A New Methodology to Evaluate the Cure of Resin-Impregnated Paper for HPL

This paper presents a study on the curing conditions of several resin-impregnated papers and its impact on the performance of HPL (high-pressure decorative laminate). A new methodology for evaluating the bond strength development between the different layers of a HPL(overlay, decorative, and kraft papers) was developed using ABES (Automated Bonding Evaluation System) equipment. The proposed method can be applied to the study of the curing step of the different impregnated paper and the development of bonds between them (overlay paper on decorative paper, decorative paper on kraft paper, and kraft paper on kraft paper) trying to simulate the hot-pressing of an industrial HPL. This will permit to establish a more adapted temperature gradient in hot-press in order to achieve the same curing rate for all layers and provide a good final overall product quality.     

Peptoid Efficacy against Polymicrobial Biofilms Determined by Using Propidium Monoazide‐Modified Quantitative PCR

Biofilms containing Candida albicans are responsible for a wide variety of clinical infections. The protective effects of the biofilm matrix, the low metabolic activity of microorganisms within a biofilm and their high mutation rate, significantly enhance the resistance of biofilms to conventional antimicrobial treatments. Peptoids are peptide‐mimics that share many features of host defence antimicrobial peptides but have increased resistance to proteases and therefore have better stability in vivo. The activity of a library of peptoids was tested against monospecies and polymicrobial bacterial/fungal biofilms. Selected peptoids showed significant bactericidal and fungicidal activity against the polymicrobial biofilms. This coupled with low cytotoxicity suggests that peptoids could offer a new option for the treatment of clinically relevant polymicrobial infections.     

Cover Image,Volume 66, Issue 2

The cover image, a 3D stationary salami structure of a green/red/black ternary polymer blend and the separated red and green continuous structure, is by QUI TRAN‐CONG‐MIYATA, based on the Editorial In Focus section: Polymer Research at KIT, Japan, DOI: 10.1002/pi.5248 .

     

MODELING VACUUM-CONTACT DRYING OF WOOD: THE WATER POTENTIAL APPROACH

ABSTRACT

A two-dimensional mathematical model for vacuum-contact drying of wood is presented. The moisture and heat equations are based on the water potential concept whereas the pressure equation is formulated considering unsteady state conservation equation of dry air. Most of the model parameters were determined during independent experiments. The set of equations is then solved in a coupled form using the finite element method. The validation of the model is performed using experimental results obtained during vacuum-contact drying of sugar maple sapwood. The experimental and calculated data are in good agreement. Nevertheless, some discrepancies are observed which can be attributed to the boundary conditions used and to the fact that heat transfer by convection was neglected.     

HIGHLIGHTS OF IDS'92

ABSTRACT

High energy consumption and increasing consumers interest in new products are two problems worthy of note in the drying of food. Difficulties in producing high-quality food and degrading transformations of the material during drying are mentioned. The kinetics of quality degradation due to drying is described. The role of water activity in maintaining product quality is emphasized. Examples of drying methods and tendencies toward a reduction in quality degradation of dried food products are shown.     

EFFECT OF FREE STREAM TURBULENCE ON HEAT AND MASS TRANSFER FROM A SPHERE

A model has been proposed for the momentum eddy diffusivity induced by free stream turbulence intensity. The eddy diffusivity model is applied to a sphere situated in a uniform crossflow in the presence of free stream turbulence. Numerical solution of the governing momentum and energy equations with the proposed eddy diffusivity model yielded results for the heat/mass transfer rates. The numerical predictions of the present work are compared with experimental data and the agreement between the two is seen to be very good.     

ANALYSIS OF BATCH DRYING DATA USING SAS

An analysis technique is described which uses the nonlinear curve fitting capabilities of the Statistical Analysis System (SAS) to analyze batch drying data. The technique does not require any apriori assumptions about whether a constant rate period exists. Rather, the only assumptions necessary are the possible forms of the equations which can be used to describe the drying phenomenon. The program will then determine, based upon statistical techniques, where each equation should be used during the drying process in order to best describe the overall drying process. Two examples are given; the first analyzes the drying of. sand, a material having a constant rate period; the second analyzes the data describing the drying of French fried potato pieces.