What we have written on the cold chain145 / 154

A sealed ice pack is never opened, only frozen. A refillable container is filled to the line, closed so the seal seats, and tested for leaks by turning it upside down.

Separate vehicle, cooling and working-hour bottlenecks. Actual trips, utilisation, breakdown and total-cost records inform the investment choice.

Water grows by about 9 percent in volume as it freezes. A pack with no room left for that expansion bulges; one that stays swollen after thawing is taken out of use.

Compare deliveries to the same area in a pilot. Track vehicle loading, route, fees and each supplier's separate product records.

An ice pack melts until the heat entering the container has used up its latent heat. The time is the ratio of the two; in your own container the logger chart shows when the plateau ends.

Match deposit balances to container movements. Keep dispatch, return, damage and discrepancies traceable in one ledger.

The container sets the time more than the pack: insulation, outside temperature, number of packs and lid openings. In an insulated container with eutectic plates it reaches up to 24 hours.

Gel pouches hold gelled water, eutectic plates hold brine and PCM packs a special blend; the liquid inside an ice pack depends on the product family.

Do not assume every transport pack needs a passport. Verify product group, EU application date and buyer request, and keep material and repair data traceable.

An ice pack absorbs heat as it melts. A eutectic plate melts at a set point below zero; for GEBHARDT plates that point lies between -3 and -21 °C.

How conduction, convection and radiation are cut by insulation, and how a box's heat gain follows from its K value, surface area and temperature difference.

Product leaving the blast freezer goes to cold storage as fast as practicable. Store, packing line and vehicle must be ready before the cabinet is emptied, and the exit time is recorded with the lot.