Polymer pack keeps water crystal clear

Polymer pack keeps water crystal clear

Packaging of swimming pool chlorine crystals has traditionally been in bulk using industrial sized drums, but Arch Chemicals wanted to supply the product in single-use.
Packaging of swimming pool chlorine crystals has traditionally been in bulk using industrial sized drums, but Arch Chemicals wanted to supply the product in single-use, one-per-day sachets for convenience and ease-of-use.
The chlorine crystals are chemically extremely aggressive, and Bristol-based contract packer Weston White realised that standard packaging materials were not suitable for this kind of application. The company then contacted National Flexible's film consultancy service for assistance. After testing the effect of the chlorine crystals on a range of film materials, National Flexible produced a hybrid polymer that could withstand the chlorine's aggressive nature.
The material is a combination of two polymers, Valeron and Surlyn, which produced the necessary pack characteristics of puncture resistance, moisture barrier properties and seal integrity to ensure the crystals would have an extended shelf-life, even when stored in a high moisture pool environment.
George Slack, National Flexible's product development manager, confirmed that the sachets met all the requirements: "It was an interesting challenge, but we were able to create a film specification which is user-friendly and reasonably priced".
Weston White's proprietor Bob Cooke adds: "As specialists in the sachet market this is probably as difficult a job as we could get, but it has gone wonderfully well".
The sachets, launched in May this year, are packaged in boxes of 50 and are available from specialist pool equipment suppliers.