Definition of Primary Process
Locating the dividing line between primary and secondary processing of wood products. September 5, 2011
Question
I am trying to understand the forum's focus, a la the posting guidelines. "Discussing topics related to primary processing and drying of lumber." So help me, what is the primary process? Sawing, drying, moving, edging...
Forum Responses
(Sawing and Drying Forum)
From contributor S:
To me the primary process would be:
1. Find a tree to chop down
2. Cut the tree up into logs
3. Get the logs onto the sawmill
4. Saw the logs into lumber
5. Process the lumber by trimming, edging and drying.
Since this process requires investment of money, I suppose marketing the wood products would be part of the discussion as well.
From Professor Gene Wengert, forum technical advisor:
Primary means the processing of the log and its initial production pieces. Secondary would be processing the pieces. In this sense, drying is usually included as a primary process, but anything after drying is secondary.
From the original questioner:
Okay, so cutting a tree down, moving it to a sawmill, moving logs at the mill are primary? But taking a skid of lumber to the customer is secondary?
From contributor J:
"Primary" just means "first." Primary processing is the first stuff you have to do to make lumber out of a tree. The exact line that's drawn to differentiate between primary and not-primary is somewhat arbitrary. Gene's guideline is sure to be where that line is customarily drawn.
It's fairly straightforward to say that everything up to and including drying is traditionally called "primary." Shipping dry lumber to the customer is definitely not primary, but it's not necessarily secondary either. This plate of beans is easily over thought.
From contributor M:
To me, primary process means turning logs into lumber. Secondary would be, anything else that comes from the byproducts, such as wood chips you sell or wood pellets from the sawdust, etc.
From Professor Gene Wengert, forum technical advisor:
Wood chips are usually considered primary, as chips are made at the same time that lumber is being produced. That is, it involves conversion of the log. Chips made in the woods are primary as well. At times, rarely, dry material can be chipped, and then it would be secondary.
If pellets are made directly from a log, then they are primary, but if made at a different site using log byproducts, then they are more likely to be called secondary as the slabs or other waste would have been sold (versus immediate processing at a mill without any sale).
Bark from a debarker would also be a primary product.
From contributor M:
I stand corrected Doc. You are correct.
From contributor R:
Primary came from the word prima, which means first or best, so it's the first stage of making lumber.
From Professor Gene Wengert, forum technical advisor:
First stage of making any wood product from the log.
