What is Single-End Sizing Machine? Irregular Sizing (Slashing)

by Engr. Kh. Mashiur Rahman | Apr 15, 2019 | Spinning

Single-end Sizing Machine

• Single-end Sizing Machine4arn materials: Cotton, Polyester Cotton, Kevlar, Carbon, Glass, Jute or similar
• mg materials: PVA, Starch, Wax etc.
• ier of packages to be sized at a time: 1 or more Speed: 190 m / min or higher Sizing temperature range: 90-100 °C Length measuring sensor
• Electrical-heating in sizing tank
• Hot air drying
• Yarn break sensor
• Power back up for emergency shut down in safe mode Real time data acquisition / analysis system (fixed) All parts / accessories required to make machine operational on site List of similar installed machines in universities/industry in Pakistan and worldwide with their contact information.
• List of trained engineers available for after sale service/maintenance keel Capacity for Sizing: 12-16 beams or Spindles
• Drying System: Electrical or Steam heated with speed and temperature controlled
• Size Cooker: Detachable and temperature Controlled Spare parts: 01 set
• Output: Ready for Sectional Warper with minimum of 2000 mm width (Sectional Warper included) Read about Singeing Machine and Desizing Machine Works

Side to Side and End to End Shade Variations-

Definition and Causes: In medium to heavy weight woven fabrics, which are dyed in Jigger machines or in a continuous dyeing range, this is a very common and reoccurring problem.

Generally, the main causes are

• Incomplete de-sizing of the fabric (removal of yarn’s starch),
• The uneven distribution of dyes during the dyeing process.
• This is due to the fluctuation and variation of the pressure in the winding and unwinding rollers.
• In knit and some light weight woven fabrics which are dyed in Jet dyeing systems, this problem can rarely be seen.
• This, however, occurs more in the finishing process and will be discussed in the finishing section.

Preventive Suggestions:Regular maintenance and upkeep of the dye machines will contribute towards reducing this problem. Preparation of the greige goods prior to the dyeing is also very important.

Corrective Measures:In most cases, stripping and removing the base color and re-dyeing will correct the problem.

In severe cases, over-dyeing to a darker shade or black may be the only solution.

Irregular Sizing (Slashing)-

Definition and Causes: During the slashing process, in order to increase the tensile strength of the yarns and prevent breakage, starch based chemicals are applied. In some cases uneven application of the starch causes uneven surfaces in the yarn which can cause breakage and holes.

Preventive Suggestions:Correct and precise slashing is of utmost importance.

Corrective Measures:For this problem no corrective measures are available.

Yarn Breakage-

Definition and Causes: Due to the elastic nature of the Elastane-based stretch yarns, controlling the in-feed tensions of these yarns, fed individually or in plated form, is a critical part of the knitting process.

Slight increase in the applied tension will result in breakage of the yarn particularly in finer counts (20, 30, and 40 Denier counts).

Preventive Suggestions: Constant measurements of the tension must take place. For most structures, the tension should not exceed 4 grams.

Corrective Measures: For this problem no corrective measures are available.

Oil Stains-

Definition and Causes:

• The distinctive oil stains which appear on the surface of the greige goods are normally a result of knitting machine’s needle lubrication system.
• During the knitting loop formation, due to machine’s speed of revolution and the frictional forces between the yarns and the needles, a certain degree of heat is generated.
• In order to prevent the elevation of this temperature, at certain pre-determined intervals the lubrication system is made to function and sprays of oil mists are applied to the needles and the cam areas.
• During this process and in a lot of cases the greige goods get contaminated.
• Normally, however, if the oil that is used is of the water-soluble and natural based type it can easily be removed by a simple scouring process.
• In some cases, as a cost saving measure, some knitters use non-emulsified type of oil which is rather difficult to remove. These types of oil stains will appear as lighter shade spots after dyeing.
• Another type of oil stains are the ones from the silicone based lubricants that are normally applied to the Spandex yarns.
• In some cases, during the knitting process, and due to the generated heat some residue of this lubricant remains on the fabric. This type of oil stain is also very difficult to remove.

Preventive Suggestions:

• The use of water-soluble knitting oil is strongly recommended.
• Also, to the extent possible, Spandex yarns with non-silicone lubricant must be used.
• Corrective Measures:
• In most cases an “oil-scavenger “type of industrial detergent will be able to remove the stains.
• In more severe cases a strong solution of an alkaline based chemical such as Sodium Hydroxide or Soda ash may be required.
• When dealing with Spandex related stains care must be taken to ensure that the stretch and the recovery of the yarn is not adversely affected.

Runs and Slippage-

Definition and Causes

These are common problems with basic synthetic knit structures such as Single jersey and Interlock, particularly when textured filament yarns of higher filament contents are used (96 and above).The causes are basically the slippage of the fibers and the ease with which the knitting loops can slide over each other.In most cases, these runs are directional which means that the start of the knitting roll exhibit more runs than the end of the roll.

Preventive Suggestions:

In order to reduce and control these runs and stabilize and reinforce the Wales, at the start of the knitting, for approximately 30 knitted courses, cotton yarns are knitted in to the greige goods. This is also repeated at the end of the roll. This will ensure that no runs occur during the dyeing process thus reducing the fabric damage.

Corrective Measures

During the finishing process, in order to reduce the fiber slippage, the dyed fabric needs to be treated with an anti-slippage chemical through padding. This chemical is usually a solution of Colidal Silicate. Basically this chemical increases the fiber’s coefficient of friction and creates a non-slippage condition.

The application of this treatment might, however, affect the softness of the fabric and must be used in small quantities.