FACTORS INFLUENCING PERFORMANCE OF PRE-CONDITIONED (FROZEN) GEL ICEPACKS
1. No. of hours the Gel Icepacks are pre conditioned (frozen) at minimum -18 Deg C in the deep freezer.
Note:
- The Icepacks needs to be conditioned for a minimum of 48 hours.
- For better results condition for 96 hours +
2. How the Gel Icepacks are pre conditioned in the deep freezer (SoP).
Note:
- It is important that the Icepacks gets sufficient breathing space around it for proper conditioning. In other words Gel Icepacks needs to kept in perforated crates or shelves with air gaps between each stack of Icepacks in the deep freezer which allows faster heat exchange between the freezer and Icepacks.
- If the Icepacks are loaded in the crate without air gaps the Icepack may not be fully conditioned (even though for human touch & feel the Icepacks looks Frozen physically) in the deep freezer even after 48 hours or more time in the freezer.
- The Icepacks should never be conditioned (frozen) in the original end packing corrugated box as corrugated boxes are poor conductor of heat.
- The Icepacks should neatly stacked FLAT one above the other with sufficient air gaps in between each stack of Icepacks.
- The Icepacks should never be thrown into the deep freezer in a disorderly manner as the same can get frozen with deformed shape.
- Follow FIRST IN FIRST OUT policy for freezing the Icepacks should be followed in the deep freezer.
3. How the pre conditioned (frozen) Icepacks are packed in the insulated box along with the product.
Note:
- The positioning of the Icepacks inside the Insulated box also plays a role as cold air is denser and normally moves from top to bottom.
- For better results the pre conditioned Icepacks should be packed on the top and sides of the product inside the insulated box.
4. Ambient temperature, temperature of product during packing and quantity or weight of product.
Note:
- The ambient temperature outside could be say 45 Deg C in summer and in winter the ambient temperature outside could be say 10 Deg C this therefore will also have an impact.
- The volume, weight and temperature of the product at the time of packing into the insulated box along with the pre conditioned Icepacks will have an impact on the performance.
5. Quality & specifications of the insulated box used.
Note:
- There are various types of insulated boxes available in the market which has a major impact on the temperature retention properties of the Icepacks.
- The most commonly used insulated boxes are EPS (Expanded PolySterne) & XPS (eXtruded PolySterne). The performance of XPS insulated boxes are much better when compared to EPS insulated boxes.
- Also the specifications of the EPS & XPS boxes plays a major role in maintaining the 2 to 8 Deg C during transit.
- It is observed that EPS or XPS boxes with higher thickness & density gives better insulation properties and therefore less heat (cold) loss during transit.
- Also moulded EPS or XPS boxes gives better insulation properties when compared to boxes assembled with sheets of EPS or XPS.
6. Quantity & weight of pre conditioned (frozen) Gel Icepacks used per insulated box
Note:
- The quantity and weight of pre conditioned (frozen) Gel Icepacks should be based on validation trials conducted with simulated conditions.
- For example if you use only 2 Nos. of 500 gms pre conditioned (frozen) Gel Icepacks inside 1 insulated box where you actually need say 4 Nos. 500 gms pre conditioned (frozen) Gel Icepacks to achieve say 36 hour of 2 to 8 Deg transit time, the 2 Nos. of 500 gms Gel Icepacks could start to become soft or under perform.
