The Use of Ozone to Kill Fungi in Wood

Systems for the controlled generation, circulation and destruction of residual ozone have been commercialized and these systems could be used to eliminate pests from solid wood packaging materials such as pallets. A preliminary test with small cubes showed that ozone fumigation could kill decay fungi in wood. Subsequent trials with larger wood samples were less ineffective, suggesting that the inability of ozone to penetrate deeply into wood will limit its potential for pest mitigation.     

Precisely positioning pallets in multi-station assembly systems

In multi-station assembly systems, common for mass-customization manufacturing strategies, the product being assembled is held in a fixture attached to a pallet, and the pallet is conveyed between workstations. In high-precision assembly systems, variation in the position of the pallet is one of the largest sources of variation within the error budget, reducing quality and yields. Conventional approaches to locating pallets use pins and bushings, and a method for predicting their repeatability is presented. This paper also presents an exact constraint approach using a split-groove kinematic coupling, which reduces variation in pallet location by an order of magnitude.     

An investigation of pallet design using alternative materials for cold room applications

This paper presents an investigation into the improvement of existing design and materials for pallets used in material handling applications. The objective was to develop a pallet design made from alternative materials such as composites of recycled corrugated paperboard and plywood for cold room lifting needs. Several new designs are proposed and analysed using the finite element method (FEM) and related information of weight, loading and safety conditions. Among these, five designs are recommended – one is made of plywood, two are made of corrugated paperboard, and two are made of specially constructed composite materials. The selection process aimed to ensure pallets were safe and stable and involved checking for maximum deflection while lifting and for catastrophe failure due to maximum stresses under Rankine’s theory of failure. We conclude that plywood, corrugated paperboard and a composite of the two materials can be utilised successfully to manufacture stable and strong pallets. Using FEM analysis and simulation studies on Pro/Mechanica FEM software, we were able to suggest several optimum designs with one-third the weight and all of the functionality of traditional pallets.     

小型弹药托盘集装方案

依据我军部队小型弹药供应保障实际及其包装箱情况，分析了影响小型弹药托盘集装的主要因素，提出了小型弹药托盘集装方案，明确了对小型弹药0.5t集装托盘的基本要求。     

Study of lateral shocks observed during fork truck and pallet jack operations for the handling of palletized loads

This study measured the lateral impact levels that occur when fork trucks are used to handle palletized loads. The existing ASTM-D4003 standard on pallet marshalling recommends a 40 G, 10 ms shock or a 10G. 50ms shock to simulate impacts on pallet loads due to fork truck equipment. This study investigated the validity of these levels since no previous studies documenting these levels is provided in the ASTM standards.⁵ A set of ten impacts were conducted in the two different scenarios using boxes, bins and drums. These scenarios represent a palletized load on a fork truck impacting a similar stationary pallet load and an empty fork truck impacting a pallet load. Results are presented for each category of impacts performed in terms of average and maximum levels measured. The average peak acceleration for the data collected was 36 G and the average duration of impact was 4.3 ms. An analysis describing the limiting conditions for the shock acceleration G and the duration T as a function of the fork truck weight, impact speed, pallet weight and impact condition was determined. This showed that the impacts should have the product of maximum shock (in G) and duration (T) mms lying between 37.2 and 368 for half-sine shocks.     

On the role of a queueing network model in the design of a complex assembly system

This paper describes the modeling, analysis and re-design of a complex assembly system consisting of many processes (assembly, testing and inspection) and resources (machines and operators) and an advanced material handling system with intricate routing logics. It presents a systematic approach using both analytical and simulation models for the evaluation and modification of the complex assembly system. It demonstrates the application of a queueing network model to quickly generate rough-cut solutions and provide qualitative information for the evaluation of design alternatives. Iteratively, processes and resources that affect the system performance are identified, one at a time, and the system modified accordingly, until a satisfactory performance is obtained. The preliminary analyses using the queueing network model help to identify bottleneck processes, estimate optimal pallets, and determine a more efficient system layout. The use of the analytical model significantly reduces the number of the lengthy simulation runs. A detailed simulation model is subsequently employed for fine-tuning and further improvement. Compared with the original design, significant improvements have been made: a higher throughput, a reduced cycle time with less operators, and lower WIP inventories.     

Evaluation of a palletising aid

As an aid to manual stacking of boxes on to a shipping pallet, a rotating and levelling palletising aid was proposed. To evaluate the injury-reduction potential of this device, two simulations were run using manual handling personnel. Low-back stress, evaluated with a biomechanical model, decreased to safe levels and heart rate decreased to a level appropriate to sustained work when using the palletising aid. An economic justification was made in terms of reduced injury costs and reduced manning levels.     

Numerical modelling of the temperature increase in frozen food packaged in pallets in the distribution chainModélisation numérique de l'augmentation de température des produits alimentaires congelés palettisés dans la chaîne de distribution

Frozen food can undergo temperature rise essentially during handling processes which are the weakest links of the cold chain: delivery, loading or unloading operations and temporary storage where pallets are generally handled in an ambience above 0°C. In this study, the temperature rise in a pallet is investigated numerically and experimentally. A three-dimensional finite-volume heat transfer model is developed using Phoenics Computational Fluid Dynamics (CFD) software. Food temperature within the pallet is predicted as a function of time of exposure, ambient conditions, product initial temperature, palletization and thermal characteristics of products and packaging. The experiments are carried out with packaged frozen fish pallets placed on a closed or open dock. The temperatures are recorded, at different levels in pallets over 25- to 85-min periods. The model shows good agreement with experimental results.