Laser và ứng dụng laser để cắt vải, da trong công nghiệp

LIÊN NGÀNH cơ KHÍ ĐỘNG Lực Laser and using laser cutting fabric, leather in industry Laser và ứng dụng laser để cắt vải, da trong công nghiệp Ngo Huu Manh*, Mac Thi Nguyen, Nguyen Thi Hong Nhung *Emai[.]

LIÊN NGÀNH cơ KHÍ - ĐỘNG Lực

Laser and using laser cutting fabric, leather in industry

Laser và ứng dụng laser để cắt vải, da trong công nghiệp

Ngo Huu Manh*, Mac Thi Nguyen, Nguyen Thi Hong Nhung

*Email: manh.weldtech@3mail.c0m

Sao Do University Received date: 15/8/2021 Accepted date: 01/5/2022 Published date: 30/6/2022

Abstract

Laser technology provides advantages in cutting complex geometries, stable quality and possibility to utilize fabric and leather materials in economically best way Constant quality is important in industrial processes of laser technology cutting Additionally, laser technology is very flexible in terms of geometries such as complex geometries, individual parts and small scale products Products which small size and volumes are application laser cutting can be more beneficial due to without a need to change cutting tool But disadvantages of laser pro­ cessing include high initial investment costs Therefore, this paper investigates advantages and disadvantages

of laser cutting and provides comparison between laser cutting and mechanical cutting

Keywords: Cutting parameters; laser; fabric cutting; leather cutting; laser cutting.

Tóm tắt

Công nghệ laser có nhiều ưu điểm khi cắt các hình dạng phức tạp, chất lượng cắt ổn định và hiệu quả kinh tế cao khi cắt vật liệu vải và da Chất lượng ổn định là yếu tố quan trọng của công nghệ cắt laser trong sản xuất công nghiệp Bên cạnh đó, công nghệ laser có khả năng linh hoạt cao khi cắt các hình có biên dạng phức tạp, các chi tiết đơn lẻ và các sản phẩm kích cỡ nhỏ Các chi tiết có kích thược và khối lượng nhỏ được cắt băng laser sẽ thuận lợi hơn do không cần thay đổi công cụ cắt Nhưng nhược điểm của quá trình cắt bằng laser là chi phí đầu tư ban đầu cao Vì vậy, bài báo này đánh giá những ưu và nhược điểm của cắt laser và đưa ra so sánh giữa phương pháp cắt laser với cắt cơ học

Từ khóa: Chế độ cắt; laser; cắt vải; cắt da; cắt laser.

1 INTRODUCTION

Currently technologies which are applied for leather

cutting include slitting knifes, die press techniques and

manual cutting Use of laser technology has grown sig­

nificantly during recent years due to number of advan­

tages over conventional cutting methods such as flexi­

bility, high production speed, possibility to cut complex

geometries, easier cutting of customized parts and less

leftovers of leather makes laser cutting more and more

economically attractive to apply for leather cutting

Figure 1 Laser cutting techniques used by artists:

Cutting with scissors, draw-gauge knife and straight knife [1]

Tools which are used for cutting of leather include scis­

sors, knifes and draw-gauge knifes These tools are

applied depending on the cut object shape and raw

Reviewer: 1 Assoc Prof Dr Tran Ve Quoc

2 Dr Vu Van Tan

leather material Scissors can be used for relatively thin leathers whereas thicker leather is cut with knives Draw-gauge knifes are the most effective for straight lines Curved lines and sharp edges are best achieved with straight knives [1]

Nowadays, there is a clear difference in cutting tech­ nologies applied to leather Industrial leather process­ ing serves the purpose of mass production of leather items in order to satisfy the demand of essential prod­

ucts like clothes, shoes, bags, etc This demands from

technology to be economically efficient, fast, adaptive and to provide maximum possible results with mini­ mum possible cost Manual cutting with use of scis­ sors and special knifes is used in leather crafting This allows to produce individual unique items whose value

is not determined by functionality but based more on visual effects and design features

We are known that, laser technology enables cutting

of a great variety of material from metals to non-me- tallic materials Laser energy can be applied directly

on desired objects with easy control of its power and intensity Leather is suitable material for laser cutting This makes laser an attractive tool for leather cutting

It provides high quality cutting, easy change of cutting geometry and production in short time but on the oth­

er hand requires high initial investments and requires special knowledge of laser operation Beside that it

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has thermal effect on leather that might be an issue in

some applications

The systems are applied in industrial leather cutting [2]:

+ Swing arm cutting presses

+ Log slitting, strip cutting and guillotining machines

+ Manual travelling head press

+ Manual fixed beam press

+ Receding head press

+ Leather cutting systems

+ CNC knife cutting tables

+ Waterjet cutting systems

Die cutting press is one of the most traditional meth­

ods of leather cutting Waterjet cutting and CNC knife

cutting tables were applied in leather cutting applica­

tions in relatively recent times [3] This development

allowed application of automatic vision based systems

for inspection, distribution and optimization of cutting

procedure [4],

CO2 laser cutting and engraving machines are widely

used to cut or engrave the leather materials, mostly in

shoes, bags, cloth or other industries Generally, the

cutting speed can reach 5-30 mm per second, the en­

graving speed may reach 600 mm per second [3],

The economy of the laser cutting process mainly de­

pends on two productivity aspects: Nesting and cutting

sequence Nesting is a process of positioning of parts

to be cut on given material with the main aim to mini­

mize waste Nesting is often done based on operator

experience and it becomes a challenge in case of large

production volumes Besides that, it does not guaran­

tee the most efficient utilization of material Nesting

software is used nowadays to enhance material utili­

zation and improve flexibility Cutting sequence targets

the optimal cutting procedure for minimum cycle time

The objective of cutting sequence is to find the shortest

path to accomplish cutting procedure [5], The challeng­

es with nesting and cutting sequence occur in leather

cutting due to irregular shapes, contours and quality

zones of natural leather Such problems are especial­

ly common in automotive industry for instance in cut­

ting of large pieces of car seats [6] The role of nesting

software increases when leather cutting is applied in

industrial scale [7],

Lasers are also reported to be applied for cleaning

of leather surface Nd:YAG lasers with wavelength of

1064, 532 and 266 nm were applied for this purpose

Laser irradiation was applied to historical leather arte­

facts in order to remove pollution substances and re­

cover original leather color [8, 9],

Advantages of laser cutting: One of the main advan­

tages of laser cutting is production at standard quality

Laser cutting also maintains production in shorter time

with higher quality Due to ability to apply CAD/CAM

and CIM system in design, it is possible to manufac­

ture absolutely identical designs Moreover, problems

associated with conventional technologies, such as

worn out design markers and dies, storage space and

destruction of out-of-date ones are eliminated when la­

ser cutting technology is used Thus, laser cutting sys­

tem provides a positive contribution to the environment from this particular point of view as well [10],

In the artworks, leather crafting or leather craft is the practice of making leather into craft objects or works

of art, using shaping techniques, coloring techniques

or both

And in this paper investigates the most beneficial appli­ cations of laser cutting of leather, describes its advan­ tages, drawbacks and provides an overview on poten­ tial use of laser as industrial or craftsmen cutting tool

2 EXPERIMENTAL 2.1 Equipment and material

The laser cutting tests were carried out in Mechanical laboratory of Sao Do University (SDU) Laser cutting of fabric and leather were carried out as a part of project

in 2017 of SDU

Used laser source was Trumpf TLF 500 HQ CO2 la­ ser which produces maximum nominal laser power of

500 w The wavelength of the laser was 10.4 pm The cutting tests were made using an XY table For these cutting tests focal length of 127 mm (5”) was used The cutting gas was compressed air of 3,0 bars pressure

Figure 2 Laser cutter

Laser cutting tests were performed with animal leather (originated from cattle) about 5 mm thickness (for most

of the leather) and fabric about 10mm thickness (for 5-10 layer)

2.2 Cutting method

Using CO2 laser cutting technology to cut animal’s leather and fabric The cutting process was performed

on a laser cutting machine manufactured by the au­ thor’s team The cutting program was created on the computer and the laser cutter will run according to that program And this cutting process is automatic

!

Figure 3 Design model on the computer

LIÊN NGÀNH cơ KHÍ - ĐỘNG Lực,

3 RESULTS AND DISCUSSION

3.1 Leather cutting tests

Laser cutting tests were performed in order to find

optimal laser cutting parameters Particular attention

was paid to laser cutting speed with the aim to obtain

the highest cutting speed possible Dependence of

laser power and cutting speed was also investigated

Laser cutting parameters can be found in Table 1

Table 1 Laser cutting parameters

(W)

Cutting speed (m/

min)

Description

Laser cutting of leather can be done at high cutting

speed with relatively low laser power requirements

Dependence of laser power in relation to cutting speed

can be described as linear meaning that increase of

laser power by two times leads to four times faster cut­

ting speed

3.2 Fabric cutting tests

Laser cutting tests were performed in order to find opti­

mal laser cutting parameters Particular attention were

dependenced of laser cutting speed and laser power

Table 2 Laser cutting parameters

(W)

Cutting speed

3.3 Laser cutting and mechanical cutting

Comparison of laser cut and mechanically cut leather

samples was carried out based on visual evaluation of

cut edges

a Laser cutting b Die cutting c Blade cutting

Figure 4 Comparison of laser and mechanical cutting

of black leather

Laser cutting of leather causes carbonized cut edge due to thermal impact of laser beam This is not ob­ served in mechanical cutting methods Blade cutting provides the best result from leather structure point of view And die cutting (punching with a sharp edge die) causes some change of leather structure that can be observed as jamming of top layer of leather

Cutting leather with hand (blade or knife tools) is time consuming and it never gives an exact end result due

to the nature of technique used The hand cutting tools are suitable for unique design and custom made items where the nature of hand making is also an important technical and visual feature Laser cutting could easily replace handicraft in variety of operations

Especially making of prototypes can benefit significant­

ly by the use of laser Laser cutting would serve also as

a tool for individual solutions and decorative and com­ plex designs that would be difficult to achieve with any other method Piercing and pattern making on leather can be taken to a complete new level due to the pos­ sibilities of laser technologies Due to its sustainable characteristics, laser has potential to be developed as

a competitive method also for industry

3.4 Effect of laser cutting

Effect of laser cutting on leather of different colors was evaluated visually based on images of laser cut edges Laser cutting causes slight carbonization of cut edge due to thermal influence This effect is more visible

in case of light color leather such as white or yellow This effect has to be taken into account when laser cutting is considered Laser cut edge of dark and es­ pecially brown leather can be considered as the most suitable for laser cutting whereas light colored leath­ ers can have easily noticeable laser cut edge Material thickness was varied as well, slight adjustment of laser cutting parameters was needed in order to obtain com­ plete cutting

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a Black b Brown c Yellow

d Purple e Red f White

Figure 5 Comparison of different laser cut leathers

For pieces where the variation in size or design is ne­

eded laser is an ideal tool For cutting leather it has

some advantages compared to other techniques The

cutting marks of laser on leather are nearly invisible

and the technique gives a finished touch to the mate­

rial The technique is exact and it does not cause stre­

tching to the material, as hand cutting would cause

There can be some extra work caused by the marks of

carbonizing which can be washed with wet cloth from

the leather Also the leather needs to be ventilated af­

ter cutting to eliminate the odor of burning

ii

a Green b Blue c Black

Figure 6 Comparison of different laser cut fabric

For cutting fabric it has some advantages compared to

other techniques The technique is exact and it does

not cause stretching to the material, as hand cutting

would cause Also the fabric needs to be ventilated af­

ter cutting to eliminate the odor of burning

Time ($)

Figure 7 Diagram of the relationship between cutting

efficiency and number of cutting layers

Generally, it can be said that laser cutting is the most suitable for cutting of complex geometries as it provides high flexibility, easy set up and nesting, fast change of geometries and high adaption ability to different mate­ rial properties (such as thickness) On the other hand, high flexibility, easy set up and nesting together with high cutting speeds and constant cutting quality reveal potential for industrial applications Easy applicability

of nesting and cutting sequence software together with laser technology is another aspect which implies po­ tential in industrial applications However, carbonized cut edge may be a limiting factor in this case Remov­

al of carbonized marks and odor of smoke after laser cutting require special arrangements what is not very suitable for large volume production

4 CONCLUSIONS

Laser cutting of fabric and leather were carried out us­ ing CO2 laser with the wavelength of 10.4 pm Laser cutting speed is dependence laser power source Laser cut edge quality was examined based on micro­ graphs Comparison of laser cut and mechanically cut show that, laser cutting is causes carbonization of cut edge which was the most distinctive difference among cutting methods

Thermal effect of laser beam on cut edge was seen dif­

ferent depending on fabric and leather color Laser cut

edge of dark and especially brown leather can be con­ sidered as the most suitable for laser cutting whereas light colored leathers can have easily noticeable laser cut edge

ACKNOWLEDGEMENTS

This publication has been written as part of results in

2017 research project of Sao Do University Authors thank all participants and input to this article

REFERENCES

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[2] Anon (2015)., CO2 Laser marker in Leather Indus­ try, available:

, referred: 20/04/2015

http://www.glorylaser.com/solution- show.asp?id=12

LIÊN NGÀNH cơ KHÍ - ĐỘNG Lực _

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co.uk/cutting-applications/cutting-leather.asp, re­

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http://www.gct-online

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AUTHORS INFORMATION

Ngo Huu Manh

- 2016: Graduated of Doctor of Mechanical engineering, Hanoi university of Science and Technology

- Current Job: Lecturer Head of Department of Science management and International cooperation, Sao Do university

- Research fields: Mechanical engineering, welding technology, surface technology,

- Phone: 0936847980 Email: manh.weldtech@gmail.com

Mac Thi Nguyen

- 2010: Graduated of Master science of Mechanical engineering, Hanoi university of

- Current Job: Head of Subject of Faculty of Mechanical engineering, Sao Do university * 1

- Research fields: Mechanical engineering, material technology, design of machine and robot

I - Phone: 0389481166 Email: nguyenmacthi@gmail.com

Nguyen Thi Hong Nhung

- 2011: Graduated of Master science of Mechanical engineering, Hanoi university of

- Current Job: Lecturer of Faculty of Mechanical engineering, Sao Do university

- Research fields: Surface technology, material technology

I - Phone: 0788289275 Email: hongnhungsaodo@gmail.com