Process Redesign of a Structural Foam Molded HDPE Trench Drain for the Construction Industry

Our customer was using a competitor’s straight injection molding process to manufacture a line of linear trench drains. These single-cavity molds ran very long cycles and the parts had issues with warp and dimensional tolerances. We helped redesign the line for low-pressure structural foam molding. This includes 17 different size trenches, which are all 80” long, 6” wide and range from 6” to 20” in depth. We achieved a 20% part weight reduction and 40% cycle time reduction, compared with the straight injection parts. We managed the aluminum mold build and designed a pair of tools with interchangeable plates so any two of the 17 sizes can run in one machine at the same time. Long term capability studies were performed to validate new processes and its effects on warp and shrink/expansion over time and temperature variations.

Process Redesign of a Structural Foam Molded HDPE Trench Drain

Process Redesign of a Structural Foam Molded HDPE Trench Drain

Process Redesign of a Structural Foam Molded HDPE Trench Drain

Highlights of the Process Redesign of a Structural Foam Molded HDPE Trench Drain Project

Product Name

Linear Drainage / Trench Drain

Product Description

This trench drain is used to redirect water to a specific location.

Industry for Use

Construction

Applications

Residential, Transportation, Sport, Utility, Commercial, Industrial, Civil, Mechanical

Capabilities Applied/Processes

Primary:
Co-Engineering

  • Process Design/Process Redesign
  • Tooling Design
  • Mold Build

Structural Foam Molding (Low-Pressure)

Secondary:
Custom Assemblies to Print for Job Sites

Tooling

Interchangeable Plates

  • Any two of the 17 sizes can run in one machine at the same time
  • Manufactured to close tolerances for interchangeability
Tooling Material Used

Aluminum Core and Cavity Plates

Equipment Used to Make Tooling

Haas Gantry Mill

Equipment Used to Mold Part

Uniloy Milacron Low Pressure Structural Foam 500 ton Machine

Overall Part Dimensions

Length: 80”
Width: 6”
Height: 6″ – 20″
Weight: 12 lbs. – 27 lbs.
Wall Thickness: 0.200 – 0.375″

Tightest Tolerances

Dimensions: ± 0.062” to ± 0.250”
Wall Thickness: ± 0.010”

Material Used

High Density Polyethylene with Nitrogen Injected

Benefits/Features

Part Weight Reduction: 20%
Cycle Time Reduction: 40%

In Process Testing/Inspection Performed

Long term capability studies were performed to validate new processes and its effects on warp and shrink/expansion over time and temperature variations

Volume

Tens of Thousands Annually

Delivery/Turnaround Time

Stock all 17 SKUs.
Available J.I.T Shipment.

Standards Met

Customer Specifications, 2D CAD Drawing Specifications

Secondary Operations

Welding Plastic and Metal
Metal Cutting and Machining
Custom Palletizing