Dynamic mechanical analysis of magnetic tapes at ultra-low frequencies
The purpose of this thesis is to investigate the correlated effects of temperature and frequency on the viscoelastic behavior of magnetic tapes, using a custom, ultra-low frequency, dynamic mechanical analyzer. The long-term mechanical and thermal properties of magnetic tapes can be simulated using high temperature and low frequency dynamic mechanical analysis (DMA) experiments. These experiments investigate how the viscoelastic characteristics of tape samples influence the extent to which the tape deforms. The experiments and analyses implemented in this paper examine the influence of the molecular structure on the viscoelasticity of magnetic tapes. Experiments were performed on a variety of magnetic tapes, including poly( ethylene terephthalatc) (PET), poly( ethylene naphthalate) (PEN), metallized poly( ethylene terephthalate) (MPET), and metallized Spaltan (M-SPA). To determine characteristic relating to the magnetic tape substrates, additional experiments examined PEN and PET substrates by removing the front and back magnetic layers from the tape sample. Due to the viscoelastic behavior of the tapes, a time delay was present between the strain and stress signals, which was determined using a Fourier transform program. The elastic modulus (E), storage modulus (E'), loss modulus (E"), and loss tangent (tan 8) were obtained from the time delay for each of the DMA experiments
Polymers Mechancial properties, Polymers Thermal properties, Electrical and Computer Engineering, Engineering
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