1. Direct and Indirect
Rapid Tooling

2. RAPID TOOLING
Rapid Tooling refers to mould cavities that are either directly or indirectly fabricated using Additive Manufacturing techniques.
There are primarily used to create multiple prototypes. Additive Manufacturing techniques are not economical when more than one prototype needs to built for the same component,

3. Rapid tooling (RT) denotes manufacturing on a slim timeline.
advantages to rapid tooling trades is that it decreases the time and cost of the product
disadvantages are that it is not as accurate as tooling produce by CNC/CAM and also shorter lifespan of the tooling.
Another disadvantage is smaller batch size of products can be produce using RT’s tools.

4. Rapid tooling is mainly used for specific needs including prototyping and troubleshooting existing problems.
Rapid prototyping is not often used for large scale and long term operations for a part. Nevertheless, rapid tooling is starting to be used to create moulds for commercial operations because the time lag is so short between start to finish and since a CAD file is the only thing needed for the design stage.[1] 
Since alternate methods require precious time and resources, rapid tooling provides a way to quickly provide moulds for the required products. This allows companies to quickly make commercial products with the advances of additive manufacturing.[2]

5. In addition, rapid tooling provides the customization necessary for personal applications.
Instead of tedious trial and error measurements, rapid prototyping processes allow scientists and doctors the ability to scan and digitize the item or patient. Then by putting it through a CAD program, a personal custom mold can be created to fix the problem.
An example of this procedure is for dental patients. Originally to fabricate an oral application, an alginate impression or a wax registration is used to fit the teeth with the mold. With new advances, doctors can take a scan of the dental arches to correctly and quickly make a mold out of silicone for the patient. This allows for better accuracy and more acute customization of the mold in the future.[3]

6. Importance of RAPID TOOLING
The term Rapid Tooling (RT) is typically used to describe a process which either uses a Additive Manufacturing(AM) model as a pattern to create a mold quickly or uses the Additive Manufacturing process directly to fabricate a tool for a limited volume of prototypes . a) Decrease total time : Tooling time is much shorter than for a conventional tool. Typically, time to first articles is below one- fifth that of conventional tooling.

7. Importance of RAPID TOOLING
b) Minimize the cost: Tooling cost is much less than for a conventional tool. Cost can be below five percent of conventional tooling cost.
c) Increase the productivity:
d) Shorter tool life: Tool life is considerably less than for a conventional tool.
e) Wider Tolerances: Tolerances are wider than for a conventional tool.

8. RAPID TOOLING METHODS (RTM)
Called rapid tool making (RTM) when AM is used to fabricate production tooling
Two approaches for tool-making:
Indirect RTM method
Direct RTM method

9. Soft Tooling:
It can be used to intake multiple wax or plastic parts using conventional injection moulding techniques. It produces short term production patterns. Injected wax patterns can be used to produce castings. Soft tools can usually be fabricated for ten times less than a machine tool.

10. Hard Tooling:
Patterns are fabricated by machining either tool steel or aluminum into the negative shape of the desired component. Steel tools are very expensive yet typically last indefinitely building millions of parts in a mass production environment. Aluminum tools are less expensive than steel and are used for lower production quantities.

11. Comparison of Soft & Hard Tooling
Soft Tooling
Low Cost Tooling
Excellent For Medium-Low Volumes High Mix
Higher Piece Part Cost
Faster Lead Time And Response
More Flexibility To Change Design
Increased Product Variance
Hard Tooling
Higher Cost Tooling
Lower Piece Part Cost
NO Design Flexibility
Repeatability
Longer Lead Time Due To Tooling Lead Time
Process For High Volumes

12. Indirect RTM Methods
As AM is becoming more mature, material properties, accuracy, cost and lead time are improving to permitting to be employed for production of tools.
Indirect RT methods are called indirect because they use AM pattern obtained by appropriate AM technique as a model for mould and die making.
Pattern is created by AM and the pattern is used to fabricate the tool
Examples:
Patterns for sand casting and investment casting
Electrodes for EDM

13. Indirect Tooling (Pattern Based Tooling)
Indirect tooling methods are intended as prototyping or pre-production tooling processes and not production methods.
Most any rapid prototyping process can yield patterns for indirect tooling.

14. Example of indirect RTM method: Sand Casting
Fig: Manufacturing steps in sand casting that causes that uses rapid-prototyped patterns

15. Example od indirect RTM method: Sand Casting
Fig: Manufacturing steps in sand casting that causes that uses rapid-prototyped patterns

16. Role of Indirect methods in tool production:
AM technologies offer the capabilities of rapid production of 3D solid objects directly from CAD. Instead of several weeks, a prototype can be completed in a few days or even a few hours.
Unfortunately with AM techniques, there is only a limited range of materials from which prototypes can be made. Consequently although visualization and dimensional verification are possible, functional testing of prototypes often is not possible due to different mechanical and thermal properties of prototype compared to production part.

17. Role of Indirect methods in tool production
All this leads to the next step which is for AM industry to target tooling as a natural way to capitalize on 3D CAD modeling and AM technology. With increase in accuracy of AM techniques, numerous processes have been developed for producing tooling from AM masters.

18. Techniques for Indirect RT
RTV
Cast Kirksite 3D
Keltool
Composite tooling
Spray metal tooling
RIM
Vacuum casting
RSP

19. Silicone Rubber Tooling
The most widely used indirect RT methods are to use AM masters to make silicon room temperature vulcanizing moulds for plastic parts and as sacrificial models or investment casting of metal parts. These processes are usually known as Soft Tooling Techniques.
The purpose of silicone RTV tools is to create urethane or epoxy prototypes, often under vacuum (hence the term vacuum casting)

20. Silicon Rubber Tooling:
It is a soft tooling technique. It is an indirect rapid tooling method.
Another root for soft tooling is to use AM model as a pattern for silicon rubber mould which can then in turn be injected several times. Room Temperature Vulcanization Silicones are preferable as they do not require special curing equipment.
This rubber moulding technique is a flexible mould that can be peeled away from more implicate patterns as suppose to former mould materials.

21. Steps in making Silicon Rubber Tooling
First an AM process is used to fabricate the pattern. This pattern is then finished to the quality in which final parts are required.
Next the pattern is fixed into a holding cell or box and coated with a special release agent (a wax based creoseal or a petroleum jelly mixture) to prevent it from sticking to the silicon.

22. Steps in making Silicon Rubber Tooling
The silicon rubber typically in a two part mix is then blended, vacuumed to remove air packets and poured into the box around the pattern until the pattern is completely encapsulated.
After the rubber is fully cured which usually takes 12 to 24 hours the box is removed and the mould is cut into two (not necessarily in halves) along a pre determined parting line and the pattern is removed from within.

23. Steps in making Silicon Rubber Tooling
This results in formation of the core and cavity. Because the material is flexible, undercut release is not a problem.
The silicon mould is placed back together and repeatedly filled with hot wax or plastic to fabricate multiple patterns.
These tools are generally not injected due to the soft nature of the material. Therefore the final part materials must be poured into the mould each cycle.
These moulds are suitable for small to medium- sized parts with batch of pieces in materials replicating properties of thermoplastics.

24. 3 Flip pattern and 1. RP Pattern mould second side .RTV Moulding
compound

25. 4. Cut RTV Pattern along parting line and rem.ave pattern
5. Mould Urethane or other plastic
6. Plastic -with filler to be removed

28. Wire Arc Spray:
These are the thermal metal deposition techniques such as wire arc spray and vacuum plasma deposition. These are been developed to coat low temperature substrates with metallic materials. This results in a range of low cost tools that can provide varying degrees of durability under injection pressures.

29. The concept is to first deploy a high temperature, high hardness shell material to an AM pattern and then backfill the remainder of the two shell with inexpensive low strength, low temperature materials on tooling channels.
This provides a hard durable face that will endure the forces on temperature of injection moulding and a soft banking that can be worked for optimal thermal conductivity and heat transfer from the body.

31. Steps in making Wire Arc Spray Tooling
In Wire Arc Spray, the metal to be deposited comes in filament form. Two filaments are fed into the device, one is positively charged and the other is negatively charged until they meet and create an electric arc.
This arc melts the metal filaments while simultaneously a high velocity gas flows through the arc zone and propels the atomized metal particles on to the AM pattern.

32. Steps in making Wire Arc Spray Tooling
The spray pattern is either controlled manually or automatically by robotic control. Metal can be applied in successive thin coats to very low temperature of AM patterns without deformation of geometry.
Current wire arc technologies are limited to low temperature materials, however as well as to metals available in filament form.
Vacuum Plasma Spray technologies are more suited in higher melting temperature metals. The deposition material in this case comes in powder form which is then melted, accelerated and deposited by plasma generated under vacuum.

33. 3D Keltool
3D Keltool is a powder metal process used to make injection-mould inserts and other durable tooling from master patterns
It is very similar spray metal tooling
Keltool was originally developed by 3M in and was sold and further developed by Keltool Inc. In 1996, 3D Systems purchased the technology from Keltool Inc. and renamed it 3D Keltool

34. 3D Keltool
The word "Keltool" refers to the proprietary powder metal sintering process, which involves infiltrating a fused metal part with copper alloy.
This alloy fills in the voids
in the
otherwise
porous
material, producing a surface with the
finish and
hardness necessary for an injection mould

35. This process requires a master pattern, typically an SLA model,
This process requires a master pattern, typically an SLA model, that can be used to develop a silicone mould that will then be used to produce the Keltool mould.
The Keltool mould is then processed with a copper infiltration and sintered to increase its strength and cure the mould.
The finished Keltool part has the hardness of a A6 Tool Steel and can be machined like a traditional hard tool.

36. 3D Keltool Process:
This process is based on metal sintering process. This process converts AM master patterns into production tool inserts with very good definition and surface finish.
The production of inserts including the 3D Keltool process involves the following steps.
Fabricating the master patterns of core and cavity.
Producing RTV silicon rubber mould from the pattern.

37. Filling the silicon rubber mould with metal mixtures to produce green parts duplicating the masters. Metal mixture is powdered steel, tungsten carbide and polymer binder with particle sizes of around 5 nm. Green parts are powdered metal held together by polymer binder.

38. Firing the green parts in a furnace to remove the plastic binder and sintering the metal particles together.
Infiltrating the sintered parts (70% dense inserts) with copper in the second furnace cycle to fill the 30% void space.
Finishing the core and cavity.
3D Keltool inserts can be built in two materials. Sterlite of A6 composite tool steel. The material properties allow the inserts using this process to withstand more than 10lakh mould cycles.

39. Process chain of 3D Keltool:
Master pattern
Silicone casting
Casting with a tool steel/Tungsten carbide/epoxy mixture
Burn-out of binder, sintering and infiltration with copper in an oven
Tool insert ready for production

42. Spray metal tooling It is very similar to aluminum filled epoxy
In this process, against the RP pattern low temperature metal alloys is sprayed
A thin metal coating is then arc-sprayed on the resultant
mould surface
It gives higher strength and maximum tool life
This process is suitable for larger parts

43. Process:

44. RP Model
Metal spraying
Finished Model

45. Spray metal tooling

47. Advantages: Very good for large parts No or less shrinkage
Highly accurate

48. RSP Tooling RSP stands for Rapid Solidification Process
We create a plastic model using SLA
And then we make moulds with either by epoxy tooling or spray
metal onto it
But most of the cases, ceramics are used
What’s significant in that is that we atomize the metal down to as
small as 5 microns.
When the metal hits the ceramic, because of the small size of the droplets, they freeze very quickly, thus the rapid solidification.
This process results in extremely fine grain structure and the alloys generally stay in solution and there is very little internal stress

49. RSP working principle

50. Cast Kirksite Kirksite is a zinc-aluminum alloy with excellent
wear resistance. (94 percent Zn, 6 percent Al) with a melting point of 385oC)
The process for making cast kirksite tooling begins much like the process for epoxy-based composite tooling, except that two additional reversals are required to permit the creation of tooling in a more durable material

51. Cast Kirksite tooling

52. Cast Kirksite Process:
First, a shrink-compensated master pattern of the part is produced, typically using an RP process.
A rubber or urethane material is then cast against the part master to create patterns for the core and cavity set, which will be cast in kirksite.
Plaster is then cast against the core and cavity patterns to create moulds into which the kirksite is cast.
Once the kirksite is cast into the plaster moulds, the plaster is broken away, and the kirksite core and cavity are fit into a mould base

53. Epoxy Tools (Composite Tooling)
Epoxy tools are used to manufacture prototype parts or limited runs of production parts. The mould life normally is up to 200 pieces.
This process is similar to that of vacuum casting. The only difference being that instead if silicone rubber, the material used is aluminium filled epoxy. Once the mould is made from this material, it can be put on a moulding machine and components can be moulded in actual material of choice.
Epoxy tools are used as:-
Moulds for prototype injection plastic
Moulds for casting
Compression moulds
Reaction Injection Moulds

54. The fabrication of moulds begins with the construction of a simple frame around the parting line of AM model.
Sprue, gates and runners can be added or cut later on once the mould is finished. The exposed surface of the model is coated with a release agent and epoxy is poured over the model.
Aluminum powder is usually added to epoxy resin and copper cooling lines can also be placed at this stage to increase the thermal conductivity of the mould.

55. Aluminum filled epoxy tooling

56. Metal inserts are placed in areas where the epoxy is unlikely to withstand the pressures of the injection-moulding process.
Epoxy is then cast against the pattern and parting line
block combination to create the first side of the tool.
Once the epoxy is cured the assembly is inverted and the parting line block is removed leaving the pattern embedded in the side of the tool just cast.
Another frame is constructed and epoxy is poured to form the other side of the tool.
Then the second side of the tool is cured. The two halves of the tool are separated and the pattern is removed.

57. Time:
Composite tooling generates injection moulded parts in 2 to 6 weeks
Production Rate:
The moulding process will have a cycle time of 5 to 15 minutes
Accuracy
Accuracy is dependent on the AM model. If using SLA model, typically about +/-0.005" to +/ "
Cost
Dependent upon the cost of the master pattern, and overall size of the part.
An SLA master pattern can cost between USD$300 to USD$1000, on average, and the epoxy tool is typically between USD$800 and USD$1000

58. Composite Tool Life Expectancies
Thermoplastic
Tool Life(# shots)
Acetal
Nylon
Nylon {Glass filled)
PC/ABS blends
Polyea rbonate
Polyethylene
Polypropylene
Polystyrene
Investment Casting Wax

59. Another approach known as soft surface rapid tool involves machining an oversized cavity in an Aluminum plate.
The offset allows for introduction of casting material which may be poured into the cavity after suspending the model in its desired position and orientation.

60. Some machining is required for this method and this can increase the mould building time but the advantage is that the thermal conductivity is better than for all epoxy models.

61. Unfortunately epoxy curing is an exothermic reaction and it is not always possible directly to cast epoxy around a AM model without damaging it. In this case a Silicon RTV Mould is cast from AM pattern and silicon RTV model is made from the mould and is used as pattern for aluminum fill deposited.

62. A loss of accuracy occurs during this succession of reproduction steps
A loss of accuracy occurs during this succession of reproduction steps. An alternative process is to build an AM mould as a master so that only a single silicon RTV reproduction step is needed because epoxy tooling requires no special skill or equipment.
It is one of the cheapest techniques available. It is also one of the quickest. Several hundred parts can be moulded in almost any common casting plastic material.

63. Disadvantages of Epoxy Tools
Epoxy Tools have the following limitations.
Limited tool life
Poor thermal transfer
Tolerance dependent on master patterns
Aluminum filled epoxy has low tensile strength

64. Sand Casting Tooling:
Sand casting is often used to produce large metal parts with low requirement of surface quality.
Rapid prototyping techniques can be utilized to fabricate master patterns using sand moulds.
These moulds are produced by placing rapid prototyping patterns in sand box which is then filled and packed with sand to form the mould cavity.

65. When employing rapid prototyping techniques it is much more convenient to build patterns which include compensation for shrinkage of the castings as well as additional machining stock for areas requiring machining after casting.
The other benefits are that it significantly reduces lead time and increase pattern accuracy.

66. Laminate tooling (LOM Tools)
LOM process produces parts using sheets of paper.
Experiments to build moulds directly or coated with thin layer of metal has been reported.

67. Moulds built this way can only be used for low melting thermoplastics and are not suitable for injection moulding or blow moulding of common thermoplastics.
For this reason, new materials based on epoxy or ceramic capable of withstanding harsh operating conditions have been developed.

68. Polymer sheets: These sheets consist of glass and ceramic fibres in a B-staged epoxy matrix. Parts made with this material require post curing at 175oc for one hour. Once fully cured they have good compressive properties and heat deflection temperature of 290oc.

69. Ceramic sheets: Two ceramic materials have been developed for LOM, a sinterable AIN ceramic and a silicon infiltrable SiC ceramic. Both materials are mixed with 55% by volume of polymeric binder.
The ceramic process is less advanced and requires more software and hardware modifications to the LOM Machine

70. Direct Tooling:
Indirect methods for tool production necessitate a minimum of one intermediate replication process. This might result in a loss of accuracy and to increase the time for building the tool. To overcome some of the drawbacks of indirect method, new rapid tooling methods have come into existence that allow injection moulding and die casting inserts to be built directly from 3D CAD models.

71. Direct RTM Method AM is used to make the tool itself Example:
3DP to create a die of metal powders followed by sintering and infiltration to complete the die

72. Rapid Tooling for a Rear-Wiper Motor Cover
Figure Rapid tooling for a rear-wiper motor cover. Source: Courtesy of 3D Systems, Inc.

73. Direct RT Direct AIM Copper polyamide Prometal LENS DMLS
Laminated Tooling

74. Classification of Direct Rapid Tooling methods:
Direct Rapid Tooling Processes can be divided into two main groups
1st group:
It includes less expensive methods with shorter lead times.
Direct RT methods that satisfy these requirements are called methods for firm tooling or bridge tooling.
AM processes for firm tooling fill the gap between soft and hard tooling.

75. 2nd group:
Solutions for hard tooling are based on fabrication of sintered metal steel, iron copper powder inserts infiltrated with copper or bronze.
It includes AM methods that allow inserts for pre production and production tools to be built.
These methods come under hard tooling.

76. Classification of Direct RT methods:
Firm Tooling Methods
Direct AIM
DTM COPPER PA TOOLING
DTM SANDFORM TOOLING
ELECTRO OPTICAL SYSTEM DIRECT CHRONING PROCESS
LOM TOOLING IN POLYMER
3DP CERAMIC SHELLS

77. Hard Tooling Methods
EOS DIRECT TOOL
DTM RAPID TOOL PROCESS
LOM TOOLING IN CERAMIC
3DP DIRECT METAL TOOLING

78. DIRECT AIM: DIRECT ACES INJECTION MOULDS:
ACES refer to Accurate Clear Epoxy Solid.
Stereolithography is used to produce epoxy inserts for injection mould tools for thermoplastic parts because the temperature resistance of curable epoxy resins available at present is up to 200oC and thermoplastics are injected at temperature as high as 300oC. accordingly specific rules apply to the production of this type of projection tools.

79. Direct AIM (ACES Injection Moulding)
In the AIM process, the mould is "grown" using the SLA process.
The mould is similar to a regular part SLA, but is the negative image and cut into two halves.
The cavity can be filled with a variety of materials, including:
Thermoplastics
Aluminum-filled epoxy
Ceramics
Low-melt temperature metals

80. Direct AIM tooling

81. Procedure for Direct Aces
Using a 3D CAD package, the injection mould is drawn.
Runners, gates, ejector pins and clearance holes are added and mould is shelled to a recommended thickness of 1.27mm.
The mould is then built using accurate clear epoxy solid style on a Stereolithography machine.
The supports are subsequently removed and the mould is polished in the direction of draw to facilitate part release.

82. The thermal conductivity of SLA resin is about 300 times lower than that of conventional tool steels (.2002 W/mK for cibatool SL5170 epoxy resin)
To remove the maximum amount of heat from the tool and reduce the injection moulding cycle time, copper water cooling lines are added and the back of the mould is filled with a mixture made up of 30% by volume of aluminum granulate and 70% of epoxy resin.
The cooling of the mould is completed by blowing air on the mould faces as they separate after the injection moulding operation.

83. Disadvantages:
Number of parts that can be obtained using this process is very dependent on the shape and size of the moulded part as well as skills of good operator who can sense when to stop between cycles to allow more cooling.
Process is slightly more difficult than indirect methods because finishing must be done on internal shapes of the mould.

84. Also draft angles of order up to one and the application of the release agent in each injection cycle are required to ensure proper part injection.
A Direct AIM mould is not durable like aluminum filled epoxy mould. Injection cycle time is long.

85. Advantages: It is suitable for moulding up to 100 parts.
Both resistance to erosion and thermal conductivity of D-AIM tools can be increased by deposition of a 25micron layer of copper on mould surfaces.

86. Cast Kirksite Tooling
Kirksite is a zinc-aluminum alloy with excellent wear resistance.
The process for making cast kirksite tooling begins much like the process for epoxy-based composite tooling.

87. Procedure

88. First, a shrink-compensated master pattern of the part is produced, typically using an AM process.
A rubber or urethane material is then cast against the part master to create patterns for the core and cavity set, which will be cast in kirksite.
Plaster is then cast against the core and cavity patterns to create molds into which the kirksite is cast.
Once the kirksite is cast into the plaster molds, the plaster is broken away, and the kirksite core and cavity are fit into a mold base

89. Life of cast kirksite Tooling varies from 50 to 1000 pieces till 20,000 pieces.
Castkirksite tooling would be typically chosen for medium-sized production quantities of larger parts without tight dimensional requirements.

90. Advantages Complex shapes can be molded with kirksite tooling.
It offers a more durable mold than epoxy or spray metal tooling.

91. Disadvantages
Mould is not as accurate as an epoxy or spray-metal mould because of the reversals and the material shrink in the metal-casting process.

92. Quickcast Process
QuickCast is a process that allows for the creation of direct shell investment castings using "QuickCast" Stereolithography (SLA) patterns.
The
QuickCast method allows you
to rapidly build Stereolithography,
highly accurate resin patterns in
bypassing the expensive and time-consuming step of
tooling. •
traditional methods.
QuickCast
facilitates
rapid
production of
small
quantities
of metal
parts in
much less
time
than
Instead
of the SLA part being completely solid,
QuickCast eliminates 95% of the internal mass of the part.

93. QuickCast Process:

94. QuickCast Stereolithography resin model and steel casting

95. Investment casting patterns made by QuickCast

96. Copper Polyamide This process uses the essence of SLS
Here we use Copper Polyamide powder matrix
Copper Polyamide is a new metal plastic composite
designed for short tooling applications
Tooling inserts are produced directly in the SLS
machine with a layer thickness of 75 µm.

97. Subsequent
finishing is necessary before their
integration in the tool base.
During the CAD stage, Copper polyamide inserts a shelled and cooling lines, ejector pin guides, gates and runners are included in the design and built directly during the SLS process.

98. Then the insert surface are sealed with epoxy and
Then the insert surface are sealed with epoxy and finished with sand paper and finally the shell inserts are packed up with a metal alloy.

99. Advantages
Inserts produced from copper polyamide are easy to machine and finish.
Heat resistant and thermal conductivity are better
in most plastic tooling materials.
The
cycle times of moulds employing copper
polyamide inserts are similar to those of metal
tooling.

100. Direct Metal Laser Sintering (DMLS)

101. Lenses Laser Recoater arm Metal powder bed Part Powder feed position
Build position

107. Materials Currently available alloys used in the process
include and stainless steel, maraging steel, cobalt chromium, inconel and 718, and titanium Ti6Al4V.
Theoretically, almost any alloy metal can be used in this process once fully developed and validated.

108. Applications DMLS is a very cost and time effective technology.
DMLS is used to manufacture direct parts for a variety of industries including aerospace, dental, medical and other industries that have small to medium size, highly complex parts and the tooling industry to make direct tooling inserts.