Vacuum Form Mold for Car Front Bumper

The job they gave us wasn’t one for the non-professionals. A South America-based automotive client tasked Borke Mold Specialists with designing, casting, CNC machining, and then vacuum forming a critical component for a car, an automotive front bumper cover. All of this was to be performed and executed within the next eight weeks. Building game-changer custom frames on an innovative deadline is one of our specialties here at Borke Mold Specialists. Not only did our company rise to the occasion, we won an SPE “Part of the Year” award because of our hard work.

Using a traditional injection mold CAD model as our basis, we first created a wood pattern to better determine our aluminum casting. The wood pattern allowed us to understand how best to apply the composite mold in terms of exact dimensions. Then, programming a Milltronics BR-50 Bridge CNC machine with MasterCAM software, we were able to craft aluminum molding with a dimensional length of 41″, a width of 25″, and a height of 22″. The cast aluminum itself came out with a wall thickness of ½” with a vacuum hole-size #72.

With tightest tolerances of ±.005″ on CNC machined components and ±1/32″ on the main body (tolerances that still provided for a .006″in shrinkage allowance), we then milled and mounted brass guides, employing components including 3/8″ in outside diameter copper tubing, a 1 ½” in outside diameter bore rotating air cylinder, ½” thick brass rods, and stainless steel lines that would provide a cooling cast into the back of the mold. After forming the mold itself, we capped it off by performing a light sandblast grit finish and testing the mold at a local vacuum former. With an estimated weight part of 600 lbs., our mold was geared and ready to be manufactured to the tune of 2,500 parts per year.

Finally, we shipped it off to our client in South America. After all that, all that was left for us to do was to win our SPE award of the year.

Cast Aluminum End View Loose Piece

Cast Aluminum behind Loose Piece

Sandblast Finish for TPO Material

Mold Manufacturing of Bumper Vacuum Form Mold Project Highlights

We created a vacuum forming mold for an automotive bumper cover to replace a typical injection molded bumper. This component won a parts competition, SPE part of the year.


  • Convert Injection Mold CAD Model to Vacuum Form part

Aluminum Casting

  • Create Wood Pattern To Create Aluminum Casting

CNC Machining

  • Programming done Through MasterCAM software
  • Milling of Mounting and Brass Guides

Machine Cast Aluminum to Match Main Body
Vacuum Forming

  • Tested the Mold at a Local Vacuum Former Before Shipping to South America

Milltronics BR-50 Bridge type CNC machine

Length: 41″
Width: 25″
Height: 22″
Wall Thickness: ½”
Vacuum Hole Size: #72

±.005″ On CNC Machined Components
±1/32″ On Main Body
.006″ In Shrinkage Allowance

  • 150° Operating Temperature on Mold

Stainless Steel

  • Light Sandblast Grit Finish
  • Cast Aluminum Mold
  • Ø3/8″ Copper Tubing
  • Ø1 ½” Bore Rotating Air Cylinder
  • 1/8″ Thick Bronze Plate
  • ½” Thick Brass Rods
  • Thermocouples
  • ½” Rubber Hose and Clamps

Air Cylinders & Locking Mechanism

  • Hold Loose Piece in Place During Forming

Pulley System

  • Plastic part will pull the Loose Piece Out of The Way
  • The pulley system Reduced 20lb piece to 3lbs

Brass Components

  • Serve as Guide Rods

Stainless Steel Lines

  • Provides Cooling cast into the back of the mold

Mold Manufactured to Produce 2,500 Parts Per Year

  • CNC templates of the some sections and set them on the mold. Also used a CNC with adaptive CMM head to check 20 locations on the mold
  • South America

Customer supplied print, 3D CAD Drawing of an Injection mold

  • Plastic parts for Aircraft seating

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