Abstract:
Systems, methods and apparatus for the production of quality finger jointed dimensioned lumber, molding stock, poles or beams from green rough trim blocks by sorting, drying, finger jointing and finishing, thereby producing a commercial product having a higher commercial value.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of U.S. Provisional Patent Application No. 61/836,746 filed Jun. 19, 2013, and entitled “Systems, Methods and Apparatus for the Production of Finger Jointed Dimensioned Lumber and Molding Stock From Green Rough Trim Blocks”, which is incorporated herein by reference. 
    
    
     BACKGROUND 
     The present invention relates generally to systems, apparatus and methods for the production of finger jointed dimensioned lumber, molding stock, poles and beams produced from sawmill green rough trim. 
     The United States (U.S.) has substantial timber forests as a source of logs for the production of forest products such as paper, dimensional boards, sheets boards, poles, beams and pressed formed wood fiber products. Though the number of U.S. forest acres have been reduced by 50% over the past 200 years, logs are now harvested on a rotational basis providing a sustainable supply of timber. Furthermore, production facilities continually optimize their wood fiber usage which is typically the most expensive component of their product. 
     As an example, the production of dimensional lumber is a sequential process starting with de-limbed green logs and ending with stacks of dried boards having width, length and thickness dimensions. The sequential process usually comprises the following steps:
         Log bucking (cutting the tree length logs into saw length);   Primary breakdown of the saw log;   Secondary breakdown of the rough cants, fitches, and boards;   Length trimming of the green boards;   Collating, stacking, and drying of like-sized green boards;   Surface finishing (planing or molding) of the dry rough boards;   Length trimming of the finished dried boards;   Collating and stacking for commercial distribution.
 
These sequential steps are common whether the lumber facility is a small single band mill or a high volume multi-primary breakdown facility. The processing of cylindrical poles (as utility poles, for example) and wooden beams utilize similar processes.
       

     One type of forest product high volume production mill is a chip and saw (“CNS”) facility. A CNS facility produces dimensional lumber from timber that has a diameter ranging from mid-sized to small. The CNS production concept was developed to produce higher value dimensional lumber while providing a source of white chips for paper production using the smaller diameter logs. A typical CNS facility generates an average of more than five-hundred tons of dry biomass byproducts per day. (According to Marks Mechanical Engineering Handbook, the standard for “dry” is defined as twelve percent moisture content or less.) These biomass byproducts typically comprise white chips, bark, sawdust, and wood shavings. The white chips produced by a CNS facility are sold to paper-producing mills for processing into paper and cellulose products. The bark, sawdust and shavings are either used at the CNS facility as a thermal energy source or sold as lower value byproducts. While manufacturing dimensional lumber, a CNS facility will also produce green rough trim blocks having a moisture content of over 40% as well as dry trim blocks with moisture content under 20%. According to Southern Pine Inspection Bureau (“SPIB”) guidelines, construction grade lumber two inches thick with a moisture of 19% is known as KD19. 
     Green rough trim blocks are chipped and added to the white chips that are sold to the paper production industry or to post mill processing facilities such as pellet manufacturers. The production plant continually optimizes the log bucking and primary breakdown to minimize the number and amount of green rough trim blocks produced due to their lower value. CNS production mills currently produce approximately 14% of their production volume as green rough trim blocks. Approximately 40% of the green rough trim blocks can be converted into finger jointed dimensional lumber while approximately 20% of the green rough trim blocks can be converted into finger jointed molding blocks used to manufacture molding trim. 
     The dry trim blocks are ground into fuel for direct fired drying kiln or sold as low value stock for additional processing such as pallet components; truss web; or finger jointed dimensional lumber. Finger jointed lumber manufactured from dry finished trim blocks typically does not have sufficient fiber for finishing into dimensional lumber following the finger jointing process. The resulting boards have undesirable steps and offsets at the finger joints and inferior joints due to the insufficient material prior to the finger jointing process. 
     The production of dimensional lumber follows industry grading rules such as those promulgated by the SPIB. These rules provide the following minimum allowances for thickness, width, and length of the finished products:
         Thickness: based on a quarter system expressed as four quarter, (one inch); five quarter, (one and one quarter); eight quarter, (two inches), etc.;   Width: based on two inch increments starting with a four; six; eight; ten; and twelve; and   Length: based on two foot increments; six; eight; ten; twelve; fourteen; sixteen; eighteen and twenty.
 
All finished dimensions are based on dry lumber; therefore, the production mill must allow for shrinkage due to drying and other process variables. Thickness and width are fractional inch increases while the length increase is in inches. Following primary and secondary breakdown, the green lumber is trimmed, for example, on two foot lengths. In the past, the resulting green rough trim blocks have been collected and chipped into white chips at a commodity value. Processing the green rough trim blocks into finger jointed dimensional lumber and finger jointed molding blocks can increase their utility and value.
       

     An issue with the production of kiln dried lumber is the defects incurred during the drying process. Warping, checking, splitting, and case hardening all reduce the amount of dried rough boards available for finishing into dimensioned lumber for market. 
     What is needed is a system, method and apparatus to utilize green rough trim blocks for production of high quality finished finger jointed dimensional lumber and molding stock. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to systems, apparatus and methods utilizing green rough trim blocks for the production of dried finger jointed dimensional lumber, molding stock, poles and beams using apparatus and steps that dry the blocks followed by finger-jointing, planing and trimming. This invention discloses several embodiments for achieving these objectives. 
     If there is sufficient green rough trim block production then the finger jointing system can be co-located with a sawmill that generates the green rough trim blocks as a by-product, and where the existing lumber production facilities and machinery can be used to process the finger jointed trim blocks. A preferred embodiment is the co-location of the selection and drying of the green rough trim blocks with a sawmill that generates the green rough trim blocks as a by-product and a finger jointing facility designed to accept the dried rough trim blocks from multiple lumber production facilities. 
     According to the present invention, the green rough trim blocks are collected and subjected to a first sorting step based on grain density, shape, and defects using optimization hardware and software. Selected and sorted green rough trim blocks are then randomly stacked into a container with open mesh sides for kiln drying, and then placed into a dry kiln at the beginning of the drying cycle along with standard length green dimension lumber, poles or beams and thereby exposed to the drying process. At the end of the drying cycle, the unfinished trim blocks have a desirable uniform low moisture content, have low warping and are suitable for finger jointing. The dry rough trim blocks are then delivered to a finger jointing system where they are rough planed, followed by a second sorting step to be sorted by selection criteria to reject trim blocks such as, for example, ones that include edge wane or knots. The selected trim blocks are then processed through the finger jointing production system including finish planing and length trimming. The finished finger jointed dimensioned lumber, molding stock, poles or beams are then stacked for sale. 
     In a preferred embodiment, a finger jointing production plant receives dried trim blocks from multiple lumber production facilities. The finger jointing plant is sized and optimized for the volume of green rough trim blocks produced by multiple lumber production facilities. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The novel features which are believed to be characteristic of this invention are set forth with particularity in the accompanying drawings and the following description, both as to its organization and method of operation, together with further objects and advantages thereof. These may best be understood by reference to the following description taken in connection with the accompanying drawings, in which: 
         FIG. 1  is a flow diagram of an embodiment for the production of finger jointed lumber and molding stock using green rough trim blocks in accordance with this invention at, for example, a co-located lumber and finger jointing production facility. 
         FIG. 2  is a detailed flow diagram for the production of finger jointed lumber and molding stock using dried rough trim blocks selected in accordance with this invention. 
         FIG. 3  is a flow diagram for the production of dried rough trim blocks at a separate lumber production plant for finger jointing at a separate facility in accordance with this invention. 
         FIG. 3A  is a diagram for the production of finger jointed dimensioned lumber and/or molding stock with a finger jointing plant receiving dried rough trim blocks from multiple lumber production facilities in accordance with the flow diagram of  FIG. 3 . 
         FIG. 4  is a perspective view of a container for drying green rough trim blocks. 
         FIG. 5  is a perspective view of a container randomly filled with selected green rough trim blocks for kiln drying. 
         FIG. 6  is an end view of the filled container of  FIG. 5  positioned with dimensional lumber for kiln drying. 
         FIG. 7  is a perspective view of green rough trim blocks of different grain density and defect content. 
         FIG. 8  is a perspective view of a rough finger jointed board produced from kiln dry rough planed trim blocks. 
         FIG. 9  is a perspective view of a finished length and partially surface finished finger jointed blocks produced from kiln dried rough trim blocks. 
         FIG. 10  is a perspective view of a stack of equal size and length finished finger jointed blocks. 
         FIG. 11  is an exploded perspective view of a finger jointed pole according to this invention. 
         FIG. 12  is an exploded perspective of a finger jointed beam according to this invention. 
     
    
    
     DETAILED DESCRIPTION 
     A first embodiment of a co-located system in accordance with the invention is depicted in  FIG. 1  and designated generally by reference numeral  300 . 
     The system  300  comprises a lumber production facility  200  having a drying system  200 A and a finger jointing production facility  100 . The green rough trim blocks  20  produced by the lumber production facility  200  shown as flow  111  are dried by the drying system  200 A and delivered as flow  125  to the finger jointing facility  100 , for processing into finger jointed blocks and molding stock that are the commercial finger jointed products of the production facility  300 . 
     Continuing with  FIG. 1 , the lumber production facility  200  receives logs and bucks them at step  210  (cut to rough lumber dimension length) for processing into dimensional lumber. Step  220  produces the primary and secondary breakdown of the bucked logs from step  210 . Green rough boards are optimized, length trimmed and sorted at step  230  where green rough trim blocks  20  are produced during production of the dimensional green lumber as a by-product of the lumber production facility  200 . During optimization of the green rough boards at step  230 , green rough trim blocks  20  are separated into rejected green rough trim blocks  22  and green rough trim blocks  21  for drying. Rejected green rough trim blocks  22  are delivered to the chipper  235  to be rendered into green chips  60  and sold at step  280 . The green rough trim blocks  21  for drying moves as flow  111  into the drying system  200 A. 
     Turning to  FIGS. 1, 4, 5, and 6 , the green rough trim blocks  21  for drying are randomly stacked into a container  350  ( FIG. 4 ) with opposing sides  320 , opposing ends  310  and closed bottom  330 . The container  350  with the green rough trim blocks  21  randomly stacked as shown as elements  55  in  FIG. 5 , and then moved for drying to area  240  shown as flow  115  in  FIG. 1 . 
     The containers  350 , with the randomly stacked green rough trim  21  blocks for drying are then kiln-dried by system  500  in  FIG. 6 . Container  350  is sized to fit with a stack of dimensional lumber inside the drying kiln  500 . The container  350  is placed on the top of a stack of green dimensional lumber  510 . Dry heated air  550  shown as flows  553 ,  555 ,  557  is pushed through the stack of lumber  510  and the container  350  by reversible fan  570 . High moisture content air  559  enters the reheating area where the vents  580  and  581  are actuated to control the humidity of the heated air  550  and thereby controls the rate of drying. 
     Reversible fan  570  forces the heated air  550  to flow in the direction as indicated as arrows  553 ,  555 ,  557  and the opposite direction when the revisable fan  570  reverses. This provides uniform drying of the kiln charge made up of the lumber stack  510  and the container  350 . The dried rough trim blocks  31  are delivered as flow  125  to the finger jointing system  100 . 
     Turning now to  FIG. 2 , the dry rough trim blocks  31  are received by the finger jointing system  100  as flow  125  at receiving area  130 . A variety of techniques for finger jointing are well known in the art, as shown in U.S. Pat. Nos. 4,248,280 and 4,941,521 which are incorporated by reference. 
     According to this invention, the dry rough trim blocks  31  move as flow  131  into the rough plane at step  140  where they are lightly surface planed prior to optimization at step  150 . The dry rough planed trim blocks  33  move as flow  141  into the optimizer, trimmer, and sorter area  150 . 
     Referring to  FIGS. 2 and 7 , the dry rough planed trim blocks  33  are inspected and sorted for desired criteria  155 , and separated into bins  156 A,  156 B,  156 C,  156 D. The dry rough planed trim blocks  33  with defects  26 ,  27  and/or undesirable grain  25  ( FIG. 7 ) are rejected blocks  28  and move as flow  153 , to a chipper  157  where they are rendered into dried chips  62  and moved as flow  127  for sales at step  180 . 
     Continuing with  FIG. 7 , as an example, suitable selection criterion  155  at step  150  in  FIG. 2  for the dry rough planed trim blocks  33  based on coarse grain and defect content includes:
         1. The coarse grain clear trim block  24  is desirable for the present invention of producing finger jointed boards.   2. A dense grain clear trim block  25  is not desirable.   3. A dry rough planed trim block  33  with edge wane  26  is not desirable for finger jointing.   4. A dry rough planed trim block  33  with knot defect  27  is not desirable for finger jointing.       

     The above criteria are given as examples. Multiple selection criteria  155  are used at step  150  for sorting the dry rough planed trim blocks  33  to achieve the desired finger jointed product. 
     Returning to  FIGS. 2, 8, 9 and 10 , a series of the dried rough finish sorted trim blocks  57 , from group  35 A,  35 B,  35 C, or  35 D moves as flow  151  from the selected sort bin  156 A,  156 B,  156 C, or  156 D to the finger jointing process at step  160  where they are finger jointed as shown at reference numeral  620  in  FIG. 8 ; trimmed to length as shown with reference numeral  80  in  FIG. 9 , and finished planed as shown with reference numerals  710 ,  720  in  FIG. 9  to become finished finger jointed dimensional lumber and/or molding blanks prior to moving into the package maker  170  as flow  161 . 
     One skilled in the art would recognize that the number of sort bins  156  is based on the predetermined sorting criteria  155  and is not limited to four bins as disclosed in the embodiment of  FIG. 2 . 
     In some embodiments, the dried rough finish sorted trim blocks  57  are grain oriented as illustrated as block  610  in  FIG. 8  and processed by the finger joint system  100  of  FIG. 2  to produce a finished finger joint  620  on the dried rough finish block  59 . Grain orientation  610  improves the strength and resistance to warping of the finger jointed dimensional lumber and/or molding stock. 
     The finished finger jointed materials are stacked at step  950  ( FIG. 10 ) at the package maker  170  ( FIG. 2 ) and move as flow  171  to the sales area  180 . 
     Referring to  FIG. 3A , there is shown a preferred embodiment of a system  200  in accordance with this invention where the lumber production facility is  400  and the finger-joint facility  100  are not co-located together. Each lumber production facility  400  is comprised of a lumber production facility  200  ( FIG. 1 ) and a co-located drying system  200 A for the production of dry rough trim blocks  31 . 
     Turning to  FIG. 3 , the system comprises a lumber production facility  200  with a drying system  200 A and a shipping system  126 . The green rough trim blocks  20  produced by the lumber production facility  200  shown as flow  111  are dried by the drying system  200 A and shipped as flow  125  to the finger jointing facility. 
     Now noting  FIG. 3 , the lumber production facility  200  receives logs and bucks at step  210  (cut to rough lumber dimension length) for processing into dimensional lumber. Step  220  produces the primary and secondary breakdown of the bucked logs from step  210 . Green rough boards are optimized, length trimmed and sorted at step  230  where green rough trim blocks  20  are produced during production of the dimensional green lumber as a by-product of the lumber production facility  200 . During optimization of the green rough boards at step  230 , green rough trim blocks  20  are separated into rejected green rough trim blocks  22  and green rough trim blocks  21  for drying. Rejected green rough trim blocks  22  are delivered to the chipper  235  to be rendered into green chips  60  and sold at step  280 . The green rough trim blocks  21  for drying moves as flow  111  into the drying system  200 A. 
     Turning to  FIGS. 3, 4, 5, and 6 , the green rough trim blocks  21  for drying are randomly stacked into a container  350  ( FIG. 4 ) with opposing sides  320 , opposing ends  310  and closed bottom  330 . The container  350  with the green rough trim blocks  21  randomly stacked as shown as element  55  in  FIG. 5 , and then moved for drying to area  240  shown as flow  115  in  FIG. 1 . 
     The containers  350 , with the randomly stacked green rough trim  21  blocks for drying are then kiln-dried by system  500  in  FIG. 6 . Container  350  is sized to fit with a stack of dimensional lumber inside the drying kiln  500 . The container  350  is placed on the top of a stack of green dimensional lumber  510 . Dry heated air  550  shown as flows  553 ,  555 ,  557  is pushed through the stack of lumber  510  and the container  350  by reversible fan  570 . High moisture content air  559  enters the reheating area where the vents  580  and  581  are actuated to control the humidity of the heated air  550  and thereby controlling the rate of drying. 
     Reversible fan  570  forces the heated air  550  to flow in the direction as indicated as arrows  553 ,  555 ,  557  and the opposite direction when the revisable fan  570  reverses. This provides uniform drying of the kiln charge made up of the lumber stack  510  and the container  350 . The dried rough trim blocks  31  are delivered as flow  125  to the finger jointing system  100 . Turning now to  FIG. 2 , the dry rough trim blocks  31  are received by the finger jointing system  100  as flow  125  at receiving area  130 . The dry rough trim blocks  31  move as flow  131  into the rough plane at step  140  where they are lightly surface planed prior to optimization at step  150 . The dry rough planed trim blocks  33  move as flow  141  into the optimizer, trimmer, and sorter area  150 . 
     Referring to  FIGS. 2 and 7 , the dry rough planed trim blocks  33  are inspected and sorted for desired criteria  155 , and separated into bins  156 A,  156 B,  156 C,  156 D. The dry rough planed trim blocks  33  with defects  26 ,  27  and/or undesirable grain  25  ( FIG. 7 ) are rejected blocks  28  and move as flow  153 , to a chipper  157  where they are rendered into dried chips  62  and moved as flow  127  for sales at step  180 . 
     Continuing with  FIG. 7 , as an example, suitable selection criterion  155  at step  150  in  FIG. 2  for the dry rough planed trim blocks  33  based on coarse grain and defect content includes:
         1. The coarse grain clear trim block  24  is desirable for the present invention of producing finger jointed boards.   2. A dense grain clear trim block  25  is not desirable.   3. A dry rough planed trim block  33  with edge wane  26  is not desirable for finger jointing.   4. A dry rough planed trim block  33  with knot defect  27  is not desirable for finger jointing.       

     The above criteria are given as examples. Multiple selection criteria  155  are used at step  150  for sorting the dry rough planed trim blocks  33  to achieve the desired finger jointed product. 
     Returning to  FIGS. 2, 8, 9 and 10 , a series of the dried rough finish sorted trim blocks  57 , from group  35 A,  35 B,  35 C, or  35 D moves as flow  151  from the selected sort bin  156 A,  156 B,  156 C, or  156 D to the finger jointing process at step  160  where they are finger jointed as shown by reference numeral  620  in  FIG. 8 ; trimmed to length as shown by reference numeral  80  in  FIG. 9 ; and finished planed as shown by reference numerals  710 ,  720  in  FIG. 9  to become finished finger jointed dimensional lumber and/or molding blanks prior to moving into the package maker  170  as flow  161 . 
     One skilled in the art would recognize that the number of sort bins  156  is based on the predetermined sorting criteria  155  and is not limited to four bins as disclosed in the embodiment of  FIG. 2 . 
     In some embodiments, the dried rough finish sorted trim blocks  57  are grain oriented as illustrated as block  610  in  FIG. 8  and processed by the finger joint system  100  of  FIG. 2  to produce a finished finger joint  620  on the dried rough finish block  59 . Grain orientation  610  improves the strength and resistance to warping of the finger jointed dimensional lumber and/or molding stock. 
     The finished finger jointed materials are stacked at step  950  ( FIG. 10 ) at the package maker  170  ( FIG. 2 ) and move as flow  171  to the sales area  180 . 
     In other embodiments, the rough planed finger jointed blocks are sold to specialty production plants for the manufacturing of molding. 
     The finger jointing technique described above using green trim blocks to make dimensional lumber is also applicable to the use of delimbed and bucked logs for the fabrication of poles (such as utility poles, for example) and beams as will now be described with reference to  FIGS. 11 and 12 . 
     Noting  FIG. 11 , a pole  800  of a desired dimension is made from log segments  810  and  814 , each of which has a respective end  812 ,  816  that has been prepared for finger jointing. After finger jointing and setting of the adhesive, the log  800  formed of the segments  810  and  814  is then planed to a desired uniform diameter consistent with the needs of a pole application, again such as a utility pole. 
       FIG. 12  illustrates a beam  850  of a desired length fabricated from three beam segments  852 ,  856  and  860  each of which has a respective end  854 ,  858  and  862  finished with fingers suitable for jointing with the adjacent one of the segments in order to obtain a beam  850  of the desired length; it will be appreciated that other segments may be added to achieve the desired beam length. 
     While the invention has been described with respect to certain specific embodiments, it will be appreciated that many modifications and changes may be made by those skilled in the art without departing from the spirit and scope of this invention.