Paper superficial waviness: Conception and implementation of an industrial statistical measurement system

Abstract

The development of proper measurement methodologies for product evaluation is a critical issue to papermakers since their customers are increasingly demanding in regard to new product development and product quality.This paper addresses the conception of a measurement system to assess objectively and systematically paper superficial waviness in industrial practice. Such a system is based on mechanical stylus profilometry. The measurement system conception process is presented in this article, considering all of its stages: (i) gage selection and auxiliary components creation, (ii) drawing of a measurement procedure, (iii) assessment of the system capacities (through a repeatability and reproducibility (R&R) study), (iv) design of an appropriate categorical scale for paper waviness classification, and (v) validation of the classification model.The definition of the categorical scale encompassed the sensorial and instrumental characterization of several sheets of paper. The corresponding classification model strongly relies on the quality of judgments made by a panel of experts, and therefore the definition of a golden standard was carefully conducted. Two distinctive methodologies were used to assess the perceptiveness of the judges regarding paper superficial waviness, and linear discriminant analysis with stepwise variable selection for dimensional reduction was then applied to build a final classification model.The system conceived can be very helpful in the field of product design and process development, besides its obvious application to the monitoring of paper superficial quality. In fact, it can play an important role as an instrument used to define process-structure and structure-properties relationships, which may help in achieving faster product design time cycles.

Network‐induced supervised learning: Network‐induced classification (NI‐C) and network‐induced regression (NI‐R)

“…The variables that are more relevant for classification are those pertaining to cluster 2 (in the case where full‐order partial correlations are employed), as discriminants from this cluster are always selected, independently of the combination size considered (see Figure ). This cluster is formed by the profilometry descriptors [Ra, Rq, Rt, RS, RSm, Rdq, RKu], which were already found to be good candidates for describing the roughness behavior of the paper surface …”

“…However, for each of the 36 observations available, besides the classification labels used to implement the classification methods, another type of measurement was collected, for each sample, using an equipment called, the “Bendtsen tester”. The measurement principle of this instrument, consists of quantifying the amount of air that escapes, during a given period of time, between a standardized ring put over the paper sheet and the sheet itself, at constant pressure . This equipment is able to provide an inferential measure of surface roughness, in a short period of time, but its interpretation is not clear, as many aspects of the paper structure can interfere.…”

Morphological Analysis of KDP-Crystal Workpiece Surfaces Machined by Ultra-Precision Fly Cutting

“…This effect is most visible for the medium vibration frequency range. Costa et al [4] addresses the conception of a measurement system to objectively and systematically assess paper superficial waviness in industrial practice. Cao et al [5] studied the surface waviness of woven ceramic matrix composites and found that surface waviness exerts a tremendous influence on use performance and working life, and the influence degree is dependent on the particular type of surface waviness.…”

Theoretical And Practical Investigations Of V-Block Waviness Measurement Of Cylindrical Parts

“…As a result, development of appropriate measurement methodologies for product evaluation becomes the critical issue [1]. Particularly important is development of measuring methods that can be used to perform in-situ measurements directly on a machine tool, often in unfavourable industrial conditions.…”

“…An important of a cylindrical surface is its texture for. From the structural point of view, any surface can be treated as overlapping three types of irregularities, i.e., the form and position error (roundness error for cylindrical surfaces), waviness, and roughness [1,4]. Because the proper interpretation of geometric tolerance in many cases is difficult, especially for universal students and inexperienced engineers, a graphical and multimedia software was developed in order to facilitate understanding the rules of geometrical tolerances [5,6].…”