WHY IS SPIRALL BETTER ?
 
Comparison between Moulded chemical storage tanks and fabricated “Spirall” tanks (using German technology)
 
Sr. No
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Moulded (Tank)
Fabricated Tank)
1. Raw material

Mixture of LDPE & HDPE powder available locally is used.

Rotomoulding grade of LDPE in Granule form is WHITE in colour, to which Black master batch is ADDED to get UV Properties and then EXTRUDED. Later the extruded material in granule form is PULVERISED to be used as RAW MATERIAL for moulded tanks.

Recycling upto 10% is done.

Physical and Other Properties like corrosion resistance are affected due to recycling.

Inconsistent Thickness due to process Limitation may affect properties.

Only Imported HDPE Virgin Material in Granule Form is used.

HDPE is not available in powder form. The machine accepts only granular form.
It is available in BLACK colour with UV properties already incorporated in the material during manufacturing stage and not added afterwards.

Recycled Material is not used.

As Virgin Material is used, properties are not affected.

Process Limitation does not exist. Thickness is constant with same properties.

2. Density
LDPE Density is 0.93 gm/cc. Molecular Strength is lower. Corrosion Resistance is also lower.
HDPE Density is 0.96 gm/cc. So Higher Molecular Strength gives higher Corrosion Resistance.
3. Manufacturing

SINGLE CONSTANT WALL

Stagewise Manufacturing is not Done.

VARIABLE AND STEP WALL

Stagewise Fabrication is possible. Multi Process Vessels can be made.

4. Wall Thickness

High Wall Thickness cannot be achieved.

Consistency is not present as this depends on Machine RPM and Heat distribution. Both highly uncontrollable Factors.

Thickness consistency is most Deceptive as proper Heat Distribution cannot be controlled Wall strength is lower.

High Wall Thickness upto 100mm can be easily achieved.

Consistent Wall Thickness is achieved even for Multi Process Vessels hence Superior resistance.

Wall Thickness is independent of Heat and Machine RPM so wall thickness is constant and strength is superior.

5. Repair
Not easily done. Needs skilled labour. Often it does not stay for a long time and it is costly.
Very easily done with HOT AIR methods. Besides it is cheap.
6. Finished Product
Every application cannot be Serviced. Multi Process Area and certain Chemicals.
Each and every application can be independently serviced as well as a group.
7. Capacity
Limited upto 20KL.
Any Capacity upto 20KL and upto 40KL. Besides Larger Capacities upto 100KL can also be easily manufactured.
8. Thickness Calculation
Manufacturing is based on Raw material weight consideration.
Raw material weight does not factor during calculation and manufacturing.