【正文】 s 115 g39。s) on the vertical axis of the figure, and draw an imaginary horizontal line across the chart at this level. This separates the chart into two sections: ? our fragility line and lower, where the packaged item will be able to survive the anticipated shock level, and ? the section above our line where the shock levels are high enough to damage the product Step 3 Calculate Cushion Requirements ? choose a thickness of 2 inches for the thinnest cushion thickness. 5. Determining Static Loading and Bearing Area ? The useable part of the curve is bounded by a static loading of psi at the low end, and psi at the high end. This tells us that, with a 2inch cushion, we can apply a static loading anywhere within this cushioning range and still protect to 50 g39。 Lesson 15 Seven Steps for Cushioned Package Development 第 15課 緩沖包裝設計七步法 Introduction ? Packaging can be unnecessarily expensive in a couple of ways: 1. Inadequate design results in shipment damage 2. Overdesign or poor design (more protection than is required or materials being incorrectly used ) results in excessive material cost. ? The procedure can be broken down into seven basic steps. Introduction 1． Determine Product Fragility Determine the amount of mechanical shock the product can survive on its own by evaluating “fragility” or “gfactor ”. 2. Determine Conditions Consider the handling and transportation environment the product will face and establish the amount of shock the product may encounter (“drop height”). 3. Calculate Cushion Requirements Use dynamic cushioning curves to determine thickness, static loading and bearing area. Introduction 4. Recognizing Design Constraints Check for important problems including pressive creep, cushion buckling and extreme temperature effects. 5. Design Prototypes and Test Build a prototype and determine its actual performance. 6. Consider Vibration Effects Determine the natural frequency of any ponent which is prone to vibration damage, and pare it against the vibration characteristics of your package design. Introduction 7. Monitor Performance Monitor the performance of your design to determine when internal changes in the design might alter the requirements for package performance. ( Another way for cushion design: Five steps for package cushion design ) 動畫 Step 1 Determine Product Fragility ? Fragility is normally expressed in units of “g’s” and indicates the maximum deceleration the product can withstand without being damaged. The more fragile a product is, the lower its gfactor（ Table ） . Step 1 Determine Product Fragility Table Approximate fragility of typical packaged Articles Extremely Fragile Aircraft altimeters, gyroscope