Functional Product Packaging

Formulations cured by light will clearly need a light source, and this can be incorporated into the product. For industrial or after-market applications, many types of visible-light or UV sources are available, whereas for consumer products, visible light delivered by battery-operated LEDs is preferred.

In the latter case, the product will usually require careful formulation to ensure that it is sufficiently sensitive to the lower energies available. But if this can be done, then incorporating such light sources into the packaging can provide novelty that marketers can exploit and consumers enjoy.

The light-cured cyanoacrylate adhesives that we developed for the consumer marketplace while I was working at Afinitica presented a challenge – how to provide the customer with a source of light at the suitable frequency. The solution we created was to incorporate a low-power blue LED within the product pack, offering both customer convenience and novelty. This product went on to be branded ‘Fix & Flash’by Bostik, and has been very well received by customers. 

Alternatives that we also considered were including an adapter to allow the LED to be run off a mobile phone or other common device (see our patented example), so avoiding issues around transporting lithium-ion batteries. Alternatively, one could eliminate the issue of charging altogether, by using clockwork-powered components (also patented)!

Packaging design can clearly contribute to the stability of a reactive product, but also to its activation. For example, adhesives that cure anaerobically by a radical mechanism can be stabilised by air-permeable packaging, since oxygen is a radical stabiliser.

Changes in pressure can also be called upon to release products – for example using an aerosol-type package. Pressure packs can also be used to force mixing of a catalyst or an initiator in products, while carefully-engineered ‘bag-on-valve systems’ can also be a fruitful line of enquiry for providing dispensing precision.

Placing such technology in the hands of consumers can be a marketing coup in its own right, especially in conjunction with viscosity-adjusted formulations that allow use of a product in various orientations.

Dispensing two-part adhesive formulations easily and conveniently is a considerable challenge. Two-part packages such as double-barrelled syringes are a traditional approach, but they are inherently unsealed, and can suffer from sticking of pistons and variation in mixing ratios. Pressure packs using bag-on-valve (BOV) technology are popular for some single-component pastes (especially cosmetics), but could this approach be extended to two-component adhesives? 

While working at Loctite, I was the lead inventor on work (later patented) showing that using modified valve pedestals and a static mixing actuator indeed enables BOV technology to be applied to two bags rather than just one. The result is a dispenser that is convenient and novel, as well as providing effective sealing of the components.