Zaj Duab Xis Ntsib Plywood (42 Duab): Qhov Ntev Thiab Qhov Hnyav Ntawm Cov Ntawv Raws Li GOST, Cov Chaw Tsim Khoom Hauv Russia Thiab Tuam Tshoj, Cov Yam Ntxwv Thiab Daim Ntawv Thov

2024 Tus sau: Beatrice Philips | [email protected]. Kawg hloov kho: 2024-01-18 12:13

Muaj ntau hom yeeb yaj kiab hauv tsev thiab txawv teb chaws ntsib plywood ntawm kev muag khoom. Hauv kab lus peb yuav muab cov lus piav qhia ntawm lawv, xav txog cov yam ntxwv thiab daim ntawv thov.

Nws yog dab tsi?

Zaj duab xis ntsib plywood yog plywood uas tsis ntshai dej thiab tiv taus cov khoom puas vim yog lub plhaub tiv thaiv tshwj xeeb uas npog nws los ntawm sab nraud. Cov txheej sab hauv, zoo li plywood zoo tib yam, tau ua los ntawm ob peb txheej ntawm glued thiab nias veneer (ntu ntu ntawm cov ntoo ntoo ntawm 1 txog 10 hli tuab), fiberboard lossis ua ke ntawm cov ntaub ntawv no. Txhawm rau muab cov dej noo tiv taus ntau ntxiv, txheej txheej veneer kuj tseem tuaj yeem ua rau cov dej tsis sib haum sib xyaw.

Feem ntau, thev naus laus zis los tsim cov yeeb yaj kiab ntsej muag plywood cuam tshuam nrog cov hauv qab no:

• veneer txheej tau pleev xim nrog cov dej tsis sib haum thiab cov nplaum sib txuas thiab koom nrog los ntawm kub nias (siab ntawm 13 txog 30 kg / cm², kub - 130 ° C);
• qhov saum npoo ntawm cov ntawv plywood uas tau ua tiav yog xuab zeb thiab zaj duab xis laminating yog siv rau qhov sov;
• qhov kawg ntawm laminated plywood tau tiv thaiv nrog cov khoom sib xyaw acrylic, qee zaum lawv kuj tseem laminated, tab sis qhov no zoo heev nce tus nqi ntawm cov khoom.

Qhov tshwm sim yog cov cuab yeej siv thev naus laus zis uas yuav tsum tiv taus 50-100 kev hloov pauv mus los, rau-teev kub hauv dej, tiv nrog nruab nrab alkaline, dej kub ua pa lossis ua kua ua kua. Nws cov nplaim yog tiv taus pwm, qhib hlawv, yooj yim los ntxuav, tso cai siv cov hlau txuas . Nyob rau tib lub sijhawm, nws pheej yig, lub teeb yuag, thiab yooj yim rau txheej txheem. Nws yog cov yam ntxwv tshwj xeeb no uas qee hom yeeb yaj kiab ntsib plywood muaj, thiab qhov no ua rau lawv tsis muaj qhov cuam tshuam hauv ntau yam kev lag luam - los ntawm cov rooj tog tsim khoom rau kev tsim dav hlau. Txawm li cas los xij, txhawm rau txhim kho kev tiv thaiv kev ya raws, lawv cov impregnation thiab txheej txheej tuaj yeem muaj feem pua ntawm cov tshuaj phenols lom uas tsim kev puas tsuaj rau kev noj qab haus huv.

Tab sis muaj cov khoom tshwj xeeb uas ua tau raws li qhov xav tau ntawm Lavxias thiab thoob ntiaj teb tus qauv (BFU 100 DIN 68705, GOST) raws li chav kawm ntawm kev tso tawm (tso tawm) ntawm phenol . Lawv tuaj yeem siv nyab xeeb sab hauv tsev. Hauv lawv cov muaj pes tsawg leeg, phenol-formaldehyde tsis siv lossis siv rau hauv qhov muaj txiaj ntsig zoo, thiab tsis yog cov khoom siv ntawm txheej txheej sab saud, tab sis tsuas yog sab hauv xwb.

Tsis tas li ntawd, cov nplaim tau npog nrog cov yeeb yaj kiab tiav thiab cov kua roj vanish, uas tsis muaj kev phom sij thiab thaiv cov pa phem.

Yam ntxwv

Txhua daim ntawv zoo yuav tsum muaj cov yam ntxwv hauv qab no:

• ntom ntawm laminate - 120-300 g / m², nyob ntawm seb hom yeeb yaj kiab - qhov no muab lub zog siab thiab cov khoom tsis muaj dej;
• laminate tuab - 0, 4-10 hli, txheej tuab dua, siab dua qhov tsis kam rau cov neeg kho tshuab kev nyuaj siab thiab cov tshuaj txhoj puab heev;
• chav kawm tso tawm rau plywood siv hauv thaj chaw nyob yuav tsum yog yam tsawg E1 (tsis ntau dua 10 mg rau 100 g ntawm plywood hnyav), rau txhua lwm yam haujlwm - tsis qis dua E2 chav kawm (tsis ntau dua 30 mg rau 100 g ntawm plywood hnyav);
• cov dej noo ntawm cov khoom - 5-10%;
• qhov ntom ntom ntawm ib daim ntawv ntawm zaj duab xis ntsib plywood yog qhov nruab nrab 650 kg / m³ - qhov no ua kom muaj zog thiab muaj peev xwm tiv taus cov khoom hnyav piv rau cov uas cov khoom siv ntoo tuaj yeem tiv taus (rau kev sib piv: qhov ntom ntom ntawm beech - 650 kg / m³, ntoo qhib - 700 kg / m³, ntoo qhib ntoo - 950 kg / m³);
• siab tshaj plaws tensile lub zog - 40 MPa;
• siab tshaj plaws zoo li qub khoov lub zog - 60 MPa.

Txhawm rau ua kom muaj zog zoo dua qub, tiv taus khoov thiab ua kom nruj, daim ntawm cov veneer tau tso tawm nruj me ntsis coj mus rau hauv tus account cov kev taw qhia ntawm cov fibers . - Kev teeb tsa tuaj yeem siv tau ntawm cov ces kaum ntawm 30 °, 45 °, 60 ° lossis 90 ° rau cov ntawv uas nyob ib sab lossis ntug ntawm daim ntawv. Tab sis txhua qhov xwm txheej, cov veneer tau muab tso ua ke nrog kev hwm rau txheej txheej hauv nruab nrab. Yog li ntawd, feem ntau cov ntawv plywood muaj cov lej sib txawv ntawm cov txheej (3, 5, 7, 9), txawm hais tias tseem muaj 4 txheej txheej.

Qhov hnyav ntawm zaj duab xis ntsib plywood ntawv nyob ntawm seb hom khoom siv raw li cas. Qhov hnyav ntawm ib square meter ntawm laminated birch plywood (FOB) yog 1.95 kg nrog tuab 3 hli, nrog tuab 30 hli - 19.5 kg.

Ib txheej txheem ntawm cov plywood uas muaj qhov ntev 2440x1200 mm thiab tuab 4 mm hnyav 7.7 kg, nrog tuab 21 mm - 40.6 kg.

Saib

Zaj duab xis ntsib plywood tau muab faib ua ob peb hom nyob ntawm nws cov yam ntxwv thiab cov khoom siv rau nws tsim khoom.

Los ntawm cov khoom siv ntawm kev tsim khoom

Qee cov ntoo tawv tawv, tshwj xeeb tshaj yog cov ntoo, yog qhov zoo tshaj rau kev ua plywood-resistant plywood. Nws muaj ntau cov lignin - lub ntuj polymer uas muab cov khoom siv dag zog thiab tib lub sijhawm ua kom muaj zog, tiv taus kom ncab thiab zaws . Vim yog cov qauv pore tsim nyog, cov khoom ntawm cov resins thiab cov nplaum tau zoo nkag mus rau hauv cov khoom thiab ua kom tsis muaj nws, muab cov dej noo tsim nyog tiv taus. Yog li ntawd, raws li GOST 53920-2010, cov khoom lag luam zoo uas tsis muaj dej noo nrog txheej txheej yuav tsum tau ua los ntawm cov ntoo veneer sib xws rau qib siab A thiab B. Cov khoom lag luam no tau cim FOB lossis FOF.

Tus txheej txheem tso cai tsim cov khoom lag luam nrog txheej txheej sab saum toj ntawm cov ntoo thiab cov txheej sab hauv ntawm alder, maple, beech, elm, aspen lossis conifers . Yog tias siv cov ntoo poplar, tom qab ntawd cov khoom ntxiv raug tso cai tsis pub ntau tshaj 10% ntawm tag nrho cov ntawv, vim tias cov ntsiab lus siab dua ntawm cov ntoo xoob no tuaj yeem cuam tshuam tsis zoo rau lub zog thiab kav ntev ntawm plywood. Kev sib xyaw ua ke plywood yog qhov xav tau, uas yog ua los ntawm cov txheej txheej sib txawv ntawm cov ntoo thiab cov ntoo thuv, uas tso cai rau koj los ua ke qhov zoo ntawm cov ntaub ntawv no kom tau txais tus nqi pheej yig thiab zoo plywood ntawv. Txhua tus ntoo thuv plywood kuj tseem tsim tau. Ntoo coniferous, vim nws cov qauv, tsis muaj qhov cuam tshuam rau impregnation, yog li ntawd, nyob rau hauv cov nqe lus ntawm kev tiv thaiv noo noo, xws li plywood yuav qis dua birch. Tab sis ntawm qhov tod tes, nws hnyav dua qhov hnyav thiab pheej yig, yog li ntawd nws zoo heev rau cov haujlwm uas xav tau cov khoom siv tau yooj yim thiab txhim khu kev qha - piv txwv li, rau kev vov tsev, cladding.

Los ntawm hom kev sib koom ua ke

Kev nyab xeeb kev noj qab haus huv tau txiav txim siab tsis yog tsuas yog los ntawm cov veneer thiab cov khoom siv laminate, tab sis kuj los ntawm cov muaj pes tsawg leeg uas cov veneer tau pleev xim thiab nplaum. Hom impregnation tau qhia thaum cim plywood:

• FC - urea -formaldehyde;
• FSF - phenol -formaldehyde;
• FBV, FBS - bakelite (phenol -resole).

Rau thaj chaw nyob thiab tsev neeg ua haujlwm, plywood FC thiab FSF tau siv. Plywood FC yog qhov zoo tshaj plaws ib puag ncig ib puag ncig - cov tshuaj urea -formaldehyde muaj cov tshuaj lom tsawg tshaj plaws thiab tsis ua kom sov ntawm chav sov. FSF plywood tau suav tias yog qhov muaj ntau yam tshaj plaws, thiab feem ntau ntawm cov khoom tsim tawm hauv Russia yog hom no.

Cov kua nplaum uas phom sij tshaj plaws, tab sis tseem muab cov khoom ua tau zoo tshaj plaws, yog bakelite; nws tsuas yog siv rau kev xav tau kev lag luam.

Los ntawm hom laminate

Plywood yog laminated nrog phenolic, melamine lossis polyvinyl chloride (PVC) zaj duab xis

• Phenol-formaldehyde zaj duab xis - Kraft ntawv impregnated nrog phenol-formaldehyde cob. Muaj cov yam ntxwv xim xim tsaus nti (yog tias tsis muaj xim xim ntxiv). Cov txheej no yog tuab heev, muab cov dej noo tiv taus, ua haujlwm tau zoo. Tab sis nws tsuas yog siv rau kev ua haujlwm sab hauv thiab sab nraum zoov, vim nws muaj cov tshuaj lom formaldehyde. Tab sis rau kev tsim cov ntawv rov ua dua tshiab thiab thav ntawv ib ntus - qhov no yog qhov kev xaiv zoo tshaj plaws.
• Melamine ntawv ci - Cov ntawv kraft tau pleev xim nrog cov yas melamine-formaldehyde uas muaj kev nyab xeeb dua, uas tsis tso cov tshuaj phem rau hauv chav sov (qis dua 40 ° C). Yog tsis siv cov xim pleev xim, xws li zaj duab xis yog lub teeb daj lossis pob tshab, hauv qab nws cov qauv ntuj ntawm veneer tau pom meej. Xws li plywood sab nrauv zoo li veneered (lamination thiab veneering yog cov thev naus laus zis sib txawv). Tab sis feem ntau cov yeeb yaj kiab tau pleev xim rau ntau yam xim thiab ntxoov, kos duab lossis txawm tias 3D nyem uas ua raws li cov khoom siv ntuj tsim los siv. Xws li plywood tuaj yeem siv hauv thaj chaw nyob, rau kev tsim cov rooj tog.
• Polyvinyl chloride (PVC) zaj duab xis - ib txheej yas yas, uas yog siv rau qhov kub ntawm cov plywood. Qhov no yog ib puag ncig zoo ib puag ncig thiab muaj kev nyab xeeb - raws li cov qauv huv huv, polyvinyl chloride raug tso cai rau kev tsim cov tais diav thiab txawm tias ntim rau pub ntshav. Ib qho ntxiv kom zoo dua ntawm cov yas txheej yog lawv qhov zoo nkauj thiab ntau txoj kev xaiv rau cov xim thiab xim.

Mesh, txheej txheej tiv thaiv plam qee zaum thov ntxiv rau hauv qab laminate. Rau qhov no, tshwj xeeb nplua-mesh polymer mesh tau siv. Kev tiv thaiv plywood yog xav tau rau hauv pem teb hauv tsheb, rau kev tsim ntau yam decking, ntxiv rau kev ua haujlwm. Plywood ntawm hom FSF nrog txheej txheej formaldehyde feem ntau yog siv los ua lub hauv paus.

Los ntawm hom thiab qib ntawm txheej

Cov txheej tuaj yeem ua du lossis corrugated, matte lossis glossy, ib sab lossis siv rau ob sab. Nyob ntawm seb hom txheej txheej, cov cim hauv qab no tau siv:

• F - nto du;
• W - mesh nto;
• SP - du nto rau tha xim;
• U - liab qab veneer tsis muaj txheej.

Raws li qhov ua tau zoo ntawm daim ntawv thov laminate, cov khoom siv, raws li GOST, tau muab faib ua 3 qib

• Qib 1 sib piv rau qhov ua tau zoo tshaj plaws - nto ntawm cov khoom yuav tsum tsis muaj thaj chaw uas tsis yog laminated thiab tsis xws luag;
• Qib 2 tso cai tsis pub ntau tshaj 10% ntawm qhov muag tsis pom kev uas tsis txo cov yam ntxwv ntawm cov khoom;
• cov khoom uas muaj ntau qhov tsis xws luag raug xa mus rau qib qis tshaj, qib 3.

Yog hais tias ob sab muaj qhov sib txawv saum npoo, ob qhov txiaj ntsig tau qhia hauv qhov cim los ntawm kev sib cais. Piv txwv, F / W - zaj duab xis ntsib plywood, npog nrog zaj duab xis du ntawm ib sab thiab ntxig rau lwm qhov, qib 1/2.

Qhov ntev (kho kom raug)

Rau cov ntawv plywood, muaj qhov pom tau zoo qhov ntau thiab tsawg. Tom qab tag nrho daim ntawv plywood loj dua, tsawg dua nws qhov nruj, thiab yog thaj chaw loj dhau, nws yuav khoov zoo li ntawv, deforming hauv nws tus kheej qhov hnyav . Vim li no, zaj duab xis laminated yuav tev tawm, thiab cov plywood nws tus kheej yuav tawg, thiab nws yuav tsis ua cov ntaub ntawv zoo lossis cov rooj tog zaum zoo.

Raws li GOST, cov ntawv tau tsim nrog ob sab ntawm 1200, 1220, 1250, 1500, 1525 hli . Plywood, qhov ntev ntawm ib lossis tag nrho sab uas ntau dua 1525 hli, suav tias yog hom loj. Raws li GOST, nws tau tsim nrog ob sab ntawm 2400, 2440, 2500, 3000, 3050 hli. Qhov loj tshaj plaws yog 2440x1200, 2500x1250, 3000x1500 mm, lawv suav hais tias yog ntau yam ntau yam.

Cov ntawv tuab tuaj yeem yog 4, 6, 9, 12, 15, 18, 20, 21, 30 thiab 40 hli . Hauv cov lus tshaj lij, cov ntaub ntawv txog 12 hli tuab yog hu ua ntawv, ntau dua 12 hli - phaj. Cov neeg tsim khoom kuj tuaj yeem tsim cov ntawv raws li lawv qhov loj me. Ntawm qhov nyiam qhov ntau thiab tsawg hauv qhov ntev thiab dav yog 1525x1830, 1525x2950 mm, hauv tuab - 8, 10, 24, 27 mm. Ntau lub tuam txhab muab cov khoom lag luam zoo li no.

Tsis tas li, plywood tuaj yeem ua rau tus kheej qhov ntau thiab tsawg . Qhov no muaj feem cuam tshuam yog tias koj xav tau daim ntawv plywood ntawm qhov tsis yog-tus qauv qhov ntev thiab nrog cov khoom tshwj xeeb uas tsuas tuaj yeem muab faib rau hauv lub hoobkas. Piv txwv li, plywood nrog qhov ntev atypical, laminated ntawm ob sab thiab xaus, yog xav tau rau kev tsim khoom ntawm lub Hoobkas thiab cov rooj tog tsim qauv, thiab tau siv rau kev teeb tsa lub qhov rais sills.

Tsis tas li ntawv nrog tshwj xeeb qhov ntev thiab txheej txheej yog xav tau rau ntau lub hom phiaj kev lag luam, kev tsim khoom ntim khoom, ntim khoom.

Chaw tsim tshuaj paus

Ntawm Lavxias kev ua lag luam, feem ntau yog cov khoom lag luam hauv tsev thiab Suav, thiab ib feem me me ntawm kev ua lag luam tau tsau rau Finnish plywood. Cov khoom tsim tawm hauv Suav teb yog qhov xav tau vim nws tus nqi qis, tab sis nws qhov zoo tsis tuaj yeem lav tau los ntawm ib yam thiab yuav tsis sib xws nrog qhov tau teev tseg hauv daim ntawv . Koj tuaj yeem hla dhau ob qho khoom lag luam zoo uas ua tau raws li Lavxias thiab cov txheej txheem thoob ntiaj teb, thiab cov khoom lag luam los ntawm qib qib raw khoom, muaj qhov feem pua tseem ceeb ntawm cov ntoo veneer, tsis muaj kev nyab xeeb ntawm kev tso tawm.

Finnish plywood tau suav tias yog kev nyab xeeb tshaj plaws - nws qhov zoo thiab kev phooj ywg zoo tau lees paub los ntawm cov ntawv pov thawj thoob ntiaj teb thiab European . Ib qho ntxiv, Finns tau suav tias yog cov thawj coj hauv ntiaj teb hauv kev lag luam, tsim thiab qhia cov thev naus laus zis tshiab rau hauv kev tsim cov khoom siv ntoo, tshwj xeeb, cov nplaum zoo dua. Tab sis Finnish plywood yog kim dua li cov neeg hauv tsev.

Cov khoom lag luam tsim tawm hauv Russia, feem ntau, tsis txawv ntawm Finnish raws li tus yam ntxwv thiab kev nyab xeeb, ua raws li kev xav tau thoob ntiaj teb thiab GOST tus qauv, yog tsim los ntawm cov khoom siv raw khoom hauv tsev zoo siv cov thev naus laus zis niaj hnub no. Cov npe khoom lag luam yog dav heev, thiab koj tuaj yeem yooj yim nrhiav cov khoom lag luam nrog cov khoom xav tau.

Kev yuav cov khoom siv los ntawm lub tuam txhab paub zoo uas tau txais lub koob npe zoo yog qhov lav ntawm qhov zoo thiab ntseeg tau ntawm cov khoom. Ntawm cov thawj coj Lavxias hais txog ntim thiab zoo ntawm plywood yog Vyatka Plywood Mill, Sveza Group, thiab Zavetluzhie LLC.

Cov ntawv thov

Zaj duab xis ntsib plywood pom nws siv nyob rau hauv ntau yam lag luam

Hauv kev tsim kho ib leeg, laminated plywood yog cov khoom siv tsis tseem ceeb rau kev tsim cov qauv thiab cov ntas ib ntus . Nws tiv taus cov kua ua kua, kev nyuab siab, tuaj yeem ntxuav tau yooj yim nrog cov kuab tshuaj thiab pab txo qis kev ua haujlwm, vim nws tuaj yeem siv tau 50-100 zaug. Koj tsis tuaj yeem txawm yuav cov ntaub ntawv zoo li no, tab sis tsuas yog xauj nws. Nrog nws txoj kev pab, lub hauv paus ntawm cov tsev ntiag tug thiab ntau chav tsev nyob, kab, choj, hauv pem teb tau txhim tsa. Rau kev ua haujlwm, cov ntawv laminated FSF nrog cov tuab ntawm 18-21 hli nrog qhov du lossis ntxaij nto feem ntau siv. Xws li plywood kuj tseem siv dav rau kev tsim kho ib ntus ntu, hauv av, thiab laj kab.

Rau sab nrauv thiab sab hauv kev ua haujlwm tiav, tiv taus cov dej noo thiab tiv taus cov plywood nrog cov txheej laminated du . Tib lub sijhawm, rau kev ua haujlwm sab hauv hauv thaj chaw nyob, nws raug nquahu kom siv FC plywood nrog melamine lossis yas txheej. Nws muaj cov txiaj ntsig zoo tshaj tawm, thaum ua kom tsis muaj dej noo. Nws tuaj yeem siv rau npog ob qho tib si sov thiab ntub thiab chav tsis sov, piv txwv li, lub tsev hauv tebchaws, chav dej. Rau kev dai kom zoo nkauj, feem ntau yog siv daim ntawv nyias nyias ntawm 8-12 mm - lawv muaj qhov ntxim nyiam, qhov hnyav, yooj yim rau txheej txheem, tiv cov hlau txuas.

Tsis tas li, zaj duab xis ntsib plywood tau dav siv los ua txheej txheej rau hauv av screed, cov khoom siv rau kev tsim cov qhov rooj.

Kev tsim cov khoom ntim ruaj khov, tiv taus dej yog lwm thaj chaw uas zaj duab xis ntsib plywood yog qhov tsis tseem ceeb vim nws cov khoom tshwj xeeb . FK plywood nrog txheej yas tau tso cai siv rau kev thauj khoom noj, tshuaj thiab khoom siv kho mob. Nws ntseeg tau tiv thaiv cov khoom thauj, tsis ua kom puas thaum cov kua txiv hmab txiv ntoo lossis cov khoom lag luam tshuaj tsoo saum npoo, thiab muaj cov kab mob tua kab mob. Ua tsaug rau cov yam ntxwv no, laminated plywood feem ntau siv los ua cov txee thiab tso saib cov ntaub ntawv rau cov chaw muag tshuaj thiab khw muag khoom, cov chaw khaws khoom, cov khoom rau khaws cov tshuaj hauv tsev. Rau cov haujlwm no, ob daim nyias nyias 6 thiab 9 hli tau siv, nrog rau tuab 30-40 hli - nws txhua yam nyob ntawm qhov hnyav thiab qhov ntev ntawm cov khoom thauj lossis qhov hnyav uas lub txee yuav tsum tiv taus.

Hauv kev lag luam thauj mus los, nws yog ib qho tseem ceeb kom ua kom qhov hnyav ntawm cov qauv tsim kom ntau li ntau tau yam tsis muaj kev poob nws txoj kev nyab xeeb thiab kev ntseeg tau . Zaj duab xis ntsib plywood ua txoj haujlwm no zoo. Cov phab ntsa thiab cov qhov rooj ntawm cov tsheb thauj khoom, cov tsheb thauj khoom ib nrab, npog cov tsheb ciav hlau, cov nkoj thiab dej hiav txwv tau tsim los ntawm FSF cov ntawv nrog tuab ntawm 18-30 hli. Mesh non-slip plywood yog qhov zoo tshaj plaws rau hauv pem teb hauv pej xeem thiab tsheb lag luam. Cov rooj thauj mus los rau pej xeem kuj feem ntau yog ua los ntawm laminated plywood. Nyias 6mm plywood yog siv rau cladding tsheb txias thiab cov tub yees muaj.

Hauv kev tsim khoom ntawm lub Hoobkas thiab tsim rooj tog, laminated plywood tau siv dav heev niaj hnub no . - nws suav nrog kev nyab xeeb zoo, tus nqi qis thiab cov txuj ci zoo nkauj thiab cov yam ntxwv zoo nkauj, zoo nyob hauv txhua qhov chaw. Bearing phab ntsa thiab qhov rooj ntawm cov rooj tog hauv txee, txee rau yam hnyav yog ua los ntawm plywood FC nrog tuab ntawm 20-30 hli. Cov plywood nyias (4-6 hli) tau siv rau sab nraub qaum. Cov khoom 15-21 hli yog qhov tsim nyog rau tsim cov txee txheem. Lub tsev tsim muaj npe nrov los ntawm thoob plaws lub ntiaj teb nquag siv laminated plywood hauv lawv cov phiaj xwm.