Wrapid Holdings photoresist film storage, Bradford

Type of works: supply of EcoCooling's ECP side discharge coolers.

Wrapid Holdings Limited has special clean room operations in Bradford for slitting specialist films. It has a long term contract with Dupont for the conversion of Riston^® dry photoresist films which are used in the production of printed circuit boards. These are produced for distribution throughout Europe, the Middle East and Africa. Mill-size film rolls are delivered from their global manufacturing facilities to Bradford for storage prior to conversion in the special purpose-built clean room facility, operating to BS EN ISO 9001-2000 standards.

These photoresist films must be kept below 25°C otherwise irreversible degradation takes place. In the past this had been managed by ensuring that the films were stored at the lowest tiers of the warehouse. As manufacturing volumes have increased this is now no longer always possible. A solution was needed to ensure the storage criteria were complied with during the weather conditions experienced in the UK. An installation consisting of five ECP16000 side discharge evaporative coolers was made at low level. The discharge air was directed down the middle of the corridors and extraction was provided at high level. This provides a cross-flow ventilation pattern exploiting the natural convection currents. Cool air is brought in at the lowest levels and the warm air is extracted at high level.

The actual temperature performance over a four day period is shown. This is during a very hot period of weather. It is unusual for the temperature in the UK to exceed 30°C. An evaporative cooling solution also ‘smoothes’ the temperature profile experienced over a 24 hour cycle.