Browse Prior Art Database

Evaporative cooling of injection mold inserts

IP.com Disclosure Number: IPCOM000008058D
Publication Date: 2002-May-15
Document File: 3 page(s) / 28K

Publishing Venue

The IP.com Prior Art Database

Abstract

This invention broadly relates to evaporative cooling of a machine component. In particular, this invention relates to evaporative cooling of mold inserts for the production of plastic preforms; preforms are used to produce blow-molded bottles. Through the use of latent heat of evaporation, more energy is removed from the plastic per mass of cooling medium, and per area of cooling channel that directly cools plastic, when compared to convective heat transfer method. Secondly, since the evaporation of the cooling medium occurs at the surface of the cooling channel there is no impact of a boundary layer on the cooling efficiency. The same amount of heat should be removed from the plastic in a shorter time thus leading to faster cycle times.

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Field of the Invention

       This invention broadly relates to evaporative cooling
of a machine component. In particular, this invention relates
to evaporative cooling of mold inserts for the production of
plastic preforms; preforms are used to produce blow-molded
bottles.

Summary of the Prior Art

       Presently, contact cooling between a preform and a
molding surface or take-off tube relies on adequate water flow.
Since the heat removal by the water is essentially convective
heat transfer in a turbulent medium, the cooling efficiency is
related to the thickness of the fluid boundary layer, which
cannot be overcome in any convective heat transfer case. The
cooling efficiency is also related to the amount of surface area
that the heat is removed from.

Summary of the Invention

       The primary objective of the invention is to use the
latent heat of evaporation to cool plastic in a mold or take-off
tube.

       Through the use of latent heat of evaporation, more
energy is removed from the plastic per mass of cooling medium,
and per area of cooling channel that directly cools plastic,
when compared to today's convective heat transfer method.
Secondly, since the evaporation of the cooling medium occurs at
the surface of the cooling channel there is no impact of a
boundary layer on the cooling efficiency. The same amount of
heat should be removed from the plastic in a shorter time thus
leading to faster cycle times.

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       An advantage of this invention over prior art includes
more ef...