preform

Everyday

1. (technical) A preform is an object that has been partly shaped before its final shape, such as the small plastic tube that is blown up into a drinks bottle. tree →
2. (verb, rare) To preform is to shape something beforehand. tree →

In the lessons

In design and technology lessons, plastic bottles start as preforms that are heated and blown into moulds. In ordinary spelling it is often a mistake for «perform». Phrases: a bottle preform.

Examples

• Plastic bottles start as small preforms. tree →
• The machine heats the preform and blows it into a bottle. tree →
• We looked at a preform in technology class. tree →
• The preform looks like a thick test tube. tree →
• Glass fibre is pulled from a preform. tree →
• A preform is heated until it is soft. tree →

Note

A trap: «preform» (shape beforehand) is NOT «perform» (act, sing, do). Most of the time you want «perform». Pre- means «before».