Hi,

For a project I want to switch from injection moulding of plastics to sintering (p/M) of aluminium.
I would like to know if this technique (p/m) can compete with plastic injection moulding what costs concerned. Is there anyone who knows about the cost efficiency of p/m when speaking of rather large quantities (100.000's)?

Kenneth

 

Without knowing more details about your part if is very difficult to answer your question concern the cost reduction potential of switching from injection molded plastics to powdered metal aluminum. I can think applications where the cost could be lower. I can think of a lot more applications where the cost would be higher.

Depending on the application it may also be possible to change the design and configuration of your part either process would provide you with preferred results in terms of direct cost to manufacture, cost of product, cost of ownership for the final assembly, and overall performance.

Niel Leon
Unicorn Technical Services
http://www.uni-tech-serv.com
Bringing Your Vision to Reality

 

Depending on what you want to do you can certainly save money by doing conformal cooling using maraging steel using the DMLS process. Here is a blog to outline conformal cooling and then another outlining costs involved.

DMLS using Conformal Cooling by GPI Prototype
http://directmetallasersintering.blogspot.com/2009/11/conformal-cooling.html

DMLS costs and processes
http://directmetallasersintering.blogspot.com/2010/01/dmls-direct-metal-laser-sintering-costs.html

Tim Ruffner
GPI Prototype
http://gpiprototype.com

 

Thanks for the replies.
In most cases I think it can be concluded that metal sintering is more expensive.
I will look at the DMLS technique but I believe this will be very costly.

Kenneth

 

Hi, I belive sintering is combacting the power material by applying pressure & heat to get the desired shape. This type of process is done for thermosetting plastics ( like baklite etc) . Injection molding is used for thermoplastics like nylon etc.

Correct me, If I am wrong!

 

Bakelite is a thermosetting plastic that becomes rigid once heated and cooled. Subsequent heating causes it to decompose but not melt. The precursor is a liquid, not a powder. It is not sintered. Teflon parts and stock shapes are made by sintering powder, but I am aware of no other plastics that are processed that way.

Sintering classically refers to a baking process that fuses powdered metal grains together after they are compacted mechanically in a mold.

A boss of mine once got sucked into replacing an injection molded plastic part design with a sintered aluminum part. The vendor managed to not reveal the real cost of the part until the tooling had been purchased. It worked out to about five times the cost of the injection molded part, but that was in modest volumes of a couple thousand parts a year.

The economics might have worked out differently for larger volume, and especially so if some features of the part actually needed to be made of metal.

 

As the above poster pointed out, sintered metal parts potential have a lot of additional costs when compared to plastic injection molded parts. The cost of production must be looked at carefully including reviewing the tooling amortization costs across production.

I have found that there are a very limited number of applications where converting to a powdered metal part from a injection molded part make sense from an overall design stand point, and even fewer where the primary justification is economic.

 

I think you are wrong, first who would get a sintered metal part if its going to be injection molded unless doing a tool insert. You would normally either get the SLA or SLS first before going into injection molding. As for metal sintered costs...I have created a blog, I will post that here in a minute, however studies have shown and proven to be that if you create a DMLS tool insert using conformal cooling not only will you save money and time in regards to your tooling you will also reduce cycle time by up to 70%. To me that is some great savings!

Now let's think about this. As far as a DMLS part goes, if you were to get lets say a nozzle with a turbine made by CNC, how long would that take and how much? If the part was 3/4 diameter and 3" long. You're looking at at least 2-3 weeks in CNC if it can even be done, DMLS would be a matter of hours and the cost would be much less!

Here is the blog!

http://directmetallasersintering.blogsp ... costs.html

 

Thank you for the information. The thing is that first I was calculating with parts made by injection moulding. I would like to find out how much more expensive sintering is because it seems I can not do without parts of metal instead of plastic. And conventional tooling is not suitable for such large amounts.
If sintering turned out to be 5 times more expensive with a series of a couple 1000's then I suppose this will be less than 5 times with higher series.

 

The original question as posted here asked if it would be less expensive to produce a part as a PM if it is already being built as an injection molded part. You can refer to my original response above.

Your comment concerning insert molded parts is one of those applications where converting to a PM part would be appropriate as one possible cost reduction method, but I have found that simply changing materials on one part to reduce the costs of a product has its own set of serious challenges and pitfalls.

As for using DMLS, that is a totally different process which usually is not appropriate for producing 100,000's of pieces of the same part in a year. The key is always to select the optimal process for producing the desired design at the appropriate stage in the design, development, and manufacturing process.

To take the thoughts about using the optimum manufacturing process to produce the desired results to the next level, I know company that produces components for heart lung machines, and dialysis machines who got rid of a bunch of injection molds and is now producing the parts using SLA. Actually they are producing what used to be assemblies as monolithic SLA components. The total cost of production was cut in half and they paid for the new machines in less then one year.