Query

We are making a ladies top which has long shoulder straps. The straps have cording on both edges. We are first runstitching the strap with cording strip and then turning it inside out manually. After giving the final top stitches on both sides we are getting looseness (jhol) in the backside. Buyer QC is not accepting it. Please suggest remedy. Whole operation is done manually and no folder or attachment is being used.

Eves Fashion, India

SOLUTION  Prabir Jana, Technical Advisor, StitchWorld

Reason:- Generally both fabric layers are cut of equal width and even after runstitching, the strap construction will look flat and no looseness will be visible on either side. During the final topstitching the operator sees only the face side. On the face side, topstitch is maintained 1/16" inside the seam uniformly, while, on the back side, the operator tries to pull the fabric inside so that any “unwanted” piping does not occur. Resulting non-uniform and narrower piping (less than 1/16") and even sometimes a stitch in a ditch appears in the back side. After both the edges are topstitiched, obviously the bottom fabric layer will be wider than the face layer, resulting in looseness; this is beyond the control of the operator.

Remedy:- It is suggested that BOTH fabric layers should not be cut of equal width. Let’s trim the width of the one fabric layer slightly (say 1/8"). While runstitching, the narrower fabric should be kept on top and stitched. After runstitching, the strap should be turned inside out as usual. Now, topstitching should be done keeping narrower layer at the bottom. Let the operator sew topstitch as earlier. As the bottom layer is of narrower width, no looseness (jhol) will be formed. How much the bottom layer should be trimmed will depend on the strap width and fabric type and may be decided after trial and error.

Strap runstitching with equal width of fabric

Strap runstitching with unequal width of fabric

Defective strap with loose fabric

Correct strap without loose fabric

Query

For spreading m/c, is there any time standard for payments? If I wish to calculate the time, what are the processes I can consider as preparation time and the main spreading time? When overlapping layers, at a time the roll finishes, is it considered as a preparation time? Please advise me the correct way to measure the time.

Shaimaa Puettmann, Free zone-Amreia-Alexandria, Egypt

SOLUTION :  Paul Timson, GSD

Standard Times for spreading activities

As is the case for any repetitive task, Standard Times for spreading (and indeed for cutting) may be obtained through work measurement, and these can of course be used for payment purposes (as well as planning) but there are two very important areas that need careful consideration.

Firstly, the complexity of the activities that surround the spreading process – collecting cloth, unwrapping the rolls, loading the cloth to the carriage, setting up the table, positioning the end clamps, spreading the fabric – all have to be categorised and considered in terms of their respective times and, most importantly, their frequency of occurrence.  For example, the operative may collect several rolls of cloth, but will typically only set up the end clamp once per lay.  Each activity may be measured to determine the Standard Time required to complete each task, but to measure such activities with conventional Time Study, however, is all too often difficult and inaccurate.

Second, the lay parameters (in terms of length and depth) will dictate the overall Standard Time for the lay and it is almost impossible to extrapolate such results from conventional measurement techniques – at least not without timing every variation in length and depth, and not without considerable manual calculation, which is itself prone to error, time consuming and therefore an inconsistent and costly exercise.

So, a far more accurate, consistent and dependable means of such measurement is to use a Pre-determined Motion Time System (PMTS).  To the best of the authors  knowledge, however, there is no PMTS that deals specifically with the cutting room environment, other than “GCD” (the sister product to the word renowned “GSD”).

Once a lay has been analysed using GCD, the lay parameters are then defined in terms of length and depth and the overall Standard Time follows. Additionally, a “matrix” may be set up whereby the system calculates the Standard Times for any given combination of length and depth, and this provides a table of values that may be used as a benchmark for operator performance, payment and cut order planning in the cutting room.

The process of Preparation

Typically, one would consider any activity up to the main spreading activity as being “preparation”. Such preparatory activities could include collecting and reading cutting instructions, preparing the table with base paper, fetching the marker, marking the length and width on the base paper, obtaining cloth from the cloth store, preparing the carriage and end clamps, unwrapping the cloth and loading the cloth to the carriage, obtaining and loading tissue paper on the carriage etc. etc. Only when the main spreading activity is started should the process of “preparation” be consider to have ended. 

The main spreading activity then starts and, again, this may be measured through the use of GCD, which accommodates both manual and machine controlled spreading (and all types of cutting from round and straight knife, to band knife and automated cutting).  The time required for manual spreading will be determined by the number of paces the operative has to execute to get from one end of the table to the other whilst spreading cloth and this will include any additional activities such as stopping to straighten, smooth or flatten the cloth along the length of the table.  It will also include any cutting activity that may be required at the end of each ply.  Automatic spreading is accommodated within GCD by choosing the appropriate spreading machine, and the run speeds and cutting times associated to that machine are then used to calculate the time per lay.  In both cases, the length and depth of the lay will dictate how long the overall time will be, but GCD automatically re-calculates Standard Times based upon those lay parameters and activities and the frequency of occurrence.

Preparation or not?

The task of overlapping layers when a roll comes to an end part way down a lay does occur as part of either manual or automatic spreading and would, in the author’s opinion, normally be considered to be part of the main spreading activity, rather than “preparation”.

SOLUTION : Keerthi Abeywickrama, CTO, SewEasy

On first part of the question I would say, the payment criteria vary from country to country and company to company. Based on 100 BSI rating scale, if the motivational payments start around 70 performance level and go up to 120, it can be considered as professional incentive scheme.

On second part of the question, I am assuming that the industrial engineering practitioner is trying to develop  standard data blocks that can be reused in specific area of the spreading fabric for cutting. I am also assuming that he is developing a standard data block for “overlapping”, at a lower confidence interval.

To account for differences in fabric and lay types, the variable and constant elements within spreading cycle should be isolated and built in to a formula so that there would be no need to repeat the entire ‘timing and rating’ process if and when the need for higher accuracy occurs. The practitioner can reuse such a data block irrespective of the number of times the overlapping occurs, in any given lay. Categorizing the “overlapping” under spreading or preparation, should lead to same outcome.

Going one step further, if the practitioner draws the work station layout, and document the method before carrying out this study he or she may be able to prevent the reinventing of wheel associated with most manual time studies.

SOLUTION :  Roger Thomas, Pro SMV

Calculation of time for using a spreading machine:

The items to be included in the time to calculate the time for spreading a lay would include the following

1. Layout marker, mark table, lay underpaper. This should be calculated per metre and then applied to the length of the lay
2. Calculate the time for removing the covering on the roll pf fabric == you then need to know how many rolls will be used in the lay
3. Calculate the time to ‘load’ each roll
4. Calculate a time to lay 1 metre ==. Is the lay to be face up or layed in pairs? If singles calculate a time to cut the fabric at the end of the lay
5. Multiply the laying time by the number of metres to be layed
6. If you overlap layers (join plies from rolls of the same shade) then allocate time for this process. Since the position of the join will vary from roll to roll then you need to take several times for doing this and apply an average.
7. This average time should be allocated to each roll

SOLUTION : Ram Sareen, Head Coach / Founder -TUKAgroup, TUKATECH-TUKAWEB- TUKAcenters

The tangible savings comes from only two areas, labour savings and material savings. Depending upon the material being spread, an automatic spreader will allow you to cut straight or 90 degrees whereas you may not cut in a straight line when using scissors, resulting in about .5 to 1 inch wastage on each end, the quality of spread will also save materials, specially materials like Lycra and Spandex requires extra inches spread for relaxation whereas it may or may not come back in relaxation process but the material will be wasted anyway, cradle feed with optional override will compensate automatically. An automatic spreader will spread from 10 to 25 yards per minute. Longer the spread, faster the throughput. To calculate the speed, one must consider the motions, when starting from one end, we have at least 18 inches of acceleration distance before coming to spreading speed and about another 18 inches for deceleration before stopping. It is the distance in between where the full speed will be picked up. Depending upon fabrics, the speed will vary, knits will take longer to spread than wovens. Overlapping or splicing is not considered preparation time, it is part of roll change time, every time one finishes a roll, you must get back to starting point, load the roll, thread the fabric and take it to SPLICING position, generally, it is less than two minutes per roll.

Manual spreading is generally done by two operators for quality spreads and maximum spreading is at 4 to 5 yards per minute as an average for the day compared to 10 to 15 yards per day per person.

Query

Please advise a way to cut fabric with long pile(hair), in away that not damages the hair, the way we use is that we draw the shapes manually on the back of fabric then cut carefully with manual scissors along the lines shape by shape, cutting the base of fabric and not the hair. But this is a time consuming process...we have Wastema CNC-Cutter, is it possible to replace the knife with a special pen to draw on fabric back side? or pls advise any other way.

Shaimaa Puettmann, Free zone-Amreia-Alexandria, Egypt

SOLUTION : Ram Sareen, Head Coach / Founder - TUKAgroup, TUKATECH-TUKAWEB- TUKAcenters

There are several ways to utilise technology but you MUST stop cutting with manual scissors.

Option 1.

Depending upon the length of PILE, you may allow BUFFER in your patterns and cut on CNC machine. This will allow you to enough room on the seam to either take in more or less but that is adjusting and trimming at every seam.

Option 2.

Generally the best way is to spread FACE-UP so you can           control the NAP, in most of pile cutting the seam allowance is 0.5 inch to 0.625 inch, even if the hair on one seam may get cut off a little, the seam will compensate when turned. The trick is in MARKER MAKING, lay the adjoining pieces side by side if possible, specially the most crucial pieces, if hair is cut-off on one seam, the other adjoining seam will automatically compensate.

Query

Can interlining technician compare or certify naked interlining with composite interlining? If yes, then how?

Ravi Tiwari, S O L International

SOLUTION
Vishal Kapoor, Godolo & Godolo Exports Pvt. Ltd.

Yes. It is possible to compare to different naked interlinings with each other and with another interlining which is already fused to the outer shell fabric. To do so, we need to do a peel strength test for the naked interlinings after fusing it to the same outer shell fabric.

SOLUTION Rajkumar Rai, Interconti

Yes! You can check the construction – ends per inch and picks per inch on the base fabric of interlining and compare it with that of the fused component. Normally there should not be any change/increase in the thread density in fused component.

However after washing of fused component their could be a slight change in thread density (approx 2 – 3%) depending on the shrinkage rate of the interlining and shell fabric.

Secondly you can also check the GSM of naked interlining before fusing and compare it that of the fused component. It should be – gsm of interlining+gsm of shell fabric. There could be a nominal change in gsm of fused component. After washing (approximately 2-3% due to shrinkage).

Query

If two options of naked interlining and a fused fabric with one of the interlining are kept together, will interlining technician be able to say which interlining is being fused on the fabric out of two options? If yes then how?

Ravi Tiwari, S O L International

SOLUTION
Vishal Kapoor, Godolo & Godolo Exports Pvt Ltd

Let us say that there are two interlinings ‘A’ and ‘B’. And there is another outershell fabric which already has an interlining ‘X’ on it.

There are three ways to check:

A. Visual check. By comparing the construction of the two interlinings - ‘A’ & ‘B’ with ‘X’.

B. By fusing the two interlinings ‘A’& ‘B’ with the same outer shell fabric and comparing the hand feel obtained with the hand feel of the orignal fused (with ‘X’ interlining) fabric sample. Each interlining gives a slightly differnt hand feel on fusing.

C. If the above tests fail to give a conclusive answer then do a peel bond strength test on the two interlinings ‘A’& ‘B’ after they are fused to the outer shell fabric, comparing the results with what are obtained on the orignal fused outershell fabric with ‘X’ interlining on it.

In such a test, the peel strength is checked after fusing but before washing, after fusing and then washing, and also after fusing and then drycleaning.

Visually similar looking interlinings can give surprisingly different results. A better quality interlining will have higher peel strength after washing/drycleaning as compared to a low grade quality.

SOLUTION
Rajkumar Rai, Interconti

Additionally you can also check the bending angle factor and physically handfeel. Bending angle can be checked by following method: Fuse 5 cm width and 25 cm length of fabric using both options of the interlinings. Now keep the interlining composite on the edge of a table and gradually slide outward by 10-12 cm. The interlining composite will bend downwards on its own weight. Measure the bending angle from the horizontal plane and compare visually. Stiffer the interlining, lesser will be the bending angle.

Query

Will the count & construction of woven interlining remain same before and after interlining is fused? If yes then why?

Ravi Tiwari, S O L International

SOLUTION
Vishal Kapoor, Godolo & Godolo Exports Pvt. Ltd.

The yarn count will always remain the same.

In a bad quality interlining construction, meaning the reed and pick, could change as fusing with outershell fabric entails the application of heat and and pressure to the interlining. A good quality interlining has been stabilised at the finishing stage and will not shrink/change shape at the time of fusing.

SOLUTION
Rajkumar Rai, Interconti

Count and construction of woven interlining will remain same, because the base material is 100% cotton so there won’t be any shrinkage/dimensional change of base construction due to heat during fusing. The only change expected would be after washing due to wet shrinkage.

1. The fabric shrinks
2. The threads shrink
3. Both fabric and threads shrink

How can one identify between tension puckering and shrinkage puckering, if the previous history (washing etc) of sample is not available?

Chandrark K Karekatti

SOLUTION - Anita Buzengeiger,
Sewing Advisory, AMANN Group

Basically it is not possible to find out whether the reason for puckering in a washed garment was too high thread tension or shrinkage while washing. You at least need to have the unwashed garment (unwashed seam) or even better — some fabric and the sewing test used. So it is possible to make the usual tests to find out if the tension was to high or if the thread is reaching to the washing either with shrinkage or by getting longer (both are possible).

Is there any standard method to calculate lay spread tension? How does one optimise it for different fabric types?

Chandrark K Karekatti

SOLUTION - Ram Sareen, Head Coach, TUKAgroup

There is no way to calculate the tension in fabrics and there is no real solution in calculating the tension in spreading. It is an experienced eye that you need to look at the way the rolls are wound; even during winding, tension can vary at different parts of the roll, eg, outer core tension may be less than on the inner core. Different fabrics have different stretch properties and each fabric has a different recovery. The most stretch capability is with Lycra blends but the stretch and recovery time will vary depending upon the percentage of Lycra or Spandex. Fifty per cent Lycra content will almost behave like elastic, it will come back to its original length very quickly compared to 3% or 5% Lycra content. The rule is, "higher the Lycra content, faster the recovery - lower the Lycra content, slower the recovery.

The most difficult factor in spreading is to release the fabric from the roll in FREE AIR before if MAKES CONTACT with laid fabric on the table; if laid on top of the fabric already on table, it will cling and recovery will be very slow. It will pull the bottom ply along but, if it is FREE in the air, it will recover and can then be laid on top without tension.

Another factor a spreader machine operator must consider, depending upon the fabric tension, is the co-ordination of the speed and unwinding of fabric. The more the stretch, the slower the speed; hence more overfeed is required.

It is one of the most skilled jobs as it requires both the knowledge of fabrics and capability of handling machines simultaneously.

Please advise method to remove pen marks from canvas.

Rajesh Arora (Cotton Crafters)

SOLUTION - Vikramaditya Rajput, MD, Simtech

We suggest using the SEITZ Spotting chemicals for all such applications.

SOLUTION - Murtaza Mehdi, Washing Incharge, Orient Craft

Acetone is used to remove pen marks from all kinds of fabric except for silk and satin. The solution is easily available in all chemical shops.

How can a factory switch over from conventional form of producing garments to high-technology production systems, that is from using mostly single needle lockstitch machines to automatic machines such as automatic pocket setters etc? What financial benefits will the factory get?

Babar Ali Khan from Salam & Co.

SOLUTION - Vikram Sona, Area Sales and Mkt. Manager- South Asia, Duerkopp Adler

Your question is very interesting and at the same time intelligent. It is not so easy to switch over the culture of one company in one days time, however the management's will, its vision and looking beyond will definitely help to take such decisions.

It is very important for you to identify  the areas where the automation is possible ! You will not and cannot underline the importance of single needle machine/s. First of all there are so many automats which has the head of the single needle machine!

Please remember that with automats, you can achieve the followings:-

• Consistent quality- piece after piece.
• Not depending on the skill of the operator as his/her skill is being executed by the automats
• Doing multiple operations on one machine
• Reducing the number of operators.
• Reducing the handling time (this is one of the most important factors)
• Saving of power
• Saving of space
• Saving of thread
• Saving of manpower.

If you calculate all the above, you get the answer to both your questions.

There are some operations such as pocket welting, where you can calculate the cost saving it does and find it very easy to change over, but for some automats like automatic placket, it is not so easy for existing factories to just switch over. Moreover, the company's eagerness, progressiveness and determination plays an important role in adopting the latest technologies to their benefits.

As regards the financial benefit to company is concerned, the company has to invest first and than assess for themselves the quantum return under various heads explained above.

If not, medium sized companies like Ashapura Garments  would (Winstone) have not invested to get the latest technologies to their factories.

SOLUTION - M Prakash, General Manager, IIGM Pvt Ltd.

Today, the entire garment industry is gearing up to the global needs and to be flexible. As per your questions, the company should be doing a stable product like trouser or jeans etc to have a fully automated plant. In this changing world, we do not recommend a fully automatic plant until and unless they do only one product. However, we do recommend the following automation to increase productivity and quality. Some of the products are Gerber cutting room, Eton for sewing floor and GSD for time motion study and methods management.

Many of these automatic solutions are oriented towards one process (or operation) or a family of sub operations under one operation. eg. automatic pocket welting machine.

There can be variations in terms of size and number of pocket welts (single welt or double welt).

The savings can be clearly measured by the operation cycle time. Additional advantages like uniformity of the operation, quality, etc must also be considered.

The capacity of the new machine must be estimated in terms of number of cycles/shift (number of pcs/shift) and this should be utilised to the maximum level  by continuous feeding. (One machine could be utilised for multiple lines).

Every machine involved in the production is an investment, and there is an obvious return on this investment.

The tangible benefits are the overheads saved by the new machine with respect to the replaced number of machines and operators.

The intangible benefits are the satisfaction of the customer by uniformity of the products, better quality and better delivery times.

SOLUTION - Horst Hennig, Leading consultant PFAFF

Changing over from a conventional unit to a high tech unit depends on many factors prevailing within the unit. There are size dimensions, amount of orders, structure within the order (number of colours, sizes, fabrics etc), number of employees, leadership and character of leading the factory, mentality of workers and environment and many more such issues.

Taking the example of the production of a 1,000 pcs or more of trousers/pants per shift. I would advise that one should definitely go in for full automation of the unit. On the other hand with products like jeans or blouses rather than automatic machines the requirement is that of mid-technology i.e modern high-speed seamers that offer flexibility.

In terms of cost, complete automation of a unit requires immense investment in machinery in addition one also needs to invest in changing the mindset of the operators which is also considered as a cost. Again taking the above example technology for a 1,000 pcs would cost approx. 20% more for automatic machines than with normal technology. That means the technology must give you a pay back in not more than two years. Than it could be interesting to think about change of technology.

Query

"How can we set parameters for thread tension for different fabrics? What is the maximum thread tension we can give to needle thread and bobbin thread? At present we are running denim cargo shorts where we need maximum puckering, how can we measure thread tension?"

Anupam Kumar from TCNS.

SOLUTION -  Mario J Batory, AMMAN

They can be compared to “how does a motor work?”

For each and every machine type- construction and fabric, there are special settings necessary.

If someone wants to have a seem with additional puckering, there are special machines necessary as well as special settings, threads, needles and handling techniques.

SOLUTION -  Sanjay Sharma - Groz-Beckert

The optimum thread tension varies from fabric to fabric and besides the type of fabric it also depends on sewing thread being used and the machine type involved. But unfortunately there are no specific parameters or figures available for precise adjustment of thread tension for different kind of fabrics.

It is recommended that before starting production, the thread tensions should be adjusted for each fabric and sewing thread individually. There is a simple rule, the thread tensions should always be as low as possible and the needle  and bobbin thread should be balanced in such a way that the stitch knotting is set approximately in the center of the fabric.

As already mentioned, there are no figures available for setting thread tensions, whether optimum, high or low.

Normally, the thread tensions can only be increased up to the point where problems like thread breakages and skip stitch start occurring. Just for information, the extreme example of highest thread tensions can be in case of seat seaming in automotive industry, where thick materials are stitched by using thick needles and thick sewing threads. In such sewing operations the needle thread tensions can easily rise higher than 1000 cN, but as explained before thread tension should be as low as possible otherwise it will affect the seam appearance as well as lead to problems like thread breakages and skip stitches

The thread tensions can be measured by tension meters, which are available in the market.  There are different companies, who sell this equipment. But if you need a maximum tension puckering effect you could increase the thread tension only to the point before the sewing problems like thread breakages and skip stitching start occurring. Adjusting the feeding mechanism of the machine in a way that it pushes the fabric rather than pulling can also increase the puckering.

SOLUTION - Suresh Kamath - Coats

The thumb rule for any high quality pucker free sewing operation is to use :

a)  The finest thread possible
b)  The finest needle possible
c)  The lowest tension possible.

Speaking of thread tensions the ideal recommended thread tension for the needle thread is between 125gms to 150 gms. The corresponding bobbin thread tension should be between 35 gms - 45 gms.

Tajima - the manufacturers of multihead embroidery machines have a pen like instrument with which you can measure the needle thread tension and they also have another box like instrument with which you can measure the bobbin thread tension.

If you want to get high pucker in the denim cargo shorts I suggest that you :

a)         Increase the thread tensions both for the needle thread as well as the bobbin thread. This will cause higher thread extension and subsequently higher thread retraction leading to increased pucker.

b)         Use a coarser thread (Tex 105 or 120 DUAL DUTY) in the needle so that you intentionally cause larger weave displacement in the fabric leading to higher seam pucker. In the bobbin use Tex 60 (DUAL DUTY) thread.

c)         If possible use lock stitch in place of chain stitch, as lockstitch has the potential to cause more seam pucker than chain stitch.

We were having a style with 80 horizontal pintucks (see the photograph.) Initially we assumed that pin tuck can be made on pintuck m/c therefore all planning and costing was done accordingly. But the fabric was having 2 way stretch and no matter what adjustment we tried it could not be made on pintuck m/c. Kindly suggest any solution.

Amit Singh

Query

"What should be the proper seam strength (301 lock stitch and chain stitch) for jeans stitching so that seam doesn't break at the washing stage?"

Rajiv Singh, Chelsea Mills, Delhi

SOLUTION - Resham Sen, Consultant

Guidelines for proper seam-strength are given by ASTM D1683. According to that standard the correct requirement for heavy fabrics like 14 oz denim is 25lbs (11.3 kg).

Technically, the strength of a seam depends mainly on the following factors :

1. Stitch type
2. SPI
3. Seam type
4. Seam allowance
5. Thread strength (more specifically : loop strength )
6. Thread tension
7. Seam efficiency of the material
8. Structure of the fabric (count, construction )

Seam failure occurs due to a combination of the following reasons:

1. Rupture of the stitches (although fabric remains undamaged)
2. Rupture of the fabric yarns (although stitches remain intact)
3. Fabric yarn slippage at the seam (seam slippage : measureable as per ASTM standard D434 )

Seam failure occurs when a high degree of transverse stress is experienced by the garment when it is used by an end user. But seam failure due to WASHING ???

During washing the garment experiences severe forces of torsion and elongation but not as much transverse (across the seam) stress as it would be when the garment is being used.

So, if a manufacturer is facing seam rupture during washing, then the usual causes are :

1. Less SPI (usually 7-9 is pretty good for 14 oz denims stitched with #20 or lower thread)
2. Poor thread tension resulting in unbalanced stitch
3. Poor seam allowance (allowance of less than 11mm for 516 st with less than 6mm overedge width or improper folding of the seams through the folder of the feed-off-the-arm machine are the usual culprits)

Query

"Suggest me the right dealers for spare parts of Duerkopp, Pffaf & AMF Reece for genuine parts in India and abroad?"

Gokaldas Weil Pvt. Ltd."

SOLUTION - Vikram Sona, Duerkopp India

Duerkopp, India

Garment machinery - Mr. Viraf Turel - 022-25000934
Heavy duty or leather - Mr. Razdan - 022-3712899

Duerkopp, Germany

Duerkopp Adler AG,Potasdamer Strasse, 190,
D-33719, Bielefelid, Germany
Contact person - Mrs. Petra
Tel. No: 0049 521 925 2342
Fax No: 0049 521 9252300
Email: babenhauserheidep@duerkopp-adler.com

SOLUTION - Anil Anand

Pfaff , India

HCA Garment Machinery Pvt. Ltd.
A-94/1, Okhla Industrial Area
Phase-ii, New Delhi - 110020, India
Ph: 91 11 2638 3811/ 3804/ 3820/ 5794
Fax: 91 11 2638 3802/ 51612614
Email: hca@vsnl.net. / hca@touchtelindia.net
Web: www.hcagarmentmachinery.com

Pfaff Industrial Singapore Pte Ltd

PFAFF Industrial Singapore Pte Ltd
50 Kallang Bahru
# 06-17 to 19
Singapore  339334
Singapore
E-mail: singapore@pfaff-industrial.com.sg
Phone: + 65-62920820
Fax:     + 65-62961892

Bangladesh

Minhaz Continental Agencies Ltd
Jiban Bima Tower (9th Floor) 10
Dikusha C/A
Dhaka  1000
Bangladesh
E-mail : mgbj@linkbd.net
mgbjtd@bangla.net, mgbj1@linkbd.net
Phone: + 880-2-9563757 or 9550964 or 9563731 or 9560717
Fax: + 880-2-9563712

AMF Reece, World Headquarters

P.O. Box 15778
Richmond, Virginia
23227 - USA
PH: (804) 559-5000
FAX: (804) 559-5210
Email: marketing@amfreece.com

Query

"Suggest which machine (model) is suitable for sleeve blind hemming in blazers?"

Gokaldas Weil Pvt. Ltd.

SOLUTION - Resham Sen, Consultant

The typical machines required for blindstitching sleeve-lining with the shell at the cuff, after attaching the buttons (not possible when a pseudo sleeve-vent is made) are :

MAIER: Class 252 (medium to thick material)
            Class 352 (light to medium material )

Both are single thread blindstitchers. It is advisable to use these with electro-magnetic thread trimmer. Special folders are also available and can be suggested only after examining the seam.

UNION SPECIAL:      Model 30-210 (lockstitch blindstitcher : 314)            Earlier model was 16-460.

Query

1. "Needle holes are visible after washing ' (cotton fabric) before washing everything okay."

Nitesh Chaurasia, Texmaco, Indonesia

SOLUTION - Groz-Beckert Lab.

Depending on Fabric Type, sometimes, material damages are not visible immediately after sewing, especially when inspecting the seams only with naked eyes. But subsequent to the washing process these damaged weave threads show-up and become clearly visible.

To avoid piercing of weave yarns, needles with a ballpoint style like FFG or RG in combination with next smaller needle size, than presently used, should be applied.

In the absence of presently used needle system & size and fabric details, we could only give a general advice and would recommend to reduce the needle size step by step until the material damages disappear after washing.

2. "Is there any remedy for removing needle holes in coated fabrics after opening the seam, if we want to repair."

Nitesh Chaurasia, Texmaco, Indonesia

SOLUTION - Groz-Beckert Lab.

Unfortunately there is no remedy for removing needle holes in coated fabrics when stitches are opened for corrections. When needle penetrates the coated fabric along with thread there is no movement of yarns because yarns are prefixed due to coating, which means yarns in such cases have no chance to relax back to their original position.

Once the needle has penetrated the coating, the needle holes remain permanent inside the coating and therefore can hardly be repaired or removed.

3. "Suggest me the needle number and type for reducing puckering in micro fibre polyester fabrics? Is the needle the only reason or may be also the operator handling...its major problem during top stitch and bottom hem?

Nitesh Chaurasia, Texmaco, Indonesia

SOLUTION - Groz-Beckert Lab.

Puckering is a common problem faced while stitching fine and dense micro fibre fabrics. Mostly in such cases, puckering is caused by weave yarn displacement due to the stitch knotting of the seam. The extent of  "Displacement Puckering" depends on fineness of the fabric as well as on the sewing thread thickness and needle size. Thicker the sewing thread and needle, higher the weave yarn displacement and therefore the puckering.

To eliminate or at least to reduce the puckering we recommend following:

• Use the thinnest possible sewing thread size, to keep the stitch knotting and therefore the weave yarn displacement as small as possible.
• Reduce the sewing thread tension to the functional minimum to avoid tension related puckering.
• Preferably use GB - needles in the San 10 design with RG-point style and a maximum needle size of Nm 65.

Query

"We are facing a problem in stretch denim after medium bleach fabric is loosing its stretchability. Buyers are very particular about stretchability. Percentage of the synthetic fibre in the fabric is 4% and cotton 96%. Please give us some better solution to improve the stretchability. After doing a bleach wash on spandex denim, the stretchability is lost, is there a way to keep this in control?

United Aryan EPZ  Ltd, Kenya

SOLUTION - Naveen Dhar, Arvind Mills Ltd.

Spandex breaks when bleach is used to process it, remember never to use bleach on spandex. You should go for proper enzyme to achieve the required tone or wash standard.

SOLUTION - KG Denim Limited

The following precautions may improve stretchability:

1. Avoid higher temperature (more than 40OC) during the washing process.
2. Use only neutral enzyme for fading
3. Maintain the temperature below 40OC during the prewetting + desizing  and chlorine bleach process.

SOLUTION - Suvodeep  Mukherjee, Arvind Mills

If it is hypochlorite bleach you could try peroxide with modified recipe for less degradation of spandex. Generally spandex from DuPont (for example T40 etc.) does not get affected with either kind of bleach.

SOLUTION - Gautam Guha Thakurta

Mild bleaching with 1-2% caustic soda or other alkaline agent is not likely to degrade the spandex fibre for stretch reduction. But boiling with alkaline solution should be an issue. Boiling shrinkage rate of spandex is critical. Values of spandex fibre’s hot water shrinkage at various temperatures and shrinkage force values would be some helpful parameters.

Spandex monofilament is generally used in weft yarn. If bleaching is carried out at fabric stage and boiling is done (i. e. machine direct iron) under warp direction, tension in the weft boiling shrinkage could be worse. More warp tension means more weft direction (cross direction) shrink, this way weft spandex can get conditioned i.e. oppose stretch. And then if the stenter process causes excessive cross direction tension, the cross direction hysterisis of weft yarn could  be more, causing loss in stretchability. So the treatment under boiling/hot water is better done under controlled cross direction tension.

SOLUTION - Prof. R. Chattopadhyay, IIT Delhi

The problem may arise due to high concentration of alkali or keeping more than appropriate temperature or prolonged time of bleaching.

Query

Needle holes are visible after washing ' (cotton fabric) before washing everything is okay

— Nitesh Chaurasia, Texmaco, Indonesia

SOLUTION - Resham Sen, Consultant

This problem is difficult to answer without seeing the fabric and other stitching conditions. Anyway the prima facie evidence suggests that this is a problem created by damaged needle tips which has form some fibres from the yarn of the fabric. This is usually not visible before washing but the rigours of the washing cycle makes the damage to the yarns more prominent. What is the construction of the fabric? What type of needles are being used? Is the machine properly adjusted ( i.e. the needle tip not touching any other part of the machine and getting damaged quickly after replacement)?

SOLUTION - J. H. Jung, Orange Needles

To avoid the enlarged needle hole

1. Use ball point needles
2. Use smaller size of needles

SOLUTION - Schmetz Sewing Application Centre, Germany

Please send unwashed fabric for testing.           

Query

Is there any remedy for removing needle holes in coated fabrics after opening the seam, if we want to repair?

— Nitesh Chaurasia, Texmaco, Indonesia

SOLUTION - Resham Sen, Consultant

The problem encountered in stitching coated fabrics is the same as in stitching leather. The needle does not enter the fabric by displacing the yarns but cuts through the coat thereby causing a permanent hole, which can hardly be removed later. So thorough planning and utmost care is a necessity in stitching such coated fabrics so that they are not required to be altered.

Query

Suggest me the needle number and type for reducing puckering in micro fibre polyester fabrics? Is needle the only reason or may be also the operator handling...its major problem during top stitch and bottom hem?

— Nitesh Chaurasia, Texmaco, Indonesia

SOLUTION - Resham Sen, Consultant

Microfabrics by their very nature are prone to puckering and need various techniques while stitching.

(a) Use the thinnest needle possible with proper point type. Usually an "acute round point" helps.

(b) Make the thread tension as less as possible. Replace the thread take-up spring , tension-post assembly and thread take-up lever with those used in machines for sewing light fabrics.

(c) Replace the normal throat-plate and feed-dog with special puckering-free throat-plate and feed-dog. Often the clearance between the diameter of the hole in the throat-plate and the diameter of the needle is large enough for the microfabric to be pushed into the throat-plate hole as the needle enters it, resulting in puckering. To counter this, special throat-plates are custom-made by garment manufacturers, where the needle-hole is as small as is practically possible for the needle being used. Sometimes when this was not possible, we have also got good results in using a ply of paper under the fabric plies being sewn. When the needle sews through the fabric and the paper, the paper acts as a support and stops the fabric from being pushed into the needle-hole of the throat-plate.
After stitching, the paper can be torn away and cleared.

(d) Release the pressure of the presser-bar as much as possible. Replace the presser-spring with a lighter spring. Use a puckering-free presser-bar assembly supplied by sewing machine manufacturers.

(e) If costing and construction permits, good result is obtained by using a special fusible interlining tape in the seam.

This gives stability to the fabric and resists puckering. This method is quite common in top-stitching the arm-hole of men's dress shirts. A thorough and proper analysis of the causes of the puckering in different areas of the garment and a mix and match of the above-mentioned techniques in different proportions will definitely give better results.

SOLUTION - J. H. Jung, Orange Needles

To avoid or reduce puckering

1. Use small size of needle and thread
2. Use a smaller ball point needle
3. Use the same type of material in the thread and fabric
4. Use minimum pressure on the presser foot
5. Minimise tension of the needle thread and the bobbin or looper thread
6. Use feed dogs with finer teeth
7. Reduce the number of stitches

SOLUTION - Schmetz Sewing Application Centre, Germany

The following changes normally cure puckering while stitching microfibre.

1. Use the thinnest possible needle (‘SPI’ size 65-70)
2. Use the less voluminous thread (NO. 150)
3. Use additional transporting devices like alternating sewing foot or a walking foot.
4. Choose the optimal stitch density 4-5 stitches/min.
5. Regularly check the point of the needles because even the smallest burrs can lead to needle cuts.

SOLUTION - Y P Garg, Consultant

Micro fibre polyester fabrics - One needs to change the gauge set i.e. pressure foot, feed dog needle, hook set and use finer needle, finer thread. Keep both tension and pressure at the lowest.

Query

Do you have any standard production target for cutting section as that of sewing line (GSD)? 

— Gokaldas Weil Pvt. Ltd.

SOLUTION - Prabir Jana, Associate Professor, NIFT

First of all GSD does not give standard production target for sewing operations. GSD gives time value for basic motion sequence generally performed during sewing involving reach, move grasp etc. For setting target of any operation you will require the work content of the operation. For measuring work content you have to decide on method and motion sequence. Once motion sequence is decided, GSD can give time value for any motion sequence that you have selected. This time value is benchmark as long as the motion sequence is followed religiously. In cutting section also you can measure the work content of operations once the motion sequence for every operation is determined and standardised.

‘GSD Scimitar’ for Cutting Room, offered under licence by GSD (Corporate) Ltd is a Windows-based software system, which has been developed specifically for ease of application within the Cutting Room environment. Incorporating the integrity of the GSD database and the very best in logical and dynamic software design, GSD Scimitar provides the solution to work measurement in the cutting arena.

SOLUTION - Ulrich Veith, Veith Systems GmbH

Per Veith Pin Table we have a target production of 240 - 300 jackets or 190 -250 suits / 8 hour-day / Veith Pin Table with two operators. The variation of the figure depends on the amount of cloth roll exchanges and the height of lay packages and the type of cutting. If we have just one fabric within the lay package and we have minimum 10-15 plies within the lay package we tend to the high figure.

But, if the fabric has to be exchanged frequently, e.g. every 2nd - 4th ply (typical European production demand), the output goes down. If a customer has lay packages of average less the 10 plies the production also goes down, because of the set up time. If he in addition cuts manually and not with a CNC-Cutter (Gerber or so), the production also goes down, because bringing the marker on top of the lay package takes more time than pinning fabric and with low lay package heights this effect gets to very important. So in a bad situation, frequent cloth roll exchanges (every 1.5 th ply) one average lay package height of 5 plies, and manual cutting, the output of jackets can even drop below 180. Besides all, a very important fact is the motivation of the operators as it is still a manual work, the correct training of the people and the work preparation around the Veith Pin Table.

Query

Can you suggest how to increase productivity in the cutting section during checks fabric production?

-  Gokaldas Weil Pvt. Ltd.

SOLUTION - Ulrich Veith, Veith Systems GmbH

Our experience shows that in men's wear (jackets, suit, trousers) compared to manual spreading - blocking - single piece matching using the Veith Pin Table can save the customer easily over 50% of the labour time spent before. In addition comes a 3-5% (-7%) less fabric consumption. What is important is to know how to plan the markers correct and how to organise the work around the Veith Pin Table. Veith System supplies also the know-how transfer.

An investment can only be made if there is a reasonable ROI. In countries like India the ROI for the Veith Pin Table comes mainly from reduced fabric consumption.

Example with conservative figures:

240 jackets per day * 1.8 metre consumption * $10 / metre = $4320 / day fabric costs 3% saving on that is $129.60 saving potential per day in fabric costs.

Complete Veith Pin Table with all accessories, packing, shipping (no duties) $21,000-22,000.

Which means just because of the fabric saving the ROI comes to 170 working days, which we think is close to a reasonable figure, especially as the labour saving, the better quality etc comes on top.

(When a company comes to a situation where the sewing department is almost stopped, when checks are in production, because the cutting room does not delivery enough pieces - the ROI cannot be calculated exactly anymore, but it might be a question by survival....)

In a situation of dramatic cloth roll exchanges, the Veith Cloth Roll Magazine with integrated gantry spreader can increase the productivity by 15-20%. But this might not be enough for India, where the wages are so low that it is probably better to buy a second Veith Pin Table, which then gives 100% more productivity at almost the same investment.

Query

While buttonholing denim jackets we are facing problem of "fraying look" in the buttonholes. We are following "cut-after sewing" methodology. Can you suggest any remedy?

Also sometimes we have to do buttonholes after washing. For after washing method what buttonhole should be followed? "cut-before" or "cut-after"

SOLUTION — Resham Sen

The eyelet buttonhole will give some fraying at the holes if it is done before washing. Cut-after is the most prevalent use. It can be minimised to a great extent if the m/c is properly adjusted and the cutting dies are changed, but it cannot be totally eradicated. How much fraying is taking place and whether it is internationally acceptable or not can only be said after examining a sample. Cut-before can definitely be tried for decidedly better results (but if it is done before washing it will not lead to absolutely zero-fray.) It is quite popular to do button-hole and bar-tack after the washing is done.

This makes the manufacturers life a bit easier during the finishing process (of-course thread inventory and shade matching has to be properly managed). Cut-after is again the most accepted practice. But in an after-washing scenario the difference between cut before or after will not be as remarkable as is seen if holing is done before-washing.

Cut-before is usually used when the workpiece has fused interlining and has greater stability. However a 12-14oz denim can take both the methods in its stride.

SOLUTION — Hans Lang

The fraying can be reduced by adjusting a narrower cutting margin. Care must be taken to use a needle with a correct and undamaged point.  Generally the cut after method should be used for denim as otherwise the sewing thread in the buttonhole would be entirely exposed to the washing with an increased danger of being damaged.

SOLUTION — Y P Garg

To avoid fraying look we can use non-woven double sided fusing tape at the lower side of the button hole which will make a bond between both the plies of the placket.

To do buttonholes after washing Cut before is advisable.

Query

We use fabrics that need pintable to align grain (crepe, georgette etc.) also sometimes plaids. Currently I am using customised non-retractable pins along selvedges. I am planning to get a long (like Veith Systems) pintable. I also plan to buy a spreading machine. Can I use automatic spreading machine along with the Veith pintable?

Eves Fashion, New Delhi

SOLUTION — Ulrich Vieth

The Veith Pin Table is not designed to carry a spreading machine.

• that spreading and matching is one work step, which has to be done manually, and a spreading machine would not increase the speed.
• to work on shorter markers in order to avoid the typical problems of  the variation of the repeat size, but spreading machines are build to spread long markers.
• to block the spreading machine when the Pin Table is in use and vice versa.

Therefore a better solution is to have 2 separated lines - 1 for the spreading machine and 1 for matching, which in the end increases also the flexibility of the cutting room. For the Veith Pin Table there is only a space requirement of  typical 9 m length = 4m long Veith Pin Table plus 4m cutting table plus space for e.g. fabric..., so that this should normally not be a reason to combine things, which do not belong together.

Query

We are a manufacturer of ladies underwear and process warp knitted fabrics with elasthan content for bras. In certain seams, where we use needle system 134 Nm 70 with FFG/SES point, we experience excessive material damage problems.

Can you give us advice how to overcome this material damage problems from the needle side?

Solution - Groz-Beckert Lab

We have investigated your fabric in our sewing laboratory and have carried out several sewing tests in order to find out the best combination of needle size and point style for processing this warp knitted fabric.

The main problem when sewing this  warp knitted fabric with elasthan content is the damaging of the elasthan thread itself, due to the needle penetration. 

As the elasthan thread is part of the fabric construction, every damaged elasthan thread will create a significantly visible hole inside the fabric, as it can be seen in the picture above.

According to our tests, the best suitable point style for processing this fabric is the SKL - point style.  In comparison to the other point styles, such as FFG/SES and FG/SUK, the SKL - point style performed best.  But additionally to the SKL - point style, we had to reduce the needle size down to Nm 65 to eliminate the elasthan thread damages totally.

Needle recommendation: We would recommend you, to apply needle system 134 SAN 10 Nm 65 with SKL - point style, for processing your warp knitted fabric with elasthan content.

With this Special Application Needle SAN 10, you have the advantage of a high needle stability due to a special designed blade in combination with a max. fabric protection. The SAN 10 needle system in size Nm 65 has the same stability as the Nm 70 standard needle, which you currently use. Therefore you have, in spite of the smaller needle size, no higher risk of skip stitches or needle breakages than before.

Query

We are facing bubbling problem in the chest area of ladies jacket. The customer has complained about bubbling after the goods were finished in their warehouse. We had checked the bond strength before production and used it only after bond strength was found acceptable. We had also taken precaution to ensure that fusing temp and pressure were maintained accurately during production as recommended by the interlining supplier.  I do not understand what went wrong?.

Material used: Polyester / Wool - 65/35 - 250 Gsm
Interlining Art used: XXXX - Non-woven -40 gsm
Polyamide - MICRODOT: 50 Dots/ CM2

ABC International
Ladies jacket manufacturer

Solution - Raj Kumar Rai

The reason for bubbling is due to extended steam pressing operation carried out at buyer's warehouse. The interlining you were using had polyamide based adhesive which melts easily and quickly in  wet steam / heat condition. Too much steam exposure resulted in increased fluidity of polyamide adhesive and subsequent delamination due to rough handling of garments while they were still hot. The delamination process is also aggravated due to pull exerted on the upper part when garments are kept in hanging condition immediately after pressing.

Solution: Change your interlining to co-polyester adhesive and allow proper cooling off of garment before putting on hangers.

Product Practice: Please discuss in detail with your interlining supplier the after-treatment process / conditions given to garment to make sure that his interlining would withstand the rigours of customer handling (rather mishandling at times) during after-treatment.

Query

We are a manufacturer of men´s wear and presently we are facing serious problems when sewing a certain kind of weave fabric  especially, when stitching buttonholes with needle system 501SC Nm 110 the damages are clearly visible.

Can you recommend us the most suitable needle for this fabric to avoid material damage inside the seams?

Solution - Groz-Beckert Lab

We have investigated your fabric and buttonhole samples (see pictures below)  in our laboratory. The material damage problems, which you experience, are definitely caused by needles of a size, which are too thick for the material used.    

The fabric is very densely woven and the only way of avoiding these significant material damage problems is to use thinner needles.

According to our test results, the maximum usable needle size, without experiencing material damage problems, is Nm 80. Every needle size higher than that will cause significant damages inside the fabric, no matter what kind of point style is used. 

Needle recommendation: Generally, we recommend for sewing this weave fabric a max. needle size of Nm 80 and a ball point style FFG. 
For the buttonhole process, we recommend to apply needle system 505 SC in size Nm 80. Needle system 505 SC is the same as 501 SC but with a FFG point style.

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