Acrylic bathtub

A heated PMMA sheet is shaped into the smooth bowl of a bathtub.

Acrylic bathtub, illustrative image

Material

PMMA surface shell: PMMA

Material selection rationale

Smooth surface
Provides a continuous easy-to-wipe bowl.
Heat formability
A flat sheet can be drawn into a deep curved shell.
Shell and backing
The acrylic presents the smooth water-contact surface while the backing and supports carry loads. Sheet transparency or rigidity alone does not describe a bath.

How it becomes a product

  1. Thermoform the sheet: Acrylic sheet is warmed and drawn over a mould.
  2. Reinforce and finish: The formed shell receives a backing system, then is trimmed and drilled for fittings. The drawn shell is reinforced and mounted so its deep curved shape and fittings do not depend on unsupported acrylic sheet.

Preparation routes

Methyl methacrylate route

Addition polymerisation. MMA molecules join through their double bonds. Their ester groups remain as side groups; no acid-and-diol pair is required. The presence of ester groups in a monomer does not make this a condensation polymerisation: the growing backbone is built through carbon–carbon bonds.

Initiators and controlled curing support polymerisation. Sheet can be cast directly or made by extruding previously polymerised PMMA. Cast-sheet curing makes polymer and sheet together; extruded sheet begins with polymer made earlier.

  1. Manufacturing acrylic glass from MMAPLEXIGLAS / POLYVANTIS

Sources

  1. Environmental product declaration: acrylic bathtubs, shower trays and bath panelsDuravit
  2. Forming PLEXIGLAS sheetPLEXIGLAS / POLYVANTIS
  3. Manufacturing acrylic glass from MMAPLEXIGLAS / POLYVANTIS