Use of thermomechanical pulp fibers from waste woods for making eco-friendly cushioning material

TAPPI Journal ◽  
2010 ◽  
Vol 9 (7) ◽  
pp. 15-21 ◽  
Author(s):  
JI-YOUNG LEE ◽  
CHUL-HWAN KIM ◽  
JEONG-MIN SEO ◽  
HO-KYUNG CHUNG ◽  
KYUNG-KIL BACK ◽  
...  

Eco-friendly cushioning materials were made with thermomechanical pulps (TMPs) from waste woods collected from local mountains in Korea, using a suction-forming method without physical pressing. The TMP cushions had superior shock-absorbing performance, with lower elastic moduli than expanded polystyrene (EPS) or molded pulp. Even though the TMP cushions made using various suction times had many voids in their inner fiber structure, their apparent densities were a little higher than that of EPS and much lower than that of molded pulp. The addition of cationic starch contributed to an increase in the elastic modulus of the TMP cushions without increasing the apparent density, an effect which was different from that of surface sizing with starch. In the impact test, the TMP cushions showed a more ductile pattern than the brittle EPS. The porosity of the TMP cushion was a little less than that of EPS and much greater than that of molded pulp. The porous structure of the TMP cushions contributed to their excellent thermal insulating capacity, which was equivalent to that of EPS. In summary, the TMP packing cushions showed great potential for surviving external impacts during product distribution.

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Hiroyuki Yamada ◽  
Kohei Tateyama ◽  
Shino Naruke ◽  
Hisashi Sasaki ◽  
Shinichi Torigata ◽  
...  

AbstractThe destruction caused by ballistic ejecta from the phreatic eruptions of Mt. Ontake in 2014 and Mt. Kusatsu-Shirane (Mt. Moto-Shirane) in 2018 in Japan, which resulted in numerous casualties, highlighted the need for better evacuation facilities. In response, some mountain huts were reinforced with aramid fabric to convert them into shelters. However, a number of decisions must be made when working to increase the number of shelters, which depend on the location where they are to be built. In this study, we propose a method of using high-strength steel to reinforce wooden buildings for use as shelters. More specifically, assuming that ballistic ejecta has an impact energy of 9 kJ or more, as in previous studies, we developed a method that utilizes SUS304 and SS400 unprocessed steel plates based on existing impact test data. We found that SUS304 is particularly suitable for use as a reinforcing material because it has excellent impact energy absorption characteristics due to its high ductility as well as excellent corrosion resistance. With the aim of increasing the structural strength of steel shelters, we also conducted an impact test on a shelter fabricated from SS400 deck plates (i.e., steel with improved flexural strength provided by work-hardened trapezoidal corrugated plates). The results show that the shelter could withstand impact with an energy of 13.5 kJ (2.66 kg of simulated ballistic ejecta at 101 m/s on impact). In addition, from the result of the impact test using the roof-simulating structure, it was confirmed the impact absorption energy is further increased when artificial pumice as an additional protective layer is installed on this structure. Observations of the shelter after the impact test show that there is still some allowance for deformation caused by projectile impact, which means that the proposed steel shelter holds promise, not only structurally, but also from the aspects of transportation and assembly. Hence, the usefulness of shelters that use steel was shown experimentally. However, shelter construction should be suitable for the target environment.


Cellulose ◽  
2021 ◽  
Vol 28 (15) ◽  
pp. 9751-9768
Author(s):  
Teija Laukala ◽  
Sami-Seppo Ovaska ◽  
Ninja Kerttula ◽  
Kaj Backfolk

AbstractThe effects of bio-based strengthening agents and mineral filling procedure on the 3D elongation of chemi-thermomechanical pulp (CTMP) handsheets with and without mineral (PCC) filling have been investigated. The 3D elongation was measured using a press-forming machine equipped with a special converting tool. The strength of the handsheets was altered using either cationic starch or microfibrillated cellulose. Precipitated calcium carbonate (PCC) was added to the furnish either as a slurry or by precipitation of nano-sized PCC onto and into the CTMP fibre. The 3D elongation of unfilled sheets was increased by the dry-strengthening agents, but no evidence on the theorised positive effect of mineral fill on 3D elongation was seen in either filling method. The performance of the strengthening agent depended on whether the PCC was as slurry or as a precipitated PCC-CTMP. The starch was more effective with PCC-CTMP than when the PCC was added directly as a slurry to the furnish, whereas the opposite was observed with microfibrillated cellulose. The 3D elongation correlated positively with the tensile strength, bursting strength, tensile stiffness, elastic modulus and bending stiffness, even when the sheet composition was varied, but neither the strengthening agent nor the method of PCC addition affected the 3D elongation beyond what was expectable based on the tensile strength of the sheets. Finally, mechanisms affecting the properties that correlated with the 3D elongation are discussed.


Author(s):  
S. H. Chan ◽  
M. F. White

Abstract Measurements have been taken on an experimental rotor-bearing test rig which consists of a full size gas turbine shaft supported by two five-pad tilting-pad journal bearings. The impact test method was applied by exciting one end of the shaft in-situ by means of a hammer blow. Impact forces and response displacements were collected and analysed with suitable corrections for runout effect. Averaged frequency response spectra thus obtained were used in a parameter estimation procedure to calculate the dynamic coefficients of the tested tilting-pad journal bearing. An analytical single degree-of-freedom model was employed and one of the input parameters in the mechanical model, the effective mass, was found to significantly influence the estimated results. The measured stiffness and damping coefficients are compared with results predicted by a bearing design program. Possible sources of discrepancies between experimental and theoretical results are discussed.


2021 ◽  
pp. tobaccocontrol-2021-056807
Author(s):  
Alex C Liber ◽  
Zachary Cahn ◽  
Megan C Diaz ◽  
Emily Donovan ◽  
Donna Vallone ◽  
...  

BackgroundThe E-cigarette, or Vaping Product-Use Associated Lung Injury (EVALI) Outbreak of 2019 hospitalised thousands and killed dozens of people in the USA and raised perceptions of the dangers posed to health by electronic cigarettes (e-cigarettes). These illnesses along with continued increases in youth vaping rates lead to the passage of many state and federal laws intended to curtail the sale of flavoured e-cigarettes. Little is known about the impact of these events on US e-cigarette and cigarette retail sales.MethodsUsing Nielsen Scantrack sales data from January 2014 to January 2020 for 23 US states, we evaluate the effect of the EVALI outbreak. First-differenced state-panel regressions tracking unit sales of total-level and category-level e-cigarettes and cigarette sales controlling for price, Tobacco 21 policy coverage, product distribution, seasonality, EVALI-attributable deaths, and state-level e-cigarette policies affecting the availability of e-cigarettes (non-tobacco flavoured and total) were employed.ResultsDollar sales of e-cigarettes declined 29% from their pre-EVALI peak by January 2020. Total sales of e-cigarettes declined in response to EVALI deaths and the total e-cigarette sales ban put in place in Massachusetts adopted in its wake. Cigarette sales were largely unchanged by either the direct or indirect policy effects of the EVALI outbreak, except for in Massachusetts, where cigarette sales—particularly those smoked by young people—rose temporarily after a total ban on e-cigarette sales.ConclusionSales of e-cigarettes declined in response to the EVALI outbreak and from the most restrictive regulatory policies that were adopted in response, while sales of cigarettes were affected less.


Author(s):  
O. Knotek ◽  
B. Bosserhoff ◽  
A. Schrey ◽  
T. Leyendecker ◽  
O. Lemmer ◽  
...  

2004 ◽  
Vol 50 (3) ◽  
pp. 183-194 ◽  
Author(s):  
S.C. Stratton ◽  
P.L. Gleadow ◽  
A.P. Johnson

The impact of effluent discharges continues to be an important issue for the pulp manufacturing industry. Considerable progress has been made in pollution prevention to minimize waste generation, so-called manufacturing “process closure.” Since the mid-1980s many important technologies have been developed and implemented, many of these in response to organochlorine concerns. Zero effluent operation is now a reality for a few bleached chemi-thermomechanical pulp (BCTMP) pulp mills. In kraft pulp manufacturing, important developments include widespread adoption of new cooking techniques, oxygen delignification, closed screening, improved process control, new bleaching methods, and systems that minimize pulping liquor losses. Coupled to this is a commitment to reduce water use and maximize reuse of in-mill process streams. Some companies pursued bleach plant closure, and many have been successful in eliminating a portion of their bleaching wastewaters. However, the difficulties inherent in closing bleach plants are considerable. For many mills the optimal solution has been found to be a high degree of closure coupled with external biological treatment of the remaining process effluent. No bleach plants at papergrade bleached kraft mills are known to be operating effluent-free on a continuous basis. This paper reviews the important worldwide technological developments and mill experiences in the 1990s that were focused on minimizing environmental impacts of pulp manufacturing operations.


2014 ◽  
Vol 564 ◽  
pp. 428-433 ◽  
Author(s):  
S.N.A. Safri ◽  
Mohamed Thariq Hameed Sultan ◽  
N. Razali ◽  
Shahnor Basri ◽  
Noorfaizal Yidris ◽  
...  

The purpose of this work is to study the best number of layer with the higher impact energy using Glass Fibre Reinforced Polymer (GFRP). The number of layers used in this study was 25, 33, 41, and 49. The impact test was performed using Single Stage Gas Gun (SSGG) for each layers given above with different bullets such as blunt, hemispherical and conical bullets. The gas gun pressure was set to 5, 10, 15 and 20 bar. All of the signals captured from the impact test were recorded using a ballistic data acquisition system. The correlation between the impact energy in terms of number of layer and type of bullet from this test are presented and discussed. It can be summarise that as the number of layer increases, impact energy also increases. In addition, from the results, it was observed that by using different types of bullets (blunt, hemispherical, conical), there is only a slight difference in values of energy absorbed by the specimen.


2014 ◽  
Vol 879 ◽  
pp. 90-95 ◽  
Author(s):  
Abdul Rahman Noor Leha ◽  
Nor Amalina Nordin

Biocomposite from bamboo powder was fabricated by compression molding technique. The objective of this study was to investigate the mechanical properties of bamboo compounded with epoxy with different ratio. Tensile and flexural tests were done to characterize its mechanical properties. It was observed that the strength of bamboo-polyester was increased with increasing amount of bamboo powder. The tensile and flexural strength shows the highest value at 25 wt.% bamboo. However, the impact test shows the maximum value at 20 wt.% bamboo powder. These results exhibit the bamboo-polyester can be a good candidate to be used in many engineering applications


Author(s):  
Kenro Obuchi ◽  
Fumiaki Watanabe ◽  
Hiroshi Kuroki ◽  
Hiroyuki Yagi ◽  
Kazuyoshi Arai

Ceramic matrix composites (CMCs) have lower density and a higher service temperature limit than nickel based alloys which have been used for turbine components of aircraft engines. These properties of CMCs have the potential to reduce the weight of turbine components and improve turbine thermal efficiency with a higher turbine inlet temperature (TIT). One of the technical issues of the CMC turbine vane is a relatively lower impact resistance than nickel based alloy turbine vanes. There are various previous works about impact resistance of CMCs, but there is little work that assumed actual engine conditions. The objective of this work was to verify the resistance of SiC/SiC CMC turbine vane to the impact phenomena that occur in the actual aircraft engine. The field damage survey was conducted on actual metal turbine vanes of commercial engines overhauled in IHI. The survey made it clear that the typical damage was less-than-0.127-mm-dent at the leading edge. In addition, the dropped weight impact test using the actual turbine airfoil which is made from a nickel based alloy was conducted at ambient temperature. The amount of energy required to make the dent of a certain size that was observed in actual metal turbine vanes was estimated. Then, the dropped weight impact test using the CMC test piece with a leading edge shape was conducted at the impact energy estimated by the metal turbine airfoil. The results showed that the failure mode of the CMC test piece was local damage with dents of a certain size and not a catastrophic failure mode. From this work, the damage to be assumed on CMC vane in actual aircraft engines was identified. As a future task, the effect of the damage to the fatigue capability of CMC turbine vanes needs to be investigated.


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