Production of Technical Specified Rubber using the "Dry Process"

  By T.W. Kang , Managing Director,
                                                            Engmepho Professional Enterprise Sdn. Bhd.
                                                            14A, Jalan Pandan Indah 4/8, Pandan Indah Commercial
                                                            Centre, 55100 Kuala Lumpur, Malaysia.
                                                            Tel : 603-4948368 Fax : 603-4946368
                                                            E-mail : twkang@emp.com.my


 
Introduction

Technical Specified Rubber (TSR) was introduced in 1969 so that natural rubber production can be graded by technical specifications and not by the conventional visual standards.
 
With its introduction, technical specified rubber are now graded according to different criteria such as Dirt content, Ash content, Nitrogent content, Volatile matter, PrI, Wallace rapid plasticity and colour limit. Moreover, TSR are also graded according to their input material such as latex grades, sheet grades, field grades and blended grades including stabilised or Non-stabilised grades. Since 1969, technical specified rubber has been widely accepted worldwide.

Over the years, the production of Technical Specified Rubber for latex and field grades have been done primarily using the "Wet Process".

For latex grades production, field latex were collected, bulked, coagulated, crumbled and dried before weighing and packed into standard blocks of 33.33kg.

For field grades material such as cuplumps and tree laces, they are collected, blended, washed and cleaned thoroughly by the use of water before being crumbled, dried, weighed and packed accordingly.

The use of the "Wet Process" can have a direct detrimental impact on the environment if the waste water and air from the process are not treated before they are released back into the environment.

For sheet rubber production, which are carried out mainly by smallholders,rubber is processed into Unsmoked Sheets (USS), Ribbed Smoke Sheets (RSS), Air Dried Sheets (ADS) and Crepe. The smallholders normally collect the latex or field grades from their smallholdings and by using simple processing machinery, they convert them into sheet material and dried before they are sold. As mentioned above, sheet material are graded visually rather than through the technical specified rubber scheme.

The Dry Rubber Processing System

The Dry Rubber Processing System can be used to produce technical specified rubber by processing dry rubber from dry sheets and crepe material such as unsmoked sheets, ribbed smoke sheets, air dried sheets, brown crepe and skim crepe including off-grades of crumb rubber material. This process can be used to produce technical specified rubber grades such as TSR 5, TSR 10, TSR 20 or specially blended rubber grades depending on the quality of the raw material inputs and blending methods.
 

  Cutting Rubber Bales using an Hydraulic Cutter
 
Since the processing system does not use water at all; thus the name "Dry Process", the factory is clean and does not pollute the environment. The "Dry Process" only uses dry raw material (95% dryness) such as USS, RSS, ADS, Crepe and off-grades of block rubber.

The block rubber produced can then be specified into the respective types of technical specified rubber by using the parameters specified in the Technical Rubber Scheme.
 

Dry processing of rubber using our EMP Dry Processor  

Benefits of using the "Dry Process" for production of Technical Specified Rubber

In comparison with the "Wet Process" of the technical specified rubber production, the "Dry Process" production has a number of benefits namely:-

1. No water is used in the dry process. As such, the process does not pollute the
    environment.

2. Input raw material are also in the dried form. Smell from input raw material does not
    permeate to the surroundings if compared with wet input raw material such as cup-lumps
    and tree laces.

3. Lower Capital Investment costs in comparison to the conventional "Wet Process" system.

4. Shorter Production Cycle time and Lower Processing Costs.

5. Minimal skilled labour requirements.

6. Minimal Space Requirements.

7. Simple in Operation and Maintenance.

Cooling Tunnel       Weighing & Baling
 

STR Rubber Bales after pressing

Conclusion

The "Dry Process" can be used to complement existing rubber processing systems to produce technical specified rubber. The "Dry Process" is flexible because the system can be incorporated in the sheet/crepe process and the "Wet Process" of TSR rubber production. For rubber producers who are keen to produce Technical Specified Rubber, they should certainly explore the opportunities offered by this method of rubber processing system.

21st. September 1999