Pressure Forming Services
Pressure forming services produce plastic parts that look and feel injection-molded at a fraction of the tooling cost. By pressing heated plastic sheet against a single-sided mold with up to 100 PSI of compressed air (about seven times atmospheric pressure), pressure forming captures textures, sharp radii, embossed logos, and tolerances down to ±0.010″ on critical features. This is the right call for low- to mid-volume programs, typically under about 5,000 parts a year, where surface finish matters.
How Pressure Forming Works
Pressure forming uses the same starting point as vacuum forming: heat a thermoplastic sheet to its forming temperature, clamp it in a frame, and draw it down onto a mold using a vacuum. The difference happens next. A pressure box closes against the back of the sheet and floods it with compressed air, anywhere from 30 to 100 PSI depending on the part and material. That force pushes the plastic into every detail of the mold cavity: sharp corners, textured surfaces, embossed logos, undercuts the vacuum alone couldn’t reach.
After cooling under pressure, the part comes off the mold and goes to trimming. Most parts with complex perimeters move to a 5-axis CNC router; high-volume work runs on a steel-rule die.
The result is a part with the surface quality and dimensional control of an injection-molded one, made on tooling that costs 60 to 85 percent less.
Capabilities at a Glance
| Specification | Capability |
|---|---|
| Maximum part size | 96″ × 48″ × 24″ |
| Material thickness | 0.060″ to 0.500″ |
| Critical-feature tolerance | ±0.010″ |
| Overall tolerance | ±0.030″ |
| Surface finishes | Smooth, textured, grain-pattern, painted |
| Mold material | Cast or CNC-machined aluminum |
| Tooling lead time | 6 to 10 weeks |
| Part lead time (post-tooling) | 2 to 4 weeks |
Materials We Run
Pressure forming works with all standard thermoplastic sheet materials. Picking the right one comes down to the part’s environment, regulatory requirements, and aesthetic targets.
ABS is the workhorse for housings and enclosures. It has good impact resistance, takes paint well, and is available in FDA-compliant grades.
For tighter budgets and disposable applications (think disposable medical and packaging), HIPS handles the job at lower cost than ABS.
Polycarbonate is the call when impact strength and clarity matter. You’ll see it most often in medical equipment housings.
PETG runs clear or tinted, meets FDA requirements, and shows up in medical trays and food-contact parts.
Kydex is flame-retardant and meets FAA FST, which is why it dominates aerospace interiors and defense applications.
TPO is flexible and weather-resistant. Most automotive trim and exterior parts use it.
We can also pressure-form painted, textured, or co-extruded sheet stock. That lets you skip secondary paint operations on visible parts.
Tolerances and Surface Finish
Pressure forming holds tighter tolerances than vacuum forming because the added force pulls the sheet uniformly into the mold. Expect ±0.010″ on critical features (snap-fit edges, mounting holes, bezel openings) and ±0.030″ on overall dimensions for parts up to about 24 inches across. Larger parts widen these tolerances slightly.
For surface finish, pressure forming reproduces the mold surface faithfully: leather-grain textures, geometric patterns, embossed logos, debossed serial numbers. A textured aluminum tool produces a textured part directly, with no secondary operation needed. This is the biggest aesthetic advantage over vacuum forming, which softens fine surface detail.
Pressure Forming vs. Injection Molding
The most common reason to consider pressure forming is to avoid injection mold tooling cost. A pressure forming tool for a housing-sized part runs $8,000 to $40,000. The injection mold equivalent runs $40,000 to $150,000, and sometimes more for large parts. Lead time also favors pressure forming: 6 to 10 weeks for an aluminum pressure tool versus 12 to 20 weeks for an injection mold.
The crossover where injection molding wins on total program cost depends on part size and annual volume. For housing-sized parts at under 5,000 units a year, pressure forming is almost always cheaper. The break-even moves higher for large parts, since injection tooling scales aggressively with shot size while pressure forming tooling doesn’t. See our comparison of vacuum vs. pressure forming for a deeper breakdown.
Tooling and Lead Times
Pressure forming molds are single-sided aluminum, either cast or CNC-machined. Cast aluminum is the budget option for medium-detail parts at moderate volume. Machined aluminum is required for tight tolerances, textured surfaces, or runs over a few thousand parts a year.
Standard timelines:
- Tooling design and approval: 1 to 2 weeks
- Mold manufacturing: 4 to 8 weeks
- First-article parts: 1 to 2 weeks after tool delivery
- Production: 2 to 4 weeks per lot, depending on quantity
Faster turn is possible on simpler tools. We’ve delivered first-article parts in 5 weeks from purchase order on straightforward geometries.
Industries We Serve
Medical Devices
Diagnostic equipment housings, lab instrument enclosures, sterilizable covers. We pressure form these in FDA-compliant ABS, polycarbonate, and PETG with tolerances suitable for snap-fit assembly.
Electronics Enclosures
POS terminals, kiosks, industrial controls, instrument bezels. Pressure forming delivers the textured, branded surface finish that injection molding would, on tooling 70 percent cheaper.
Aerospace Interiors
FAA FST-compliant Kydex panels, cabin housings, ground support equipment. Pressure forming dominates this category because parts are large and volumes are moderate.
Frequently Asked Questions
What is pressure forming?
Pressure forming is a thermoplastic forming process where a heated plastic sheet is pressed against a single-sided mold using up to 100 PSI of compressed air. The added force (about seven times atmospheric pressure) lets the plastic pick up textures, sharp radii, and tight tolerances that vacuum forming alone can’t reproduce. The result is a part with the surface quality of injection molding at a fraction of the tooling cost.
When does pressure forming make more sense than injection molding?
When the program is under about 5,000 parts a year and the part is larger than a few inches across. Pressure forming tooling runs 15 to 30 percent of injection mold tooling for a comparable part, and lead time is half. Above 5,000 to 10,000 units annually, injection molding’s lower piece cost eventually overtakes pressure forming on total program cost. The exact crossover depends on part size.
What tolerances can pressure forming hold?
±0.010 inches on critical features and ±0.030 inches on overall dimensions for parts up to about 24 inches across. Larger parts widen these tolerances slightly. Specific mounting holes, bezel openings, and snap-fit edges typically hit ±0.005 to ±0.010 inches reliably.
What materials can be pressure formed?
All standard thermoplastic sheet stock: ABS (most common), HIPS, polycarbonate, PETG, Kydex, TPO, polyethylene, and acrylic. The choice depends on application: FDA compliance, flame retardance (FAA FST), impact resistance, paintability, weather resistance. ABS is the default workhorse for housings and enclosures.
How long does pressure forming tooling take to make?
Six to ten weeks for a typical aluminum pressure forming tool. Simpler tools can ship in five weeks. Compare that to twelve to twenty weeks for an injection mold and you have most of the timeline argument. First-article parts ship one to two weeks after tool delivery.
Can pressure forming reproduce textures and embossed logos?
Yes. Pressure forming reproduces the mold surface directly: leather-grain textures, geometric patterns, embossed logos, debossed serial numbers. A textured aluminum tool produces a textured part in a single forming cycle, with no secondary operation. This is the main aesthetic advantage over vacuum forming, which softens fine surface detail.
What's the maximum part size you can pressure form?
Ninety-six inches by forty-eight inches by twenty-four inches deep. Part size scales pressure forming tooling cost less aggressively than injection mold tooling, which is why thermoforming dominates large-part programs (aerospace panels, equipment housings, transportation interiors) even at higher volumes.
How does pressure forming compare to vacuum forming?
Vacuum forming uses atmospheric pressure (about 15 PSI) to draw the sheet into the mold. Pressure forming adds compressed air on the back side, up to 100 PSI, for about seven times more force. The extra force lets pressure forming pick up textures, sharp corners, and tighter tolerances. Tooling cost runs two to three times higher than vacuum forming, but still well below injection molding.
Have a part you’re considering pressure forming? Send us your drawings and we’ll come back with tooling cost, lead time, and a per-piece quote.