Optimize strand pelletizing
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Transcript of Optimize strand pelletizing
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Optimize Strand Pelletizing
BKS in a Nutshell
For more than 25 years BKS is a leading [knife] service supplier in various businesses such as Plastics, Recycling, Textile, Packing, Food etc.
BKS pelletizing and pulverizing technology is a relatively new developed business with the headquarter in Belgium [Lambermont] and a re-sharpening service center in Malaysia.
Our team of experts and the use of state of the art machinery offers manufacturing, maintenance, modification, revision and [re-] sharpening of all wear parts for pelletizing and pulverizing equipment.
With know-how and experience of pelletizing and pulverizing technology BKS offers customers added value.
Our permanent search for optimal solutions, innovation and top quality guarantee that our products and services comply above your expectation.
BKS, Beyond Expectation
1. Kind of polymer, additives, fillers, quality and homogeneity.
2. Temperature and distribution in the strands.
3. Strand speed, number of strands and cross cut surface.
4. Corrosion and wear.
5. Cutting tool material choices and combinations.
6. Cutting gap adjustment.
7. Cutting geometry and helix of the rotor knife.
8. Re-sharpening quality.
Influencing Parameters
BKS, Beyond Expectation
To be able to make a quick and reliable check on the optimization potentialBKS developed a model, where we distinguish the influencing parameters:
A) Fixed - The given situation [i.e. master batch]
B) Customer influenced - Parameters the user can influence [i.e. cooling bath]
C) Service Supplier influenced - Parameters the service partner can influence [i.e. re-sharpening]
Model
BKS, Beyond Expectation
1 - Polymer CharacteristicsFixed
The to be processed polymer is a given
Assuming we cannot simply change the material composition as most materials are developed and engineered for their application.
BKS, Beyond Expectation
2 – Strand Temperature
Customer influenced
Temperature and distribution of temperature in the strand
The higher the temperature of the strand, the less risk there is to break the material instead
of cutting it. On the other side pellets should not stick together after cutting. The temperature
is also determined by type of polymer, filler, additives and the handling of the strand before
cutting.
An important parameter of influence is the temperature homogeneity in the cross cut of the
strand. If the strand is cool on the outside but still hot [or even liquid] on the inside, negative
side effects like creation of dust, fines and shorter life time of the cutting tools will occur.
It is important to set up the granulation process in such a way that the strand temperature
is evenly divided over the cross-cut of the strand and as high as possible given the
circumstances.
BKS, Beyond Expectation
3 – Strands
Customer influenced
Speed, number and dimension
The number of strands and their speed have a direct influence on the number of cuts.The number of cuts per unit of time directly influences the life time performance of the cutting tools.
Also the diameter of the strands influences wear generated on the cutting tools.
Improvement
Cutting material choice strongly effects cutting tool life time.Optimal distribution of the strands along the cutting width extend cutting tool lifetime.BKS, Beyond Expectation
4 – Corrosion and Wear
Fixed Customer influenced
Corrosion
Has an negative influence on the cutting tool materials and can be caused by polymer,ingredients or contaminated cooling water. The cooling water quality can be influenced.
Wear
Has an negative influence on the cutting tool materials and can be caused by corrosionand/or abrasive polymer or ingredients.
BKS, Beyond Expectation
5 - Cutting Gap Adjustment
Customer influenced
Adjustment of the rotor- and bed knife
The smaller the gap between the rotor and
bed knife, the better the cutting quality and
life time performance of the cutting tools.
The feasible adjustment depends on type
and accuracy of the pelletizer.
The optimal adjustment needs to be as precise [narrow gap] as possible within the pelletizers limitation.
BKS, Beyond Expectation
Customer influencedService Supplier influenced
Material choice for of cutting tools:
Different cutting materials and combinations for bed- and rotor knives are available.The polymer to be cut, corrosion and wear are critical factors to be taken into consideration.
Bed knife materials: Tungsten Carbide, Ceramics, Stellite or Diamond.Rotor knife materials: Tool- and Stainless steels, Tungsten Carbides, Stellite
and Powder Metallurgical Materials.
The choice of cutting materials should be based on the circumstances and have an majorinfluence on the cutting- and life time performance.
6 – Cutting Materials
BKS, Beyond Expectation
7 - GeometryService Supplier influenced
Geometry and helix of the rotor knife:
The geometry [shape] and the helix of the rotor knife teeth influences the cuttingbehavior of the pelletizer.
Especially helix, rake- and relief angle have a strong influence on the cutting performance. [quality of the pellets & life time cutting tools]
Last but not least the final circular re-grindingneeds to be adjusted to the to be cut polymerfor optimal performance.
The best solution can only be found if user and service supplier work closely together.
BKS, Beyond Expectation
8 – Re-Sharpening Quality
Service Supplier influenced
Re-Sharpening Service
Not only the geometry and the wear resistance of the cutting materials are crucial forthe quality and lifetime performance. The execution of the re-sharpening has minimalsimilar influence and requires know-how.
The pelletizers construction, design/type of the bearing seat[s] and the quality level of the maintenance have a direct influence on the concentricity of the cutting rotor.
This concentricity has a direct influence on the cutting gap, effecting the pelletizersoverall performance. Optimal bearing maintenance therefore is crucial.BKS, Beyond Expectation
Summary
Conclusion
By influencing parameters - strand temperature and distribution- cutting gap adjustment- cutting materials- geometry and re-sharpening quality
we directly influence the pelletizers performance and cancontrol Maintenance, Repair and Overhaul costs.
Recommendation
Execution of this model is easily applicable in every strand pelletizing production facility.Gained information should be shared with your service partner which will result in cuttingcosts for MRO and improving overall quality.
BKS, Beyond Expectation
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Questions ?How can BKS help to control your costs
for MRO?
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Thank you for your attentionEadse de Jong
Technical Sales Manager
BKS Pelletizing & Pulverizing Technology
RUE JEAN KOCH 44800 LAMBERMONT
BELGIUM