Tooling having advantageously located heat transfer channels

• US 6,354,361 B1
• Filed: 09/01/2000
• Issued: 03/12/2002
• Est. Priority Date: 10/31/1995
• Status: Expired due to Term

• Current Assignee: Massachusetts Institute of Technology
• Original Assignee: Massachusetts Institute of Technology
• Inventors: Sachs, Emanuel, Michaels, Steven P, Allen, Samuel M.
• Primary Examiner(s): Lin, Kuang Y.
• Application Number:
  US09/654,172
• Time in Patent Office: 557 Days
• Field of Search: 164/122, 164/348, 164/132, 164/98, 164/126, 164/128, 249/135, 249/111, 249/79, 249/80
• US Class Current: 164/128
• CPC Class Codes: B22C 9/065 Cooling or heating equipment for moulds
• CPC Class Codes: B22D 17/22 Dies manufacture, see the appropriate class, e.g. B23P15/24; Die plates; Die supports; Cooling equipment for dies; Accessories for loosening and ejecting castings from dies
• CPC Class Codes: B22D 17/2218 Cooling or heating equipment for dies for permanent moulds B22C9/065; for plastics B29C45/73
• CPC Class Codes: B22D 25/06 by its physical properties B22D27/00 takes precedence
• CPC Class Codes: B22F 10/14 by jetting of binder onto a bed of metal powder
• CPC Class Codes: B22F 10/38 to achieve specific product aspects, e.g. surface smoothness, density, porosity or hollow structures
• CPC Class Codes: B22F 10/62 by chemical means
• CPC Class Codes: B22F 2998/00 Supplementary information concerning processes or compositions relating to powder metallurgy
• CPC Class Codes: B22F 2999/00 Aspects linked to processes or compositions used in powder metallurgy
• CPC Class Codes: B22F 3/115 by spraying molten metal, i.e. spray sintering, spray casting
• CPC Class Codes: B22F 5/007 of moulds
• CPC Class Codes: B22F 5/10 of articles with cavities or holes, not otherwise provided for in the preceding subgroups
• CPC Class Codes: B22F 7/004 comprising at least one non-porous part
• CPC Class Codes: B29C 2045/7362 turbulent flow of heating or cooling fluid
• CPC Class Codes: B29C 33/04 using liquids, gas or steam tyre moulds with incorporated heating or cooling means using liquids, gas or steam B29D30/0601
• CPC Class Codes: B29C 33/3828 Moulds made of at least two different materials having different thermal conductivities
• CPC Class Codes: B29C 33/56 Coatings , e.g. enameled or galvanised; Releasing, lubricating or separating agents in-mould coating B29C37/0028; using or applying separating agents B29C37/0067
• CPC Class Codes: B29C 45/7312 Construction of heating or cooling fluid flow channels
• CPC Class Codes: B29C 64/135 the energy source being concentrated, e.g. scanning lasers or focused light sources
• CPC Class Codes: B29C 64/153 using layers of powder being selectively joined, e.g. by selective laser sintering or melting
• CPC Class Codes: B33Y 10/00 : Processes of additive manufacturing
• CPC Class Codes: B33Y 70/00 : Materials specially adapted for additive manufacturing
• CPC Class Codes: B33Y 70/10 : Composites of different types of material, e.g. mixtures of ceramics and polymers or mixtures of metals and biomaterials
• CPC Class Codes: B33Y 80/00 : Products made by additive manufacturing
• CPC Class Codes: F28D 2021/0078 : in the form of cooling walls
• CPC Class Codes: F28F 13/00 : Arrangements for modifying heat-transfer, e.g. increasing, decreasing F28F1/00 - F28F11/00 take precedence
• CPC Class Codes: F28F 7/02 : Blocks traversed by passages for heat-exchange media F28D7/0008 takes precedence
• CPC Class Codes: Y02P 10/25 : Process efficiency

Abstract

Processes for providing enhanced thermal properties of tooling, particularly metal and metal/ceramic molds, made by solid free form fabrication techniques, such as the three dimensional printing process, and the tooling made by these processes are disclosed. The methods of enhancing thermal properties include incorporating integral contour coolant channels into the mold, adding surface textures to the coolant channels, creating high thermal conductivity paths between the surfaces and the coolant channels, and creating low thermal inertia regions in the mold.

Claims

1. A process for fabricating a part made of a molding material, by means of a molding cycle having a duration of τ

per part to be molded, said process comprising the steps of;

a. providing tooling having a thermal diffusivity of α

, a mold surface and an internal heat transfer channel through said tooling, said channel being spaced from said mold surface a distance less than twice (α

τ

)^½

;

b. providing said molding material to said tooling so that it contacts said mold surface;

c. providing heat transfer fluid to said heat transfer channel to facilitate exchange of thermal energy between said tooling and said fluid during said molding cycle; and

d. removing from said tooling at a time interval of τ

, a formed part.

2. The process for fabricating a part of claim 1, said providing tooling step comprising providing tooling having a heat transfer channel that is spaced from said mold surface a distance less than (α

τ

)^½

.