| 摘要 |
<p>A process for blowing a balloon from a tubular parison of a thermoplastic polymer material by radially expanding the parison at an elevated temperature and pressure, the process characterized in that: a) the polymer material includes a 'H-bonding' polymer which undergoes interchain hydrogen bonding between at least some segments thereof; b) the parison is conditioned in a high moisture environment prior to blowing, and c) the balloon is blown after moisture conditioning of the parison and without an intervening drying thereof.H-bonding polymers may be polyamides, polyurethanes or block copolymers containing a polyamide or polyurethane block. The process reduces occurrence of fish eye defects in the formed balloons.</p> |
