Cooler Shock brand hard ice packsCooler Shock ice hard ice pack fitting in 3 different refrigeratorsCooler Shock Hard Pack

Ice ³ Cooler Shock hard packs (Ice cubed)

It’s been a while since I’ve blogged. The big reason is that we were waiting to do something BIG. We’ve been working hard over the past year to develop a Cooler Shock ice pack made of a durable plastic that would still perform like our soft gel packs. There are several factors that go into making this happen. They are material choice, durability, thickness, and shape.

The challenge with plastic is that it has greater insulative properties than our nylon and foil bags. We solved this problem by increasing the surface area by 45% in order to get the same heat transfer rate as our foil packs. We did this while not increasing the overall size. How? With the ribbed surface area and the addition of 4 sides. Interestingly enough, our standard foil packs have only two sides but the hard pack has 6 sides!

We also chose HDPE plastic (high-density polyethylene) for its higher heat transfer rate and the food safety factor. HDPE is widely used in the food industry.

Durability –

We took on durability from a completely different angle compared to other hard packs. Most all other hard packs (including Yeti), use a fluid only formula. There are many negatives to this strategy. The big one for durability is that the fluid will freeze hard as a rock. This can be a problem when you drop the ice pack. The plastic must absorb the entire blow. Our Cooler Shock hard packs continue to use our heavy gel formulation which provides many benefits to the functionality of our ice pack. One big one is homogenization. It keeps the formula consistent throughout so that the entire pack performs equally well without cold and hot spots. The benefit to durability is that our formula has some give when frozen. The formula can absorb impact because the gel adds elasticity and impact absorption ability.

Thickness –

Thickness is a factor in heat transfer, durability, and weight. Our plastic pack adds nearly a pound to the ice pack. We picked the ideal thickness to minimize weight and maintain the desired heat transfer and durability. An interesting thing about the added weight (hard pack weighs about a pound more than our large soft pack) is that it offers some heat absorption ability in and of itself. This means that our hard pack actually has a higher cooling capacity than our large soft pack.

Shape –

Ahhh, shape! We worked hard and long on this one. Our ice pack is designed to freeze from the outside perimeter inwards. The hard-pack is hourglass-shaped  (concave) in the center so as the formula freezes, it expands into the center of the pack making it nearly flat when it’s frozen. No lumps and odd shapes. That was a difficult task. We had to modify our mold several times to make this shape work in the blow molding machine. We are happy we took the time to do it.

Filling model

Most Cooler Shock ice packs have the added value of the consumer adding the water weight to the pack. This allows you to get more packs for a lower cost. It’s not unusual to need 2-6 of these packs when using 45-75 quart coolers. Yes, you will save the money on ice but it can be a big out of pocket cost initially. We make this more viable for you, the consumer with our fill-and-save model. We made this pack easy to fill with an included silicone funnel and safety screw cap.

Finally, I want to explain what the personal goal was in making this pack. Cooler Shock brand ice packs achieved some great things for our consumers. We were very excited when we created a viable formula that could replace ice and outperform it. We received great acceptance and reviews from our consumers.

The one thing we could not say is that the foil packs were extremely durable or easy to stack in your freezer. This was just a factor in having excellent performing soft packs. They were designed to transfer energy well, but they took a beating over time with the constant handling and getting knocked about.

We were determined to create a pack that performed as well as our current packs but has the added benefit of great durability, life expectancy, and easy freezer placement. I wanted my customers to say “this hits all the points for me, no need for improvement”. We hope we’ve achieved that.

Thanks for listening