以落下試驗評估積層瓦楞紙板的衝擊吸收特性

To Evaluate the Shock Absorbing Characteristic of Corrugated Fiberboard by Drop Test

陳菁華(Chin-hua Chen)

指導教授 ： 江行全

元智大學/工程學院/工業工程與管理學系/碩士(2004年)

摘要

掌握緩衝材料之緩衝特性，才能達成適度包裝的目標。緩衝材料之衝擊吸收(shock absorbing)特性，可用動態緩衝曲線(dynamic cushion curve)來表示，由於該曲線僅能描述特定緩衝材料、厚度、落下高度等條件組合時，於不同靜應力(static loading)下之衝擊強度，若組合條件不同時，就必須重新試驗以建立該組合之曲線，因此該曲線雖可用來決定緩衝材料之厚度與面積，但由於設計條件變化不一，因此應用範圍有限。此外，現有建立動態緩衝曲線之試驗方法、設備與結果之應用仍有若干爭議。
瓦楞紙板(corrugated fiberboard)為一傳統之包裝材料，由於具有回收再利用之環保特性，在緩衝包裝的應用日益廣泛，但目前仍無評估其緩衝特性之適當方法，現有之相關研究多依ASTM D 1596建立特定條件組合之動態緩衝曲線，由於各廠商生產所用之原料、設備不一，無法直接引用。為減少動態緩衝曲線應用於包裝設計上之限制，擬以實驗設計方法，建立積層瓦楞紙板第一次落下之衝擊強度迴歸估算式，應用於設計實務時可以試算不同設計下之緩衝效果，或由要求之緩衝效果求出適當的設計條件，不需因條件的變更而必須另行試驗建立曲線，或因無適當曲線可使用，而以嘗試錯誤法進行設計。
本研究以常見之落下試驗機作為試驗設備，首先執行一兩水準篩選實驗，找出影響積層瓦楞紙板衝擊吸收特性之主要因子為楞型高度與厚度。再針對A楞瓦楞紙板為試樣，以厚度、落下高度與靜應力等三個因子規劃一迴歸資料收集實驗，並以In-Package法執行落下試驗(drop test)，所得之實驗數據用以配適迴歸估算式。最後將所建立之估算式應用於PC主機之緩衝包裝設計，以驗證估算式之可用性。實驗結果顯示，六種不同設計，衝擊強度實測值均在估算值95%信賴區間內，顯示應用所配適之估算式，可有效預估緩衝設計之效果，不僅可縮短設計時程，也可以降低包裝成本而達成適度包裝的目標。

關鍵字

瓦楞紙板 ； 動態緩衝曲線 ； 靜應力 ； 落下試驗

並列摘要

Knowing the characteristics of cushion materials well is the key to proper packaging. We can use “Dynamic cushion curve” to represent the shock absorbing capability of cushion materials. This curve reflects impact absorbing under different static loading in the combination of specific cushion materials, thickness, and drop height. If the combination is altered, the curve has to be reexamined. As a result, the dynamic cushion curve determines the thickness and area of the cushion materials; while its practical application is limited due to the various design conditions. Moreover, the existing testing methods, equipments and results of dynamic cushion curve are still controversial.
Corrugated fiberboard is a traditional packaging material, and gets even more popular since it’s recyclable. Except for few relative researches based on ASTMD 1596 to constitute dynamic cushion curves, there are no testing methods to evaluate its impact absorbing ability so far. However, they can’t be applying because every company uses various materials and equipments. In order to decrease the limitation of dynamic cushion curve applying on packaging design, the essay attempts generate the regression equation for predicting the first drop shock absorbing performance of the corrugated fiberboard through experimental design. Hence, we can estimate the cushion effects under different design conditions. Or we can find out proper design conditions under certain cushion effects. This prevents us from seeking new testing dynamic cushion curve due to different conditions and attempting designing through try-and-error.
Drop test is the experimental equipment of this research. Firstly, we carry out a 2 levels screening experiments finding out that it’s the drop height and thickness of the corrugated fiberboard that influence the shock absorbing capability. Secondly, we take corrugated fiberboard A as sample for experiment. We execute multi-levels drop test with In-Package method based on the factors of thickness, drop height and static loading to gather data and get the regression equation. At last, we apply regression equation to the cushion packaging design of PC mainframe. This experiment reveals that the impact intensity readings of all the six designs fall on 95% confidence interval of estimation. This stands for that the regression equation can not only shorten the time on designing, but also reduce the costs. It successfully predicts the design effects and achieves proper packaging.

並列關鍵字

Corrugated fiberboard ； Dynamic Cushion Curve ； Static Loading ； Drop Test

參考文獻

ASTM D 1596(1997), “Standard Test Method for Dynamic Shock Cushioning Characteristics of Packaging Material”, American Society for Testing and Materials, Philadelphia, Pennsylvania.

ASTM D 4169(1989), “Standard Practice for Performance Testing of Shipping Containers and Systems”, American Society for Testing and Materials, Philadelphia, Pennsylvania.

Kipp, William I. (2001), “Shock, Drop, and Impact Testing Equivalence”, http://www.kippllc.com/Shock%20Test%20Equiv.pdf. (Oct. 21, 2002)

MIL-HDBK-304C (1997), Package cushioning design, U.S. Dept. of Defense, Washington.

ASTM D 3332(1999), “Standard Test Methods for Mechanical-Shock Fragility of Products, Using Shock Machines”, American Society for Testing and Materials, Philadelphia, Pennsylvania.