as $tto infty$ in $C^{2,1}_{text{loc}} ((-1,1)times R)$ topology to a cup-like traveling wave with {it infinite} derivatives on the boundaries.