Our TPU Vacuum Casting Services

Our TPU Vacuum Casting Services

Unlock precision, flexibility, and speed in manufacturing with TPU Vacuum Casting from our shop. Our expertise in Thermoplastic Polyurethane (TPU) combined with advanced vacuum casting technology delivers high-quality, custom parts—from rapid prototypes to large-volume production.

Whether you need complex designs for automotive, medical, or consumer electronics, we ensure superior dimensional accuracy, durability, and cost-effectiveness, making us your trusted partner for all TPU casting needs.​

What is TPU Vacuum Casting?

TPU Vacuum Casting is a specialized polymer casting process that uses Thermoplastic Polyurethane (TPU)—a flexible, durable material—to create high-precision parts under vacuum conditions. Unlike traditional methods, vacuum molding eliminates air bubbles, ensuring smooth surfaces and consistent material distribution.​

Key TPU properties that make it ideal for this process include:​

• High flexibility and elasticity (retains shape after bending)​

• Excellent resistance to oil, chemicals, and abrasion​

• Temperature stability (performs well in -40°C to 120°C environments)​

• Impact resistance and durability for long-lasting parts​

The casting process definition for TPU vacuum casting involves melting TPU pellets, pouring the molten material into a mold within a vacuum chamber, and curing it to form the final part. This method balances precision and cost, making it suitable for both prototyping and low-to-medium production runs.

The TPU Vacuum Casting Process Step-by-Step

The TPUvacuum casting process involves 7 key stages, each critical to achieving high-quality results:

1. Casting Mold Preparation: We use high-grade silicone molds (from 3D-printed masters) for flexibility and detail retention. Molds are inspected for cracks or defects to avoid part flaws.​

1. TPU Mixing Process: Thermoplastic Polyurethane (TPU) pellets are mixed with optional additives for TPU (e.g., UV stabilizers, colorants) in a heated mixer. The mixture is melted to a viscosity of 500–800 cP for optimal pouring.​

1. Vacuum Chamber Operation: The mold is placed inside a vacuum chamber, which is evacuated to -95 kPa to remove air. This prevents bubbles in the final part.​

1. Pouring Technique: Molten TPU is poured into the mold at a controlled rate (10–15 mL/s) to avoid splashing and ensure even filling.​

1. Curing Process: The mold is heated to 80–100°C for 20–30 minutes (depending on part thickness) to cure the TPU. Post-curing at 120°C for 1 hour may be used for enhanced durability.​

1. Post-processing Steps: Parts are demolded, trimmed to remove excess material, and cleaned. Additional steps like polishing techniques or painting and coating may be applied.​

Quality Control in Casting: Each part undergoes dimensional measurement (using calipers and 3D scanners) and visual inspection to check for defects, ensuring compliance with tolerance specifications.

Materials Used in TPU Vacuum Casting

Choosing the right materials is essential for successful TPU vacuum casting. Below is a breakdown of key materials and their roles:​

We prioritize material compatibility to ensure additives and reinforcements work seamlessly with TPU, avoiding issues like material separation or reduced performance.

Advantages of TPU Vacuum Casting

TPU Vacuum Casting offers numerous benefits over other manufacturing methods (e.g., injection molding, 3D printing):​

• High Flexibility: TPU parts retain elasticity, making them ideal for gaskets, seals, and wearable devices.​

• Durability: Resists wear, impact, and chemicals, ensuring long part life (up to 5+ years in non-abrasive environments).​

• Cost-effectiveness: Lower tooling costs than injection molding (silicone molds cost 70–80% less than metal molds), perfect for small batches.​

• Rapid Production: Faster turnaround than 3D printing for large batches (produces 100+ parts/day vs. 10–20 for 3D printing).​

• Customizability: Easily adapts to complex designs, colors, and surface finishes without retooling.​

• Environmental Resistance: TPU parts perform well in moisture, oil, and temperature extremes (-40°C to 120°C).​

Aesthetic Appeal: Smooth surfaces and consistent coloring make parts suitable for end-use products (no post-processing needed for many applications).

Industry Applications of TPU Vacuum Casting

TPU Vacuum Casting is widely used across industries due to its versatility. Key applications include:​

How to write a spec that gets priced correctly

A drawing is a contract. If it leaves a number open, the shop fills that number in with its own default. The default is rarely the one you had in mind. Put these five lines on every RFQ and most of the back-and-forth disappears before it starts.

• A model and a drawing that agree
• Material by standard number
• Tolerance only where it mates
• Finish and the faces it applies to
• Quantity and required date

The point is not paperwork. Each line removes a decision the shop would otherwise make for you. A complete RFQ comes back priced. An incomplete one comes back guessed.

What actually drives the price

Buyers usually push on material because it is the line they can see. In practice the material is rarely the biggest number on a quote. These five lines decide most of it:

• process choice
• material
• tolerance band
• finish
• volume

Ask for the quote split by line. A supplier who cannot break it down is guessing, and you will pay for the guess. The line you can usually renegotiate is the tolerance band, not the raw material.

Problems you will meet, and the fix

Every process has a failure mode it prefers. The same four show up again and again on this kind of work, and none of them are mysteries once you know what to look for.

• A drawing that contradicts the model
• A tolerance with no datum
• A cosmetic callout with no approved sample
• A quote compared against a different scope

Catch the fault on the first part, not the hundredth. A first-article check costs an hour. A bad batch costs the whole order. Write the check into the purchase order so nobody has to remember it.

What to check on the first article

The first article is the cheapest inspection you will ever buy. Use it properly and the rest of the run becomes boring, which is exactly what you want.

• Every dimension on the drawing, with the measured value written beside it.
• The material certificate, matched to the heat or lot number on the parts.
• The finish against the sample you approved, under the same light.
• Fit against the mating part, assembled rather than measured.
• Packaging, because parts that arrive damaged were never in tolerance.

Check in this order: datums, then mating features, then cosmetic faces. If the datums are wrong, every number after them is noise. Keep the report on file. When a problem shows up in month six, that document is the only thing that tells you what changed.

How to compare two quotes fairly

Two numbers are not comparable unless the scope matches. Line them up before you decide, because a low number with three gaps is not a low number.

Same drawing, same material, same finish, same inspection. Anything else is a different job wearing the same part number. Then look at what each quote leaves out. Freight, packaging, certificates and tooling are the usual gaps.

Ask each supplier to state their assumptions in writing. The one who does is usually the one who has run the process before.

Scaling from one part to a batch

The first part teaches you the process. The hundredth teaches you the process cost.

Watch three things as volume grows: setup amortisation, tool wear, and how much hand work the finish still needs. If the unit price barely moves between ten and a hundred, the cost sits in material or in hand work, not in setup. Ask which, because only one of them is negotiable.

Lead time behaves the same way. A one-off is scheduled around other jobs. A repeat order is scheduled around your forecast. Give the shop a forecast and the lead time gets shorter, not longer.

How to read a supplier's quote

A quote is a short document with a long shadow. Four things in it decide whether the job runs smoothly, and only one of them is the price.

• The scope line. It should name the process, the material and the finish, not just the part.
• The tolerance basis. General tolerance or the drawing, and which standard it follows.
• The exclusions. Tooling, freight, certificates and inspection are the usual omissions.
• The validity date. Material prices move, and an open-ended quote is a promise nobody can keep.

Read the exclusions before you read the total. A quote that leaves out tooling is not cheaper. It is a quote for a different job.

What to send with the first order

The first order sets the pattern for every order after it. Send a complete package once and the shop files it, and the second order takes a fraction of the time.

• A STEP or native model plus a PDF drawing carrying the same revision letter.
• The material callout by standard number, not by trade name.
• The finish and the exact faces it applies to.
• Any test the part must pass: fit, seal, drop, salt spray, dielectric.
• A contact who can answer a question inside one working day.

Then write down what was agreed. An email that confirms the material, the finish and the date is worth more than a longer purchase order that leaves them open.

When this is the wrong choice

A good supplier tells you when the process does not fit. These are the cases where we say so.

• The volume is so low that setup costs more than the parts are worth.
• The tolerance is tighter than the process can hold without a second operation.
• The geometry cannot be made without a tool feature that will not pay back.
• The material you need is not available in the form the process requires.
• The schedule is shorter than the tooling or setup time, and nobody has said so yet.

None of these are refusals. They are reasons to look at a different route, and the earlier that conversation happens the cheaper it is. The most expensive mistake in manufacturing is a process chosen before the question was understood.

Planning the ramp from prototype to production

The gap between one good part and a thousand identical ones is a plan, not a machine. Three decisions close it.

First, freeze the design. Every change after tooling starts is a re-cut, and re-cuts are where schedules go. Second, decide the inspection level. A prototype is checked by eye; a production part is checked against a report. Third, agree the change process in writing, including who pays for it.

Write the ramp down as dates and owners, not as intentions. A ramp plan with three names and three dates is worth more than a page of good intentions.

What documentation to expect

Paperwork is not bureaucracy when a part fails at the customer. It is the only record of what was agreed. A normal shipment should carry four documents.

• A dimensional report covering every callout on the drawing.
• A material certificate traceable to the heat or lot number.
• A finish or coating certificate where the specification requires one.
• A packing list that matches the carton labels.

If a supplier cannot produce these on request, they are not running a controlled process. Ask for one sample set before you place the first order and you will know exactly what you are buying.

How to handle a change after the order

Changes happen. What matters is whether the change is priced, scheduled and recorded, or absorbed quietly and discovered later.

Send the change as a new revision, not as a note in an email. Ask for three answers in writing: what it costs, what it does to the date, and what happens to material or tooling already committed. Then decide.

A change without a revision number is a rumour. The shop will build what it has on file, and both sides will be right and unhappy at the same time.

Success Stories: TPU Vacuum Casting Case Studies

Our TPU vacuum casting solutions have solved unique challenges for clients across industries:​

Case Study 1: Automotive Gasket for a Leading OEM​

• Challenge: The client needed a flexible, oil-resistant gasket for engine compartments with a 2-week turnaround.​

• Solution: We used Shore A 80 TPU and rapid silicone mold making to produce 500 gaskets in 10 days.​

• Result: Gaskets met all performance tests (withstood 120°C and oil exposure for 1000 hours) and reduced costs by 40% compared to injection molding.​

Case Study 2: Medical Device Grips for a Healthcare Startup​

• Challenge: The startup required biocompatible, ergonomic grips for surgical tools with tight dimensional accuracy (±0.1mm).​

• Solution: We used FDA-approved TPU, implemented vacuum metallization for grip texture, and applied strict quality control in casting.​

• Result: 1000 grips were delivered in 5 days, with zero defects—client testimonials praised the “perfect fit and durability.”​

Our solution for Our TPU Vacuum Casting Services

YiguProto runs custom manufacturing in house, from a single prototype to a production batch. We quote the process, the material and the finish as separate lines, so you can see where the money goes instead of arguing with one number.

Send a STEP file or a drawing and you get a DFM report in one to two business days. It flags the features that add cost and the features that will not hold tolerance on the process you picked.

Every order ships with an inspection report on the features you call out. If a part misses, we make it again. Ready to price a part? Start with a free quote and DFM review, or read more about our custom manufacturing. You can also talk to an engineer before you commit to a drawing.

FAQ about Our TPU Vacuum Casting Services

The short version

Our TPU Vacuum Casting Services rewards the buyer who reads the data sheet and the drawing together. Pick the option for the property that matters, not for the price per kilo.

Tighten only what mates. Test a sample before the run. Then let the process do the rest.