AVCO-ZIM DHT

THERMOSTABLE ENZYME FOR DE-SIZING
AVCOZIM DHT is an alpha amylase enzyme which has good heat stability in the high temperature range, which can break down starch and starch derivative sizing agents within a short reaction time.

SPECIFICATION:

Appearance Brown liquid with characteristic odor.
Chemical nature Bacterial alpha amylase, heat stable.
Compatibility
  1. Should not be used in pH exceeding the pH range 7-9
  2. Can be used with hard water.
  3. Copper, zinc and their salts as well as chlorine and other oxidizing agents impair the effectiveness of AVCOZIM DHT.
Density (20°C) App. 1.1 gr/cc.
Solubility Miscible with water in any ratio.
Storage stability Store the product in closed containers in cool place. Once the containers have been opened, the contents should be used immediately. Storage for prolonged periods at temperatures over 30°C causes loss of activity. When stored in suitable conditions, shelf life is at least 6 months.

PROPERTIES & USES:

  1. AVCOZIM DHT is a de-sizing agent which to a large extent retains its activity
    even at
    relatively high temperatures. The maximum breakdown is achieved in the
    temperature
    range of 70°C to 90°C.
  2. AVCOZIM DHT is not causing any damages to the fibres.
  3. AVCOZIM DHT is used for:
    a. Hot pad roll de-sizing processes:
    b. Exhaustion processes in all equipment:
    Jigger, winch, jet, garment dyeing machines etc.

APPLICATION:

  1. The quantities and treatment time depends on the type of fabric and de-sizing method. General suggestions are:
    • For winch or jet treatment (high L.R.) – use 1-3 g/l.
    • For jig (low L.R.) – use 2-4 g/l.
    • For hot pad roll process – use 2-6 g/l
  2. At the stage of de-sizing it is desirable to remove all additives incorporated in the sizing agent such as waxes, paraffins and all soiling and staining results from fabric weaving. It is therefore important to add an emulsifying and dispersing agent with high wetting power and compatibility with enzymes. Such a products are AVCO- BIOPAL LFB, AVCO-BIOLIT 2090 and AVCO-BIOLUZE G-1099.
  3. The solubilized size must be washed out before the cloth goes to bleaching and dyeing. Best results are achieved by alkaline boiling (3-5 cc/l Caustic Soda 50%) with a complexing/dispersing agent such as AVCO-POLYQUEST PDK.
  4. Preparation of the treatment solution:
    • Use preferable hot water (85° – 90°C). Do not heat with direct steam.

    • If there is no preliminary washing process, add a wetting agent.

    • The pH should be adjusted in the range of 7 – 8.

    • Add the appropriate quantity AVCOZIM DHT.
TYPICAL RECIPES
  1. Jigger:
    AVCO – BLOPAL LFB 1 – 3g/l
    AVCOZIM DHT2 – 4 g/l

    Run 4 ends at 85° – 90°c.

    Remove size by alkaline washing at 95°C for 2 ends.
    Neutralize and rinse well.

  2. Winch or Jet:
    AVCO-BIOLUZE G-1099 1 – 2 g/l
    AVCOZIM DHT 1 – 2 g/l

    Run at 85° – 90°c for 15-30 min.

    Remove size by Alkaline wash at 95÷C for 10-15 min (use 3-5 cc/l Caustic-
    soda (50%) and 1-2 g/l AVCO-POLYQUEST PDK).
    Neutralize and rinse well.

  3. Pad-roll batching up method

    Impregnation liquor:
    AVCOZIM DHT 2 – 6 g/l
    AVCO-BIOLIT NFB 3 – 5 g/l

    Liquor temperature – 85° – 90°c

    Pick-up 80-90%
    Batch up and store under rotation.
    If the temperature of about 90°C is maintained inside a pad-roll unit, a-dwell time of 1-2 hours is adequate. If the goods are batched without the effect of heat, longer dwell times (2-6 hours) are necessary.
Remove size by washing at 90-95° C. Addition of 2 g/l AVCO-POLYQUEST PDK and
3 cc/l Caustic Soda (50%) to the first hot washing compartment improves the de-
sizing effect.
TESTING FABRICS FOR THEIR DEGREE OF DE-SIZING

Preparation of iodine solution:
Dissolve 10 gr. of Potassium Iodide (KI) in 100 ml. of water add 0.635 gr. of Iodine and shake well. Top up with water to 800 ml. and finally add Ethanol to reach 1 litre.

According to the TEGEWA – violet scale for assessing the de-sizing degree of starch, immerse a de-sized fabric sample (which is pre-rinsed in hot alkaline and cold water) in the Iodine solution for a period of about 1 min.
After immersion rinse shortly in water damp with filter paper and compare immediately with the violet scale.

Judge according to the following results:

Pure dark blue coloration= presence of non-degraded starch.

Pale blue coloration = slight starch residue on the fibre.

Red-violet coloration = starch degraded to water soluble dextrin.

Yellow coloration = complete freedom from starch.

Degradation into a reddish – violet color is adequate for solid shades.