Haque AKMM; Hasan M; Shibly MAH; Hasan MF; Rashid MMU; Huque S

Research Article

Adv Res Text Eng. 2018; 3(3): 1030.

Design, Development and Performance Analysis of Photo Voltaic Powered Solar Dryer

Sun D*¹, Chen M¹, Hyun An K¹ and Clark S²

¹Department of Textile Engineering, Heriot-Watt University, UK

²Department of Textile Engineering, SolarVis Technology Limited, UK

*Corresponding author: Sun D, Department of Textile Engineering, Heriot-Watt University, UK

Received: May 07, 2018; Accepted: July 13, 2018; Published: July 20, 2018

Abstract

The negative effects of sunlight has been known associated with the development of skin cancer, skin aging, immune suppression, and eye diseases. The UV Index is an important parameter to alert people about the need to adopt protective measures. This paper reports a design concept and techniques developed in engineering UV indexable two-layer narrow woven fabrics. The fabrics were made using a type of photochromic yarn and three reference yarns with static colours indicating the level of UV intensity based on the measurement of colour change of the photochromic yarn under different level of UV intensities.

Keywords: UV indexable textile; UV index measurement;Photochromic yarn;Two layer woven fabric

Introduction

Photochromic pigments were developed for colour changing lenses for sunglasses initially. Their application have been expended in innovative textile and fashion design and many other applicable areas. There are irreversible photochromic pigments made for some specific applications. Other photochromic pigments are reversible that are important type for textile and fashion design. According to the photochromism, the photochromic process may be categorised into several groups including triplet [1], heterolytic cleavage [2,3], homolytic cleavage [4,5], trans-cis isomeration [6,7], photochromism based on tautomerism [4,5], and photodimerisation [8]. An example of working principle of photochromic pigments is shown in (Figure 1).

Figure 1: Working principle of photochromism.

    
    
    Figure 1:  Working principle of photochromism.

Despite the beneficial effects of both solar and artificial UV radiation have been used in the phototherapy to cure or mitigate skin diseases such as psoriasis, neurodermatitis, scleroderma, lupus, erythematosus, urticarial pigmentosa, vitiligo and acne vulgaris [9- 11] solar radiation of certain range of wavelength has negative effects on human health. UV index has been used as a general term for public awareness to identify the risk of high UV doses [12]. Detrimental effects to humans such as erythema and skin cancer can be triggered by high values of effective irradiance or high UV dose [13].

UV index is calculated from a direct measurement of the UV spectral power at a given location. It requires the measurement of the intensity of UV radiation as UV Index (UVI) [14]. A UV Index reading of 3 to 5 means moderate risk of harm from unprotected sun exposure. There is no such photochromic yarn or ink that is able to indicate or respond to different UV intensities, however the depth of colour will depend on the strength of UV, e.g. colour depth increases with stronger sunlight. The UV index can be calculated from a direst measurement of the UV spectral power at a given location. It requires the measurement of the intensity of UV radiation.

UV protective textiles have been reported by applying ZnO by different techniques and approaches, onto different types of textiles, cellulosic fibres [15,16], protein fibres [17], and synthetic fibres [18]. UV protection is very important; however UV warning is another element needs to be considered alarming people about the need to use sun protection. This research reports engineering design fabric structures and UV indexable fabrics using colour reversible photochromic yarn and normal yarns with pre-identified reference colours.

Design Principle, Materials and Testing

Colour reference

The aim of the project is to engineering design textile-based accessories for indoor and outdoor wear, in this case smart watchbands will be designed and engineered. In the watchband a section of patterned photochromic yarn will be designed and its colour under UV light can be compared to other sections of the watchband made of yarns with static reference colours.

Materials

The yarns used for construction the watchband are listed in (Table 1).

Table 1: Photochromic yarn and three reference yarns. Note: The photochromic yarn was made by Guangzhou Lanjing Chemical Fibre Co. Ltd. The yarns with the three reference colours 1, 2 & 3 were supplied by J.H. Ashworth & son Ltd.

    
    
    Table 1:  Photochromic yarn and three reference yarns.
Note: The photochromic yarn was made by Guangzhou Lanjing Chemical Fibre Co. Ltd. The yarns with the three reference colours 1, 2 & 3 were supplied by J.H.
Ashworth & son Ltd.

Testing of UV index

A piece of fabric was constructed using the photochromic yarn shown in (Figure 2), which was taken in door.

Figure 2: Fabric made of chromic yarn taken indoor.

    
    
    Figure 2:  Fabric made of chromic yarn taken indoor.

A smart UV checker shown in (Figure 3)was used to measure the UV index value in different weather conditions and UV intensities. The UV checker has a semiconductor Sensor that connects to your Smartphone to measure, collect and analyze UV light.

Figure 3: UV index checker.

    
    
    Figure 3:  UV index checker.

Under all weather conditions tested and UV index values, the developed photochromic fabric (Figure 4) was tested and the corresponding colours were recorded by using a digital camera as reference colour for watchband design. In the end, three reference colours were identified corresponding to three different UV levels - low, moderate and high.

Figure 4: Comparison between the woven sample and the shade card.

    
    
    Figure 4:  Comparison between the woven sample and the shade card.

Results and Discussion

Colour change of the photochromic fabric under different UV intensities

The fabric sample (Figure 4) was taken to the sunlight in different UV intensity conditions, the change of colour was recorded under different exposure time. The colour of the woven cloth was then compared to the colours of a shade card by doing so to obtain the reference colours corresponding to different UV intensities. The shade card is the Sabac polyester core spun thread shade card from AMANN.The comparison of the colours was conducted. The following images show the colour comparison observed. In the end three reference colours were identified corresponding to low, moderate and high UVI values.

In order to use the colour change of the photochromic yarn to indicate different UV intensities, the observation time was set at 20 second in which there is an obvious difference between the colour shade in corresponding to low and moderate UV exposure. According to literature, it is possible to use photochromic material to identify UV exposure because the intensity of the colour has a linear relationship with UV irradiation [4]. Higher UV radiation triggers higher intensity of the colour. Also, the colour change time is affected by the UV radiation. The two have a negative linear relationship, shorter change time corresponds to higher UV radiation.

Fabric design and development

Three types of weave structures - plain, twill and satin were selected for the watchband cloth development. For all the three weave structures, two layer cloth is required in order for the face of the fabric has photochromic and reference yarns appear in different sections of the fabric indicated in (Figure 5).

Figure 5: Colour design with different sections in double layer watchband narrow cloth.

    
    
    Figure 5:  Colour design with different sections in double layer watchband
narrow cloth.

In this research two layer narrow fabrics (20mm wide) were planned to be used for watchband.The total number of ends of the cloth is 56, warp and weft yarn linear density are 28 and 24 in total which are14 and 12 ends (orpicks)/cm. layer respecvitely. The detailed weave design, draft and peg plan of the double cloth are shown in (Figure 6-8).

Figure 6: Weave plan of plain, 2/2 twill and 4 ends weft sateen, where: ‘×’, ‘√’ and ‘∕ ’indicate the face weave, back weave, and a separating lifter (face end lifts over back pick), respectively. ‘R’ and ‘P’ represent the Reference/ indicator Yarn and the Photochromic Yarn respectively.

    
    
    Figure 6:  Weave plan of plain, 2/2 twill and 4 ends weft sateen, where:
‘×’, ‘√’ and ‘∕ ’indicate the face weave, back weave, and a separating lifter (face
end lifts over back pick), respectively. ‘R’ and ‘P’ represent the Reference/
indicator Yarn and the Photochromic Yarn respectively.

Design, Development and Performance Analysis of Photo Voltaic Powered Solar Dryer

Abstract

Introduction

Design Principle, Materials and Testing

Results and Discussion

Conclusion

References