Ac­cu­rate, con­sis­tent au­to­mated grad­ing with USNR’s THG

Vi­sion scan­ning im­proves grade out­turn, through­put

Australasian Timber - - NEWS -

DELTIC TIM­BER was looking to up­date its com­bi­na­tion geo­met­ric and man­ual grad­ing line with a state-of-the-art au­to­mated one. Au­to­mated grad­ing sys­tems of­fer con­sis­tent ac­cu­racy, and they op­er­ate at high speed board af­ter board, shift af­ter shift, day af­ter day. THG was cho­sen for its suit­abil­ity to the mill’s process, and the strong trust de­vel­oped be­tween cus­tomer and ven­dor.

Deltic Tim­ber, head­quar­tered in El Do­rado, Arkansas, owns two sta­teof-the-art sawmills in the re­gion at

Ola and Waldo. Com­bined an­nual per­mit­ted ca­pac­ity for these two op­er­a­tions is in the range of 450 mmbf with ap­prox­i­mately 200 mmbf re­cently pro­duced at the Waldo fa­cil­ity with 150 em­ploy­ees. The Deltic

Tim­ber mills pro­duce 2x4 through 2x12 di­men­sion lum­ber, tim­bers, and spe­cialty prod­ucts in­clud­ing MSR lum­ber, ex­clu­sively from South­ern Yel­low Pine.

The Waldo op­er­a­tion pro­cesses both small and larger logs, and in­cludes a sawmill, boil­ers, dry kilns and planer mill. It re­cently up­graded its planer mill line with USNR’s Trans­verse

High Grader (THG) sys­tem, tak­ing the lum­ber grad­ing process from a largely man­ual one to an op­ti­mized line.

In­vest­ing for suc­cess

Tommy Downs, Waldo mill man­ager, com­mented on the rea­son Deltic de­cided to in­vest in this new process. “We were looking to im­prove the con­sis­tency in both through­put and grade de­ter­mi­na­tion, and bet­ter con­trol our trim­ming. We also wanted to re­move the man­ual el­e­ment and re­duce hu­man er­ror.”

Tommy ex­plained that the mill had pre­vi­ously had an­other ven­dor’s scan­ner on the line for geo­met­ric scan­ning only. This meant they still re­quired a sig­nif­i­cant num­ber of man­ual graders for the vis­ual grad­ing com­po­nent, and were ex­pe­ri­enc­ing dif­fi­culty at the planer mill keep­ing up with all of the out­put from the sawmill. The man­age­ment con­sid­ered other ven­dors, but se­lected the THG be­cause of its bet­ter fit for the lay­out of the mill, and the good re­la­tion­ship Deltic and USNR have built over the years.

The new line

The new grad­ing line in­cludes a Re­volver Lug Loader, THG scan­ning and op­ti­miza­tion sys­tem, Grade Pro­jec­tors, Grade Mark Reader and Multi-Track Fence. The mill’s strength pre­dict­ing ma­chine is po­si­tioned at the out­feed of the USNR high speed planer (in­stalled in 2007), and sprays a mark on each piece it de­ter­mines is a can­di­date for MSR. As the piece is scanned by the THG, it vis­ually eval­u­ates the piece for all grade char­ac­ter­is­tics while con­sid­er­ing the strength pre­dic­tion.

The THG then makes a grade de­ci­sion hav­ing con­sid­ered de­fects such as knots, wane, skip, splits and shakes.

The THG’s grade clas­si­fi­ca­tion is as­sisted by a sen­sor po­si­tioned at the lum­ber line end of the scan frame – the pith sen­sor. This pith sen­sor vis­ually mea­sures the end grain of the board, cal­cu­lat­ing its po­si­tion in the log to very ac­cu­rately de­ter­mine the pith lo­ca­tion. To­gether with data col­lected via high def­i­ni­tion 4-sided vi­sion scan­ning, 4-face grain an­gle mea­sure­ments (GrainMap™), and high den­sity laser pro­file mea­sure­ments, the pith is mod­eled down the en­tire length of the board to very ac­cu­rately de­ter­mine knot con­nec­tiv­ity within the piece.

The Grade Pro­jec­tor sys­tem is unique, and de­vel­oped by USNR. The Grade Pro­jec­tors are mounted above the flow and project each board’s grade onto the sur­face of the board as it passes by the check grader. Tommy said, “It works re­ally well. It helps me be­cause when

I’m on the line I can see what the THG is grad­ing each piece. I re­ally like that fea­ture.”

Re­warded with re­sults

The re­sults the mill is achiev­ing are well re­ceived. Tommy com­mented: “We de­creased our trim loss by around 2%, and we’ve cut our man­power by 3 graders. I can’t stress enough the im­prove­ment in con­sis­tency of the flow at the planer mill. The ma­chine doesn’t get be­hind in pro­cess­ing. With the

THG run­ning we have in­creased our through­put ca­pac­ity by about 4000 ft./ hour.”

Re­luc­tant to share grade up­lift per­cent­ages, Tommy did ex­press that the mill is achiev­ing good re­sults. He con­tin­ued, “It’s made a sig­nif­i­cant dif­fer­ence to our op­er­a­tion; now we can run the planer mill one day less than it takes to pro­duce the lum­ber in the sawmill. We would def­i­nitely do this again”

Tommy noted that, while this was the beta site for prov­ing the THG’s ef­fi­cacy on SYP, he al­ways felt USNR was fully com­mit­ted to the project. The re­la­tion­ship re­mains solid, with Deltic looking at more new USNR equip­ment to out­fit the mill.

Learn­ing the ropes

Train­ing for ad­vanced op­ti­miza­tion sys­tems is cru­cial to achieve the great­est return from the in­vest­ment. In Deltic’s case, four em­ploy­ees from Waldo at­tended train­ing at USNR’s Salmon Arm, BC train­ing fa­cil­ity, and this was fol­lowed up with ex­ten­sive train­ing at the mill once the sys­tem was op­er­a­tional. In house train­ing can also be per­formed in cases where mill per­son­nel sim­ply can’t get away for off-site train­ing.

Tommy notes those in­di­vid­u­als who were key to the suc­cess of this project; Mike Rus­sell, Qual­ity Con­trol, was hands-on from the start and still over­sees the THG’s op­er­a­tion, as well Kent Streeter, VP of Wood Prod­ucts was in­stru­men­tal to the project, as was Tommy him­self.

Now that the grad­ing line project is be­hind them, Tommy ex­plained that Waldo is con­tin­u­ing to eval­u­ate ways to im­prove all of its pro­cesses. The bot­tle­neck has been pushed fur­ther up the line now that the THG has sig­nif­i­cantly in­creased the through­put of the planer mill.

■ A check grader on the line views the pro­jected grade de­ci­sion from the THG and can down­grade the piece if he war­rants.

■ A generic screen shows a dry mill grade op­ti­miza­tion sys­tem pro­cess­ing South­ern Yel­low Pine. USNR's grade op­ti­miza­tion for THG, LHG (trans­verse and lin­eal dry mill grad­ing) and BioVi­sion (green mill grad­ing) offers a wide range of flex­i­ble fea­tures...

■ The Grade Mark Reader reads any marks the check grader has made to down­grade the THG's de­ci­sion. The re­vised grade and trim data will be passed to the PLC to ad­just the fence pad­dle's po­si­tion for that board ahead of trim­ming.

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