Open discussion by Dan Bridges on EPS tooling for shape molding

1. EPS shape molding Tool
Considerations
From design to a place in our tool shed and marked per customer
requirements and our custom molding number.

2. The eps shape molding tool has some key components that we have to discuss at length.
1. Design that past many application standards, in other words, an expert design that is guaranteed for
performance.
2. Venting; core vents, pin holes, slotted vents, or complete slotting of the entire tool.
3. Qualified mechanical integrity of all parts of the tool that meet the engineering design of the tool. A perfectly
designed tool that someone tried to install inferior parts in destroys the entire tool team with one weak link. IE;
less venting than recommended, subpar repair, or homemade fill injectors.
4. Draft angle designed for part ejection with resistive considerations accounted for.
5. Fill system designed for 60 second cycle and even fill to all regions of tool.
6. Stand offs, ejector bars, fill injectors, mounting bolts, and sealing materials in place and qualified.
7. Tool installation and removal from machine accounted for in design.
8. All cooling paths equaling distributed evenly in tool from inception to discharge.
9. All steam delivery and condensation removal accounted for in design.
10.Tool maintenance program written, understood and practiced.
11. Use a toolmaker with a good reputation when getting a tool made or modified. Be mindful of your product
inventory before you ship out the tool for repair for 2 weeks.

3. EPS Tool Design: Basic requirements
Qualified Aluminum, stand offs, and alignment pins installed for ease of installation.
Plates that support the mounting of the tool in the machine, chest, and seals as designed.
Draft angle for part ejection when possible and polished or Teflon coating surfaces as required.
Fill injector location for proper part fill and eps distribution.
Core vent distribution designed with even CFM to all square inches of part.
Ejector rods that support even part ejection. Bushings fitting tight on ejection rod with springs installed
correctly to return rods to bottom of placement indentation.
Cooling tube designed to deliver water to all parts of cavity evenly and GPM greater to a thicker section if
required.

4. These tools that have one dimension on one side and a different
dimension on the other side. The inherent problem is that you have
to burn one side to mold the other properly and conversely you
have to cool one side longer than required for all that heat you have
to remove from the side that has more BTU’s to release than the
other side.

5. What connections do we rely on for this tool to operate? What does it need to make great eps parts all the time on a
consistent basis?
Lets explore some of the requirements
1. A mechanically stable environment to perform in. This means precise horizontal motion that has all the mechanical
requirements to support a moving and stationary tool. A frame squared and stable that will not move or fluctuate in any
form or fashion. A series of way bars {chrome coated rods with bearings} that are designed to be lubricated and last for
many years operating at 5 days a week, 24 hours a day.
2. A method of increasing and decreasing hydraulic pressure as required for standard operating speeds of the designed chest
and supporting equipment for cycle function.
3. Mechanical supports that will allow for start, stop, and switching of parameters by inputs from connected transducers or
photo eyes, or closed loop systems.
4. A system that will remove hot water and deliver cold water to the molding machine.
5. Steam system that will deliver saturated steam free of excess water and contaminates with no pressure fluctuations.
6. Compressed air that is free of oil, water, and heat delivered at around 90 psi without pressure variations.
7. A hopper that delivers EPS material consistently. The material needs to insure the target density required for the job, no
physical changes that will effect performance, and within the prescribed age to mold in the target cycle time with stable
parameters.
8. A Sealing sytem that insures that the steam flows thru to mold, the cooling air and water can be flashed, and vacuum can
be realized to remove the heat from the part then the heat from the tool.
9. A well designed mechanical system to allow for tool removal and installation in a rapid, precise, and mechanically sound
environment. Striping bolts, out of square, and unsafe for maintenance personal should be avoided with these design’s.
10. A proven track record of performance in the eps industry that will insure performance and reliability.

6. So what do we have? We have a tool
with some features.
Material connection
for hose from hopper.
Bushings for ejector rods to push part
out.
Fill injectors to allow
for eps to fill cavity.

7. Fill hopper that stores
an amount of material
that will support 5-20
cycles and deliver foam
to all cavities.
Way bars that allow for part molding,
part ejection, and even flow.
Steam chest that support the
tool and molding pressures
with precision.
A control panel that allows for
changes and storage of all
programs required for molding
different eps molding tools. Ease
of operator interface is critical
with control panels.