03-05-2011, 05:22 PM
As I understand it, from my reading of Trains and Model Railroader and other sources, the reason behind these SIT yards [Storage In Transit] is to store plastic pellet production to cover orders of the different types of pellets between production runs.
The production plant obviously wants to make as long a production run as possible before having to stop production, clean through the plant and machinery and then set up, test and produce the next run of a different type of pellet.
Take for example food grade plastics, there are at least 6 or more types that can be recycled, and they are identified by the number within the recycle triangle. PETE bottles for soft drinks are numbered with a 1 and so on. Then there are food grade plastics which are un-numbered or numbered beyond the 6 recycling types.
Apart from food grade plastics, there are numerous other types and grades used by manufacturers of cars, furniture, office equipment, model trains, toys and just about anything else you care to mention.
I am unsure about just where various colours are added to the plastic, it maybe produced in base colours with various tints added later at the final production point or it maybe produced in the colours of the colour wheel with blending and tinting done at final production.
So at this point we know that there are a dozen or more types of plastic, you can begin to see how a logistics problem is developing here with the need to produce enough of one particular type of plastic to cope with orders until the production plant can get round to a re-run of that type of plastic. I think this may well cover the feeling.
Once empty and cleaned the covered hopper can be reused for any other type of plastic pellet as they track the type loaded by the car number.
The cars are privately owned or leased by the plastic plant.
Mark
The production plant obviously wants to make as long a production run as possible before having to stop production, clean through the plant and machinery and then set up, test and produce the next run of a different type of pellet.
Take for example food grade plastics, there are at least 6 or more types that can be recycled, and they are identified by the number within the recycle triangle. PETE bottles for soft drinks are numbered with a 1 and so on. Then there are food grade plastics which are un-numbered or numbered beyond the 6 recycling types.
Apart from food grade plastics, there are numerous other types and grades used by manufacturers of cars, furniture, office equipment, model trains, toys and just about anything else you care to mention.
I am unsure about just where various colours are added to the plastic, it maybe produced in base colours with various tints added later at the final production point or it maybe produced in the colours of the colour wheel with blending and tinting done at final production.
So at this point we know that there are a dozen or more types of plastic, you can begin to see how a logistics problem is developing here with the need to produce enough of one particular type of plastic to cope with orders until the production plant can get round to a re-run of that type of plastic. I think this may well cover the feeling.
Once empty and cleaned the covered hopper can be reused for any other type of plastic pellet as they track the type loaded by the car number.
The cars are privately owned or leased by the plastic plant.
Mark
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