Selecting and Designing a Custom Interior for a Shipping Case

There are many factors that guide a decision to use reusable packaging  such as a shipping case with a custom interior.  Pick and pluck foam either degrades over time or does not provide adequate protection for your equipment during shipment.   The commercial or military item that needs to be protected will be fielded in all types of conditions and environments.  The contents must survive repeated shock and vibration inputs and operate right out of the case when failure is not an option.  A large item that may not be fragile can have unique material handling requirements and long term storage needs.   If the item has extreme high value, is irreplaceable or extremely fragile.   These are all reasons to work with a packaging specialist to design a case and custom interior.

custom closed cell Polyethylene foam

How does a packaging specialist develop and design the appropriate tailored case interior for a specific application?

The first step will be to determine the mission profile; how the case is going to be used.  A number of questions will be asked by the specialist about how the case will be transported; car, air, truck or rolled in an airport. What is the likelihood that the case will be dropped? Will the contents need to be removed with your hands, straps, forklifts or an overhead hoist?  Additional questions about electrostatic sensitivity, presence of liquids, and concerns about FOD (foreign object debris) or inventory control needs will be asked. This gives the specialist a starting point on how to select and design the appropriate interior to protect the contents.

The second step is to gather physical information on every item that is going to be packaged in the case.  The information that is needed includes all dimensions, weight, center of gravity, desired orientation, handling points and equipment fragility.  A packaging specialist will utilize digital tools for accurate information capture.  Tools include electronic measurement equipment, scanners, digital photographs, product manuals, design check lists, and outputs from CAD software programs. 

Once all of this information is gathered, the specialist will propose one or more possible solutions.  Most requirements can be met using a custom foam interior for the selected shipping case.   The goal is to provide the maximum unit protection in the minimum package size.  A preliminary layout is created in CAD software.  Analysis is then done to determine the bearing surface areas of the key components vs. the expected or worst case drop height of the unit.  Using commercial or military guidelines the appropriate type and density of foam or foams is selected.  The foam may range from very soft 1.7# open cell polyether foam to very hard, nearly indestructible 6#/cubic foot closed cell Polyethylene foam.  

Custom Anti-static foamThe layout is then fine tuned so that the proper foam wall thickness exists to protect the key items.   Only one foam type or density may be needed or a combination of foam may be required. If inventory management is an issue a secondary high contrasting foam color on the bottom of the cavities can be utilized in the design to highlight missing items.   If a weight-bearing surface is very small or a sharp point-like an antenna or a tripod a hard plastic load spreader will be designed into the cushion to prevent damage to the item and surrounding items.  This can also be used if there is a heavy item in close proximity to a lighter or more fragile item.  The final design consideration is storage and access to lighter, less critical items or items that need to be removed frequently.  A tray can be designed to nest inside the case above the primary foam cushion.   The tray can be manufactured solely from foam, or from foam and a hard plastic sidewalls and bases.  

Once the case design is analyzed and the CAD drawing is created, the design is reviewed again to confirm the key design requirements, dimensional information, and the case content list.  The design is provided to the customer for input, review and comment.   When the design is approved, the case and interior cushion can be manufactured.

If the solution for shipment and storage of the item can not be solved with a foam interior due to an item’s very large size and handling needs, a fixed or shock-protected deck or cradle system can be designed.   All of the same physical details of the item are gathered.   The specialist needs to determine the product support interfaces and access points, along with any “keep away” surfaces.   Are there needs for storage in harsh environments, salt water, chemicals, dust, oil, or fluctuating temperatures? Are there needs for long term storage?   Items that require these features often require cases that have a cast or machined metal cradle or deck system.   The product specialist will design a cradle system that secures the item in the case, but provides access and ease of removal.  The interior may be just a platform with an interface for mechanical mounting of item, or a system using clamps, latches or straps to secure the unit.

 Custom case with latches and straps

The cradle system can be aluminum or stainless steel.  The interior design might also include insulation or heaters for long term storage.   If the item is of high value like a space telescope component, or can’t use foam because of chemical outgassing, or is very fragile like a fighter plane’s gyroscope,  a case with a floating deck would be appropriate.   A deck case is a suspended platform inside the case that is supported by either elastomeric mounts or wire rope mounts.  These mounts are sized and selected to provide the appropriate amount of shock and vibration dampening in all axis based on the weight and fragility of the payload.

When you work with a packaging specialist you will receive the benefit of his experience, technical knowledge, and design expertise.  The specialist will provide the most cost effective and technically sound shipping case interior protective solution regardless of the type of case or container that you select.

custom case with shock mounts