Loose Stock Treatments

LooseStock

FURTHER PROCESSING FOR IMPROVED QUALITY

ANDAR offers a range of specialist systems for the woollen processing route, further enhancing the value of natural wool fibres. These systems include technology for the elimination of vegetable matter from the raw material, the application of high-tech chemical finishes and equipment relating to Dye House processing. Through further refining the fibre presentation, customers can extend the performance of woollen textiles.

CARBOMASTER

 

 

carbomaster

 

 

CARBOMASTER

 

 

 

 

 

 

 

 

Carbonising is the process of removing vegetable matter from raw wool, wastes such as noils or card wastes, by acidification (usually with sulphuric acid), baking, mechanical dusting to remove the embrittled cellulose and neutralisation. The process is most important in Australia, Japan, and the Far East and increasingly in South Africa, but less so in Western Europe where there has been a considerable reduction in carbonising plants in the last 5-10 years.

 

The high fault (i.e. high vegetable-matter content) wools tend to be processed either in the country of origin or near to it. The sulphuric acid process is the typical industry standard process adopted internationally.

 

Wools with more than 2-3% VM are usually carbonised, wools with less than this can be sent to the cards and combs directly from scouring, and the cards and combs will remove the VM.

 

Carbonising Process In Brief

The raw wool is first scoured to remove any grease and dirt to enable the acidifying process to be more effective. The wet out wool is then soaked in an acid solution of 6-7% w//v along with a trace dose of non-ionic surfactant where the wool and vegetable matter absorb the acid, commencing the carbonising process.

 

Following the Acid Bowls the wool is either double squeezed or continuous centrifuged (Roussellet) to reduce the acid content of the wool prior to the dryer to protect the fibre from acid damage. The wool is then dried in a specialist drum dryer operating at low temperatures (70-80 degrees Celsius) and high airflows, drying down to a low regain of 4-6%.

 

The process is slow since sufficient time must elapse for the vegetable matter to react preferentially with the sulphuric acid and for the subsequent baking to embrittle the acidified cellulose.

 

The wool is then conveyed on to the ANDAR continuous Conveyor Dryer where the wool is baked at 110 – 120 degrees Celsius for ten minutes, causing the vegetable matter to turn to carbon.

 

Following the baking process the wool passes through multiple sets of crushing rollers where the embrittled vegetable matter is passed between fluted rollers which crush the VM allowing it to be separated from the wool. Following each crusher is a 5 drum Stepped Opener Duster to remove the charred vegetable matter dust. Generally there will be four sets of Burr Crushers integrated with 5 drum Stepped Opener Dusters.

 

The wool, now largely free from vegetable matter, contains a small residual dust volume and is highly acidic, so needs to be washed and neutralised. The neutralising line consists of up to 5 Bowls where it is neutralised with sodium carbonate, rinsing and bleaching processes to complete the carbonising process.

 

Finally the carbonised wool is dried within a drum dryer to customer specified regain prior to pressing and packaging for transport.

 

Wetting Bowl

A traditional short Scouring Bowl designed to simply wet out the wool prior to the acid bowl.

 

Squeeze Press

The ANDAR Squeeze Press minimises carry over between bowls providing isolation of specific application bowls.

Acid Bowl

A specialist Acid Applicator Bowl, constructed from corrosion resistant materials to withstand the demanding requirements of this application.

 

Acid Squeeze Press

The ANDAR Squeeze Press minimises carry over between bowls providing isolation of specific application bowls. This Squeeze Press is paired with the Acid Bowl and is designed to handle the high corrosive demands in this application.

Drying

A specialist 6 Drum Dryer is used to dry the acid soaked loose stock to less than 10% regain at low temperature. The Dryer is built with acid protection for the first two drums. The Dryers exhaust system is built to cater for the high acid content exhaust discharge.

Baking

The ANDAR Drum Dryer is used for the first baking phase to bake the loose stock at 110 -130 ºC. This bakes the easily dried VM (with the higher acid concentration) turning it to carbon, while the wool remains intact.

Crushing and Dusting


The wool is passed between fluted rollers, which crush the brittle carbonised VM. Dusters then beat the crushed dust out of the wool, which is now clean, very dry and very acidic.

 

Scoured Feed Hopper

The use of a scoured wool feeder following both the specialist Drum Dryer and the Stepped Opener Dusters allows for the wool mat to be evenly spread across the full working width of the Burr Crushers providing a uniform feed and a thinner mat that is more easily crushed.

Burr Crusher

The Burr Crusher consists of 4 pairs of fluted rollers which transport the wool and crush the vegetable matter. The dust produced in the Burr Crusher is automatically sucked away.

Stepped Opener Duster

This process is the preferred system for carbonising de-dusting duties. The wool exits the Burr Crushers and is fed onto the infeed conveyor / nip roller assembly. The ability to vary the speed of the infeed and drums allows the operator to vary the amount of opening / dusting. The nip roller retards the wool flow while the drums dust the wool. Waste is removed pneumatically and is conveyed to a cyclone.

Baking


The ANDAR Conveyor Dryer is used to bake the loose stock at 110 -130 ºC for ten minutes. This bakes the harder VM (with the higher acid concentration) turning it to carbon, while the wool remains intact.

Crushing and Dusting

The Burr Crusher consists of 4 pairs of fluted rollers, which transport the wool and crush the vegetable matter. The dust produced in the Burr Crusher is automatically sucked away.

Neutralising Line

The Neutralising Line restores the pH levels of the highly acidic loose stock fibre, through a series of warm rinsing, soda ash addition and bleaching bowls. The Neutralising line serves a dual purpose and also removes any residual dust from the crushing and dusting phases.

Final Dryer

The final stANDARd 6 Drum Dryer dries the loose stock, now free from VM contaminants, to the customers specified regain ready to be packaged or sent to the top making mill.

 

Loose Stock Applicator
The ANDAR Loose Stock Applicator System has been designed as a speciality processing system providing the flexibility of numerous uses. Targeted at vertical mills and low volume processors, this system will process around 350 kg/hr of loose stock wool.
By using enclosed bowls/chambers, gravity and carefully designed fluid dynamics have ensured maximum treatment for minimum costs, and have created an extremely efficient and flexible system.
The simplicity of the Loose Stock Applicator System has been continued by using a Unidryer to dry the processed wool, with no moving parts inside the drying chamber and low maintenance included in its design.

Scoured Feed Hopper

The loose stock fibre will generally have been processed via suitable opening equipment and therefore requires a specialist Feed Hopper to transport, open and feed the wool onto the Weighbelt. In this system, the Feed Hopper has a larger role as a storage facility, providing a continuous wool supply to the line, which can be systematically used until a new wool type or treatment batch needs to be processed.

Weighbelt

The Weighbelt controls the flow of wool to the Loose Stock Applicator Chambers, by regulating the speed of the Feed Hopper to ensure a continuous and even wool mat. This adds more control to the Loose Stock Applicator System.

Loose Stock Applicator Chamber

The material is transported through the fully enclosed applicator chamber by the liquor flow. A specially designed feed chute directs loose stock fibres into the applicator chamber. The gravity induced flow of liquor transports the fibre out of the chamber into the flush tray channel. The chambers include circulation tanks, which enable the contents to be continually re-circulated, maximising liquor use.

 

Squeeze Press

For each Loose Stock Applicator chamber there is an accompanying 500mm working width Squeeze Press. Its function is to minimise carry over between chambers, providing isolation of specific application.

Unidryer

A specifically designed Unidryer available in both steam and gas heating options to suit customer requirements. The loose stock is positively held between two porous polyester belts reducing drop off and the risk of colour contamination between batches. The use of multiple air reversals within the drying chamber ensures both sides of the wool mat are dried simultaneously, providing very even drying performance.

dye house processing

Designed specifically for Carpet Yarn spinners needing a system to take loose stock fibres from dye vessels and dry them for downstream processing. The wet fibre is delivered to the Cake Breaker from the tipping platform, which elevates and presents the dye vessel to the Cake Breaker. The fibre is then fed over the brattice providing a uniform feed of fibre prior to the Unidryer. The fibre is then dried to customer specified regain in a 2 or 3 Bay Unidryer depending upon volume and duty requirements.

 

Cake Tipper

A device to tip the loose stock dyed wool from the dye vessel into the Cake Breaker, reducing handling and providing a safe and efficient delivery of fibre.

Cake Breaker

A specialist Feed Hopper designed to handle a heavy wet dyed cake. The Cake Breaker opens the wet dyed cake and allows a uniform wool mat to be presented to the Squeeze Press. The Cake Breaker also functions as a storage/blending point for the dyed wool before drying. Designed with special internal features to provide self-cleaning functions allowing fast batch changes and minimising possible contamination.

Squeeze Press

Designed to remove excess moisture from the dyed wool, preparing the fibre for the dryer. Utilising separate infeed and outfeed conveyors to deliver the wool mat and a lurethane coated top roller to maximise squeeze efficiency.

Unidryer

A specifically designed Unidryer available in both steam and gas heating options to suit customer requirements. The loose stock is positively held between two porous polyester belts reducing drop off and the risk of colour contamination between batches. The use of multiple air reversals within the drying chamber ensures both sides of the wool mat are dried simultaneously, providing very even drying performance.