A Novel Approach of Manufacturing Sustainable Seamless Jute Bags and Evaluation of Its Properties: A Comparative Study with Commercial Bags

ABSTRACT

To reduce the adverse impact of synthetic bags on carbon footprints, greenhouse gases, and global warming, there is a rising demand for biodegradable and sustainable packaging material, especially for packing crops and food. Bags made from natural fibers are the finest alternative to synthetic ones. Jute is one of the most in-demand natural fibers in the packaging industry. Nevertheless, the traditional production method is more process-oriented, requiring more time and resulting in more expensive bags. Bowing problems induced by side seams cause sack bundles to roll during transport, which is also another issue. This study describes a unique process for producing seamless jute bags and sacks, eliminating the current processes in favor of fewer processes. A mechanical left-handed dobby loom with a cutting arrangement for separating the sacks produced continuous sack weaving. The tensile and seam strength of the produced sacks were evaluated and found to be comparable to those of commercially available sacks. In addition, one-way ANOVA and regression studies demonstrated the results significance. This developed method will increase productivity while reducing energy consumption, resulting in inexpensive packaging products and a solution to the transportation issue.

摘要

为了减少合成袋对碳足迹、温室气体和全球变暖的不利影响，对可生物降解和可持续包装材料的需求不断增加，尤其是对作物和食品的包装材料. 由天然纤维制成的袋子是合成袋子的最佳替代品.黄麻是包装行业中需求量最大的天然纤维之一. 然而，传统的生产方法更注重工艺，需要更多的时间，并导致更昂贵的袋子. 侧缝引起的弯曲问题会导致麻袋捆在运输过程中滚动，这也是另一个问题. 这项研究描述了一种生产无缝黄麻袋和麻袋的独特工艺，取消了目前的工艺，转而采用更少的工艺. 一种带切割装置的机械左手多臂织机，用于分离麻袋，生产连续的麻袋编织. 对所生产的麻袋的拉伸强度和接缝强度进行了评估，发现其与市售麻袋的拉伸和接缝强度相当. 此外，单因素方差分析和回归研究证明了结果的显著性. 这种开发的方法将提高生产力，同时减少能源消耗，从而生产出价格低廉的包装产品，并解决运输问题.

KEYWORDS:

• Seamless bag
• jute
• tensile strength
• seam strength
• elongation at break
• ANOVA

关键词:

• 无缝袋
• 黄麻
• 抗拉强度
• 接缝强度
• 断裂伸长率
• ANOVA

Introduction

Secondary packaging currently includes poly bags produced from high-density polyethylene (HDPE), low-density polyethylene (LDPE), and non-woven bags produced from polypropylene (PP). Polybags made of LDPE or HDPE raise global temperatures and emit plenty of CO₂, nevertheless jute bags reduce greenhouse gas emissions (Singh et al. 2023). Synthetic bags are popular because they are durable and affordable, but they are non-biodegradable and harm the environment. One hundred million to a trillion plastic bags are used annually, 10% of which end up in the ocean and pollute the environment (Pavel and Supinit 2017). World resources reports that 127 nations have laws restricting plastic bag use, although pollution is increasing on a massive scale (Excell 2019). The “Plastic era” is a global issue due to over 5 trillion tons of floating plastic polluting the ocean (Raha, Kumar, and Sarkar 2021). Since jute plants release 15 tons of CO₂ and 11 tons of oxygen per hectare, natural jute products are being promoted worldwide to replace synthetic items. Consequently, seamless jute products can reduce environmental effect, boost green marketing, and be an excellent solution to the alternative of plastic bags (Devi Juwaheer, Pudaruth, and Monique Emmanuelle Noyaux 2012).

Jute, called “Golden fiber,” is the second largest growing fiber after cotton because of its unique properties. Jute has a 20–50% smaller carbon footprint than synthetic fibers, making it appealing (Domingues et al. 2011; Prasad, Joseph, and Sekar 2018; Singh, Mukesh Kumar, and MITRA 2018). This research uses biodegradable, disposable, nontoxic jute for seamless bags to assure sustainability and eco-compatibility (Shahinur et al. 2022; Zhang, Khan, and Kole 2022). The demand for biodegradable jute products is increasing dramatically; which is expected to reach 4.2 billion dollars by 2028 (FAO 2023). Asian countries like Bangladesh, China, India, Nepal, Thailand, and Myanmar grow the most jute and dominate the global market (Khan et al. 2015). Global jute bags demand around 500 billion pieces (Islam 2019). Furthermore, the demand of jute bags and sacks was 2.5 billion dollars in the last fiscal year 2021–2022, where the major jute producing linear countries like Bangladesh and India exported 0.11923 and 0.284 billion dollars, respectively, that represented 4.76 and 11.36% of market share on a global scale as per Export Promotion Bureau (EPB) and Indian Jute Mills Association (IJMA) reports (EPB 2023; Statistic of Exports of Jute Goods from India - IJMA 2023). Nevertheless, the strength of sewn side seams is 25–50% lower than comparable body fabric, making that part of the bag the weakest part of the present bag (Mukhopadhyay, Chatterjee, and Majumdar 2015). Mahapatra et al. (2008) designed a long-procedure automatic jute bag production equipment that automated all traditional procedures. Although the jute industry advanced in the late 19th century, many enterprises failed to take use of new technologies. Most companies struggle to meet energy, machinery, and process expenses due to product changes, and machine adjustments. Improved production planning can save costs, maximize machine utilization, and boost revenue.

Jute sacks are commonly shipped in the shape of bundles. The sacks are arranged in a vertical manner, one on top of the other, in order to form cohesive units known as bundles. According to the local jute business, it has been observed that traditional jute bags tend to exhibit bowing at their side edges when subjected to shipping conditions, as depicted in Figure 1. This particular concern gives rise to the tendency of bundles to undergo rolling, hence leading to challenges in the process of transportation. The issue arose due to the presence of the side seam during the process of stacking bundles of sacks, resulting in a noticeable alteration in the shape of the bags. The exporters express a significant concern regarding this issue. Hence, the settlement of the aforementioned bowing issue would effectively enhance the management of the bundles of bags. Another concern pertains to the protracted manufacturing process employed in the production of commercial bags, necessitating increased time, labor, and expenditure. Therefore, this research is aimed to develop a seamless sack on a dobby shuttle loom with a minimum of four heald frames where several cutting arrangements are available, and there is no limitation regarding a four-sided bound, stitching plain weave which can be a suitable solution of aforementioned issues. Seamless jute bag offers a unique feature in that when the bags are delivered from the loom; they are self-stitched or sewn through weave, drafting and lifting plans, which reduces the process sequences of manufacturing and makes them available at a lower cost for consumer satisfaction.

Figure 1. Bundle of sacks ready for shipping (a), edge height deviation due to bowing (b).

Experimental

Materials and methods

Seamless jute bags or sacks can be produced on a dobby or jacquard loom. In this research, a left-handed shuttle-based dobby loom was used for the production of seamless continuous fabric. Bag specifications were collected from Janata Jute Mills Ltd., Narsingdi, Bangladesh, which manufactures jute bags commercially using the same specification. Our developed method is suitable for any shape in length and width.

Specifications of production parameters

Jute yarns were collected from the local market. The sack shape was chosen at 56 cm in length and 43 cm in width. The set construction of ends per decimeter (epdm) × picks per decimeter (ppdm) was (48 × 32) for samples S1-S4 and (48 × 40) for samples S5-S8, respectively. Bound selvedge was produced at a width of 7.6 cm on each side of the bag, and each bound selvedge coupled two sacks, respectively. Plain weave was selected for both end bound selvedge and the fabric’s body part. In Table 1, the manufacturing parameters are displayed.

Table 1. Specifications of jute yarn, seamless bag and loom used in this study.

Jute yarn specification
Parameters	Linear density (tex)	Twist per decimeter (tpdm)
Warp except handle portion	260	12.6 ± 0.5
Warp at handle portion	346/2	12.6 ± 0.5
Weft	216, 260, 346, and 460	12.6 ± 0.5
Jute bag specification
Bag length	56 cm
Ends per decimeter (epdm)	48
Bag width including both end bound selvedge	43 cm
Picks per decimeter (ppdm)	32 for sample no. (S1-S4) 40 for sample no. (S5-S8)
Specification of the dobby loom
Dobby type	Negative
No. of heald frames	4
Reed count in Stockport system	12’s
Denting plan	2 ends/dent for body, handle and selvedge part
No. of lattices required	~68
Shed angle of heald frame	Heald frame 1, H1 = 21.8º Heald frame 2, H2 = 22.55º Heald frame 3, H3 = 22.85º Heald frame 4, H4 = 23.10º

Weave and peg plan for warp yarn lifting

Figures 2a and 3a show the weave, drafting, and lifting plans for the body and bound selvedge portions, respectively. In the graph, the cross (×) sign represented the lifting position, and the blank demonstrated the lowering position of warp yarn to form a shed for the passage of weft yarn. F and B represent plain weave for face and back layer fabrics. The weave repeats for both body and stitching part were (4 × 4), where the vertical column and horizontal rows represented warp and weft yarns, respectively. A peg plan was prepared following the lifting plan of four heald frames H1, H2, H3, and H4. Additionally, the body part of the bag was constructed according to the weave plan as shown in Figure 2a, and binding edges were constructed by using the weave design as given in Figure 3a. According to Figure 2a, b, the bag was woven with two face and two back warp yarn along with two face and two back weft yarns, respectively. For the selvedge part, plain weave was used, as shown in Figure 3a, b. A straight draft was used to produce both body and selvedge parts, and by following the lifting plan, a peg plan was prepared for controlling the warp yarn’s lifting by heald frames. Each lattice contains the peg plan of two consecutive weft. The successive lattices were further connected to each other to form a pattern chain, as illustrated in Figure 3c. Furthermore, the lattice chains of two different lifting plans were changed according to the given fabric specifications.

Figure 2. Weave design for body part of the produced bag (a), weave diagram along with warp position at body part and handle side (b).

Figure 3. Weave design for selvedge side of the seamless bag (a), weave diagram along with warp position at selvedge side (b), peg plan with lattice chain (c).

Manufacturing process of seamless jute sacks

Pegs of the lattice chain in a pattern cylinder were used to control heald frames lifting for the required shed formation to produce double layer body fabric with both end bound selvedge and the single layer stitching fabric to couple double layers. The produced fabric in loom state condition seemed like a single layer fabric in bear eyes. Therefore, the mouth opening of the sack was created from which side the shuttle was first inserted. The seamless sack was produced continuously with double layers of body fabric and stitched bound selvedges. The bag was separated through the zigzag cutting across the middle of the bound selvedge, where zigzag cut edge prevented weft yarn from fraying, as displayed in Figure 4a. The continuous production of a seamless bag can be found in Figure 4b. With this innovative production mechanism, only a few processes were involved in completing the entire production sequence, such as weaving, cutting or separation, and final inspection, instead of the existing common industrial procedure comprising of many steps such as weaving, unwinding or opening, inspection, calendaring, laying, cutting, hemming, herakle sewing (Corteen and Parsons 1953) as shown in Figure 4b. As a consequence, the enormous process minimization from the existing industrial long processes, which may create a new era of business model in terms of depleting the manufacturing cost, product price, energy consumption, supply chain, and sustainability.

Figure 4. Separation of bag by zig-zag cutter (a), comparison between existing and developed process of seamless jute bag (b).

Specifications of the produced seamless bag and commercial bag

At first, four different types of commercial bags were purchased from Janata Jute Mills Ltd., analyzed their construction and termed as C1-C4, respectively. By keeping alignment with commercial bag, eight samples were developed using $\frac{1}{\hspace{0.17em}1}$ plain weave by varying different weft linear density and weft density. The samples are designated as S1-S8, respectively. The details of the produced samples are presented in Table 2.

Table 2. Specification of the produced samples and commercial bags used in this study.

Sample code	Seamless bag construction $\frac{Warplineardensity\left(tex\right)\times Weftlineardensity\left(tex\right)}{epdm\times ppdm}$ × Fabric width (cm)	GSM (gram per square meter)
S1	$\frac{260\times 460}{48\times 32}$ ×43	254 ± 3.22
S2	$\frac{260\times 346}{48\times 32}$ ×43	223 ± 4
S3	$\frac{260\times 260}{48\times 32}$ ×43	211 ± 3.84
S4	$\frac{260\times 216}{48\times 32}$ ×43	198 ± 4.77
S5	$\frac{260\times 460}{48\times 40}$ ×43	287 ± 4.61
S6	$\frac{260\times 346}{48\times 40}$ ×43	261 ± 4.48
S7	$\frac{260\times 260}{48\times 40}$ ×43	246 ± 4.34
S8	$\frac{260\times 216}{48\times 40}$ ×43	223 ± 3.68
Commercial bag construction
C1	$\frac{260\times 460}{48\times 40}$ ×54	299 ± 4.69
C2	$\frac{260\times 346}{48\times 40}$ ×54	285 ± 5.54
C3	$\frac{260\times 260}{48\times 40}$ ×54	256 ± 5.54
C4	$\frac{260\times 216}{48\times 40}$ ×54	234 ± 4.85

Testing methods

All the fabric specimens were conditioned for 24 hours at (65 ± 2) % RH and (20 ± 2) °C according to ASTM D1776 and BS EN 20,139 before testing, and final result was considered as the average value of five samples. The determination of tensile strength of single yarn was conducted in accordance with the EN ISO 2062: 2009 standard. This was achieved by subjecting the yarns to a universal strength tester, employing the constant rate of elongation (CRE) principle. The testing speed was recorded as 250 mm/min. The bundle yarn strength was measured in accordance with ISO 6939: 1988, utilizing the skein method. The measurements were performed using the same machine. The test speed was consistently maintained at a rate of 300 mm/min. The tensile strength of the fabrics was determined using the guidelines outlined in ASTM D5035–11: 2015. The strip method was employed, and the testing was done using the same universal strength tester at a speed of 300 mm/min. The seam strength of the samples was executed in accordance with ISO 13,935–2: 2014. The grab method was utilized, and the testing was performed utilizing the identical universal strength tester at a speed of 50 mm/min. The GSM (gram per square meter) was measured using the ASTM D 3776 standard method, employing a GSM cutter and an electric balance. The diameter of the used GSM cutter was recorded as 112.9 mm. The measurement of epdm and ppdm was conducted using a magnifying glass of (2.54 × 2.54) cm² dimension. Performances of seamless bags were statistically evaluated by SPSS V.20 software, where one-way ANOVA was applied to determine the proportion of variance.

Results and discussion

Analysis of mechanical properties

The mechanical properties of fabrics are crucial, particularly regarding the intended use. The mechanical qualities of the finished fabric depend on the fiber and yarn used to create it. Figure 5 illustrates the strength vs elongation curves of single and bundle yarn used in this study.

Figure 5. Tensile strength and elongation (%) of 460, 346, 260, and 216 tex single yarn respectively (a-d), and tensile strength and elongation (%) of 460, 346, 260, and 216 tex bundle yarn respectively (e-h).

The analysis of the results depicted in Figure 5 reveals that the yarn linear density of 216 tex demonstrates the highest tensile strength, measuring approximately 3.31 ± 0.26 MPa. In contrast, it was observed that the yarn with a linear density of 460 tex had the lowest tensile strength, which was measured to be roughly 1.74 ± 0.59 MPa. The finer yarns (216 tex) demonstrated increased tensile strength, as shown by an elongation at break of approximately 3.17 ± 0.40%. However, it was noted that coarser yarn (460 tex) demonstrated decreased levels of tensile strength, approaching the breaking elongation threshold of approximately 2.72 ± 0.32%. The experiment yielded a tensile strength of 2.26 ± 0.24 MPa for the 346 tex yarn and 2.81 ± 0.28 MPa for the 260 tex yarn. Additionally, the elongation at break for the respective yarns was determined to be 2.84 ± 0.23 and 2.97 ± 0.32%. Similar results were found for bundle yarns, with the 216 tex yarn linear density exhibiting the maximum tensile strength of 241.85 ± 8.46 MPa, while the 460 tex yarn linear density had the lowest tensile strength of 120.36 ± 7.98 MPa. The tensile strength of the 346 and 260 tex samples was measured to be 148.96 ± 5.37 and 183.69 ± 9.02 MPa, respectively. Additionally, the elongation at break for the 346 and 260 tex samples was found to be 16.34 ± 0.46 and 17.74 ± 0.33%, respectively. The yarn with a finer linear density generally demonstrated enhanced tensile strength and elongation at break due to factors such as a higher number of fiber in the yarn’s cross-section, optimal yarn twist, and longer fiber length (Sanyal 2017). Furthermore, it has been observed that the enhancement in tensile strength for both single and bundle yarns, as the linear density rises, ranges from 20% to 30%. Additionally, the rise in elongation percentage from individual to bundle yarns is approximately four to five times greater, primarily attributed to the amplified absorption of instantaneous energy (Ullah, Shahinur, and Haniu 2017).

The evaluation of a fabric’s durability is commonly based on its tensile strength, which is considered a crucial quality factor. The measurement is determined by quantifying the magnitude of force required to cause fracture in the sample, either along the warp or weft orientation. Figure 6 illustrates the standard curves representing the tensile strength and elongation at break (%) in the weft direction for seamless jute and commercial bags, respectively. In this research, the manufactured seamless and commercial bags have the same warp yarn linear density and warp density; nevertheless, the warp way tensile strength differs to a minimal level due to the variance in weft yarn linear density and weft yarn density. Therefore, weft direction tensile strength has been highlighted. Because the produced bags will be used in load-bearing applications, this research has focused solely on assessing their tensile strength, elongation at break, and seam strength properties which are the most significant characteristics of a sack.

Figure 6. Tensile strength and elongation (%) of fabricated seamless bags (S1-S8) respectively (a-h), and tensile strength and elongation (%) of commercial jute bags (C1-C4) respectively (i-l).

Table 2 shows that samples S1-S4 have identical values for warp linear density, epdm, and ppdm, the only variable is weft linear density. Similarly, for samples ranging from S5-S8, the construction of the fabric was altered with 40 ppdm. Again, the variable was the weft linear density. According to the data presented in Figure 6, the tensile strength values for samples S1-S4 were observed to be 41.45 ± 0.37, 44.55 ± 2.85, 46.80 ± 1.21, and 48.04 ± 3.39 MPa, respectively. Additionally, the corresponding elongation at break values were found to be 7.56 ± 0.12, 8.015 ± 0.41, 8.81 ± 0.44, and 9.93 ± 1.81%. Consequently, the measured tensile strength shown an increase from 41.45 to 48.04 MPa, while the elongation at break demonstrated an increase from 7.56 to 9.93%. Thus, it can be concluded that the transition from coarser to finer weft linear density resulted in a progressive increase in tensile strength and breaking elongation. In contrast, as the number of ppdm increased for samples S5-S8, tensile strength and elongation at break increased significantly compared to samples S1-S4. The S5-S8 samples exhibited tensile strength of 48.25 ± 0.57, 53.36 ± 1.84, 56.91 ± 3.12, and 62.86 ± 3.33 MPa, respectively. Additionally, their corresponding elongation at break values were measured as 10.03 ± 0.36, 11.04 ± 1.04, 11.48 ± 0.47, and 12.18 ± 0.84%, respectively. Therefore, it can be inferred that the fabric constructions of commercial bag samples C1-C4 are similar to those of samples S5-S8. Based on the data shown in the Figure 6, it was observed that the tensile strength values for samples C1-C4 were determined to be 42.07 ± 3, 54.27 ± 2.90, 56.05 ± 3.63, and 61.37 ± 1.86 MPa, respectively. Additionally, the corresponding elongation at break values for these samples were found to be 9.98 ± 1.34, 10.31 ± 0.81, 10.96 ± 0.64, and 11.9 ± 0.14%. The performance exhibited by the seamless bags manufactured was found to be similar to that of commercial bags. The observed rise in tensile strength for samples S1-S4 exhibited an approximate range of 2.5–7.5%. Conversely, samples S5-S8 displayed a higher tensile strength, ranging from roughly 16–30%, owing to the incorporation of wefts. This increase in tensile strength was comparable to that of the commercially available bags C1-C4, where the increment range is 10–29%. The higher tensile strength resulted from the sequential use of coarser to finer yarn and weft density, which allowed stress and strain to be readily dispersed (Ferdous et al. 2014). In addition, the elongation at break increased by approximately 1.2–1.3 times from S1-S4 to S5-S8 due to the instant energy captivation (Amirbayat 1993). The samples S5-S8 generated in this study exhibited comparable, and in certain cases, superior tensile strength and elongation at break when compared to commercial bags C1-C4 that have a similar construction. This difference in performance could potentially be attributed to the quality parameters of the fiber and yarn used, despite the fact that the weave structure was identical. The seam strength of bags mainly depends on weft way fabric strength which bears the stresses at the seam, sewing thread quality and stitch density, while others can be considered as minor influencing parameters (Paul et al. 2015). Following the method of grab test, the seam strength of the produced sacks and commercial bags was evaluated, and their typical seam strength curves have been presented in Figure 7. Under the direction of the warp, the bound portion of all the produced samples was tested, as were all the commercially available samples. Figure 7 demonstrates that the progressive increase in the linear density of yarn and pick density the seam strength to increase from low to high. Therefore, ppdm was 32 maintained for samples from S1-S4 and 40 was kept for samples from S5-S8, with the weft linear density being the only variable. However, it should be noted that sample S1 demonstrated the lowest seam strength, measuring at 5.6 ± 0.46 MPa, whilst sample S4 displayed the highest seam strength, measuring at 8.75 ± 0.44 MPa. The samples labeled as S2 and S3 exhibited seam strengths of 6.43 ± 0.65 and 7.14 ± 1.27 MPa, respectively. The elongation values for samples S1-S4 were determined to be 25.10 ± 2.04, 29.38 ± 2.43, 33.15 ± 2.35, and 34.67 ± 1.70% correspondingly. In a comparable manner, it is evident that the seam strength of the created sample S5 and the commercial sample C1 displayed the lowest measurements, with values of 9.05 ± 0.69 and 15.44 ± 2.25 MPa, respectively. In contrast, it is important to highlight that the S8 and C4 had the most elevated levels of seam strength, with measurements of 14.14 ± 0.91 and 23.7 ± 3.71 MPa, respectively. The measured strength of the S6 sample was determined to be 11.05 ± 1.90 MPa, whereas the strength of the S7 sample was found to be 14.15 ± 0.91 MPa. The strength values of the C2 and C3 samples were calculated as 20.53 ± 2.49 and 21.44 ± 2.61 MPa, respectively. Furthermore, the elongation at the point of fracture for the S6, S7, and S8 samples was determined to be 41.29 ± 3.62, 45.14 ± 3.06 and 47.96 ± 3.21% correspondingly. The elongation at break values of the C1-C4 samples were measured to be 29.29 ± 1.48, 32.34 ± 1.65, 35.65 ± 1.52, and 54.26 ± 7.61% correspondingly. The study revealed that commercial bags exhibited superior seam strength and elongation due to the utilization of herakle sewing technique and 2-ply yarn as the stitching thread.

Figure 7. Seam strength and elongation (%) of fabricated seamless bags (S1-S8) respectively (a-h), and seam strength and elongation (%) of commercial jute bags (C1-C4) respectively (i-l).

Statistical analysis of mechanical properties by ANOVA

The statistical analysis of variance using a one-way ANOVA was used in this study to determine the impact of weft linear density variation on seamless jute bags and commercial bags. In this case, a p-value less than 0.05 was regarded as statistically significant. From Table 3, elongation, seam strength, and GSM of the bags were significantly impacted by the change in yarn linear density for samples S1–S4; similarly, when the ppdm was increased from 32 to 40 for samples S5–S8, the sequential change of weft linear density from finer to coarser significantly influenced all the tested properties including tensile strength, as shown in Table 3. Table 3 also shows that all attributes considerably differed due to the variance in weft linear density for commercial bags (C1-C4). Table 4 displays the relative importance of the manufactured seamless bags with identical commercial bag construction. It has been discovered that samples C1 and S5 differ significantly in terms of tensile strength and seam strength, whereas samples C2 and S6 vary significantly in terms of seam strength and GSM. Samples C3 and S7 have considerable seam strength variation, whereas samples C4 and S8 have significant seam strength and GSM variance.

Table 3. ANOVA test results of S1-S4, S5-S8, and C1-C4 samples for shot count variation.

Samples	Performance properties	Source	df	Sum of squares	Mean square	F	p-value
S1-S4	Tensile strength	Factor/Shot count Error	3 16	127.102 268.655	42.367 16.790	2.523	0.094
	Fabric Elongation	Factor/shot count Error	3 16	16.229 18.395	5.410 1.150	4.705	0.015
	Seam strength	Factor/Shot count Error	3 16	26.775 12.198	8.925 0.762	11.706	.000
	GSM	Factor/Shot count Error	3 16	8605.000 420.000	2868.393 26.250	109.270	.000
S5-S8	Tensile strength	Factor/Shot count Error	3 16	562.906 123.462	187.635 7.7164	24.316	.000
	Fabric Elongation	Factor/shot count Error	3 16	16.229 18.395	5.410 1.150	4.705	.015
	Seam strength	Factor/shot count Error	3 16	68.336 26.985	22.778 1.686	13.508	.000
	GSM	Factor/shot count Error	3 16	11147.400 668.800	3715.800 41.800	88.895	.000
C1-C4	Tensile strength	Factor/Shot count Error	3 16	998.249 245.720	332.749 15.357	21.667	.000
	Fabric Elongation	Factor/Shot count Error	3 16	10.660 14.559	3.553 .910	3.905	.029
	Seam strength	Factor/Shot count Error	3 16	184.270 159.410	61.423 9.963	6.165	.005
	GSM	Factor/Shot count Error	3 16	11147.400 668.800	3715.800 41.800	88.895	.000

Table 4. Comparison of ANOVA test results between commercial and produced seamless bag.

Performance properties	p-value
	Sample (C1 and S5)	Sample (C2 and S6)	Sample (C3 and S7)	Sample (C4 and S8)
Tensile strength	.004	.612	.788	.457
Fabric Elongation	.953	.301	.232	.524
Seam strength	.001	.000	.000	.001
GSM	.053	.001	.062	.007

Production and costing

The estimated production and costs of a seamless bag have been calculated and compared to those currently available on the market. The used motor speed for the dobby loom was 960 rpm (rotation per min) with an efficacy of approximately 70%, whereas the crankshaft rpm was 171. The crankshaft rpm indicates the loom speed. In addition, the diameters of the motor and machine pulleys were 6.35 and 35.56 cm, respectively. The produced bags S5-S8 contained 40 ppdm and 122 cm of used reed space. Loom production can be calculated by dividing the rpm of the crankshaft (loom speed) by the weft per cm. Nevertheless, the following equation describes the production of seamless jute fabric.

$\frac{\mathrm{l}\mathrm{o}\mathrm{o}\mathrm{m}\mathrm{s}\mathrm{p}\mathrm{e}\mathrm{e}\mathrm{d}}{\mathrm{w}\mathrm{e}\mathrm{f}\mathrm{t}\mathrm{p}\mathrm{e}\mathrm{r}\mathrm{c}\mathrm{m}}\hspace{0.17em}=\frac{171\hspace{0.17em}\times \hspace{0.17em}60\hspace{0.17em}\times \hspace{0.17em}0.70\hspace{0.17em}}{4\hspace{0.17em}\times \hspace{0.17em}100\hspace{0.17em}}\cong 18\mathrm{m}\mathrm{e}\mathrm{t}\mathrm{e}\mathrm{r}/\mathrm{h}\mathrm{o}\mathrm{u}\mathrm{r}$

In contrast, the local weaving industry, such as Janata Jute Mills Ltd., from which commercial bags were congregated, produced approximately 13 meter/hour of fabric. In addition, the seamless bags produced on a loom/hour were equivalent to approximately 30 bags, whereas the number of commercial bags was approximately 24 with similar dimensions. Table 5 provides a comprehensive breakdown of the cost computation, with precise information on the various expenses involved. Hence, considering the observed rise in productivity and decrease in the number of processes, as presented in Table 5, it can be concluded that the produced seamless bag would offer a higher level of cost-effectiveness compared to commercially available bags.

Table 5. Cost calculation after weaving process of fabric to bag formation (courtesy to Janata Jute Mills Ltd.).

	Commercial jute bags
Sections	No. of machines	Total operators involved in 24 hours	Avg. wages (BDT)/day	Total cost (BDT)	Electricity used (KW) in 24 hrs	Cost in USD (1 $ = 108 BDT)	Seamless jute bags
Fabric opening	2	6	250	1500	180	13.88	Fabric separation process is needed
Calendaring	2	6	240	1340	357.84	12.40	Eliminated
Laying and cutting	1	12	270	3240	120	30	Eliminated
Hemming	6	78	325	25350	9.6	234.72	Eliminated
Herakle sewing	12	132	290	38280	12	354.44	Eliminated
Maintenance cost		12	320	3840		35.55	Required
Electric cost (12 BDT unit; average used 680 KW/day)				8153		75.49	Required
Total		246 (manpower/day)		81,703		756.48/day	Expected to be lower cost due to process minimization

Correlation of the mechanical properties

Figure 8 depicts the relationship between yarn linear density, strength, and elongation for both single and bundle yarn. For single yarn strength and elongation, the R-square correlation of linear fitting was 0.9689 and 0.9102, and for double yarn strength and elongation, it was 0.8772 and 0.87. The slope and intercept of the curves for single yarn strength and elongation were (−0.0062, 4.5331), (−0.0017, 3.4831) and (−0.4554, 319.68), and (−0.0271, 26.132) for bundle yarn strength and elongation, respectively. Therefore, the relationships between yarn linear density, strength, and elongation can be calculated using equations from Figure 8(a–d). The regression curves ensure that finer yarn strengthens the yarn and, as a result, more elongation occurs. The correlation between fabric construction, tensile strength, and elongation for samples (S1-S4) and (S5-S8) can be calculated using equations from Figure 8(e–h), while the seam strength and elongation can be calculated using equations from Figure 8(i–l). For samples S1-S4, the R-square correlation of linear fitting for fabric strength and elongation was (0.9643, 0.9665), and for samples S5-S8, it was (0.9915, 0.6958). Slope and intercept of the curves were (2.2141, 39.668), (0.7921, 6.6013) for sample S1-S4 and (0.5958, 9.4598), (0.5958, 9.4598) for sample S5-S8. The R-square correlation of linear fitting for seam strength and elongation of fabric was (0.9625, 0.9624) for samples S1-S4 and (0.9915, 0.9913) for S5-S8. The slope and intercept of the curves were (1.0153, 4.4461) and (3.2501, 22.455) for samples S1-S4 and (1.6462, 7.5105) and (3.6848, 33.629) for S5-S8. All the values are extremely close to the linear fit curve. The regression curves demonstrate the correlation that, as the linear density of the weft yarn increases, the fabric strength, seam strength, and elongation property also increase.

Figure 8. The linear fit curve of single yarn strength and elongation respectively (a, b), bundle yarn strength and elongation respectively (c, d), tensile strength and elongation for S1-S4 samples respectively (e, f), tensile strength and elongation for S5-S8 samples respectively (g, h), seam strength and elongation for S1-S4 samples respectively (i, j), seam strength and elongation for S5-S8 samples respectively (k, l).

Conclusion

In contemporary society, there is a prevailing emphasis on the use of sustainable packaging bags as a means to mitigate the ongoing environmental contamination resulting from the utilization of synthetic packaging bags. Furthermore, all sectors engaged in the manufacturing of packaging bags are currently grappling with diminished production rates, escalated energy and operational expenses, as well as elevated labor expenditures. In this study, a unique approach has been developed to manufacture environmentally-friendly jute bags that exhibit energy efficient, labor-intensive characteristics, and cost-effective while simultaneously preserving mechanical attributes equivalent to those of conventional commercial bags. The present study utilized a dobby loom operated by a left-handed individual to manufacture jute bags that were seamless in loom-state condition. This approach has the potential to enhance productivity by reducing the duration of time-consuming procedures. Additionally, this methodology effectively addresses the problem of side edge bowing during transportation. This study proposes leveraging the Internet of Things (IoT) to facilitate advancements in automating the selection of heald frames according to pattern design. However, the implementation of this revolutionary technology has the potential to supplant the current conventional approach to jute bag production, thereby propelling the industry toward a trajectory of both profitability and sustainability. The findings of this research have the potential to benefit not only the jute businesses, but also the country’s policy-making body in their efforts to promote the sustainable and transformative process of jute bag production.

Highlights

• The innovative technique for producing seamless bags eradicates the laborious and time-consuming procedure.

• The unique process effectively mitigates the occurrence of side edge bowing during the process of bag stacking for transportation purposes.

• Seamless bags exhibit mechanical qualities that are comparable to those of commercially available bags.

• Seamless bags have the potential to offer cost savings and improved energy efficiency compared to conventional commercial bags.

Acknowledgments

This work was supported by the grant (5921) from the Bangladesh University of Textiles (BUTEX), Dhaka, Bangladesh. The authors gratefully acknowledge the financial support from the Funding.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The authors elect not to share data.

Additional information

Funding

The work was supported by the Bangladesh University of Textiles (BUTEX), Dhaka, Bangladesh [5921].