How hard-shell suitcases are made

A hard suitcase shell starts as a flat plastic sheet that is heated until soft and then sucked into a mold.

stations: 6
things upstream: 81
raw sources: 22
steps from the ground: 9

The short version

A hard-shell suitcase is made of two halves formed from polycarbonate, ABS or polypropylene sheet heated until floppy and pulled over a mold by vacuum. The halves are trimmed, lined and joined by a zipper or a metal frame. Wheels, a telescoping handle and locks are bolted on last.

Extrude the plastic sheet

Pellets of polycarbonate, ABS or polypropylene are melted in heated barrels and squeezed through a flat die, sometimes with several layers merged. Rollers then set the thickness and surface texture of the sheet.

Goes in
Polycarbonate ABS plastic Polypropylene
Vacuum-form the halves

A sheet is heated until it softens and placed over an aluminum mold. A vacuum pulls the plastic tight against every ridge and corner, and it cools on the mold. The corners stretch thinnest, so this is where weak shells crack.
Trim and drill

Excess plastic around the edge is cut away. Polycarbonate gets too hard after forming to trim by hand without risking cracks, so factories use multi-axis CNC machines, which also cut the holes for handles and wheels.
Fit the lining

Fabric is sewn into dividers and a lining, and then glued or riveted to the inside of each half. The lining protects the clothes from the hard plastic edge.

Goes in
Polyester Sewing thread Adhesive
Add the frame or zipper

On a zipped case, a long coil zipper is riveted around both halves. On a frame case, aluminum strips are riveted around the rim, and clamps or locks hold the halves shut.

Goes in
Zipper Aluminum
Bolt on wheels and handle

Spinner wheels and a telescoping handle are screwed or riveted to reinforced plates. Sample cases go through a drop test, which is where a badly handled sheet shows up as a cracked corner.

Goes in
Steel Screw

End of the lineHard-shell suitcase

Worth repeating

Wheels on suitcases were pitched to department stores by Bernard Sadow, who was granted a patent in 1972.
Rimowa began selling the first aluminum suitcase in 1950, with grooves modeled on the skin of a Junkers Ju 52 airplane.