Search
Use the search bar or filters below to find any TAPPI product or publication.
Filters
Content Type
Publications
Level of Knowledge
Committees
Collections
Journal articles
Magazine articles
Quantification of block testing for coated paper substrates, TAPPI Journal November 2024
ABSTRACT: Block resistance is a critical property for coated paper and board substrate that will be rolled, stacked, or otherwise contact itself after coating. Small differences in the coated substrate’s blocking can determine whether the substrate can be successfully used for its designated purpose. However, this crucial property is typically evaluated using a qualitative scale that is based on subjective operator ratings and impacted by factors that include: (1) sound of coated substrate during separation, and (2) force with which substrates are separated. This paper tests the hypothesis that quantifying the block test by measuring the force required to peel samples apart improves the test by: (1) providing more standardized testing conditions by controlling peel force and rate; (2) more clearly differentiating samples that experience minimal to some blocking; and (3) maintaining customizability to evaluate customer-specific test conditions. The method developed in this study uses a standard block tester and block testing conditions, but it peels the coated paper samples using a hot tack/heat seal instrument with force measurement capabilities. This paper demonstrates, using the instrument’s heat seal capabilities, that it can measure peel forces that represent the full range of observable block scores. The efficacy of this method was evaluated by having a group of trained operators engage in a randomized, blind experiment where they assessed block resistance on a set of coated paper samples using a modified qualitative block scale and compared their results to force measurements collected using the proposed method. The sample set included two coatings that have successfully run in commercial trials with minimal blocking, and one coating that experienced significant blocking in commercial trials despite only exhibiting some blocking at standard block test conditions in laboratory testing. The quantitative test method presented in this paper clearly differentiated these samples, whereas the qualitative assessment could not predict which samples had suitable block resistance for commercial use. As any tensile tester capable of measuring with 0.1 N resolution can be used for the Quantitative Block Test, the proposed method can be widely adopted. Furthermore, this method can be used for any block condition.
Journal articles
Magazine articles
Test method and coating composition impact on measured moisture vapor transmission rate for waterborne coatings on paper, TAPPI Journal November 2024
ABSTRACT: Moisture vapor barrier is one of the necessary performance attributes for paper packages. Two methods are typically employed to assess the moisture vapor transmission rate (MVTR): the gravimetric cup method (ASTM E96) and the MOCON method (ASTM F1249). While those tests have been compared for free standing polymeric films, less is understood about their application in coated paper. Our results show that, despite a general agreement between the two methods, discrepancies exist where test protocols and material properties of coated paper impact the MVTR measurement. The measurement discrepancies can be explained by differences in local moisture concentration. Our study provides new insights on moisture vapor barrier assessment of waterborne coatings on paper and implications for achieving paper packages with improved barrier performance.
Journal articles
Magazine articles
Colloid chemical aspects of paper formation in the presence of nanofibrillated cellulose and cationic starch, TAPPI Journal September 2024
ABSTRACT: A series of experimental tests were carried out to examine colloidal-scale consequences of optionally treating nanofibrillated cellulose (NFC) with cationic starches of different charge density and dosage (0.5% or 2.0% by weight), adding that material to a furnish prepared from 100% recycled copy paper, and then subjecting the mixture to very different levels of hydrodynamic shear. Tests included optical microscopy, sediment volume tests, sediment velocity tests, and “percent fines” assessment by means of a fiber quality analyzer (FQA). In addition, the zeta potential and charge demand of the studied materials were evaluated. Optical imaging revealed that cationic starch treatment of the NFC tended to agglomerate it into multiparticle clusters, which sometimes could be mostly redispersed by hydrodynamic shear. Subsequent addition of the starch-treated NFC to the default furnish resulted in much of the colloidal material becoming attached to fibers. Subsequent shearing of the mixtures was at least partly effective in separating the clusters of NFC from the fiber surface, resulting in essentially a two-component mixture. Multiparticle NFC clusters coexisted with the fiber suspension, sometimes attached and sometimes not, depending on the details of treatments. Sediment volume tests showed that systems containing cationic starch-treated NFC tended to have a higher density after settling in comparison to untreated NFC; these findings are consistent with the cationic starch acting as a stabilizer on the solid surfaces, allowing them to slide past each other during the settling process. Application of intense hydrodynamic shear tended to result in denser sediment. Results of tests with the sediment velocity messurement and the FQA percent fines assessment did not correlate well with changes in test conditions considered in this study.
Journal articles
Effect of HYP Fibers on Bulk and Surface roughness of Wood-Free Paper, TAPPI JOURNAL April 2008
Effect of HYP Fibers on Bulk and Surface roughness of Wood-Free Paper, TAPPI JOURNAL April 2008
Journal articles
Strategies for Economical Alternatives for Wax Replacement in Packaging, TAPPI JOURNAL April 2008
Strategies for Economical Alternatives for Wax Replacement in Packaging, TAPPI JOURNAL April 2008
Journal articles
A Diffractive Gloss Meter for Local Gloss Measurements of Papers and Prints, TAPPI JOURNAL April 2008
A Diffractive Gloss Meter for Local Gloss Measurements of Papers and Prints, TAPPI JOURNAL April 2008
Journal articles
Magazine articles
Slot die coating of nanocellulose on paperboard, TAPPI Journal January 2018
Slot die coating of nanocellulose on paperboard, TAPPI Journal January 2018
Journal articles
Magazine articles
Discrete element method to predict coating failure mechanisms, TAPPI JOURNAL January 2018
Discrete element method to predict coating failure mechanisms, TAPPI JOURNAL January 2018
Journal articles
Preparation of specialized paper, Solutions! & TAPPI JOURNAL, April 2004 (349KB)
Preparation of specialized paper, Solutions! & TAPPI JOURNAL, April 2004 (349KB)
Journal articles
Performance of cationic styrene maleimide copolymers in the wet end of papermaking, Solutions! & TAPPI JOURNAL, April 2004 (198KB)
Performance of cationic styrene maleimide copolymers in the wet end of papermaking, Solutions! & TAPPI JOURNAL, April 2004 (198KB)