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Size does matter!
Special feature
Size does matter! The mass of information collected by US researchers has enabled the development of an economic simulation model for powder injection moulding… here are around 150 variables in powder injection moulding (PIM) production so developing an economic model to help the designer understand PIM production costs will provide a great boost to PIM producers in making informed decisions on the viability, or otherwise, of targeted components. Professor Randal German, Director of the Center for Innovative Sintered Products (CISP) at Penn State University, USA, presented an outline of a new economic "simulation model" for powder injection moulding at PM2TEC2003 in Las Vegas. The model, which is currently being validated at CISP and reported to be accurate to within 10 per cent for many applications, is basically divided into four main "cost" parts: tooling, feedstock, production, and batch size/complexity. It was the latter
T
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aspect on which Professor German focused in his Las Vegas presentation. Professor German stated that in developing the "cost" model a huge amount of data had been accumulated. This included some 60 commercial powders and feed-
stocks, a variety of different manufacturing scenarios (including automation), single or multiple cavity tooling, thermal or solvent debinding, batch vs continuous sintering, and variable finishing operations. Added to page 32
Figure 1. Typical cost ranges for PIM production.
October 2003 MPR
31
Special feature page 31
this are the 150 variables such as rent, labour, interest rates, overheads, etc. It became evident in developing the model that PIM costs are highly variable, and the "lowest economic batch size" shifted even between different types of PIM operations. However, the key factors which influence the economic success of PIM, said Professor German, are the size/section thickness plus the shape complexity and volume of parts to be produced. Large PIM components with greater section thickness take longer to mould and debind; larger parts means fewer mould cavities and/or larger moulding machines. He reinforced the message by stating that the smaller the part the lower the unit cost. Figure 2. Effect of section thickness on PIM moulding cycle.
Figure 5. This silicon nitride turbocharger component made by PIM was one of the parts used to validate the 'cost' simulation model developed at CISP.
Figure 3. Relative unit cost for PIM stainless steel parts in relation to weight and production volume.
Figure 4. Impact of multiple cavities on PIM tooling and project costs.
32 MPR October 2003
Professor German stated that trials using sixteen PIM case studies had been done to validate the "cost model" developed at CISP. He reported that there had been a 97 per cent correlation to "predicted" and "actual" prices. In one validation example using a PIM silicon nitride turbocharger component weighing 85g, the actual selling price was put at $20 each for an annual volume requirement of 250,000. The "cost model" predicted $17.22 each and by increasing the volume of turbocharger parts to 3 million, the unit cost would be reduced to only $4 each. In his "rule of thumb" summary, Professor German reported that the industry average PIM component weighs in at 32g, and has an average per part price of $0.92 but a per kilogram price of $115. Powder costs are said to make up approximately 32 per cent of this price. He did not believe batch sizes as low as 5,000 pieces to be viable, stating that PIM only starts to become attractive over the 100,000 parts/year range. Bernard Williams
metal-powder.net
Size does matter! The mass of information collected by US researchers has enabled the development of an economic simulation model for powder injection moulding… here are around 150 variables in powder injection moulding (PIM) production so developing an economic model to help the designer understand PIM production costs will provide a great boost to PIM producers in making informed decisions on the viability, or otherwise, of targeted components. Professor Randal German, Director of the Center for Innovative Sintered Products (CISP) at Penn State University, USA, presented an outline of a new economic "simulation model" for powder injection moulding at PM2TEC2003 in Las Vegas. The model, which is currently being validated at CISP and reported to be accurate to within 10 per cent for many applications, is basically divided into four main "cost" parts: tooling, feedstock, production, and batch size/complexity. It was the latter
T
metal-powder.net
aspect on which Professor German focused in his Las Vegas presentation. Professor German stated that in developing the "cost" model a huge amount of data had been accumulated. This included some 60 commercial powders and feed-
stocks, a variety of different manufacturing scenarios (including automation), single or multiple cavity tooling, thermal or solvent debinding, batch vs continuous sintering, and variable finishing operations. Added to page 32
Figure 1. Typical cost ranges for PIM production.
October 2003 MPR
31
Special feature page 31
this are the 150 variables such as rent, labour, interest rates, overheads, etc. It became evident in developing the model that PIM costs are highly variable, and the "lowest economic batch size" shifted even between different types of PIM operations. However, the key factors which influence the economic success of PIM, said Professor German, are the size/section thickness plus the shape complexity and volume of parts to be produced. Large PIM components with greater section thickness take longer to mould and debind; larger parts means fewer mould cavities and/or larger moulding machines. He reinforced the message by stating that the smaller the part the lower the unit cost. Figure 2. Effect of section thickness on PIM moulding cycle.
Figure 5. This silicon nitride turbocharger component made by PIM was one of the parts used to validate the 'cost' simulation model developed at CISP.
Figure 3. Relative unit cost for PIM stainless steel parts in relation to weight and production volume.
Figure 4. Impact of multiple cavities on PIM tooling and project costs.
32 MPR October 2003
Professor German stated that trials using sixteen PIM case studies had been done to validate the "cost model" developed at CISP. He reported that there had been a 97 per cent correlation to "predicted" and "actual" prices. In one validation example using a PIM silicon nitride turbocharger component weighing 85g, the actual selling price was put at $20 each for an annual volume requirement of 250,000. The "cost model" predicted $17.22 each and by increasing the volume of turbocharger parts to 3 million, the unit cost would be reduced to only $4 each. In his "rule of thumb" summary, Professor German reported that the industry average PIM component weighs in at 32g, and has an average per part price of $0.92 but a per kilogram price of $115. Powder costs are said to make up approximately 32 per cent of this price. He did not believe batch sizes as low as 5,000 pieces to be viable, stating that PIM only starts to become attractive over the 100,000 parts/year range. Bernard Williams
metal-powder.net