Storage box

PP moulded into a lightweight, rigid container.

Storage box, illustrative image

Material

Box body: PP

Material selection rationale

Rigid walls
Keep stored items together in a self-supporting container.
Lightweight
Make the empty box easy to carry and move.
Ribs and rim
Local thickening and a shaped rim resist bending without making the entire box solid or heavy.

How it becomes a product

  1. Melt and inject: PP pellets are melted and pushed into a mould shaped like the box.
  2. Cool and release: The polymer cools into the moulded shape before the box is removed. Cooling and shrinkage are managed so the broad base and rim retain useful shape rather than warping.

Preparation routes

Propene route

Catalytic addition polymerisation. Propene molecules join into chains. A suitable catalyst controls chain growth and the arrangement of the methyl side groups. Catalyst-controlled arrangement of methyl groups can favour regular packing. The monomer formula alone does not describe this tacticity.

A coordination catalyst system is used; it is not counted as a monomer. A thermoplastic moulding or foam uses already-made PP, not propene reacting inside the final product.

  1. Poly(propene): manufacture and usesChemical Industry Education Centre, University of York

Sources

  1. Poly(propene): manufacture and usesChemical Industry Education Centre, University of York
  2. TROFAST storage box: material informationIKEA