The correct answer is (c) Feed rate
Best explanation: Feed rate does not affect stretch rate in tender frame process. Stretch rate is determined by the chain speed, divergence angle and extent of orientation. The thermoplastic film is stretched in the machine direction (MD) and the extent of orientation is determined by the ratio of the width of the film entering to the width of the film leaving the system. The film is then fed to a tender frame where a series of clips (mounted side by side on endless chains that diverge at constant angle) grasp both edges of the film and draw it in the transverse direction (TD) as it travels forward at an increasing speed.