Load rate and dispenser matching

Load rate is quoted in blend sheets as if it were a property of the compound. It is not. It is a property of the compound, the matrix and the dispenser together, which is why a figure borrowed from a different dispenser type is a starting point rather than an answer.

What the matrix does

A rubber septum, an EVA matrix and a liquid formulation release the same active at different rates, and they age differently. Rubber takes up a lipophilic compound readily and releases it slowly; a liquid formulation releases quickly but loses the volatile fraction early; a polymer matrix sits between the two depending on the loading. The same compound at the same load will therefore produce three different release curves.

What the supplier can hold constant

• Composition of the lot, including the isomeric ratio, reported on the certificate.
• Packing that limits headspace, so the material that reaches the blending house is the material that was released.
• Lot identity, so that a change in field result can be traced to a change in input rather than guessed at.

What we cannot hold constant is the release curve, because it is created downstream of us. That is why enquiries about release rate are answered with a specification rather than with a number.

Reading a fall-off in catch

If catch drops late in the season, the first hypothesis should be the dispenser, not the active: the matrix has aged and the rate has fallen. The second should be storage of the finished lure, particularly if it spent the off-season somewhere warm. Only after those two should the material be suspected — and by then there is usually a certificate to check it against.

What to send with an enquiry

The dispenser type, the intended season length, the load rate you are working to and the climate the lure will sit in. With those four, the answer is specific. With a compound name alone, the only honest answer is the specification of the material.

Actives used at load are concentrated in the acetate esters; the quality and documentation page describes what travels with each lot.

Describe the dispenser and the season