Medical Equipment Display Shells in polypropylene: Thick Gauge Forming and Specification

Vacuum formed display shells are used across medical equipment because they can be produced without the tooling spend of injection moulding and without the weight of sheet metal. This page covers how 10 mm polypropylene sheet is formed for medical equipment, what tolerances are realistic, and what has to be on the drawing before tooling starts.

The route below is the one used for most of the display shells shipped from this plant: sheet is heated on the forming machine, drawn over an aluminium or composite mould, cooled on a jig, then trimmed on a 5-axis router. For display shells the sheet gauge is selected from the load case rather than from habit, and polypropylene is the material most often specified for this combination.

Typical specification

Where these parts are used

• imaging equipment panels for medical equipment
• device trolleys for medical equipment
• monitor shrouds for medical equipment
• dialysis machine covers for medical equipment
• display shells in general medical equipment builds

How the part is made

1. Drawings are reviewed and a manufacturability report is issued with wall thickness, draft and radii marked up.
2. Tooling is cut: aluminium for production volumes, composite or printed moulds for samples and first articles.
3. Sheet is dried when the material needs it, then heated to forming temperature on the machine.
4. The sheet is formed over the mould with vacuum and, where the draw is deep, with plug assist.
5. The part cools on a jig so the shape is held while the material stabilises.
6. Trimming is done on 5-axis routers or with a dedicated trim fixture to meet the drawing.
7. Parts are inspected, fitted with inserts or hardware if required, packed and shipped.

Material notes: polypropylene

Polypropylene survives repeated impact and most cleaning chemicals. Its low forming temperature keeps cycles short, but it shrinks more, so the mould is cut with the shrink factor built in.

Design tips for this part

• plan the trim line on a flat face so the router can hold tolerance
• use corner radii of at least three times the sheet thickness to avoid thinning
• keep a draft angle of at least 3 degrees on vertical walls so the part releases cleanly
• call out the finish on the drawing: mould texture, paint, or as-formed gloss
• hold the draw ratio near 1:1 for deep parts, or specify plug assist

Quality and inspection

First article inspection covers critical dimensions, wall thickness, colour and texture against the approved sample. Moulds, trim fixtures and programmes are stored against the part number, so a repeat order matches the first batch.

Cost and lead time

Tooling is the main cost driver at low volume, so a 10 mm display shells for medical equipment is usually quoted with a composite or printed mould first and the aluminium tool cut once the design is frozen. That keeps the first article cost low and gives a real part to test before the production tool exists. The result is shorter lead time compared with the alternatives, and a piece price that stays stable across repeat releases.

• Sample tooling: 7–15 working days
• Production tooling: 3–4 weeks
• Repeat orders run on stored tooling with no new proving run

Frequently asked questions

How long does tooling take?

Sample and first article tooling is usually cut in 7 to 15 working days. Production aluminium tools take 3 to 4 weeks depending on size and cooling layout.

Can you match an existing part?

Yes. Send a sample or scan and the part can be reverse engineered, with the wall thickness and material measured from the sample.

What quantities make sense?

Vacuum forming pays off from roughly 25 pieces up to several thousand a year. Below that, printed or composite tooling keeps the setup cost low.

Getting started

Send the drawing or a photo of the current display shells with the quantity and the finish. The first reply is a manufacturability review with the wall thickness, material and a quotation, so the decision is made on facts rather than on a price alone.