Since 1990, L. L. Brown, Inc. has specialized in the production of
tooling for the plastic thermoforming and vacuum forming industries.
During this time, we have developed cutting-edge technology, and
state-of-the-art production techniques, allowing us to produce
products at a reasonable cost in a short amount of time.
- The ability to produce the most intricate mold with
incredible turnaround is our hallmark. If you would like to
learn about how we produce thermoform tooling click
- Our master tooling allows faster mold setups, which
maximizes machine run time and decreases project tooling costs.
To learn about master tooling click
- Continuous shape thermoforming presents many
challenges. To learn more about our patented process for sealing
during forming click
The process of mold production begins with a design. This can either
be done completely by L. L. Brown, Inc. or imported from customer
files into our CAD system using a variety of different formats,
including DXF, DWG, PRT, CADL, and IGES. From there, the geometry is
manipulated and exported to our Computer-Aided Manufacturing
software, where the mold program is written. This CAM system
provides the ability to cut virtually any shape imaginable with both
two and three dimensional surfaces, such as blended, 3-D swept, and NURBS.
All tools are manufactured to your mounting requirements (i.e.
cooling, air, mounting holes).
L. L. Brown, Inc. utilizes cutting-edge software which can build a
"solid" model that is able to be measured, rotated, and sectioned
on-screen. This allows us to test the mold program at each stage of
development before any material is cut. Not only does this allow us
to construct a "virtual" mold which can be compared to the original
idea, but it also is very helpful in the detection of "wild moves"
which can occur with even the best programmer. This is one of the
many tools we use to implement the highest level of quality control.
The final mold product can be inspected using our Coordinate
Measurement Machine (CMM).
While manufacturing is the most important step in the mold
production process, it is also the least time consuming due to our
comprehensive preliminary work. Because L. L. Brown, Inc. is a full
service manufacturing organization, we can draw from a variety of
different machining capabilities including CNC milling (60" x 30"),
CNC turning (10" dia.), and manual machining such as milling,
turning, grinding, and plate sawing. This gives us the opportunity
to be more versatile not only in the styles of molds we produce, but
also in the ways in which we produce them. In addition, we retain an
extensive inventory of aluminum plate, ranging in thickness from
1/4" to 2". If material outside this range is required, it can be
custom ordered with a minimum lead time.
Frequently, the mold is only part of the completed product. L. L.
Brown, Inc. has extensive experience in the production of special
tooling, including plug assists, water plates, and master tooling.
To provide total service, we also maintain working relationships
with third party vendors in areas such as powder coating and gun
Some Additional Points
L. L. Brown, Inc. acknowledges the two-tiered nature of our
business. In other words, if you don't get the job, we don't get the
job. We also understand that there are three selling points for you
as a vendor.
- The time to delivery
- The quality of the part
- The price
Keeping these points in mind, we have found that two things make
us stand out from the crowd in our field. We are accustomed to
quick turnarounds. It is not unusual for us to be able to deliver a
tool within two weeks of receiving a part design, leaving the
customer with more time to perfect their design as well as their
We are accustomed to working with customers' CAD geometry. The
benefits of cutting to "your geometry" are two-fold:
- It eliminates added possibility for error.
- It allows us to offer additional savings on the final price
of the tool.
The concept and goal behind “Master Tooling” is to
allow the customer to have greater flexibility with
their mold base. This means that you are able to use
the same tooling build-ups for many different
projects. This “master tooling” can be built with
many features in mind to allow faster mold setups,
maximize machine run time, and to decrease project
tooling costs, all of this with the emphasis on
increased productivity and profitability.
Master Mold Bases
This portion of the tooling includes a cooling plate
along with a series of parallels (or standoffs) that
can be constructed to a given height. This entire
package is then able to mount into your machine and
your project tooling to it. Various height parallels
can be made to give you increased flexibility in the
thickness of your project tooling. Quick change
cylinders are able to be incorporated into this
build-up to allow for rapid changeovers and ease of
Front and Rear Clamp Assemblies can be easily added
to this build-up in order to pinch off and isolate
the plastic sheet during forming. These sheet clamps
prevent distortion by holding the sheet flat prior
to engagement of the mold or plug assist.
Adjustable Pressure Boxes
On the opposite side of the forming tooling package,
is the pressure box assembly. These boxes can be
made of many different overall heights so that many
project tools can use the same pressure box. With
regard to master tooling pressure boxes, the box is
constructed of a certain mold width with 3
stationary walls. The forth (front) wall can be
positioned at various increments along the pressure
box base. This front wall is normally adjustable in
1” increments over your desired range of mold
lengths or indexes. The front and rear walls have
sheet clamp grooves to work with the front and rear
clamp assemblies to grip the sheet. All 4 walls
include a gasket track for the specified “O” or “H”
style silicone cord.
Upper and Lower Trim Build-ups
Part die cutting can at times be the most difficult
part of a production run. It is necessary to keep
these build-ups simple in order to “shim” and
“tweak” the right areas in order to get the best die
cut possible. This tooling also needs to be made
solid and true.
For the upper trim assembly, we use a simple plate
system to easily adjust to different height parts.
Simply add or subtract plates to the build-up to
match-up with your cutting die to get your desired
height. Assembly brackets are mounted to the top
plate in this assembly, therefore, allowing all
other plates to be slide into place and mounted
quickly in order to get your correct build-up. Each
plate has a standard mounting pattern which allows
you to standardize the mounting pattern on the
The lower trim assembly consists of a master plate
that will mount to the machine platen with a series
of parallels (standoffs) which can be added or
removed to achieve your desired mold width. Mounted
to the top of these parallels are standard cutting
anvils for your various mold widths. Of course the
top plate of the cutting anvil will be your cutting
surface, usually stainless steel plate. This design
allows you to “swap” out cutting anvils (various
widths) in order to adjust the cutting surface – the
rest of the build-up will always remain in the
machine as your “master”.
One of the more common types of thermoforming is
what is often referred to as continuous shape thermoforming. This
process is used to produce a part of unlimited length on a
thermoforming machine using an index of only two or three feet. It
is of particular use to manufacturers making media for the cooling
tower or waste water treatment industries.
L.L. Brown, Inc. has developed and patented a revolutionary gasket
sealing tooling technology for the continuous shape thermoforming
industry. This tooling technique was developed due to the difficulty
in sealing the mold during the continuous shape thermoforming
process. This sealing technique incorporates a custom made and
replaceable gasket which allows the tooling set to seal along a very
complex surface. This advancement allows the industry to maximize
the mold size that can be run and produce a more economical and
efficient sheet with every machine cycle.