Melting Rate of Pressed-on-Hot-Wall-Melting in a Spinning Machine
1973 Volume 37 Issue 12 Pages 1205-1211,a3
Details
1973 Volume 37 Issue 12 Pages 1205-1211,a3
Theoretical melting rate V is obtained using many approximations. For a flat wall, the relation between non-dimensional melting rate Vγ=0 and non-dimensional pressure P/μc is
where N is a coefficient concerned with temperature dependence of viscosity. For a fin-type wall, correction factor V/Vγ=0 is obtained.
Regarding melt spinning of plastics, 1) pressure and viscosity have little effect, 2) wall temperature has a large effect, 3) interval of outlet grooves and index of temperature dependence of viscosity have medium effect, 4) wall speed moving across the direction of pressure has no effect, 5) thickness of molten plastics film is about 0.1 mm, and nearly constant in several types of melters, 6) optimal fin shape can be decided for a pair of V and heat conductivity of wall metal, 7) for example, “I. C. I.-type pressure melter” with aluminum wall, optimal shape is nearly an isosceles triangle of height double the base, and even then V is only 1.6 times Vγ=0.
