Second Method.

Biggest difficulty during chemical treatment of flax fibre is due to lignin into fibre. Lignin is more stable then other noncellulic admixtures and components in fibre. Use of liquid ozone for bleaching is effective in the case.

Following parametres were selected for evaluation of flax fibre after treatment and technological process itself:

• the same parameters as in the table above;

• damage of fibre;

• duration of each technological step;

• expenditure of chemical;

• methods and means of environment cleaning.

Duration of treatment was 60 and 120 minutes. For technological process intensification surface active agents (SAA) were used.

The results of liquid ozone treatment of fibre showed the followings:

• the treatment provides good fibre quality with the reduction of process duration in 3-5 times, satisfactory level of fibre dispergation and solution of mineral admixtures. Fibre whiteness was 78-80%;

• the technology does not need hot water, steam and any other chemical except ozone and SAA;

• absence of hot water, steam and any other chemical except ozone and SAA provides less destruction of fibre;

• process goes at the temperature about 20°C;

• use of SAA provides soft handle fibre.

Quality of fibre preparation was evaluated also by samples colour intensity and saturation after dyeing. Results of evaluation were satisfactory.

Cottonized fibre prepared in such a manner was used for manufacturing of the some new medical products and packing materials for food. Medical products are following: hygroscopic wadding, surgical bandages, belts and bandages for rheumatic fever patients.

Raw flax fibre is used for medical purpose goods production as well. Main attention is paid in the case for maintaining of such a feature of flax fibre as aseptic ability. Hygroscopicity of a flax wadding was 26-27 gr. When hygroscopicity of a cotton one is normally 19-20 gr. Medical products from flax fibre (shield, bandages) are aseptic because of the feature of flax fibre itself.

Notes:

superpose – накладати (одну річ на іншу)

bleach – білити, відбілювати

dispergate -

hydrogen peroxide – перекис водню

admixture - домішок

lignin - лігнін

saturation – насичення, пропитка

steep – пропитка, пропитувати

scoure – чистка; мити, змивати

wadding - вата

bandages - бинти

shields – щити, екрани

Exercise 24. Answer the following questions.

1. What quality of flax fibre does new technology for cottonized flax fibre preparation enable to get?

2. How has the technology been tested?

3. What volume of flax fibre is produced in Ukraine?

4. How many ways was treatment of cottonized fibre carried out by?

5. What does the first method consist of?

6. What parameters is quality of fibre preparation evaluated by?

7. What is used for bleaching in the second method?

8. What did the results of liquid ozone treatment show?

9. What are flax fibre medical products?

10. Why are medical products from flax fibre aseptic?

Exercise 25. Agree or disagree with the following sentences.

1. New technology for short flax fibre cottonization allows to extend the field of short flax fibre use.

2. Treatment of cottonized fibre is carried out in three ways.

3. Silicon-organic chemical is not dissolved in water.

4. The technology of flax fibre preparation by means of silicon-organic chemical is ecologically clean.

5. The chemical cannot be used for any kind of cellulosic fibre.

6. Cottonized fibre was not used for manufacturing of medical products.

7. Medical products from flax fibre are aseptic.