Difficulties and Solutions for Automated Production of Bedding
Home textiles, clothing and industrial textiles constitute the three pillars of the textile industry together. In Europe and the USA, the total consumption of home textiles accounts for about 1/3 of the entire textile category, and the proportion of consumption in my country's home textile industry has also been gradually increasing in recent years. Bedding is an important category in the home textile industry, and it is a category with a relatively high consumption among current household textile products. Bedding is a typical labor-intensive product, and the main production processes include cutting, sewing, embroidery, printing, sorting and inspection. With the continuous increase in labor costs and the disappearance of the demographic dividend, bedding companies urgently need to accelerate industrial upgrading, improve the degree of production automation, and improve production efficiency, and achieve high-quality development.
1 Basic concepts
(1) Bedding usually refers to bedding textiles used for covering, warmth, decoration, protection, etc., referred to as bedding. The main products include bed sheets, quilt covers, pillowcases, mattresses (also known as protective pads, quilts), quilt cores, pillow cores, bedspreads/bed covers, fitted sheets, bed flags, bed guards, etc. Bed sheets, quilt covers, and pillowcases are usually called set products, and mattresses, quilt cores, and pillow cores are also called core products.
(2)Automated production refers to the process in which machinery, equipment, systems, or processes (production, management processes) achieve the expected goals in accordance with requirements without or with few people directly involved, through automatic detection, information processing, analysis and judgment, and manipulation and control. The automated production of bedding mainly includes a series of processes such as cloth inspection, material loading, material feeding, sewing, cutting, inspection and packaging.
2 Automated production of bedding
2.1 Production characteristics of bedding
(1) The main raw materials of set bedding are fabrics, and the main raw materials of core products are fabrics and fillings. The auxiliary materials include zippers, buttons, cords, lace, etc.
(2) The basic process flow of bedding production is: fabric inspection - cutting - sewing - finishing - inspection - packaging. Core products also have filling and quilting processes. Special products may also have ironing, embroidery, printing and other processes. These existing processes are basically completed manually, and the degree of automation is very low.
(3) Labor-intensive products, the main production processes are cutting, sewing, inspection and finishing, packaging, etc., which use a lot of labor.
2.2 Current status of automated production of bedding products
2.2.1 Kit products
Kit products already have single-product automated production equipment, such as bed sheet four-side sewing production lines, quilt cover automatic production lines, and pillowcase production lines. These equipment have been used in the domestic market for more than 10 years, but the adaptability, maturity and popularity of this type of equipment are not high. Currently, only some large home textile foreign trade export production enterprises and a few brand home textile enterprises are using them. The main feature of this type of equipment is that it can sew continuously, breaking the original process sequence of cutting first and then sewing. Taking the kit as an example, the process flow becomes: fabric inspection and marking - trimming - sewing - cutting (avoiding cutting) - sewing - re-sewing - finishing - inspection and packaging (Figure 1). In this process, infrared automatic detection, AI artificial intelligence recognition, PLC control and other technologies are used.
2.2.2 Core quilt products
The automation of core quilt products is mainly reflected in logistics, such as the use of hanging lines, partial folding and packaging, etc. In the main production links of products, my country does not have mature production equipment. Very few foreign trade production enterprises have used Spanish core quilt production lines, but the equipment has a small range of application and can produce some simple quilt cores with trimming, single-component pillow cores, etc. The equipment mainly has functions such as automatic filling, automatic quilting and cutting, and trimming.
2.2.3 Production efficiency comparison
Taking the simple four-side sewn sheets and rice bag pillowcases for foreign trade as an example, considering the material change time, the output is shown in Table 1. As shown in Table 1, the automated production efficiency can be increased to 10 times.
3 Difficulties in automated production of bedding
Automated production equipment for bedding has been in the market for more than 10 years, but there are still some bottlenecks in the process of advancing automation of bedding. Its development is very slow, and the current penetration rate is less than 10%.
3.1 Large capital investment
Automated bedding equipment has not yet formed a mass production scale. The initial design and development investment is large, and its cost is high. The existing kit production equipment, such as the relatively mature domestic single bed machine and pillowcase machine, are priced at around 2 million, and the quilt cover machine is priced at around 2.5 million. The equipment cost of quilt cores and pillow cores is higher than that of some imported equipment. At present, most home textile bedding companies are small and medium-sized production companies, and the profit margins of bedding companies are not high. These investments are very stressful for companies.
3.2 Low product adaptability
Bedding automation equipment has low adaptability. For example, the bed sheet machine can only make square corners, not rounded corners; pillowcase machines are divided into rice bag pillowcase machines and envelope pillowcase machines, and the principles of the two devices are different; special processes such as hand-gripping technology, zipper installation technology, and lacing technology of quilt covers cannot be embedded in the automation link; fabric adaptability is weak, and there are some restrictions on knitted fabrics; it is not suitable for small batch and multi-variety production mode, etc., which brings many concerns to bedding companies in selecting models.
3.3 Waste of raw and auxiliary materials
Continuous sewing equipment and edge trimming equipment both involve trimming and aligning fabrics or semi-finished products, which makes the fabric width cannot be fully utilized. In addition, continuous sewing must avoid cutting when encountering fabric joints and defects. Compared with manual cutting, it lacks flexibility, resulting in waste and increased costs.
3.4 Sewing stitch problems
Automatic continuous sewing is widely used in the automated production of bedding, but most of the stitches are chain stitches, which cannot be reversed and are easy to fall apart at the beginning and end of sewing.
4 Solutions to promote automation in the home textile industry
The home textile industry must accelerate the transformation and upgrading and achieve high-quality development by accelerating the promotion of production automation. In view of the development bottlenecks mentioned above, combined with the development of production automation and intelligent technology, as well as the characteristics of the home textile industry, the following solutions are proposed.
4.1 Dealing with the problem of large investment in automation upgrades
(1) Domestic automation equipment manufacturers should find ways to reduce costs and lower equipment prices so that more companies can afford them.
(2) Enterprises need to calculate the input-output account. The use of automated equipment can save labor costs, and thus calculate the investment payback period. Investment payback period = equipment investment/(labor costs saved per product after deducting equipment manufacturing costs × annual output). This calculation method does not take into account the factor of capital interest, which can be offset by the sales growth brought about by equipment investment. After the calculation, the enterprise conducts a comprehensive assessment and decides whether to invest.
(3) You can apply for the government's smart transformation and digital transformation and industrial upgrading projects to obtain special subsidies.
(4) You can consider planning enterprise investment once and implementing it in steps to reduce the pressure of one-time investment.
4.2 Multiple methods to solve the problem of poor adaptability
(1) Disassemble the process, design the corresponding automated equipment or product switching tooling according to the disassembled process, and flexibly integrate the process logistics equipment such as hanging chains, assembly lines, AGV, etc. To achieve rapid product switching. For example, in the production of bed sheets, the first step is to sew the two sides and cut them, then transport them to the designated workstations through AGV, and finally sew them through rail cars. For example, in the production of pillow cores, first customize an automated production of pillow core shells, then customize an automatic filling device, and also provide a series of sealing, beating, and rolling equipment, which can be connected in the middle by hanging.
(2) Disassemble the process, design the corresponding automated equipment or product switching tooling according to the disassembled process, and flexibly integrate the process logistics equipment such as hanging chains, assembly lines, AGV, etc. To achieve rapid product switching. For example, in the production of bed sheets, the first step is to sew the two sides and cut them, then transport them to the designated workstations through AGV, and finally sew them through rail cars. For example, in the production of pillow cores, first customize an automated production of pillow core shells, then customize an automatic filling device, and also provide a series of sealing, beating, and rolling equipment, which can be connected in the middle by hanging.
(2) Equipment companies should consider the difficulties of home textile industry manufacturers and carry out flexible transformation and research and development of equipment to improve the adaptability of equipment. Equipment companies can jointly develop with multi-variety and small-batch bedding manufacturing companies, use project management thinking, let technical personnel participate in the planning, design, sales, production and other links of equipment throughout the process, analyze the production process characteristics of each company's products, and formulate automated production plans that meet the company's current situation. For example, in pillowcase production equipment, some fabrics are fed horizontally, while others are fed vertically; some products are rice bag style, while others are envelope pillows; some products have openings on the side, while others have openings on the back. Equipment companies need to carefully study various different situations and customize them according to the company's situation.
(3) Bedding companies should adjust the production organization form and optimize the product structure based on the characteristics of the equipment, disassemble the production process of some small batch products, and automate the production of batches of single processes with the same process and the same raw materials to increase the production automation ratio. In addition, methods such as rapid switching of raw and auxiliary materials should be studied to reduce waiting time for the process and improve production efficiency.
4.3 Strengthen process control and reduce waste
To strengthen the management of fabric acceptance, AI technology can be used in combination with information processing technology to customize automatic fabric inspection equipment to mark fabrics. In the process of automatic sewing and cutting, AI and other technologies can be used for identification and avoidance of cutting, and combined with the automatic edge alignment system for adjustment to minimize fabric cutting.
4.4 Compensation and improvement of stitches
(1) The main compensation method at present is to retain the longer chain sewing start and end threads to ensure that the stitches do not fall off. Another method is to reinforce them manually later, but this reduces production efficiency.
(2)It is recommended that equipment companies increase the research and development of equipment. First, strengthen the research and development of flat stitch stitches, improve the flat stitch shuttle, and replace the shuttle with a large thread ball. Second, increase the use of large shuttles and the stability of automatic shuttle changing technology to improve production efficiency and reduce the adverse effects of stitches on products.
5 Conclusion
Automated production technology will develop rapidly in the next few years. This paper analyzes the problems existing in the current automated production of bedding products and proposes solutions from the aspects of investment, adaptability, process control, and stitches. It is hoped that this will bring some inspiration to related companies.