How much a tool will cost is dependent on
several different factors, including the size and complexity of its parts, how
many cavities it contains, its tolerances, the tools and steel used, the
earning actions of the tool, its anticipated lifespan, the particular resin
used for the part, and the part’s aesthetics. While all of these costs will
eventually be recouped once a certain number of parts have been produced, it’s
important to note that the real cost will also have to take into account the
manufacturing process and the molding cycle as well. For instance, a three
plate or hotrunner may be more expensive at first, but unlike two plate tools,
they don’t need anyone to operate them or separate the parts. This will mean
that you save money on the piece part price, even though the tool cost is
Don’t put the full responsibility for tool
buying on your purchasing department, though. That’s because there will likely
be factors that they don’t fully understand. Make sure that you determine and
specify your tool requirements in full before you start the buying process.
Ideally, you’ll want to choose the right tool for the lowest cost, produced by
an experienced and knowledgeable molder. The checklist below details the
various areas of interest that you need to consider when purchasing a mold.
1. How many dimensions are required on the
print- this will determine the cavity complexity, as well as the part
2. The number of different surface finishes
which will be necessary.
3. The number of necessary tight tolerances
and their requirements.
4. Part surface area in square inches.
5. Any required functions in mold
operating, such as earning or unscrewing.
6. Balanced tool requirements- these can be
determined by tolerances.
7. Part resin.
8. Number of cavities in the part,
determined by tolerances and part volume required.
9. Tool type, e.g. hotrunner, two plate, or
When you have answered all of those
questions, you’ll want to figure out the amount and type of materials and
components that you’re going to need, and use supplier catalogs to come up with
a total cost.
With that done, you’ll then need to put
together a list of manufacturing and assembly procedures. Make sure you include
the total number of cavities, and whether or not CAD/CAM information is
available to use to cut those cavities. After that, the cooling requirements
are considered, and the cooling line placements around the cavity for
temperature control are determined accordingly.
With all this information at your
fingertips, you will be able to calculate the estimated time required for each
procedure, and how much it will cost you per hour. You’ll then have to add
extra costs such as the heat treatment, polishing, finishing, surface
texturing, and so on, to take into account every aspect of the project. If you
have all this information when buying the first few molds, then your buying
department will be better equipped to fully analyze the factors in a specific
job, and then create a realistic price range for your budgeting and tool
The first time you buy a mold, especially
if you don’t have a lot of experience with mold design and construction, it
will take time to curate all this information. In most cases, the wage rates
and the amount of time needed for operations will simply be a rough estimate. The
only way to obtain a precise final cost is to talk to the suppliers themselves,
and comparing their answers with your tool quotations. It’s easier to put
together specific information if you are as precise as possible with informing
the tooling source how to prepare their quotation. Ideally, this should include
a breakdown of all the components and functions, as well as a schedule. The
amount of time required for the mold design will add to the total cost, even
before you have selected a particular mold builder. The costs can vary from
$3000 for a simple design without any further changes, to over $8000 for a
complex, frequently revised design. In fact, mold design costs comprise between
5-10% of the total manufacturing price, even for a simple job. The average mold
takes up to 1500 hours to design, build, finish, and prove out. If you are able
to, you should choose a tooling source with injection molding capability that
can sample the tool to prove out. This will save a great deal of time and money
on sending the mold back and forth if any revisions are needed.
The best way to gain an affinity for mold
estimated is with practice. All departments involved will need to provide their
full assistance in preparing the tooling estimate. A good way to learn the
ropes is to visit mold builders who have experience with producing molds of the
same size and complexity as the one that you will need. By checking over the
quality of their previous work, you should have a good idea of whether or not
they can perform to the required level. This will also give you the chance to
examine their tools as well. Once you have visited tool builders, requests
quotes from them, as well as other molders who possess their own mold building
sources. Of course, you will need to have an in-depth description of the part
requirements to obtain an accurate quote. You might also want to choose a
supplier who will be able to accommodate any changes to features that you might
require at a low cost. Remember, the more effort you put into obtaining fully
accurate quotes, the more money you stand to save in the long run.