|Title of Invention||
A COMPUTER-INTERFACED INSTRUMENT FOR PREDICTING FABRIC TAILORABILITY
|Abstract||This invention relates to a novel design of low cost, computer-interfaced fabric tailorability tester. This single machine working on a Constant Rate of Extension (CRE) principle evaluates the low stress fabric properties pertaining to fabric tailorability viz., extension, compression, and bending. The low stress evaluations help to arrive at parameters the fabric tailorability. The output is in the form of tailorability chart that serve as ready reckoner for judging the suitability of fabric for tailoring operation, particularly in mas production.|
|Full Text||THE GAZETTE OF INDIA : EXTRAORDINARY [PART II - SEC 3 (ii)]
THE PATENT ACT 1970
(39 OF 1970)
The Patents Rules, 2003
PROVISIONAL / COMPLETE SPECIFICATION
(see section 10 and rule 13)
1. TITLE OF INVENTION
Design and Development of a Low Cost, Computer-Interfaced Instrument for Predicting Fabric Tailorability
(a) NAME: The Synthetic and Artsilk Mills' Research Association
(b) NATIONALITY: Indian
(c) ADDRESS: Sasmira Marg, worli, Mumbai - 400 030, India.
Ph: 24935351-2, Fax: 24930225
3. PREAMBLE TO THE DESCRIPTION:
The following specification particularly describes the invention and the manner in which it is to be performed:
Properties like feel, handle, appearance and tailor ability of fabrics have been traditionally assessed subjectively. Fabric objective measurement provides a scientific means to quantify overall quality and performance characteristics of a fabric in terms of these parameters. In the free trade environment of the post WTO world, it would be widely required to assess fabric properties like tailor ability, objectively. Fabric objective measurement would be used as a tool for fabric specification, inspection, product and process development, process control, quality assurance and agreement between the buyer and seller of fabric.
There are two different instruments available for evaluating fabric characteristics. The instruments are meant to predict feel, handle and appearance of fabrics, mainly suiting fabrics, intended for garment manufacturing. First is the Kawabata evaluation system, KES-F system, which has four instruments to measure sixteen low stress characteristics
of fabrics that determine that compression, bending, extension, shear and frictional properties of fabrics. These properties combinedly determine the feel and handle of fabrics, which can be computed as a single digit on a 0-10 scale and the total hand value (THV) predicted on 0- 5 scale. It also computes total appearance value (TAV) on 0-5 scale. The advantage of this system are highly sensitive and accurate measurement of low stress fabric properties. This system helps to quantify the subjective properties of handle and appearance of the fabrics. However, the KES-F system is based on complex empirical relationships. The output charts are not easy to comprehend and not suitable for use by the shop floor technicians on day-to-day basis. So also the system is too expensive (around Rs. 2 corers), to be popular amongst the common fabric and garment manufacturers. Till date it has found scope only in research and development activities.
The second instrument, comparatively adopting simpler method developed by CSIRO in Australia is also being used. This method called the FAST (Fabric Assurance by Simple Testing) for determining fabric tailor ability. This method uses a set of four instruments to evaluate low stress fabric properties namely bending, extension, compression and dimensional stability. These properties help to predict the tailorability or ease of garment making-up of a given fabric. This method is simpler more focused to fabric tailorability properties. However, it is still not popular amongst fabric and garment manufacturers due to its prohibitive cost (around Rs. 40 lakhs).
In the post WTO scenario, the power loom sector in India has wide potential buyers in automated garment industries, within the country as well as globally. The fabrics that go in for mass garment production are sourced from various suppliers. It is essential that these multi-source and multi-batch fabrics are expected to be evaluated with a standardised testing method that could predict their behaviour during and post stitching operation, particularly in mass production. The fabric tailorability property should be quantified This would help to minimise defects and reworking in the garments produced. In such increasingly quality conscious trade circles both the buyer and seller may require simple instruments to quickly predict suitability of a particular fabric
for garment making-up. The fabric manufacturers also require to know modifications to be carried out to achieve optimum tailorability. The proposed invention was aimed at developing indigenously, a single, low cost, computer-interfaced Constant Rate of Extension (CRE) tester for predicting the fabric tailorability, quickly, accurately in a simplified manner for day - to - day quality control by the shopfloor technicians in the garment industry.
4. DESCRIPTION (Description shall start from next page)
The invention relates to development of a computer -interfaced, low cost instrument for assessing fabric tailorability
The invention relates to and covers:
• A single machine that evaluates all low stress properties, namely extensibility, compressibility and bending of fabrics pertaining to fabric tailorability.
• Incorporating a method to evaluate fabric stiffness on a CRE type tester.
• A computer- interfaced fabric tailorability tester, with unique software.
• A fabric tailorability tester, which gives easy to comprehend outputs in, terms of ready - reckoner fabric tailorability charts.
• A low cost fabric tailorability tester.
Description of the instrument:
The instrument developed for predicting fabric tailorability is principally a Constant Rate of Extension (CRE) Tester.
The following are the main parts of the testing system:
I. Cross head shaft
The cross head shaft (1) is twin ball screw type driven by an AC motor. The motor has seven speed modes ranging from 1 mm/min to 10 mm/min. It is connected and driven through the data interface connector. The controls for selection of speeds (2 a) and load cell (3) are available on the base of the crosshead (see Fig. 1).
II. Load cells
The instrument crosshead is split into two tiers to accommodate the two load cells used for evaluation. Both the load cells are pancake type. The upper load cell has capacity 2 k gf and resolution of 0.1 gf It can work in both extension and compression modes. The lower load cell has a capacity of 200 gf with resolution of 0.01 gf. This works in the cyclic mode during the test. The load cells are connected to the circuitry provided at the base of the crosshead (see Fig. 1).
HI. Fabric grips
The instrument has separate sets of griping assemblies (4) for each of the tests to be performed. The extensibility test use the vice type grips, compressibility test uses the flat grips and bending test uses the slot and blade type arrangement for performing the test. The details of the same have been described in the later section.
IV. Data interface connector
The data interface connector (6) drives the entire system via the main supply. It is also connected to the computer RS - 232 terminal and helps to link the test software to the actual test assembly (crosshead with the load cells). There is two way flow of data at this connector; the software controls from the computer system controls the testing and evaluation at the crosshead and the test data are received and recorded by the computer system (see Fig. 1).
V. Computer assembly
A computer assembly (5) comprising of a Central Processing Unit (CPU), monitor, keyboard and printer are essential. The CPU is connected to the interface connector and also the monitor. The windows based test software available on the CPU hard disk
controls the testing, recording and analyses of the test data. A printer and keyboard for data input and output respectively are also connected to the CPU.
VI. Power Supply (UPS):
A Uninterrupted Power Supply (UPS) (7) ensures stabilized power supply of 230 V AC , 15 A, single phase power supply to the system.
The Fig. 1 depicts the entire set-up of the testing instrument.
The objectives of this invention and related specifications is elaborated as below
A single machine that evaluates all low stress properties of fabrics pertaining to fabric tailorability
Fabric tailorability is influenced by various fabric properties like fabric weight, thickness, its extensibility, resilience, stiffness and dimensional stability. Fabric weight and thickness are very well quantified on the existing instruments i.e., weighing balance and fabric thickness tester respectively. The properties of extensibility, resilience and stiffness evaluated by traditional methods are not focussed on determining fabric tailorability. This is because; the process of fabric tailorability subjects the fabrics to very low levels of stresses, which are required to be quantified. In this invention, a single Constant Rate of Extension (CRE) tester has been used to evaluate the low stress fabric extension, compression (resilience) and bending (stiffness). The developed CRE tester works in extension and compression modes to determine the low stress fabric properties. The details of each mode have been discussed below:
Mode 1: Extensibility Test:
The low stress extensibility of fabrics is evaluated on this tester in warp, weft and bias directions. The detailed specifications of the test are as listed below:
(warp, weft, 45 ° bias)
2 k gf, resolution of 0.1 gf
100 mm x 50 mm
170 mm x 50 mm ravelled
The test strips mounted on the vice type grips (as shown in Fig.2) are subjected to the extension force from zero to 100 g/ cm of fabric strip. The extensibility of fabrics in warp and weft directions is recorded at a stress of 100 g/cm and depicted as E100- So also, evaluation of fabric formability characteristics (F) is carried out from fabric extensibility of fabrics at stress level of 5 g/cm and 25 g/cm. The bias direction evaluation of extension of fabrics helps to determine the shear rigidity (G) of the fabrics.
Mode 2: Compressibility Test:
The low stress compressibility of fabrics is evaluated on this tester in compression mode. The detailed specifications of the test are as listed below:
Compressibility 2 k gf, resolution of 0.1 gf 1 mm/min 0.1mm Flat type, 1000 sq.mm 100 mm x 100 mm
The test samples mounted on the flat grips (top grip, 1000 sq.mm and bottom grip, 2500 sq.mm) ( as shown in Fig.3) are subjected to the compression force from zero to 100 g/ sq.cm of fabric sample. The change in displacement of the fabric is depicted as change in thickness when stress is increased from 2 g/sq.cm to 100 g/sq.cm. The values of initial
thickness of the fabric (D) and change in thickness of the fabric (ST) are recorded as measure of resilience property of the fabric.
Mode 3: Bending Test:
The low stress bending of fabrics is evaluated on this tester using principle of three -point bending. The detailed specifications of the test are as listed below:
Test mode Load Capacity Crosshead speed Displacement resolution Sample mounting Depressing Blade Sample size
Compressibility 200 gf, resolution of 0.01 gf 10 mm/min 0.01mm
Flat base with slot of 10 mm x 150 mm x 10mm Length 250 mm, thickness 1 mm Square, 100 mm x 100mm
The fabric sample loosely mounted on the base with slot is depressed by the blade to a displacement of 8 mm (as shown in Fig.4). The force required to depress the fabric in all the four directions, face - warp and weft and back - warp and weft, is evaluated and a cumulative bending force (B) is determined for the fabric.
Incorporating a method to evaluate fabric stiffness on a CRE type tester.
Generally, stiffness of the fabrics is evaluated using the cantilever principle. However, in the developed instrument, which works on CRE principle, the 3 - point bending test method is more feasible. Accordingly the ASTM D 6828 -02 method of evaluating fabric stiffness on slot and blade principle was adopted. The details of the test mode have been depicted in the Mode 3 of the First Objective. Each test runs in a cyclic manner, wherein bending force required to depress the fabric in to the slot to desired depth (8 mm) is recorded for warp and weft directions for both face and back fabric. The cycle completes after all these four readings of bending force are recorded and a cumulative value of bending force is obtained.
A computer- interfaced fabric tailorability tester, with unique software.
The developed fabric tailorability tester has a computer interface. The test program controls the test parameters, performance of the test, intermediate controls and recording and analyzing of the data. The final outputs in the form of control charts with upper and lower limits are recorded as Tailorability charts for the fabrics (as shown in Fig. 5).
The Fabric Tailorability Chart have the various low stress tailorability parameters plotted on the X - axis. The various parameters are listed below:
E 100l & E1002 : Fabric Extensibility % at stress of 100 g/cm in warp and weft directions, respectively.
Fl & F2 : Fabric Formability in warp and weft directions , respectively
G : Shear rigidity of the fabrics
B : Bending force of the fabrics
RS 1 & RS 2 : Relaxation shrinkage of the fabrics in the warp and weft directions respectively, (evaluated externally and values fed to the software).
HE1 & HE2 : Hygral expansion of the fabrics in the warp and weft directions
respectively, (evaluated externally and values fed to the software)
D2 : Thickness of the fabrics at 2 g/cm2
ST : Compressibility of the fabrics, change in thickness under increase of
pressure from 2 g/cm2 to 100 g/cm2
W : Weight of the fabrics, (evaluated externally and values fed to the
The Y-axis indicates the acceptable limits for the various properties. The unacceptable
limit zones have been indicated in the chart as distinct zones viz., blue zone lower
unacceptable limit for a particular property and red zone as upper unacceptable limit for a
particular property. The green bars indicate that the particular fabric tailorability property
is within acceptable limits and the fabric is suitable for tailoring.
A fabric tailorability tester, which gives easy to comprehend outputs in, terms ready — reckoner fabric tailorability charts.
The fabric tailorability charts with control limits serve as ready reckoners. They help the user easily identify, whether a particular tailorability parameter is within range or out of
range. In case, the parameter is out of range, the type of problem that could result is also identified.
A low cost fabric tailorability tester
This fabric tailorability tester is relatively lower in cost (estimated cost Rs. 8 - 10 lakhs) as compared to the existing instruments, viz., KESF system and FAST system. The lower cost and comparable performance should help to popularise the instrument even amongst the small-scale fabric and garment manufacturers.
Scope and / or ambit of the invention
The following advantages of the invention can be enlisted:
1. A single computer - interfaced instrument can be used to evaluate all the low stress fabric properties pertaining to fabric tailorability.
2. The instrument gives outputs in the form of fabric tailorability charts that are easy to comprehend by the shopfloor technicians
3. Evaluation of fabrics on this instrument would help to predict the behaviour of fabrics before they are taken up for stitching operation.
5. It would help to avoid garment defects and reworking.
6. The instrument would find application with garment industry, where mass scale production of garments is taken - up from multi - batch and multi- sources.
7. It would also be helpful to the fabric exporters to avoid rejects of their fabrics.
8. The cost of the instrument is relatively less as compared to other existing instruments.
7. ABSTRACT OF THE INVENTION
This invention relates to a novel design of low cost , computer-interfaced fabric tailorability tester. This single machine working on a Constant Rate of Extension (CRE) principle evaluates the low stress fabric properties pertaining to fabric tailorability viz., extension, compression, and bending. The low stress evaluations help to arrive at parameters that determine the fabric tailorability. The output is in the form of tailorability chart that serve as ready reckoner for judging the suitability of fabric for tailoring operation, particularly in mas production.
1. A novel instrument for evaluating fabric tailorability has been invented.
2. (a) The developed instrument evaluates all the fabric parameters pertaining to fabric tailorability.
2. (b) A novel method of evaluating fabric stiffness on a CRE tester has been established
3. The instrument has a computer interface for performing the test and recording and analysing the data of the test, with an unique software developed for the purpose.
4. The instrument gives output charts that serve as ready reckoner for fabric tailorability performance.
5. The invention helps to solve the problem of heterogeneity of fabrics taken up for mass production of garments from multi - sources and multi-batches.
6. The developed instrument is relatively lower in cost as compared to the similar existing instruments.
6. DATE AND SIGNATURE
Dated this 16th day of...May ..2007.
The Controller of Patents,
The Patent Office, Mumbai
|Indian Patent Application Number||934/MUM/2007|
|PG Journal Number||10/2009|
|Date of Filing||18-May-2007|
|Name of Patentee||THE SYNTHETIC AND ART SILK MILLS ASSOCIATION (SASMIRA)|
|Applicant Address||SASMIRA, SASMIRA MARG, WORLI, MUMBAI|
|PCT International Classification Number||A41H42/00,G06F17/00|
|PCT International Application Number||N/A|
|PCT International Filing date|