Thick Gauge polypropylene Cowls in 3 mm – Rail Transit Interiors Range

These polypropylene cowls are thick gauge vacuum formed parts supplied to drawing for rail transit interiors. They are formed from polypropylene sheet at 3 mm, trimmed on 5-axis routers and inspected against the drawing before packing. Buyers choose this route where a metal fabrication is too heavy, or where injection moulding tooling cannot be justified for the volume.

Product specification

Key features

• One piece shell replaces a fabrication, so assembly hours drop
• polypropylene keeps the weight down while stiffness is held through the formed shape
• Soft touch coating finish as standard, further finishes on request
• Trimmed on 5-axis routers, so mounting holes and cut outs match the drawing
• Tooling stored against the part number for repeat and spare orders
• PPAP or ISIR on request

Typical applications

• ceiling end caps
• wall panels
• luggage rack trays
• seat shells
• cowls used across general rail transit interiors builds

How it is made

1. The sheet is formed over the mould with vacuum and, where the draw is deep, with plug assist.
2. Drawings are reviewed and a manufacturability report is issued with wall thickness, draft and radii marked up.
3. The part cools on a jig so the shape is held while the material stabilises.
4. Tooling is cut: aluminium for production volumes, composite or printed moulds for samples and first articles.
5. Parts are inspected, fitted with inserts or hardware if required, packed and shipped.

Material: 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 notes

• keep a draft angle of at least 3 degrees on vertical walls so the part releases cleanly
• use corner radii of at least three times the sheet thickness to avoid thinning
• plan the trim line on a flat face so the router can hold tolerance
• avoid sharp steps in the mould, which show as chill marks on the finished surface

Finishing and assembly options

• soft touch coating
• clear protective film
• as formed gloss
• Threaded inserts, PEM fasteners and brackets fitted before dispatch
• Mating parts can be trial assembled before the first article ships

Quality

Sheet thickness is checked on the formed part at the points shown on the drawing, and the readings go into the report. First article inspection covers critical dimensions, wall thickness, colour and texture against the approved sample.

• UL94 V-0 grades available
• ISO 9001 quality system
• food contact declarations available

Packing and delivery

Parts are stacked with interleaved film and packed in export cartons on pallets. Standard lead time to first article is 3–4 weeks, and repeat releases ship against stored tooling without a new proving run.

Frequently asked questions

Can you make it in another material?

Any grade in this family can be swapped in. Send the requirement and the material will be quoted with the price difference shown.

What quantity can I order?

Sample quantities start at one piece off printed tooling. The process pays back from about 25 pieces a year and runs well into several thousand.

Are spare parts available later?

Tooling is stored against the part number for the life of the programme, so replacements or spare panels can be released at any time.

Request a quotation

Send the drawing or a photo of the current cowls with the quantity and the finish required. The reply covers material choice, wall thickness, tooling route and price, so the decision is made on a complete picture.