A New Device for Needle stitch Non woven Bags Automatic Process

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2018 2nd International Conference on Modeling, Simulation and Optimization Technologies and Applications (MSOTA 2018) ISBN: 978-1-60595-594-0

A New Device for Needle-stitch Non-woven Bags Automatic Process

Lin WANG

1

and Ya-zhou CHEN

2,*

1

College of Computer Engineering, Jimei University, Fujian 361021, China 2

College of Mechanical and Energy Engineering, Jimei University, Fujian 361021, China *Corresponding author

Keywords: Needle-stitch, Non-woven, Hand bag, Automatic process device, Design.

Abstract. As needling non-woven hand bags are usually sewed manually so an automatic process device is designed in order to reduce its process cost, lighten its labor intensity and improve its process efficiency. This device is mainly composed of a pull-apart mechanism, a leveling mechanism and a press and transmission mechanism. The work principle of these mechanisms have been thoroughly analyzed. How to determine its main parametric has been discussed. The action process of them has been given and the 3D modelings have been established. Using this new device the handle of a bag and the body of a bag can be sewed in one step. A prototype testing result proves that this device is feasible.

Introduction

A Non-Woven fabric is also called a non-woven cloth and it is widely used in daily life. Compared with an ordinary plastic bag, a non-woven bag can be decomposed naturally which make it has the characteristic of green, environment-friendly and pollution-free. There are two main production processes for a non-woven handbag[1]: (1) an ultrasonic welding method; (2) a needle-stitch weave method. Because the control process is relatively easy the former has basically realized an automatic process. However, due to the difficulty in feeding and positioning of a soft base fabric, a non-woven bag production process which used a needle-stitch sewing method is still depended on the workers manually. It can bring on problems such as a low processing efficiency, a high labor intensity, a high processing cost and a poor consistency of product quality. It is one of the key technical problem that hoped to be solved when an automatic or a semi-automatic needling stitch process can be realized[2-4].

The Work Principle of This Device

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提手 直边

侧边

袋底

袋身 包边

a straight edge

a bag body a handle

a wrapping edge a side edge

a bag bottom

(a) a handle

(b) a bag body

3

2

0

m

m

330mm

95m m 140mm

30mm

fold a straight edge pull and level a handle

( c ) a semi finished hand bag

Figure 1. A Handbag Structure. Figure 2. The Process Procedure of a Handle Bag.

A kind of chain forming device is proposed in this paper to realize a non-woven bag automatic processing. This device are mainly composed of a chain transmission mechanism, a guide rail, a pull-apart mechanism, a cutting mechanism, a pressing and transmission mechanism, a leveling mechanism, a bag-body conveying mechanism and a sewing mechanism, and so on(Figure 3).

The chain transmission mechanism is composed of eight sprockets, which includes four active sprockets, four driven sprockets and four chains. Two chains form a working unit which can drive a pull-apart mechanism that installed on it to and fro.

The guide track limits the track or the path of the pull-apart mechanism.

The pull-apart mechanism is the main working part. It is mounted on a pair of chains through an attachment plate.The handle of a handbag is wound around the column of a pull-apart mechanism(see Section How to Design a Pull-apart Mechanism). When the chain is driven by a chain sprocket, the pull-apart mechanism will moves along the X direction (Figure 3), at the same time because the bottom of the pull-apart mechanism is constrained by a guide rail so it will also moves along the Y direction. As a result a handle is pulled from a straight line into a U-shape so a handle can been automatic gotten.

a leveling mechanism

Y

X a drive sprocket

a drive sprocket shaft a chain a cutting tool

a guide rod a mounting block

a leveling mechanism

a pull-apart mechanism a driven sprocket a driven sprocket shaft

a chain drive mechanism a guide rail

a pull-apart mechanism

a cutting mechanism

a press and transmission mechanism

(b) A side view (a) A top view

Figure 3. A Schematic Diagram of a Chain Forming Processing Device for a Handbag.

When a handle is wound on the column of a pulling-apart mechanism, it is in an upright state. In order to sew a handle with the body of a handbag, a handle must be adjusted from a upright state to a horizontal state. A leveling mechanism (Figure 3) is used to realize this function. A handle can be leveled in two horizontal state which showed in Figure 4. Comparing with Figure 4(a) and Figure 4(b) it can be found that the handle in Figure 4(b) is distorted, so the handle in Figure 4(a) is a correct leveled form and the handle in Figure 4(b) is a wrong leveled form. A leveling mechanism is designed in order to leverage a handle when its state is as in Figure 4(a) and its work principle will be explained in Section How to design a leveling mechanism.

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After the operation of a pull-apart mechanism a handle comes in pairs. Using a cutting mechanism it can be cut into two separate parts. There may be two cutting method:(1) designing an upper blade and a lower blade and using them to realize a handle cutting; (2) designing a rotary disk cutter to realize a handle slitting. Considering the difficulty of the mechanism implementation, a circular disc cutter which the diameter of it is 300mm and the thickness of it is 1.5mm is designed.

Before a handle is cut off it is in a tension state due to wind around the column of a pull-apart mechanism. After a handle is cut by a disc cutter, a whole handle will be divided into two separate parts. Without an external pull force a single handle will be in a free unconstrainted state and will lead a soft non-woven fabric handle rebound which made it cannot keep a U pattern any more. So a handle press and transmission mechanism is designed and its work principle will be explained later.

The bag body conveying mechanism is designed to realize a body coil material continuous supply. The initial shape of a body coil material is cylindrical. In order to ensure a reliable delivery of a soft non-woven fabric bag body, a certain tension must be maintained among the soft bag bodies. In order to avoid a left side excessive deviation or a right side excessive deviation the horizontal conveying position of a bag body must be adjusted in a real time. The bag body conveying mechanism is mainly composed of a feeding part, a unwinding part and a rectifying part. The feeding part is composed of a pair of roll-to-roll rubber rollers and there is a certain amount of friction between with the rubber rollers. When a bag body is passed through it, the friction force will send the bag body forward. The unwinding part is driven by a pair of gears which is controlled by a magnetic powder braker. It can exert a reverse braking force on the unwinding part which can make a body coil material in a tension state so that it can be transported reliably. Though a feedback signal the rectifying part can realize a left side compensation movement or a right side compensation movement so that the horizontal conveying position of a bag body conveying mechanism can be adjusted in a real time[1].

A shaped handle and a shaped bag body can be transported into a sewing mechanism through a press and transmission mechanism, so that a handle and a bag body can be sewn into the shape shown in Figure 2(c) at one time. A sewing machine is made up of an industrial multi-needle sewing machine and its controller. A semi-finished non-woven bag can be cut into separate parts through a cross-cutting machine and it can be sent to subsequent processes for further process.

How to Design These Main Mechanisms

How to Design a Pull-apart Mechanism

The pull-apart mechanism is the main working component. The key design parametric of it is according to the length (l) of a non-woven bag handle:

r b c a

l 2   (1)

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c

a

r b

the pull-apart mechanism

传动链 提手拉 分机构

提手

导轨

X

Y

the chain

the handle

the guide rail

绕柱35

安装块31 调整板36

导杆34 滑动块33

链条附板 滚子32 a mounting block

a column an adjust panel

a chain attaching

plate a runing pulley a sliding blocka guide rod

(a) The size relation of the pull-apart mechanism (b) The 3D modeling

Figure 5. The pull-apart mechanism.

A 3D model of the pull-apart mechanism is established(Figure 5(b)). It is mainly composed of a mounting block, a running pulley, a sliding block, a guide rod, a winding column and an adjustment plate, etc. The inspiration partly come from the patent[5-6]. The pull-apart mechanism is installed on the chain attaching plate through a mounting block and the chain attaching plate is installed on the chain transmission mechanism. The running pulley of the pull-apart mechanism is a common cylindrical roller bearing, which is confined to the guide rail. When the running pulley moves along the X direction it can roll along the inner wall of the track, so the rolling friction force is small. The sliding block is equipped with a linear bearing so that it can realize a Y direction straight line motion along the guide bar. The column can be rotated along the axis of the column so that when the handle is wound around a column it can maintain certain tension without being pulled apart due to excessive tension. The adjustment plate is designed to adjust the work position of a pull-apart mechanism which can reduce the influence of an installation error or a manufacturing error. Therefore, the designed mechanism is more ingenious. The assembly relationship between a pull-apart mechanism, a chain drive mechanism and a guide rail is shown in Figure 5(b).

How to Design a Leveling Mechanism

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the roller

rod1

the initial state of a handle

the roller

rod1

the final state of a handle

rod1

rod2

rod3

the roller rod1

rod2

rod3 the roller

the initial state of a handle

the final state of a handle

(a)The Upper Part of a Leveling Mechanism (b)The Lower Part of a Leveling Mechanism Figure 6. The Action Principle of a Leveling Mechanism.

放大

mangnify

限位杆

上支撑杆 上支撑杆

轴承座

连杆1

下支撑杆 轴承座

滚轮

下支撑杆

拉簧 连杆2

a spring a connecting rod1 a connecting rod2

an upper support bar

a roller

a lower support bar a bearing block

a limited rod a bearing block

(a) the 3D assembly model (b) the partial magnified view

Figure 7. The Leveling Mechanism.

A leveling mechanism 3D model is designed (Figure 7) and a partial magnified view of the left of it given in Figure 7(b). The upper leveling mechanism (Figure 7(a)) and the lower leveling mechanism (Figure 7(b))are connected together by a connecting rod2 which can enable them to move simultaneously. When the roller in Figure 7(b) is touched with the mounting block of a pull-apart mechanism (Figure 7), the roller will be jacked up and the leveling mechanism is triggered. When the pull-apart mechanism is pulled forward by the chain, the leveling mechanism cannot be triggered if the roller is untouched with the mounting block. So that when this mechanism avoids an interference between a leveling mechanism with a handle at the same time it can move intermittently. Therefore, the whole mechanism is designed skillfully.

How to Design a Press and Transfer Mechanism

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Left synchronous belt capstan

A sewing mechanism

A cutting mechanism Tensioining

wheel

A pull-apart mechanism

A guide pulley synchronous

belt

Left synchronous belt driven pulley

A cutting mechanism Tensioining

wheel A guide pulley

synchronous belt

Right synchronous belt capstan

A sewing mechanism Right synchronous

belt driven pulley

A pull-apart mechanism

(a) the left handle press and transfer mechanism (b) the right handle press and transfer mechanism Figure 8. The press and transfer mechanism.

Conclusion

In order to improve an automatic production level of a needle-stitch non-woven bag and reduce the number of workers, an automatic processing device for a needle-stitch non-woven bag was designed. The working principle of it and the design and calculation process of its main parts are introduced. Compared with the method of sewing a handle and a bag body separately, the device designed in this paper can realize an automatic sewing process of a handle and a bag body in one step. The device can simplify the production process of a needle-stitch non-woven bag, can reduce the labor intensity of workers and can greatly improve production efficiency. A prototype machine has been made and the testing result proved that this device is feasible.

References

[1]Wei Can. Research on Key Technologies in Automatic Processing of Non-woven Bags[D].Fujian: Jimei University, 2013.

[2] Wei Can, Chen Ya-zhou, Pi Jun. Automatic feed mechanism for non-weaven bag handles[J].Journal of Jimei University (Natural Science), 2012, 17 (6): 460-464.

[3] Chen Ya-zhou, Zheng Tian-yi, Pi Jun.etc. An automatic sewing production line for a handlebar and a body of a non-woven bag. CN201310204408. 6[P]. 2015-12-03.

[4] Zhang Xue-long, Wang Yun-feng, Xie Ting-yu. etc. Work study applied to an enterprise production line optimization and redesign - a case study[J]. Modern Manufacturing, 2015(3):27-32.

[5] Xu Yun-lin. A Paper bag flat rope hand-in mechanism, 101402266.B[P], 2010-06-23.

Figure

Figure 4. A schematic diagram of how to leveling a handle.

Figure 4.

A schematic diagram of how to leveling a handle. p.2
Figure 1. A Handbag Structure.                        Figure 2. The Process Procedure of a Handle Bag

Figure 1.

A Handbag Structure. Figure 2. The Process Procedure of a Handle Bag p.2
Figure 3. A Schematic Diagram of a Chain Forming Processing Device for a Handbag.

Figure 3.

A Schematic Diagram of a Chain Forming Processing Device for a Handbag. p.2
Figure 5. The pull-apart mechanism.

Figure 5.

The pull-apart mechanism. p.4
Figure 6. The Action Principle of a Leveling Mechanism.

Figure 6.

The Action Principle of a Leveling Mechanism. p.5
Figure 7. The Leveling Mechanism.

Figure 7.

The Leveling Mechanism. p.5
Figure 8. The press and transfer mechanism.

Figure 8.

The press and transfer mechanism. p.6

References

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