Better quality, lower energy consumption

The name Nestler is not only an insti­tu­tion in Lahr, but also in the world of cor­ru­gat­ed board. As one of the largest and most effi­cient cor­ru­gat­ed board plants in Ger­many, the com­pa­ny reg­u­lar­ly sets new bench­marks. Inno­va­tion and sus­tain­abil­i­ty are the dri­vers behind the suc­cess of this long-estab­lished com­pa­ny, which is part of the Palm pack­ag­ing group. In the heat­ing and trac­tion part of the cor­ru­gat­ed board plant (CBP), a heat­ing belt from GKD — Gebr. Kuf­ferath AG con­tributes towards this success.

With around 400 employ­ees, Nestler Well­pappe pro­duces 140 mil­lion square meters of cor­ru­gat­ed board per year. Found­ed in 1871 as a brew­ery in Lahr, Nestler start­ed afresh in 1923 as a cor­ru­gat­ed board plant. In 1999, the Palm Group acquired the fam­i­ly com­pa­ny, which has deep roots in the Black For­est region and has retained its orig­i­nal name to this day. The com­pa­ny’s affil­i­a­tion with the Palm Group is reflect­ed in the excep­tion­al­ly broad range of ser­vices it pro­vides. The dif­fer­ent cat­e­gories of cor­ru­gat­ed board include fine, medi­um and coarse cor­ru­ga­tion with sin­gle to triple walls rang­ing from 0.8 to 15 mil­lime­ters in thick­ness and with dif­fer­ent cor­ru­ga­tion pro­files or cor­ru­ga­tion com­bi­na­tions — all made with paper from the Palm Group. The paper used is almost exclu­sive­ly recy­cled paper. Vir­gin fiber is only added to increase sta­bil­i­ty for spe­cial appli­ca­tions such as for frozen food. The range of high-qual­i­ty print­ed pack­ag­ing, dis­plays and exact­ing pack­ag­ing con­struc­tions also includes many vari­a­tions. From the size of a cig­a­rette box to the size of a pal­let con­tain­er: As pack­ag­ing for trans­porta­tion or shelf-ready pack­ag­ing, as col­lapsi­ble box­es, die-cut, heavy-duty, haz­ardous goods or com­bi­na­tion pack­ag­ing — cus­tomized prod­ucts from Nestler can ful­fill any such chal­leng­ing tasks. This ver­sa­til­i­ty of pro­duc­tion in large and small batch sizes for count­less spe­cial appli­ca­tions and max­i­mum val­ue cre­ation makes Nestler the part­ner of choice for around 1,400 cus­tomers in the south of Ger­many, Switzer­land and the Alsace region. More than half of these cus­tomers are com­pa­nies from the elec­tri­cal engi­neer­ing, mechan­i­cal engi­neer­ing, chem­i­cal, paint and var­nish, rub­ber, wood and paper indus­tries — often with very com­plex requirements.

In addi­tion to the exten­sive pro­duc­tion range and decades of exper­tise, a fur­ther USP of Nestler is its extra­or­di­nary ser­vice capa­bil­i­ties. Large cus­tomers from indus­try and the mail order busi­ness ben­e­fit from a ware­hous­ing and deliv­ery ser­vice with which they can receive their prod­ucts with­in 24 hours. “More and more cus­tomers are count­ing on this adher­ence to desired deliv­ery dates,” explained Nestler CEO Andreas Jung. He added: “For us, OTIF (On-Time-in-Full) is there­fore one of our most impor­tant strate­gic goals.” This is guar­an­teed thanks to the fleet of 30 com­pa­ny-owned trucks. If desired, Nestler can also pro­vide com­plete assem­bly and opti­miza­tion of pack­ing process­es as a ser­vice. The com­pa­ny is con­tin­u­ous­ly striv­ing to improve pro­duc­tiv­i­ty, cost-effec­tive­ness and sus­tain­abil­i­ty of the solu­tions. “We opti­mize prod­ucts and process­es based on the STEAM prin­ci­ple, Save The Earth And Money, to reduce their car­bon foot­print,” explained Andreas Jung. Three core areas are giv­en par­tic­u­lar atten­tion: The opti­mized inter­ac­tion of area, weight and sta­bil­i­ty reduces the mate­r­i­al con­sump­tion of con­ven­tion­al con­struc­tions. Improved lay­out reduces clip­ping, pro­cess­ing time and ener­gy costs. Resource con­sump­tion and the CO2 impact are also reduced thanks to clev­er­ly devised truck load­ing, which results in few­er trips.

On course to save energy in the CBP

Nestler also puts these ideas into prac­tice in the heat­ing and trac­tion sec­tion of the 120 meter long cor­ru­gat­ed board plant of BHS. The CBP has a work­ing width of 2.50 meters, with two one-way machines as well as pull strips and rein­force­ment fibers. It works at a speed of 350 meters per minute and, thanks to an opti­mized steam sys­tem, enables cool­er cor­ru­gat­ing. This means it is pos­si­ble to reduce the steam pres­sure to 0.5 bar — where­as min­i­mum val­ues of two to three bar are usu­al in the indus­try. As a result, it was pos­si­ble to reduce the spe­cif­ic ener­gy con­sump­tion by ten per­cent, which is also reflect­ed in an eight per­cent reduc­tion in glue con­sump­tion. The 16 meter long heat­ing and trac­tion sec­tion is equipped with 18 heat­ing plates and works with a plate-roll clamp­ing sys­tem, which com­bines con­tact shoes and rollers. For opti­mized point load­ing, how­ev­er, the first three heat­ing sec­tions have only rollers. What­ev­er the prod­uct, the heat­ing belt trans­ports an aver­age of 30,000 square meters of sin­gle and dou­ble-wall cor­ru­gat­ed board an hour. Depend­ing on the prod­uct mix, the board is exposed to a steam pres­sure of up to 16 bar — with sur­face weights of up to 1,400 grams. Nestler’s expec­ta­tions of its dimen­sion­al and track­ing sta­bil­i­ty are cor­re­spond­ing­ly demanding.

In 2015, the cor­ru­gat­ed board man­u­fac­tur­er switched from a con­ven­tion­al heat­ing belt to the Con­duc­to 3313 heat­ing belt, which at the time had been new­ly launched by the tech­ni­cal weavers GKD — Gebr. Kuf­ferath AG. This deci­sion was tak­en due to the claim that this belt would enable sig­nif­i­cant sav­ings in terms of dri­ve ener­gy. “This is not insignif­i­cant where the CBP is con­cerned,” said Eva Labus­ga, Head of CBP, Plan­ning and Pro­duc­tion Con­trol, explain­ing the moti­va­tion for the switch. The con­struc­tion of poly­ester monofil­a­ments with aramide rein­force­ment in the edge area and bronze wires inter­wo­ven in the run­ning direc­tion makes the Con­duc­to 3313 sig­nif­i­cant­ly lighter in com­par­i­son with oth­er prod­ucts on the mar­ket. Thanks to spe­cial ther­moset­ting, it is also per­ma­nent­ly dimen­sion­al­ly sta­ble. Despite the low weight, the belt’s robust design guar­an­tees the required even pres­sure for opti­mal con­tact between the cor­ru­gat­ed board and the heat­ing plates. The open mesh struc­ture ensures imme­di­ate full-sur­face mois­ture evap­o­ra­tion of the cor­ru­gat­ed board. Due to the faster dry­ing and result­ing improved flat­ness of the cor­ru­gat­ed board, Nestler was able to increase the process speed by eight per­cent. “We are able to run the sys­tem faster because the con­di­tion of the board allows it,” said the Head of Production.

The GKD belt also sur­passed the pre­vi­ous­ly used con­ven­tion­al mod­el by far in terms of run­ning per­for­mance: 180 mil­lion run­ning meters in three years with­out a sin­gle down­time caused by the belt speak for them­selves. “That’s real­ly, real­ly good,” said Eva Labus­ga. “The pre­vi­ous belt last­ed for a max­i­mum of two years.” In addi­tion, this self-clean­ing belt exhib­it­ed no soil­ing — nei­ther super­fi­cial adhe­sions of paper and glue nor clog­ging. Based on tar­get­ed mea­sure­ments on the con­ven­tion­al and new belt, Nestler test­ed the con­sump­tion of dri­ve ener­gy, which was rel­e­vant in the deci­sion to switch: Due to its lighter weight, the Con­duc­to 3313 achieved a 15 per­cent ener­gy sav­ing over the pre­vi­ous­ly used belt.

Top values also with the latest generation of belts

Nonethe­less, they stopped run­ning this GKD belt after three years, even though it was not show­ing any signs of change despite the long run­time. “I actu­al­ly want­ed to keep using it, to see how its end-of-life would exhib­it itself,” said the Head of Pro­duc­tion. “But after these good expe­ri­ences, we chose instead to test the new belt from GKD, the Con­duc­to 3322.” This fur­ther devel­oped belt promised two improve­ments which were of inter­est for Nestler too: The smooth sur­face of the 3313 had ini­tial­ly caused prob­lems in terms of trac­tion. This was grad­u­al­ly cor­rect­ed through the appli­ca­tion of sil­i­cone strips and grind­ing. In addi­tion, the oper­at­ing staff had found the noise lev­el of the 3313 uncom­fort­able. To check, Nestler took noise mea­sure­ments: In the com­par­i­son, both the con­ven­tion­al belt and the 3313 had the same deci­bel val­ues, but the fre­quen­cy of the GKD belt was slight­ly high­er. That’s why the noise lev­el imme­di­ate­ly after installing the belt was per­ceived as loud­er. After a week of run­ning time, how­ev­er, the lev­el bal­anced out to the usu­al level.

With the devel­op­ment of the Con­duc­to 3322, GKD has per­ma­nent­ly resolved these two issues. Its con­struc­tion of two and a half-ply hybrid mesh com­bines an inter­nal struc­ture of poly­ester monofil­a­ments and addi­tion­al bronze wires in the run­ning direc­tion with a warp of sta­ple fiber yarn. The edge is rein­forced with aramide, as with the pre­de­ces­sor mod­el. The tex­tile mate­r­i­al means grip is sig­nif­i­cant­ly bet­ter. “We no longer have to rough­en the belt,” said Eva Labus­ga. In addi­tion, it is qui­eter than the 3313 and there­fore com­pa­ra­ble with con­ven­tion­al belts from the out­set in terms of noise lev­el. Its 1.1 mil­lime­ter larg­er thick­ness (Con­duc­to 3313: 4.6 mil­lime­ter, Con­duc­to 3322: 5.7 mil­lime­ter) makes no dif­fer­ence in oper­a­tion. Con­ven­tion­al belts are up to eight mil­lime­ters thick. The small­er belt thick­ness makes it sig­nif­i­cant­ly eas­i­er to han­dle dur­ing replace­ment, so that assem­bly is sig­nif­i­cant­ly eas­i­er and quick­er: “The belt can be replaced in three to four hours. That’s half the time you need for con­ven­tion­al belts,” said Eva Labus­ga. The thin­ner for­mat of the GKD belts also had a pos­i­tive effect on the seams, which are much fin­er as a result. Hav­ing said that, some improve­ments were required at the begin­ning: “A non-mark­ing seam is gen­er­al­ly very dif­fi­cult, and with fine cor­ru­ga­tion on white paper, it comes down to tenths,” explained the Head of Pro­duc­tion. That’s why choos­ing the right clip for the seam on the 3322 ini­tial­ly required some effort. But the expe­ri­enced expert sees this as “all part of the devel­op­ment work.” With this new belt from GKD too, she sees the fast, even evap­o­ra­tion as the main advan­tage: Despite its tex­tile share, the Con­duc­to 3322 is in no way infe­ri­or to the Con­duc­to 3313 in terms of air per­me­abil­i­ty. “It main­tains the top val­ues that we have already achieved with the pre­de­ces­sor mod­el in terms of dri­ve ener­gy (15 per­cent sav­ing), and there are also no dif­fer­ences between the two GKD belts as far as the con­sump­tion of steam ener­gy and glue are con­cerned.” For her, one things is for sure: “Both belts def­i­nite­ly rep­re­sent a qual­i­ty improve­ment. The sig­nif­i­cant­ly bet­ter flat­ness in all qual­i­ties increas­es the pro­cess­ing qual­i­ty and there­fore also the qual­i­ty of the end prod­uct.” How­ev­er, thanks to its self-clean­ing sur­face, the Con­duc­to 3313 stood out as far as super­fi­cial adhe­sions were con­cerned. The 3322 requires a high-pres­sure clean­er to remove adhe­sions. Unlike con­ven­tion­al belts, how­ev­er, nei­ther of the GKD belts has any ten­den­cy to block­age. Eva Labus­ga’s ver­dict on the heat­ing belts from GKD is there­fore accord­ing­ly pos­i­tive: “Using it as the upper belt has only been of ben­e­fit. Not for one sec­ond have I regret­ted tak­ing this path togeth­er!” That’s why she can also imag­ine soon test­ing the Con­duc­to 3322 as a low­er belt. “I have only ever had good expe­ri­ences with the GKD belts. So I’m always open to test new prod­ucts. GKD has always deliv­ered on its promises.”