Effect of blank pre-conditioning humidity on the dimensional accuracy and rigidity of paperboard trays

2018 ◽  
Vol 33 (2) ◽  
pp. 348-357
Author(s):  
Sami-Seppo Ovaska ◽  
Panu Tanninen ◽  
Esa Saukkonen ◽  
Kaj Backfolk

Abstract Optimization of storage conditions is essential for successful converting of paperboard. This paper investigates the effect of blank moisture content on the dimensional accuracy and rigidity of press-formed paperboard trays. The trays were manufactured from uncoated, pigment-coated and extrusion-coated paperboards and multi-layer materials using fixed process parameters. Because of the different layer structures and coatings, the paperboards showed different hygroscopic behavior. Prior to converting trials, the bursting strength of paperboards under different moisture conditions was assessed. It was found that the moisture content has only a minor influence on bursting strength, but moisture affects blank curling tendency and dimensional accuracy of the tray. A high blank moisture content led to a loss of the dimensional stability and load-bearing capacity of trays, although based on earlier knowledge it is evident that the moisture content should be high for successful press-forming. As expected, a low blank moisture content increased the prevalence of ruptures in forming but the resulting trays were stiffer and their dimensional accuracy was better. It was suggested that the increased stiffness is related to a more efficient moisture removal during the press-forming, so that the fiber network is more effectively consolidated due to e. g. the formation of hydrogen bonds.

Author(s):  
O. A. Zadorozhna ◽  
T. P. Shyianova ◽  
M.Yu. Skorokhodov

Seed longevity of 76 spring barley gene pool samples (Hordeum vulgare L. subsp. distichon, convar. distichon: 56 nutans Schubl., two deficience (Steud.) Koern., two erectum Rode ex Shuebl., two medicum Koern.; convar. nudum (L.) A.Trof.: one nudum L. та subsp. vulgare: convar. vulgare: nine pallidum Ser., three rikotense Regel.; convar. coeleste (L.) A.Trof.: one coeleste (L.) A.Trof.) from 26 countries, 11 years and four places of reproduction was analyzed. Seeds with 5–8% moisture content were stored in chamber with unregulated and 4oC temperature. The possibility of seed storage under these conditions for at least 10 years without significant changes in germination has been established. The importance of meteorological conditions in the formation and ripening of seeds for their longevity is confirmed. The relationship between the decrease of barley seeds longevity and storage conditions, amount of rainfall, temperature regime during the growing season of plants is discussed.


Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 98 ◽  
Author(s):  
Yi Cui ◽  
Shuyi Gao ◽  
Ruiyun Zhang ◽  
Longdi Cheng ◽  
Jianyong Yu

The aim of this paper is to study the hygroscopic behavior of hygroscopic exothermic fiber-based materials and to obtain a better understanding of the thermal performance of these fibers during the moisture absorption process. The temperature distribution of different kinds of hygroscopic exothermic fibers in the process of moisture absorption, observed by infrared camera, demonstrated two types of heating performance of these fibers, which might be related to its hygroscopic behavior. Based on the sorption isotherms, a Guggenheim-Anderson-de Boer (GAB) multi-layer adsorption model was selected as the optimal moisture absorption fitting model to describe the moisture absorption process of these fibers, which illustrated that water sorption capacity and the water–fiber/water–water interaction had a significant influence on its heating performance. The net isosteric heats of sorption decreased with an increase of moisture content, which further explained the main factor affecting the heat dissipation of fibers under different moisture contents. The state of adsorbed water and water vapor interaction on the fiber surface were studied by simultaneous thermal analysis (TGA-DSC) measurement. The percentage of bound and unbound water formation at low and high humidity had a profound effect on the thermal performance of fibers. It can therefore be concluded that the content of tightly bound water a strong water–fiber interaction was the main factor affecting the heating performance of fibers at low moisture content, and the content of loosely bound water reflected that water sorption capacity was the main factor affecting the heating performance of fibers at high moisture content. This was further proven by the heat of desorption.


2014 ◽  
Vol 962-965 ◽  
pp. 1235-1238
Author(s):  
Mei Mei Hao ◽  
Xi Hong Li ◽  
Hai Dong Liu ◽  
Wei Qiao Yang ◽  
Chong Xiao Shao ◽  
...  

Under the condition of nine kinds of storage, In this thesis, through the determination of acid value of soybean oil, to search for the best storage condition, used to prevent the soybean oil acid value rise, through the analysis of the acid value data, We find the best storage condition, is 0°C, 6% moisture content, and PVC plastic wrap packaging.


2008 ◽  
Vol 5 (2) ◽  
pp. 1237-1261 ◽  
Author(s):  
A. P. Schrier-Uijl ◽  
E. M. Veenendaal ◽  
P. A. Leffelaar ◽  
J. C. van Huissteden ◽  
F. Berendse

Abstract. Our research investigates the spatial and temporal variability of methane (CH4) emissions in two drained eutrophic peat areas (one intensively managed and the other less intensively managed) and the correlation between CH4 emissions and soil temperature, air temperature, soil moisture content and water table. We stratified the landscape into landscape elements that represent different conditions in terms of topography and therefore differ in moisture conditions. There was great spatial variability in the fluxes in both areas; the ditches and ditch edges (together 27% of the landscape) were methane hotspots whereas the dry fields had the smallest fluxes. In the intensively managed site the fluxes were significantly higher by comparison with the less intensively managed site. In all the landscape element elements the best explanatory variable for CH4 emission was temperature. Neither soil moisture content nor water table correlated significantly with CH4 emissions, except in April, where soil moisture was the best explanatory variable.


2019 ◽  
Vol 62 (3) ◽  
pp. 661-671 ◽  
Author(s):  
Jia Wu ◽  
Xiangyang Lin ◽  
Shengnan Lin ◽  
Paul Chen ◽  
Guangwei Huang ◽  
...  

Abstract. The effects of packaging and storage conditions on the moisture content and instrumental and sensory textural properties of raw and salty light roasted (SLR) California almonds were studied under different storage conditions. The controlled combinations included low, medium, and high temperatures and low and high relative humidity (RH). Almond samples were packaged in cartons or polyethylene (PE) bags with and without vacuum. Both absorption and desorption of moisture by almonds were observed during storage and were dependent on the packaging and storage conditions. In general, gradual changes were observed for samples with PE and vacuum PE packaging in most of the storage conditions, while the samples packed in cartons showed more dramatic changes because these unprotected samples were more vulnerable to seasonal changes in humidity. The SLR almonds showed consistent moisture gains, while the raw almonds tended to lose moisture content in most of the storage conditions. This may be attributed to the low initial moisture content of the SLR samples. All raw samples packed in cartons became softer over time. The softening tended to be enhanced by high storage humidity and temperature. The raw almonds packaged in PE bags were firmer than those packed in cartons but also became softer over time. The firmness of the SLR samples was generally lower than that of raw samples, probably because roasting reduced the density and mechanical strength of the kernels. The firmness of PE packaged SLR samples increased in uncontrolled storage conditions and in higher storage temperature and humidity conditions but decreased slightly in lower temperature and humidity conditions. Vacuum packaging did not affect the firmness much. Using PE packaging and maintaining the RH below 50% and the temperature below 25°C are effective in stabilizing both raw and processed almonds. Keywords: Almond, Firmness, Nonpareil, Packaging, Relative humidity, Sensory, Storage, Temperature, Texture.


2008 ◽  
Vol 4 (1) ◽  
pp. 61-75 ◽  
Author(s):  
Tímea Kaszab ◽  
Ferenc Firtha ◽  
András Fekete

The objective of the work reported here was to determine changes in the moisture content, firmness characteristics, color attributes and NIR absorbance of two carrot cultivars during storage. There was a definite loss in the moisture content that caused changes in the firmness. This result shows that carrot firmness is very sensitive to the moisture content. The firmness — especially the cutting force — is a good characteristic for predicting changes in carrot moisture content during storage. The color characteristics — a* and b* — showed a slight change in the function of the moisture content. However, these color characteristics are suitable for distinguishing the phloem and xylem parts of carrot cultivars. There were not found definite changes in the NIR absorbance as the function of the moisture content. Consequently, the specific cutting force and the impact stiffness coefficient are good characteristics of the carrot moisture content and the mass reduction during storage under non-ideal conditions.


2017 ◽  
Vol 2 (1) ◽  
pp. 22-27 ◽  
Author(s):  
Pankaj B. Pathare ◽  
Tarl M. Berry ◽  
Umezuruike Linus Opara

Abstract Ventilated corrugated paperboard packaging is the most widely type of packaging used in postharvest handling and transportation of fresh horticultural produce, during which the package may be exposed to different environmental conditions. Ventilated packages should be designed in such a way that they can provide uniform airflow distribution without compromising mechanical integrity. This study investigated the effects of different storage conditions (−0.5°C at 90% RH; 4°C at 90% RH, 10° C at 90% RH) on the mechanical performance of two types of ventilated packaging [‘Supervent’ (4.7% vent area) and ‘Standard’ (3.1% vent area)] used for handling citrus fruit. The effects of storage condition on moisture content of package was also studied. Standard packaging showed higher compression strength than supervent packaging, presumably due to less vent area on the package. Maximum compressive strength reduction was found at storage temperature 4°C for both packages. The compressive strength of both packages decreased with increase in moisture content.


2014 ◽  
Vol 136 (1) ◽  
Author(s):  
Changsoo Jang ◽  
Bongtae Han

Hygroscopic and thermal expansion behavior of advanced polymers is investigated when subjected to combined high temperature and moisture conditions. An enhanced experimental–numerical hybrid procedure is proposed to overcome the limitations of the existing methods when used at temperatures above the water boiling temperature. The proposed procedure is implemented to measure the hygrothermal strains of three epoxy molding compounds and a no-filler underfill over a wide range of temperatures including temperatures beyond the water boiling temperature. The effects of moisture content on the glass transition temperature (Tg) and coefficient of thermal expansion (CTE) are evaluated from the measurement data. A formulation to predict the Tg change as a function of moisture content is also presented.


2018 ◽  
Vol 40 (3) ◽  
pp. 246-252 ◽  
Author(s):  
Daniel Felipe de Oliveira Gentil ◽  
Sidney Alberto do Nascimento Ferreira ◽  
Elizabeth Rodrigues Rebouças

Abstract: Psidium friedrichsthalianum is a species whose fruit can be used to make juices, jellies/jams and sweets, and its seedlings serve as rootstocks with resistance to Meloidogyne spp. The aim of this study was to evaluate the performance of seeds of this species at different germination temperatures, and to verify the effects of different moisture levels on their storage in two experiments. In the first, six germination temperatures (15, 20, 25, 30, 35, and 40 ºC) were evaluated, and in the second, seeds with different moisture levels (15.4, 9.8, 9.0, 8.4, and 8.2%) were stored in sealed containers at 20 °C for 0, 1, 3, 6, 9, and 12 months. Seed germination was favored by temperatures of 20 ºC and 25 ºC, reaching 93% and 87%, respectively, along with the highest germination speed indexes (2.582% day1 and 2.568% day-1) and shortest germination times (37.9 and 36.9 days). Temperatures of 30 °C and 35 °C maintained the seeds quiescent, while 40 °C was lethal. In storage, the seeds tolerated desiccation to 8.2% moisture content and could be stored in sealed containers at 20 ºC for 12 months, with germination higher than 70%.


2017 ◽  
Vol 57 (10) ◽  
pp. 2148 ◽  
Author(s):  
J. Viaene ◽  
V. Nelissen ◽  
B. Vandecasteele ◽  
K. Willekens ◽  
S. De Neve ◽  
...  

Storage and application of cattle farmyard manure (CFM) can cause considerable environmental problems through nutrient losses to soil, water and air, if not properly handled. We investigated different storage conditions of CFM at field scale to reduce nitrogen (N) losses to the soil, meanwhile optimising the agronomical quality of the CFM. The treatments differed in terms of storage method (stockpiling, extensive composting or co-composting with bulking agents) and coverage (no cover, plastic or geotextile cover). Over the different treatments, the ammonium-N concentrations under the piles in the 0–90 cm soil layer amounted to a maximum of 4.2% of the initial manure N content. We were able to assess the relative importance of each of the two processes resulting in a higher mineral N concentration under the piles, i.e. direct leaching from the CFM to the soil on the one hand, and a smaller indirect effect of elevated soil temperatures (up to 37°C) under the piles resulting in higher N mineralisation in the top soil on the other hand. NH4+-N was the most important component of mineral N under all heaps due to limited oxygen diffusion to the soil. N leaching and end-product quality were affected by a combination of treatment option (i.e. storage and cover) and initial manure characteristics. When CFM was characterised by a low volumetric moisture content and high C : N ratio, so in case of straw-rich CFM or CFM with added bulking agents, composting led to the least N leaching and most stable end product. When CFM was characterised by a high volumetric moisture content and low C : N ratio, stockpiling and covering (plastic or geotextile) resulted in lower N leaching to the soil. Stockpiling and covering the CFM with a geotextile resulted in a more stable end product than did covering with a plastic.


Sign in / Sign up

Export Citation Format

Share Document