Penrose states that quantum effects can occur even in relatively large
systems when energy differences remain small. This is just the situat
ion with polymer materials. A quantum description by Penrose of the fo
rmation of quasi-crystals can be rewritten to apply to polymer crystal
lization. The implications of the need to take account of quantum effe
cts are discussed. Another approach based on the quantization of energ
y levels in clusters of atoms offers a possible explanation of heat se
tting in nylon and polyester fibers. Finally some problems of the inte
rpretation of quantum theory are discussed.