Relating bending stiffness measurements across various free span lengths

TAPPI Journal ◽  
2020 ◽  
Vol 19 (8) ◽  
pp. 419-424
Author(s):  
DOUGLAS CASH ◽  
BENJAMIN FRANK
Keyword(s):  
Intrinsic Property ◽  
Standard Test ◽  
Bending Stiffness ◽  
Test Method ◽  
Corrugated Board ◽  
Different Types ◽  
Practical Tool ◽  
Bending Behavior ◽  
The Relationship ◽  
Corrugated Fiberboard

Bending stiffness should be an intrinsic property of a material, so it is puzzling that the TAPPI Standard Test Method T 836 “Bending stiffness, four point method” specifies span lengths when testing different types of corrugated fiberboard. These specified spans often limit the samples that can be measured with this method. To better understand the relationship between bending stiffness and span length, we performed measurements on a range of materials at different spans. The results provide a practical tool enabling comparison of bending stiff-ness measurements made at various span lengths. Additionally, this note discusses several areas that could serve as the foundation for more fundamental work exploring the bending behavior of corrugated board.

An evaluation of ECT sample height for small flute board grades and Box Manufacturer’s Certification compliance

TAPPI Journal ◽  
2009 ◽  
Vol 8 (6) ◽  
pp. 24-28
Author(s):  
CORY JAY WILSON ◽  
BENJAMIN FRANK
Keyword(s):  
Compressive Strength ◽  
Compressive Load ◽  
Test Sample ◽  
Test Methods ◽  
Test Method ◽  
Initial Development ◽  
Sample Height ◽  
Relationship Of ◽  
The Relationship ◽  
Corrugated Fiberboard

TAPPI test T811 is the specified method to ascertain ECT relative to box manufacturer’s certification compliance of corrugated fiberboard under Rule 41/ Alternate Item 222. T811 test sample heights were derived from typical board constructions at the time of the test method’s initial development. New, smaller flute sizes have since been developed, and the use of lighter weight boards has become more common. The T811 test method includes sample specifications for typical A-flute, B-flute, and C-flute singlewall (and doublewall and triplewall) structures, but not for newer thinner E-flute or F-flute structures. This research explores the relationship of ECT sample height to measured compressive load, in an effort to determine valid E-flute and F-flute ECT sample heights for use with the T811 method. Through this process, it identifies challenges present in our use of current ECT test methods as a measure of intrinsic compressive strength for smaller flute structures. The data does not support the use of TAPPI T 811 for ECT measurement for E and F flute structures, and demonstrates inconsistencies with current height specifi-cations for some lightweight B flute.

scholarly journals Effect of repeated electrical breakdowns on mineral and natural ester insulating oils

2021 ◽  
Vol 10 (6) ◽  
pp. 2989-2996
Author(s):  
Sharin Ab Ghani ◽  
Mohd Shahril Ahmad Khiar ◽  
Imran Sutan Chairul ◽  
Muhammad Imran Zamir
Keyword(s):  
Breakdown Voltage ◽  
Electrical Discharge ◽  
Electrical Breakdown ◽  
Standard Test ◽  
Test Method ◽  
Power Transformers ◽  
Insulating Oil ◽  
Different Types ◽  
Increasing Demand ◽  
Natural Ester

Transformer insulating oils are exposed to repeated electrical discharge or breakdowns inside power transformers. Durability tests are conducted to analyze the ability of oil to resist decomposition due to such high electrical stresses. With the increasing demand for alternative insulating oils for oil-immersed transformers, it is worthy to compare the performance of different types of insulating oils (conventional mineral-based insulating oil and natural ester-based insulating oil) under repeated electrical breakdown. In this paper, the AC breakdown voltage of different mineral-based and natural ester-based insulating oils is reported. Durability tests were conducted based on the AC breakdown voltage behavior of insulating oils after 50 electrical breakdown shots. The AC breakdown voltage of each insulating oil sample was assessed according to the ASTM D1816 standard test method. Based on the results, it can be concluded that the dissimilarity in chemical composition of the insulating oils has a significant effect on the AC breakdown voltage behavior of these oils under repeated electrical breakdowns.

A New Evaluation Index of Coke High Temperature Properties - Starting Reaction Temperature

2011 ◽  
Vol 194-196 ◽  
pp. 61-66
Author(s):  
Xu Zhang ◽  
Jian Liang Zhang ◽  
Hao Guo
Keyword(s):  
High Temperature ◽  
Standard Test ◽  
Test Method ◽  
National Standard ◽  
Evaluation Index ◽  
Thermo Gravimetric ◽  
High Temperature Properties ◽  
Reaction Index ◽  
Solution Loss Reaction ◽  
The Relationship

The coke reaction index and solution loss reaction starting temperature were tested by the thermo gravimetric test. According to the relationship between the temperature and the index，a new test method, which evaluates coke high temperature properties by the coke solution loss reaction starting temperature, was put forward. The new method has many merits such as expediently operation and reliable results compared with the method and results of the national standard test.

scholarly journals Development of a Test Method to Evaluate Durability of Pavement Joints under Winter Conditions

2021 ◽  
Author(s):  
Conrad Babicz
Keyword(s):  
Visual Inspection ◽  
Strength Loss ◽  
Standard Test ◽  
Test Method ◽  
Concrete Slabs ◽  
Freezing And Thawing ◽  
Premature Failure ◽  
Different Types ◽  
Evaluation Techniques ◽  
Different Levels

In areas with cold winters, premature failure in concrete pavement joints is a frequent phenomenon, yet there is no standard test method for evaluating their durability. In this study, the effectiveness of several evaluation techniques for concrete joint durability were evaluated. Concrete slabs with saw cuts representing joints were made, and exposed to different freezing and thawing/ wetting cycles, and different salt solutions (NaCl, CaCl2, and MgCl2). The durability of the joints was evaluated using measures of strength loss, mass loss, and a visual inspection. It was found that under these exposure conditions, the strength loss and visual inspection modes of evaluation could discern different levels of damage between different types of exposures, and also different concrete mixes (e.g. Different cement contents, strength and the presence or absence of SCM). Further research is required to evaluate the effects of sealants, saturated bases, and higher salt concentrations.

Determination of Resistance to Abrasive Wear. XI. Influence of the Type of Abrasive

1949 ◽  
Vol 22 (1) ◽  
pp. 268-276 ◽  
Author(s):  
R. G. Newton ◽  
J. R. Scott ◽  
W. H. Willott
Keyword(s):  
Comparative Method ◽  
Standard Test ◽  
Test Method ◽  
Large Area ◽  
Method Of Calculation ◽  
Different Types ◽  
Short Run ◽  
Two Sides ◽  
Abrasive Paper

Abstract Tests with the du Pont machine show that the practice of expressing abrasion test results as an abrasive index, i.e., abrasion-resistance relative to a standard rubber, does not enable different types of abrasive to be used indiscriminately because these are found to give widely different abrasive indices for the same rubber; thus, some abrasives may give four times as high an index as others. If attention is confined to abrasive papers, as distinct from bonded abrasive wheels, this variation is reduced, but is still large enough to be a serious factor in accurate work. It is clear that, even when this comparative method of testing is used, standardization of the abrasive paper is essential to reduce discrepancies between results obtained in different laboratories. Discrepancies will still exist, however, because abrasive paper is not uniform, and there is evidence that abrasive indices determined on different portions of the same paper may differ as much as those from different types of paper. To minimize the effect of this nonuniformity, two courses are open. (1) All the rubbers to be compared could be abraded on one and the same area of paper, preferably a large area to avoid wearing the surface, e.g., by giving each rubber a short run on each of the several paper discs used, instead of using a different disc for each rubber. (2) Different specimens could be tested on the two sides of the machine provided this has a pivotted arm. It is shown that this technique has several advantages. The factors that cause the abrasive index to vary from one abrasive to another are not known; it appears, however, that the degree of abrasiveness is not a determining factor. The two methods of calculating abrasion loss—as cc. per hr. and cc. per H.P.-hr.,—usually do not give the same abrasive index; in any standard test method it is therefore essential to state which is to be used. The variation of the abrasive index from one abrasive to another is the same whichever method of calculation is used.

scholarly journals Development of a Test Method to Evaluate Durability of Pavement Joints under Winter Conditions

2021 ◽  
Author(s):  
Conrad Babicz
Keyword(s):  
Visual Inspection ◽  
Strength Loss ◽  
Standard Test ◽  
Test Method ◽  
Concrete Slabs ◽  
Freezing And Thawing ◽  
Premature Failure ◽  
Different Types ◽  
Evaluation Techniques ◽  
Different Levels

In areas with cold winters, premature failure in concrete pavement joints is a frequent phenomenon, yet there is no standard test method for evaluating their durability. In this study, the effectiveness of several evaluation techniques for concrete joint durability were evaluated. Concrete slabs with saw cuts representing joints were made, and exposed to different freezing and thawing/ wetting cycles, and different salt solutions (NaCl, CaCl2, and MgCl2). The durability of the joints was evaluated using measures of strength loss, mass loss, and a visual inspection. It was found that under these exposure conditions, the strength loss and visual inspection modes of evaluation could discern different levels of damage between different types of exposures, and also different concrete mixes (e.g. Different cement contents, strength and the presence or absence of SCM). Further research is required to evaluate the effects of sealants, saturated bases, and higher salt concentrations.

Tire Treadwear — A Comprehensive Evaluation of the Factors: Generic Type, Aspect Ratio, Tread Pattern, and Tread Composition Part I: Introduction and Details on the Organization of the Program

1986 ◽  
Vol 14 (4) ◽  
pp. 201-218 ◽  
Author(s):  
A. G. Veith
Keyword(s):  
Aspect Ratio ◽  
Comprehensive Evaluation ◽  
Test Method ◽  
Interactive Effects ◽  
Data Analyses ◽  
Main Effect ◽  
Systematic Determination ◽  
Relationship Of ◽  
The Relationship

Abstract This four-part series of papers addresses the problem of systematic determination of the influence of several tire factors on tire treadwear. Both the main effect of each factor and some of their interactive effects are included. The program was also structured to evaluate the influence of some external-to-tire conditions on the relationship of tire factors to treadwear. Part I describes the experimental design used to evaluate the effects on treadwear of generic tire type, aspect ratio, tread pattern (groove or void level), type of pattern (straight rib or block), and tread compound. Construction procedures and precautions used to obtain a valid and functional test method are included. Two guiding principles to be used in the data analyses of Parts II and III are discussed. These are the fractional groove and void concept, to characterize tread pattern geometry, and a demonstration of the equivalence of wear rate for identical compounds on whole tread or multi-section tread tires.

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