Sizing Defects Causes and Remedies

Last Updated on 17/09/2025

Sizing Defects / Faults:

Sizing is an important weaving preparatory process where warp yarns are coated with a protective film of size material (starch, PVA, etc.) to improve strength, abrasion resistance, and smoothness. The quality of sized beams is important for good performance in weaving. If the process is not properly controlled, different sizing defects may occur, which reduce weaving efficiency and fabric quality. A number of faults occur that need to be properly rectified so as to ensure good quality weaver’s beams. The commonly occurring sizing defects and their causes and remedies are discussed in this article.

List of Sizing Faults:

1. Broken Ends
2. Missing Ends
3. Crossed Ends
4. Sticky Ends
5. Uneven Sizing
6. Defective Selvedge
7. Ridges on the Beam
8. Underslashed Warps
9. Overslashed Warps
10. Sticky Warps
11. Over Dried Warps
12. Gum Spots and Smears
13. Non Uniform Size Regains
14. Crossed and Lost Ends
15. Improper Build of Beam
16. Incorrect Warp Length
17. Dirt Stains in Warp
18. Shinnery
19. Sandy Warp
20. Hard Sizing
21. Size Dropping
22. Excessive Lappers
23. Low Elongation at Break

Causes and Remedies of Sizing Defects

1. Broken Ends:

Breakage of warp yarn ends during or after the sizing process is one of the common defects  in sizing. These broken ends lead to gaps, weak spots, or irregularities in the warp sheet wound on the size beam.

Causes and Remedies of Broken Ends:

Causes:

1. Weak yarn strength or poor quality warp.
2. Excessive tension during sizing.
3. Mechanical faults in size box or rollers.
4. Abrasion by lease rods or guides.
5. Improper drying temperature making yarn brittle.

Remedies:

1. Use good quality warp yarn.
2. Maintain correct sizing tension.
3. Regular maintenance of rollers and guides.
4. Smooth lease rods to reduce abrasion.
5. Control drying temperature properly.

2. Missing Ends:

Missing ends are absent or lost during or after the sizing process, leading to gaps or cracks in the woven fabric. Missing ends, i.e., total number of ends in the back beams, some of the ends which are missed in the warping itself. The remedy is that the ends are to be joined afresh into the back beams.

Causes and Remedies of Missing Ends:

Causes:

1. Ends missed during warping.
2. Breaks during sizing not joined properly.
3. Careless handling while transferring to beams.
4. Slippage of yarn from rollers or guides.
5. Operator negligence in mending broken ends.

Remedies:

1. Proper checking of ends during warping.
2. Join broken ends afresh in sizing.
3. Careful handling during beam transfer.
4. Ensure guides/rollers are properly adjusted.
5. Supervise operators to reduce negligence.

3. Crossed Ends:

Crossed ends are formed during sizing and therefore the warp ends are not present in their proper place on the beam. Hence there is chance to knot the missing end to the other end in the sized beam. The size beam flanges have to be kept in good condition and care should be taken in mending the broken ends.

Causes and Remedies of Crossed Ends:

Causes:

1. Improper arrangement of ends during sizing.
2. Damaged size beam flanges.
3. Improper lease insertion.
4. Negligence while knotting broken ends.
5. Ends slipping from their correct position.

Remedies:

1. Maintain proper warp arrangement and lease order.
2. Keep size beam flanges in good condition.
3. Ensure correct lease rod functioning.
4. Mend broken ends carefully in proper order.
5. Regularly check end alignment during sizing.

4. Sticky Ends:

Sticky ends are formed due to the improper cooking of the size ingredients. The stickiness; has to be reduced after the drying process by using revolving lease rods.

Causes and Remedies of Sticky Ends:

Causes:

1. Improper cooking of size ingredients.
2. Excessive concentration of size paste.
3. Inadequate drying after sizing.
4. Uneven moisture distribution.
5. Use of incompatible chemicals in size.

Remedies:

1. Cook size materials properly with correct recipe.
2. Maintain proper viscosity of size paste.
3. Ensure uniform and complete drying.
4. Use revolving lease rods to separate sticky ends.
5. Select chemicals compatible with yarn type.

5. Uneven Sizing:

Uneven sizing occurs when warp yarns receive non-uniform application of size, resulting in some yarns being over-sized and others under-sized. This leads to weak and strong spots in the warp sheet, affecting weaving efficiency and fabric quality.

Causes and Remedies of Uneven Sizing:

Causes:

1. Due to over and under sizing
2. Irregular speed of warp sheet through the size box.
3. Non-uniform pressure of squeeze rollers.
4. Uneven viscosity or temperature of the size paste.
5. Improper maintenance of size box or rollers.

Remedies:

1. Maintain uniform size application across all warp ends.
2. Ensure constant warp speed through size box.
3. Adjust squeeze rollers for uniform pressure.
4. Control size paste viscosity and temperature properly.
5. Regular maintenance of size box, rollers, and guides.

6. Defective Selvedge:

The selvedge ends in a weaver’s beam cause more difficulty in unwinding the ends during weaving. Sunken and bulged selvedges are defective selvedges of the sized beams. Sunken selvedges can be controlled by correctly setting the expandable comb at the head stock. For the bulged beams the beam pressing roller is set in correct manner so that it reaches to both flanges.

Causes and Remedies of Defective Selvedge:

Causes:

1. Uneven size paste at edges.
2. Faulty alignment of brushes/rollers.
3. Unequal selvedge tension.
4. Improper edge drying.
5. Worn-out guides or rollers.

Remedies:

1. Uniform size paste distribution.
2. Correct setting of brushes/rollers.
3. Maintain equal tension across warp.
4. Proper drying control at edges.
5. Regular maintenance of machine parts.

7. Ridges on the Beam:

Ridges on the beam are formed when the ends that are taken in one dent of the comb do not spread out. To minimize this defect, the dancing roller at the head stock should be adjusted properly.

Causes and Remedies of Ridges on the Beam:

Causes:

1. Uneven winding of warp sheet.
2. Improper beam tension.
3. Faulty pressure of beam rollers.
4. Variation in yarn thickness or density.
5. Damaged or rough beam surface.

Remedies:

1. Maintain uniform winding tension.
2. Adjust beam pressure correctly.
3. Use smooth and well-maintained rollers.
4. Ensure uniform yarn density across width.
5. Keep beam surface clean and defect-free.

8. Underslashed Warps:

Underslashed warps are warp yarns that receive less size than required during the sizing process. As a result, the yarns are not properly coated, remain weak, and fail to gain the necessary strength, smoothness, and abrasion resistance.

Causes and Remedies of Ridges on the Beam:

Causes:

1. Due to insufficient size concentration
2. Improper size feed to the size box
3. Variable size level
4. Low viscosity or diluted size paste.
5. Strong squeezing of warp

Remedies:

1. Maintain correct viscosity and concentration of size paste.
2. Ensure proper yarn immersion in the size box.
3. Adjust squeeze roller pressure uniformly.
4. Control drying temperature and moisture properly.
5. Regularly check and align rollers and guides.

9. Overslashed Warps:

In this case warp yarns receive more size than required during the sizing process. Instead of improving performance, the excess size makes the yarn stiff, brittle, and sticky, causing weaving problems.

Causes and Remedies of Ridges on the Beam:

Causes:

1. High viscosity or over-concentrated size paste.
2. Due to insufficient splitting of starch at size preparation
3. Weak squeezing
4. Too deep immersion of the warp into the size box

Remedies:

1. Maintain correct viscosity and concentration of size paste.
2. Control yarn immersion time in the size box.
3. Adjust squeeze roller pressure properly.
4. Monitor size pickup percentage regularly.
5. Ensure proper machine settings and maintenance.

10. Sticky Warps:

Warp ends stick together due to improper drying.

Causes and Remedies of Ridges on the Beam:

Causes:

1. High sizing speed
2. Low drying temperature

Remedies:

1. Reduce sizing speed.
2. Increase drying temperature to optimum.

11. Over Dried Warps:

Warp becomes brittle and weak due to excess drying.

Causes and Remedies of Ridges on the Beam:

Causes:

1. Low sizing speed
2. Long stoppage of machine during sizing
3. Very high temperature in the drying section

Remedies:

1. Maintain proper sizing speed.
2. Avoid long machine stoppages.
3. Keep drying temperature within limit.

12. Gum Spots and Smears:

Local lumps or spots of gum appear on warp sheet.

Causes and Remedies of Ridges on the Beam:

Causes:

1. Splashes of size get on the squeezed warp
2. Bad stirring of starch at preparation
3. Improper coating of felts on the squeezing rollers

Remedies:

1. Prevent splashes of size on warp.
2. Stir starch properly during preparation.
3. Use properly coated felts on squeezing rollers.

13. Non Uniform Size Regains:

Warp yarns regain moisture unevenly, giving irregular strength.

Causes and Remedies of Ridges on the Beam:

Causes:

1. Irregular heating of the size in the box
2. Dilution of the size with live steam
3. Non uniform pressure of squeezing rollers

Remedies:

1. Ensure even heating of size in the box.
2. Avoid live steam dilution in size.
3. Maintain uniform roller pressure.

14. Crossed and Lost Ends:

Warp ends cross each other or get lost during sizing.

Causes and Remedies of Ridges on the Beam:

Causes:

1. Lease rods are set too far apart
2. Broken ends are improperly pieced up
3. Bad warping

Remedies:

1. Keep lease rods close and properly set.
2. Piece broken ends correctly.
3. Avoid bad warping practices.

15. Improper Build of Beam:

Beam surface becomes uneven or ridged.

Causes and Remedies of Ridges on the Beam:

Causes:

1. Incorrect spreading of yarn ends in the reed dents

Remedies:

1. Spread yarn ends evenly in reed dents.

16. Incorrect Warp Length:

Warp length differs from required measure.

Causes and Remedies of Ridges on the Beam:

Causes:

1. Disarrangement of the measuring and marking mechanism
2. Improper adjustment of measuring and marking mechanism

Remedies:

1. Arrange measuring and marking mechanism correctly.
2. Adjust measuring mechanism properly.

17. Dirt Stains in Warp:

Dark spots or stains appear due to contamination.

Causes and Remedies of Ridges on the Beam:

Causes:

1. The size boxes and machine metal parts are dirty
2. The size is cooked in non-galvanized iron kettles.

Remedies:

1. Keep size box and machine parts clean.
2. Cook size in galvanized kettles only.

18. Shinnery:

Glossy, shiny patches appear on warp yarn.

Causes and Remedies of Ridges on the Beam:

Causes:

1. Due to the friction between the yarn and drying cylinder

Remedies:

1. Reduce friction between yarn and drying cylinder.

19. Sandy Warp:

Rough surface on warp due to hard particles in size.

Causes and Remedies of Ridges on the Beam:

Causes:

1. Due to not crushed or grind the size material

Remedies:

1. Crush or grind size materials properly before use.

20. Hard Sizing:

Warp becomes stiff and harsh.

Causes and Remedies of Ridges on the Beam:

Causes:

1. Excessive application of size material

Remedies:

1. Control and reduce excess size application.

21. Size Dropping:

Size flakes drop off from warp during weaving.

Causes and Remedies of Ridges on the Beam:

Causes:

1. Due to not optimum viscosity of the size solution

Remedies:

1. Maintain optimum viscosity of size solution.

22. Excessive Lappers:

Excessive lappers are due to stickiness and high breaks while sizing. This leads to more migration of ends and cross ends, leading to higher breaks. High stretch also results in higher lappers and cross ends.

23. Low Elongation at Break:

Low elongation at break is due to excessive stretching of warp during sizing. Some sizers purposefully keep a higher stretch to get an advantage of higher length of fabric, but this leads to higher breakages at loom, and the loom efficiency drops down, and there shall be a big loss. It is essential to measure the stretch and maintain zero stretch to get a higher elongation at break, a good working of loom and a fabric with a good feel.

Conclusion

Sizing is a critical process in weaving preparation that protects warp yarns, improves strength, and ensures smooth weaving. However, improper control of size application, drying, tension, or machine settings can lead to various sizing defects such as broken ends, sticky warps, uneven sizing, gum spots, and defective selvedge. These faults reduce weaving efficiency, cause fabric defects, and increase production costs. Proper monitoring of size paste, machine parameters, drying, and warp handling along with timely maintenance can minimize these faults and ensure high-quality woven fabric.

References

Mazharul Islam Kiron

Founder & Editor of Textile Learner. He is a Textile Consultant, Blogger & Entrepreneur. Mr. Kiron is working as a textile consultant in several local and international companies. He is also a contributor of Wikipedia.

Share this Article!