• Journal of Biosystems Engineering
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• 제27권4호
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• pp.335-340
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• 2002

Recently, in Korea, round bale wrapping silage made by fresh rice straw are partially utilized. The colors of stretch film using far wrapping the fresh rice straw round bale are white, green and black. The light transmittance of green and white color stretch film was not founded the difference. However, the light transmittance of black color stretch film was largely difference of two stretch films. This study was carried out to measure qualities of fresh rice straw wrapping silage by softening processing of fresh rice straw and colors effects of wrapping stretch film. The analyzed factors were the light transmittance of stretch film, variation of the temperature in fresh rice straw round bale and qualities of the silage in crude protein, ADF, NDF, organic acid, etc. It was difficult to find in this study the colors effects of stretch film on silage qualities by the silage wrapping. But, when make fresh rice straw wrapping silage, wrapping silage fermentation effect goes well more if handle softening the fresh rice straw.

• 한국축산시설환경학회지
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• 제5권2호
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• pp.79-86
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• 1999

Recently more dairy farmers are interested in the utilization of stretch film for wrapping silage material. Most of stretch film are imported from abroad and one domestic product was developed, but its quality has not yet been tested. Therefore this study was executed to offer basic data on this material to the farmers. Measured items were tensile load, extension ratio, and tear propagation strength of stretch films. Comparisons were made among the white color of domestic product(Kw), and white(Fw), black (Fb) and green color(Fg) of foreign products. The result were summarized as follows: 1. Tensile loads of lengthwise direction in stretch films were 557.4, 377.4, 282.6 and 398.4kgf/$\textrm{cm}^2$ in Kw, Fw, Fb and Fg, respectively, and tensile loads of width direction were 415.9, 418.1, 360.2 and 433.0kgf/$\textrm{cm}^2$ in Kw, Fw, Fb and Fg, respectively. 2. Extension ratios of lengthwise direction were 650, 462.5, 512.5% and 537.5% in Kw, Fw, Fb and Fg, respectively, Extension ratios of width direction were 930, 962.5, 950 and 1,000% in Kw, Fw, Fb and Fg, respectively. 3 Tear propagation strength of lengthwise direction 187.9, 148.9, 157.3 and 142.8kgf/cm, and tear propagation strength of width direction were 141.4, 129.8, 140.4 and 106.6kgf/cm in Kw, Fw, Fb and Fg, respectively. 4. In the light transmittance, there was no difference between white and green color stretch film, but it was very low in black one. Therefore, it is thought that research on quality of roll bale silage treated with each stretch film would be needed.

• 한국공간구조학회논문집
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• 제16권1호
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• pp.35-42
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• 2016

Until recently, almost all ETFE film structures that have been erected is the cushion type because there are problems at lower allowable strength under elastic range and viscosity behaviour such as creep and relaxation of ETFE films under long-term stresses. But the number of tension type structures is currently increasing. This paper proposes the stretch fabrication of ETFE film to verify the applicability of ETFE films to tensile membrane structures. First of all, to investigate the possibility of application on tensile membrane structures, the stretch fabrication test is carried out, and it is verified that it is possible to increase the yield strength of the film membrane structures. After simulating the experiment also carries out an analytical investigation, and the effectiveness of the elasto-plastic analysis considering the viscous behavior of the film is investigated. Finally, post-aging tension measurement is conducted at the experimental facilities, and the viscosity behavior resulting from relaxation is investigated with respect to tensile membrane structures.

• 한국공간구조학회논문집
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• 제14권3호
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• pp.85-92
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• 2014

Most of the structural forms in which ETFE film is used are the cushion(pneumatic membrane structures) and tension type(tensile membrane structures), which have been generally accepted to be the most efficient forms. Tensile membrane structures are pulled outward from the exterior to introduce initial stress. And such structures offer the advantage of a natural shape formed by tensile stress and eliminate the need for blast air. Recently, the number of tension type structures is increasing. However, there are problems of creep and relaxation of ETFE films under long-term stresses. In this paper, the stretch fabrication method is proposed for stretching the film into the plastic region during initial tensioning as a way to increase its strength. And its effectiveness is confirmed by investigating experimental and analytical test using ETFE films.

• 월간포장계
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• 통권202호
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• pp.96-101
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• 2010

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 C
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• pp.1171-1173
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• 1995

Polyimide thin films were fabricated through the vapor deposition polymerization method, and the structure and capacitance characteristics of them were investigated in detail. It was found that the chemical structure and uniformity of the film could be stabilized with curing. The peaks of $720cm^{-l},\;1380cm^{-1}\;and\;1780cm^{-1}$ show C=O stretch mode, C-N stretch mode and carbonyl stretch mode, and those of polyimide which cured over $300^{\circ}C$ were fixed. It was found that capacitance was changed in proportion to temperature.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 2000년도 동계 학술대회 논문집
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• pp.135-140
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• 2000

• Journal of Biosystems Engineering
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• 제42권3호
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• pp.136-146
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• 2017

Purpose: This paper presents an appropriate wrapping method by analyzing the pressure distribution applied to a bale surface, along with the change in pressure according to an increase in the number of film layers in rice straw bales, which account for 74% of the total bulky feed supply in Korea. Methods: A model with the shape of an actual bale was fabricated to analyze the distribution of surface pressure in bale wrapping, and the pressure was measured. Experiments were conducted to analyze the pressure using eight different layer numbers (2, 4, 6, 8 10, 12, 14, and 16 layers) at five wrapping speeds (27, 29, 31, 33, and 35 rpm). Results: The maximum pressure applied to a circular bale by the film occurred at the center of the end of the bale, whereas the minimum pressure occurred at the center of the bale side. An extreme value ratio between the minimum and maximum pressures was distributed as 8.5-56.6%, which was improved with an increase in rotation speed. The an uneven pressure distribution occurred because the number of film overlaps was 8.24-times greater at the center of the bale's end than at the center of the ba le side. At a level 5 rotation speed, the minimum pressure was $P_{LV5-M1}=0.0625{\sigma}^2+36.173{\sigma}-36.753$ ($R^2=0.9845$) at $M_1$, and the maximum pressure was $P_{LV5-M6}=5.5552{\sigma}^2+41.05{\sigma}-39.071$ at $M_2$, revealing a correlation of $R^2=0.9983$. Conclusions: To replace four layers with six layers, 2-4 layers were added only to the side of the bale, and the minimum pressure at $M_1$ was then improved from that at four layers to that at six layers, and the amount of film consumed for 4-6 layers was reduced by 84.6%.

• Elastomers and Composites
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• 제57권3호
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• pp.114-120
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• 2022

The tensile properties of the extruded PC film were measured in the extrusion direction and perpendicular to the extrusion direction. The measured properties were the elastic modulus and Poisson's ratio at the glass transition temperature of PC. The measured orthotropic properties of the film were used for the computer simulation of vacuum forming. In this simulation, three mold shapes were tested: dome, trapezoid, and cubic, and the vacuum was applied between the mold surface and the heated film. The stress, strain, thickness, and stretch ratio distributions of the film in different mold shapes were observed and compared. The thermoforming simulation method used in this study and the obtained results, considering the determined orthotropic properties, can be applied to the thermoforming of various three-dimensional shapes.

• Korean Chemical Engineering Research
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• 제48권2호
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• pp.193-197
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• 2010

현재 포장 공정에서 사용되고 있는 stretch wrapping 공정은 초기 포장기의 장치 구비 등의 가격문제와 사용 후 폐기되는 포장재의 처리문제가 심각하다. 이에 대해 미끄럼 방지 접착제(Slip-resistant adhesive)를 사용하여 물류를 고정하여 운반하는 방식은 간단한 접착제의 도입으로 폐기물 발생이 없고 공정이 간단하며 비용이 매우 낮은 장점을 지닌다. 본 연구에서는 다습한 환경에서 polyethylene 필름 상에 미끄럼 방지 접착제를 적용했을 경우 접착력이 저하되는 것을 peel test를 통해 확인하고 적절한 첨가제의 선정 및 도입을 통해 접착력을 개선하는 연구를 수행하였다. 이를 통해서 maltodextrin의 첨가 시에 내습성에 대한 개선으로 인해 미끄럼 방지 접착력의 저하가 억제되었으며 10 wt% 도입 시에 최적의 성능을 나타내었다.