Waste Pharmaceutical Blister Packages as a Source of Secondary Aluminum

Waste pharmaceutical blister packages (WPBs) are a source of solid waste, which are composed of plastics and aluminum, therefore acting as a potential source for secondary aluminum. The structure of WPBs makes the recycling of aluminum notably more complex than typical aluminum recycling. Currently, WBPs are disposed of as municipal solid waste; thus, aluminum is lost from the circulation during incineration. In this work, three types of WPBs were studied, each with two plastic layers and a metallic layer. Delamination of WPBs to separate aluminum and plastic(s) was investigated by using a solution of organic solvents. The effects of temperature (30–50°C), acetone to isopropanol ratio (0–100 vol.%) and different types of WPBs on delamination behavior were investigated. The results suggest that aluminum separation and recovery from WPBs is 100% at optimum conditions. Moreover, an overall indicative flowsheet for recycling and post-processing of segregated aluminum from the plastic is also suggested.

Difference in polypropylene fragmentation mechanism between marine and terrestrial regions

Two kinds of marine polypropylene (M1-PP and M2-PP) and one land PP (L-PP) samples were collected from two beaches and land in Japan, respectively, to study the fragmentation mechanisms. Delamination was observed on both M1-PP and M2-PP surfaces. Moreover, there was no delamination but an abrasion patch structure on the surface of L-PP. The delamination was studied using an advanced oxidation process-degraded PP as the marine PP model. The number and shape of cracks varied with an increase in degradation time. The fluctuations in the values and ratios of the carbonyl index as well as the weight change ratio were due to repeated oxidation and delamination. We found that the delamination behavior depends on the oxidation state. Poly(oxyethylene)8 octylphenyl ether (POE8) surfactant treatment caused the delamination to speed up, which is a typical characteristic of polyolefin environmental stress cracking (ESC). These results reveal that delamination is based on ESC.Article Highlights Two kinds of marine and one land polypropylene (PP) samples were collected from two beaches and land, respectively, to study the fragmentation mechanisms. Delamination was observed on both of marine PP surfaces. Moreover, there was no delamination but an abrasion patch structure on the land PP surface. We found that the delamination was based on environmental stress cracking mechanism by employing a marine PP model.

Theoretical and numerical investigation of the mode I delamination of composite laminate with uneven thickness

In this paper, a theoretical analysis model and two simulation methods are applied to characterize the quasi-static and fatigue delamination of composite laminate with uneven thicknesses. The test data of partially reinforced double-cantilever beam (DCB) were used as benchmark to verify the analysis model and simulation, and cohesive zone models (CZMs) and virtual crack closure technique (VCCT) are used in simulation. It’s shown that the partially reinforced DCB has a unique double-peak load-displacement relationship, and produces instability development during the delamination. By comparing the results of simulation and experiment, it is found that the simulation based on the exponential CZM can simulate the delamination process of partially reinforced DCB under both quasi-static and fatigue loading; while VCCT method will generate a straight delamination front edge in the area of reinforcement, and lost the micro-damage of the previous loading step between load steps, and result in an incorrect delamination behavior.