TCP Reliable releases new Phase Change Material (PCM) Packaging

Today, most products which require thermal protection are shipped using ice, frozen gel packs, or frozen bottles filled with liquids that freeze at 0° C to help hold the product at temperature. These refrigerant materials are called “phase change materials” because they undergo a phase change from solid to liquid at constant temperature. During this transition, they can maintain the phase change temperature (in this case, 0°C) for extended periods of time. The phase change materials are then packed around a temperature-sensitive product in a specific arrangement and placed inside an insulated shipper, completing the package.

As an example, if a temperature-sensitive product needs to be maintained in the 2° – 8°C range and cannot be frozen, special packaging precautions must be taken. Since the phase change materials in use today hold temperatures at 0°C (the freezing / melting temperature of water) refrigerated bags are placed between the frozen phase change materials and the product to prevent freezing. Sometimes dunnage or air gaps are required as buffers to separate the phase change materials from the temperature-sensitive product. This method requires considerable weight, size, and a very specific arrangement of frozen and refrigerated phase change materials and dunnage in order to hold the required temperature range. If during shipment, the packing arrangement is shifted, the thermal results could vary drastically.

The TCP (Thermal Control Panel) is a new approach to thermal product protection. The panels are blow molded bottles with tabs that allow them to be interconnected in a variety of ways. Inside the TCP’s, special formulations of chemicals are used whose phase change temperatures are at the optimum storage temperature of the temperature-sensitive product. If the temperature-sensitive product must be maintained within 2° – 8° C, the TCP is filled with a material that undergoes phase change at 5°C. This is exactly in the middle of the desired range. Because it can hold 5°C longer than a conventional phase change material (which undergoes phase change at 0° C, and has very little heat capacity at 5°C), significantly less material is required. In addition, the phase change material can be placed in direct contact with the temperature sensitive product because there is no risk of freezing. This reduces the size of the final package because no dunnage or air gaps are required.

Technical Advances

In the TCP, matching the phase change materials for thermal shipping applications to the specific product requirements is an advance over the current methodology. The design takes advantage of the fact that when a material undergoes a phase change from solid to liquid or liquid to solid, an enormous amount of energy is required. This property is called the latent heat of the material. Most importantly, this transition takes place at constant temperature, meaning that the temperature sensitive product is held at the phase change temperature for a longer time. By matching the phase change temperature to the product requirements, the most optimal thermal protection is provided for the least amount of material.

Design Advances

The blow molded container was designed with tabs that allow multiple TCP’s to be interconnected with extruded connectors. The bottle is ultra-sonically welded to assure a leak-proof seal. With this design, the bottle mold does not change, but various extruded connectors can be developed inexpensively to allow various connections. The connected bottle system allows the temperature sensitive product to be surrounded and in direct contact with the phase change material. Heat transfer from the phase change material to the product then takes place by conduction instead of convection, which is thermally more efficient. In addition, because the bottle connections are rigid, the product and phase change material maintain a consistent orientation from pack out to receipt without shifting.

New Material Applications

The use of unique materials for phase change that are disposable in the public waste stream is the key new material application. Currently, the following temperature ranges are in production: +5 °C, +22°C, +27°C, -20°C.

The phase change materials were located in industries as diverse as ice skating rink coolants to cleaning lubricants for high speed food packaging lines. The knowledge of the thermal properties of these materials, specifically the latent heat and the melt point, helped identify them as candidates for a packaging application.

Economics

When using TCP’s to ship products that require temperature control, less weight and size are required. The TCP is also designed for multiple use, so the economics of shipments improve with additional uses. For a packaging system designed to hold 2° – 8° C for 48 hours, use of TCP’s in the pack out versus frozen and refrigerated phase change materials and dunnage reduced the weight by 36.5 % in a package that provided equivalent performance. The cost to ship the unit overnight was reduced by 13.5%

New Benefits to End Users

The TCP, with the variety of phase change materials now available, allow the shipment of temperature sensitive products in ways that did not exist up to this point. Because the phase change material can be placed in direct contact with the temperature sensitive product, narrow temperature ranges can be held with less thermal mass and size than ever before. The end user’s product is much easier to pack off correctly because it is less complicated. The final pack off does not require the specific placement of dunnage, bubble wrap, and gels as the current practice does.

Environmental Impact

The design of the TCP employs the 3 R’s of the packaging environmental hierarchy: Reduce, Reuse, Recycle.

Reduce – the TCP uses less packaging material than the current methods to ship temperature controlled products because of its thermal efficiency. Less weight, less size, less disposable packaging material, less fuel to ship the finished product.

Reuse – the TCP is designed to be rugged enough for reuse in the distribution system and the formulations of the phase change materials can be recycled indefinitely

Recycle – the phase change materials can be disposed in the public waste stream and the TCP container can be recycled in the polyethylene recycling stream.

For more information on these and other products from TCP Reliable, contact us at 888-827-3393 or sales@tcpreliable.com