• Determine the fragility of your product.
• Determine impact conditions the package will be subjected to.
• Calculate cushioning requirements.
• Design and test prototypes.
• Monitor package performance.

Impacts or mechanical shock is usually measured in “g’s”. The higher the “g” force your package can withstand, the more durable the product is, which is referred to as fragility. One “g” is the force of gravity or the weight of your body on the earth. Fifty “g’s” would be the weight your body exerts on the earth at the split second of impact. A 200lb person would momentary exert 10 000 lbs. The ideal way to determine your products fragility is to test it to destruction while measuring the “g’s” exerted. The fragility would be the impact before damage was sustained. It is important to ascertain the product fragility, as a rating too low will result in higher packaging costs, while a rating too high will result in damaged product.

Product Fragility

• Very delicate equipment i.e. Lasers 15-25 G's
• High end electronics 25-40 G's
• Computers, Disk drives 40-60 G's
• Televisions 60-85 G's
• Appliances 85-115 G's
• Machine tools + 115 G's

The Next Step

Determine the environment the product will be subjected to during shipment.
A parcel, which is sent by air as a single package, will encounter different impacts than one sent on a unitized skid by road.The air shipment is far more susceptible to damage and the greater the impact it will endure (drop height). If you use this method of shipping, more protection is required.

The following table is a rough guide as to the drop height the product will endure:

• 0 to 10 lbs------------- 42" --------- 1 person carrying
• 11 to 20 lbs ----------- 36 " ---------1 person carrying
• 21 to 50 lbs ----------- 30 " ---------1 person carrying
• 51 to 100 lbs---------- 24 " --------- 2 person carrying
• 101 to 150 lb --------- 18 " --------- Pallet Jack
• Over 150 lbs---------- 12 " --------- Forklift

Choosing the Foam

Individual foam has different cushioning properties. Dynamic cushioning curves are generated and graphs are produced relating deceleration (g’s) to static load (lbs./sq. inch), with different materials and thickness. Using these graphs, you can determine how many lbs./sq. inch (Psi) needs to be exerted on the foam to provided protection to a specified g force. This will determine the amount of foam required. Please contact us for cushion curve detail.

Other Factors

• Temperature: extreme cold makes the foam stiff while heat makes it softer.
• If static load (weight the product exerts on the foam) is too high the foam will loose thickness (compressive creep). It is important not to overload the foam; the weight must be spread to conform to the cushion curve selection.
• Tall or thin sections of foam will tend to bend and not allow equal loading (buckling). This reduces performance.
• Vibration: If your product is susceptible to vibration damage, it should be tested at different frequencies to ensure protection.

Summary

Once the material and design is chosen, a sample should be made and testing should be done to verify that the packaging actually works as designed.
Once the packaging is implemented, results in the field should be monitored. Damage rate should be observed and if high damage still occurs, the packaging should be revaluated immediately.

We hope this is of some help in understanding the engineering of package design, our engineers are able to design and test packaging. We might combine different foams and include corrugated cushioning to provide you with the most effective and least cost packaging.