Sher Paul Singh

Performance Evaluation of PLA against Existing PET and PS Containers

Poly(lactide) (PLA) polymers are environmentally-friendly biodegradable materials that have garnered growing attention in the past few years as food packaging materials since packages made from PLA have the advantage of being produced from renewable resources, provides significant energy savings, and can be recyclable and compostable. PLAs optical, physical, and mechanical properties have been compared to those of polystyrene (PS) and polyethylene terephthalate (PET) although studies comparing and showing the actual performance of PLA, PS, and PET packages are scarce. The purpose of this study was to investigate and to compare the role of PLA for the food service industry. Two of the commonly used materials to make containers to package fresh food, PET and oriented polystyrene (OPS), were compared with oriented PLA (OPLA). This study involved a number of tests to quantify the physical, mechanical, barrier, and compatibility properties that would affect the selection criteria for containers to be used for food service applications. Based on the results, OPLA, OPS, and PET performances were evaluated. Exposures of the three materials to weak and strong acids for seven days show a minimal reduction in the performance of these polymers. At ambient temperature, PET has the highest impact resistance followed by OPLA and OPS. PET shows the highest oxygen barrier followed by OPLA and OPS. Thus, several of the relevant properties for packaging applications of OPLA are between PET and OPS properties, suggesting that OPLA would also be suitable for some of these applications.

Measurement and Analysis of the United Parcel Service Ground Shipping Environment for Large and Heavy Packages

This study investigated the United Parcel Shipping environment for shipping large and heavy packages weighing up to 150 lb. The data were collected using instrumented packages that contained triaxial recorders to measure acceleration levels produced by drops and impacts during shipping and handling. The study showed that the existing test methods used to design and evaluate such packages for this type of shipping environment in accordance with ASTM (American Society for Testing and Materials) and ISTA (International Safe Transit Association) test methods do not replicate the levels of damage found in real shipments. The study recommends tests that would produce more realistic damage levels for this environment.

Product/Package Interaction: Effect of Physical, Chemical, and Climatic Environments

Product/package interactions were evaluated for three product/package systems: a bleach alternative laundry additive, an anti-bacterial surface cleaner, and a glass surface cleaner. The package system was comprised of high-density polyethylene bottles with induction-sealed closures. The physical environment was studied by comparing product/package systems that were exposed to simulated distribution testing with those that were not. The storage environments were ambient conditions at 73°F (23°C), and higher temperatures at 100, 120, and 140°F (38, 49, and 60°C). Damage caused by distribution testing occurred in the bottle or in the closure component of the package. Bottle defects resulting from distribution testing were dents, abrasions, and creases. Closure defects included sheared-off closures, cracks in the closure body, or nozzle cover damage. Product/package systems exposed to the four storage environments were inspected for failure, defined as product leaking from the package, during the six-month study. Failures were due to environmental stress cracking. Dents in the shoulder and bottom region of the bottle were the only simulated distribution defects that impacted the storage stability of the product/package systems, which often resulted in reduced shelf life. The primary location of all other failures was near the center of the bottle bottom edge, which was the thinnest region of the bottle. Bleach alternative laundry additive was the most aggressive product, while the two surface cleaners exhibited similar storage stability. Performance criteria of the failed bottles were evaluated to study the impact of package system properties on product/package integrity. Yield strength, modulus of elasticity, and dynamic mechanical properties of failed sample-acquired bottle side panels did not change significantly from those of the control samples. Color changes were monitored by measuring interior and exterior surface yellowness indices of bottle side panels. Although observed spectrophotometrically, these changes were not detected visually.

Physicochemical properties of whole fruit and sensory quality of fresh-cut apples pre-treated with 1-Methylcyclopropene (1-MCP)

Apple fruit quality is an important factor in minimally processed or fresh-cut slices. Ethylene action inhibitor, 1-methylcyclopropene (1-MCP) is used commercially to extend the shelf life of selected fruits, including apples. The present study was designed to assess the selected physiochemical properties of whole fruit and sensory attributes of fresh-cut slices from three 1-MCP treated apple cultivars (Jonagold, Empire, and Mutsu) that were stored for 3 months in air or 6, 9, and 12 months in controlled atmosphere. Apples and fresh-cut slices were evaluated for selected quality characteristics at 3-month intervals. Generally, the 1-MCP treatment resulted in firmer fruit and lower pH, whereas it had no or minimal effect on fruit skin color and total soluble solids. Titratable acidity values decreased in both control and 1-MCP treated apples, the only exception being 12-month controlled atmosphere stored apples that showed an increase. At each 3-month interval, fresh-cut slices (after 10-day storage at 4°C) were evaluated by a 9-member trained panel for “difference from control” on a 0–8 scoring scale; the results of these evaluations showed relatively small “difference from control” scores for the degree of browning, texture, and flavor. At the 9-month storage, a 114-member consumer panel evaluated the appearance, texture, flavor, and overall acceptability of fresh-cut slices on a 1–9 hedonic scale. Except for Jonagold slice flavor, slices from 1-MCP treated fruit exhibited similar or higher sensory scores. The overall acceptability scores were 6.78, 7.12, and 7.18 for slices from Jonagold, Empire, and Mutsu apples, respectively.

High-altitude testing and evaluation of liquid pharmaceutical glass and plastic bottles to detect leaks

This paper discusses the impact on package integrity of high-altitude shipments of glass and plastic bottles. High altitudes are encountered when trucks travel over mountain passes and when cargo and feeder aircraft transport packages in nonpressurized or partially pressurized cargo holds. This is the second research study conducted on liquid product shipments. The first was done on liquid hazardous material combination packaging. The testing of pharmaceutical packaging is critical since the integrity of the product may be compromised during shipping and handling. Current shipping tests performed in labs do not account for simultaneous pressure changes and vibration. This study shows that packages currently being used for shipments of liquid pharmaceuticals that are tested to existing ASTM and ISO shipping tests are often inadequate, and can result in a significant number of leakers. Testing under combined vibration and pressure is necessary to ensure integrity.

Measurement and Analysis of Small and Light Weight Parcel Shipping Environment

This study measured and analyzed the parcel shipping environment within Federal Express. The package sizes and weights monitored in this study represent the “light weight” and “small size” packages within the FedEx handling system. Five packages ranging in size from 0.18 x 0.19 x 1.3 m to 0.36 x 0.37 x 0.31 m and weight between 1.9 and 2.5 kg were shipped both with and without warning labels containing the text “Fragile—Handle With Care.” The shipments were done between Michigan and California or Florida using the second day air shipment mode. The data showed that neither the package size/weight or the labels had any significant effect on the severity of drop heights. The highest drop height measured was 1.85 m. The data are presented in terms of drop heights associated with the 90th, 95th, and 99th percentiles of occurrence. Impact orientation is also discussed.

A new test method and pictorial markings for packages containing liquid dangerous goods in high altitude shipments

Serious accidents have occurred over the past decade as a result of package failures during high altitude shipments on aircraft. Dangerous goods require sturdier packages since their contents can result in life-threatening incidents if exposed to the environment. High altitude shipments are encountered when trucks travel over mountain passes or when cargo and feeder aircraft transport packages in non-pressurized or partially-pressurized cargo holds. Both types of transport methods result in severe drops in pressure compared to packages transported close to sea level. The testing of packages under these conditions is critical since package integrity must be improved. Current shipping tests performed in test labs do not account for pressure changes and vibration together. This paper proposes a new test method to simulate package conditions in high altitude shipments by subjecting the package to simultaneous vibration and low pressure. It also recommends pictorial markings be used on packages to show whether or not they meet the air and ground shipping requirements.

The effect of handling on the compression strength of corrugated fiberboard containers

The ability of a corrugated fiberboard box to protect its contents is related to its compression strength. The corrugated container industry has been manufacturing corrugated fiberboard according to bursting strength and basis weight specifications. These specifications do not accurately reflect the ability of a box to meet performance requirements in the distribution environment. This study investigates the effect of package weight and the handling environment on the reduction in compression strength of corrugated containers. The mean compression strength and corresponding deflection values for three box sizes were evaluated as a function of package weight and drop height after handling. The compression strength decreased as the package weights increased and as the drop heights increased. The mean edge crush, flat crush, and bursting strength values were unchanged as the test conditions became more severe.

Measurement and Simulation of Damage to Long Light-Weight Packages in the FedEx 3-Day Saver Parcel Delivery Service

Packaged goods are shipped daily using the single parcel distribution systems offered by carriers such as FedEx, UPS, and USPS. Through these shipments, packages are exposed to dynamic forces that result in punctures, creases, scuffs, tape failures, and corner and edge crushes. This study measured the frequency and severity of these and other types of damage that occur to long light-weight packages in the FedEx single parcel environment (3-Day Saver). The results of this study showed that the most frequent type of damage in one-way shipments were creases, which represented 61.5 % of the damage events observed. Corner crushes followed with 16.7 %, edge crushes with 6.8 %, punctures with 6.7 %, and tape failures with 1.7 % of the total damages observed. Based on 58 packages shipped, the average box experienced 8.4 creases, 2.3 corner crushes, 0.9 punctures, 0.9 edge crushes, 0.8 others, 0.2 tape failures, and 0.1 scuffs per shipment. Based on these results, a test protocol was developed to reproduce this damage. The test includes vibration testing, compression testing with an edge hazard, at drop onto a point hazard, tip-over test onto an edge hazard, and corner and edge drop tests. The proposed tests correlated well with actual damage.

Effect of Internal Gas Pressure on the Compression Strength of Beverage Cans and Plastic Bottles

This study investigated the compression strength of various sized polyethylene terephthalate (PET) bottles and steel and aluminum two-piece cans. Compression tests were performed on both empty and filled containers under pressure. A stress analysis is developed to provide a simple prediction formula. The predictions are shown to be in fair agreement with actual values obtained from the compression tests. The results show that internal pressure can increase the compression strength of a beverage package by as much as three times. Erratum to this paper appears in 21(4).