Maybe you&#;re designing a snap-together case for some medical components, or two interlocking halves of a portable radio. Why build two mating parts when you can make one? Redesign the snaps so that the halves can be fit together from either direction, thus building a so-called &#;universal&#; part. Only one mold is needed, saving production expenses up front. And you can now mold twice as many of one part, instead of half the quantities of two.
It is relatively easy to remove metal from an existing metal mold. Adding metal, on the other hand, can be difficult or, for all practical purposes, impossible with rapid injection molding. To look at this from the part perspective, you can add plastic, but you can&#;t take it away. Designing with this in mind is called &#;metal safe.&#;
Some injection-molded parts go through multiple iterations until a final, workable design emerges. Instead of purchasing a new mold for every revision, a little clever planning will allow the same mold to be used multiple times. Starting with the smallest, most basic part design, mold as many pieces as needed, then re-machine the mold to include additional part features, or a larger, taller version of the same part, and mold again. This is not an exact science, but given the right part, this re-use approach can save dollars on tooling development.
Every quote for an injection-molded part at Protolabs is accompanied by a free design for manufacturability (DFM) analysis. This identifies potential problem areas, or opportunities for design improvement. Insufficient draft angles, &#;un-machinable&#; features, impossible geometries&#;these are just a few examples in which part designs can and should be improved before clicking the &#;accept&#; button. Be sure to review these suggestions thoroughly, and contact an applications engineer at Protolabs with any design-related questions.
Maybe you are after a higher volume of parts? You can still achieve high volumes using aluminum tooling with two-, four-, or eight-cavity molds depending on size and part geometry that can reduce your piece part price, although this would impact your tooling costs.
Got a family of parts that all fit together? How about multiple molding projects at one time? There&#;s no reason to build a mold for each individual part, provided A) everything is made of the same plastic, B) each part is roughly the same size (e.g., have similar processing times), and C) can all be squeezed into the same cavity, while still allowing for proper mold functioning.
In addition, maybe you can join some of those parts with a living hinge? This method is a great way, for example, to mold two halves of a clamshell-style container. These parts would otherwise need a pin-type assembly to open and close. The only caveat here is that a flexible and tough material must be used, such as polypropylene (PP).
Still another way to reduce molding costs, depending on your part volumes, is to consider on-demand manufacturing. At Protolabs, two injection molding service options are available (see table below). One is best suited for those who need smaller part quantities, usually associated with prototyping. The other option, Protolabs calls it on-demand manufacturing, is a good fit for those who require slightly larger part quantities, typically up to 10,000-plus parts from aluminum molds. On-demand production can be a great option to manage demand volatility of your parts, reduce total cost of ownership, and leverage cost-efficient bridge tooling.
Maybe you&#;re designing a snap case for medical components, or two interlocking halves of a portable radio? Why build two mating parts when you can make one? You can redesign the snaps so that the halves can be fit together from either direction, thus building a so-called &#;universal&#; part. Only one mould is needed, saving production expenses up front. And you can now mould twice as many of one part, instead of half the quantities of two.
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It is relatively easy to remove metal from an existing metal mould. Adding metal, on the other hand, can be difficult or, for all practical purposes, impossible with rapid injection moulding. To look at this from the part perspective, you can add plastic, but you can&#;t take it away. Designing with this in mind is called &#;metal safe.&#;
Some injection-moulded parts go through multiple iterations until a final, workable design emerges. Instead of purchasing a new mould for every revision, a little clever planning will allow the same mould to be used multiple times. Starting with the smallest, most basic part design, mould as many pieces as needed, then re-machine the mould to include additional part features, or a larger, taller version of the same part, and mould again. This is not an exact science, but given the right part, this re-use approach can save cost on tooling development.
Every quote for an injection-moulded part at Protolabs is accompanied by a free design for manufacturability (DFM) analysis. This identifies potential problem areas, or opportunities for design improvement. Insufficient draft angles, &#;un-machinable&#; features, impossible geometries&#;these are just a few examples in which part designs can and should be improved before clicking the &#;accept&#; button. Be sure to review these suggestions thoroughly, and contact an applications engineer at Protolabs with any design-related questions.
Maybe you are after a higher volume of parts? You can still achieve high volumes using aluminium tooling with two-, four-, or eight-cavity moulds depending on size and part geometry that can reduce your piece part price, although this would impact your tooling costs.
Have you got a family of parts that all fit together? How about multiple moulding projects at one time? There&#;s no reason to build a mould for each individual part, provided A) everything is made of the same plastic, B) each part is roughly the same size (e.g., have similar processing times), and C) can all be squeezed into the same cavity, while still allowing for proper mould functioning.
In addition, maybe you can join some of those parts with a living hinge? This method is a great way, for example, to mould two halves of a clamshell-style container. These parts would otherwise need a pin-type assembly to open and close. The only caveat here is that a flexible and tough material must be used, such as polypropylene (PP).
Along these same lines, always consider part extents. In moulding-speak, that means how big is the part, and will it fit comfortably in the mould while allowing for sprues, runners, ejector pins, and all the other considerations needed to make a mould work. Protolabs&#; maximum part size for injection moulding is currently 480mm by 751mm with a maximum depth from the parting line of 101mm deep. However, larger parts like these, in turn, require a larger mould. This may have an impact on your mould and part costs.
As always, feel free to contact an applications specialist with any questions, at +44 (0) or [ protected].
For more information, please visit Rapid Tooling For Injection Molding.