Trending Topik

» » Proses Pengecatan (Painting)

Proses Pengecatan (Painting)

Sains, Teknologi dan Ekonomi Bisnis    Sunday, May 19, 2013

Cat terdiri dari beberapa bahan dasar seperti :

  • Resin / Binder / Tedy San Chester (perekat)
Fungsi merekatkan semua komponen yg ada di campuran cat, pembentuk kekerasan dan fleksibilitas cat



“The function to glue all of components on the paint mixture, making paint hardness and flexible”
  • Solvent / Thinner (pelarut)
Fungsi melarutkan / mengencerkan cat, mengontrol waktu pengeringan



“The function to dillute / to solute of paint, controlling drying time”
  • Pigment (pewarna)
 Fungsi pewarna pada cat yg memberikan keindahan dan daya tutup cat



“The function of paint pigment is give beauty and viscosity”
  • Additive (bahan tambahan)
Fungsi menambah bahan agar kualitas dari cat sesuai yg diinginkan, pengkilap (glossy)

Proses-proses pengecatan yg ada pada industri manufactur mobil terdiri dari berbagai macam dan ini adalah pengalaman yg saya dapatkan di lapangan. Umumnya proses pengecatan bodi mobil dimulai sesudah tahap pengelasan (sering disebut Welding off / WE off) dan tahap awal pengecatan (sering disebut Painting on / PA on). Tahap-tahapnya sebagai berikut :



"The painting processes in automotive manufacturing industry consist of various kind and this is an experience that I get on the line factory. Generally painting processes car body is started after welding (often called welding off / WE off) and initial painting (often called painting on / PA on). The stages as follows : "
  1. PA on
  2. Lift up - Pre Treatment - Lift Down - Blowing Air Cleaning
  3. Electro Deposit Oven (ED Oven)
  4. Sealing (Sealer & Melt Sheet - PVC Side Seal - PVC Under Body)
  5. Inspection Sealer - PVC Oven - Final Inspection Sealer
  6. Inspection & Repair Deform - Dry sanding ED - Spray Sanding - Final Dry Sanding
  7. Primer / Surfacer Coat (Eksterior Robot - Manual Interior & Eksterior) - Surfacer Oven
  8. Dry Sanding Primer - Blowing Air Cleaning - Top Coat (Base & Clear Coat)
  9. Base Coat (Interior Manual - Eksterior Robot Coat - Eksterior & Interior Manual)
  10. Clear Coat (Interior Manual - Eksterior Robot Coat - Eksterior & Interior Manual - Top Coat Oven)
  11. Inspection Top Coat & Polishing, kalau OK lanjut ke Inner Wax tapi kalau perlu repair masuk ke Big Repair
  12. Big Repair (Repair Booth - Repair Inspection)
  13. Inner Wax & Painting Body Stock (PBS)
1.  PA on
Dalam tahap ini dari akhir pengelasan (WE off) masuk ke zona pengecatan, disini dilakukan inspeksi cacat pada bodi dan kalau belum bagus akan di repair ke zona pengelasan lagi dan kalau OK lanjut ke tahap berikutnya

"This step is final step of welding and enter into the painting zone, here is done deform inspection and if no good will be repaired to the welding zone again and if OK will go to the next step."

2.  Lift up - Pre Treatment - Lift down
Dari PA on jika OK maka dengan hanggar (hand wipe & jig set) diangkat menuju ke proses selanjutnya yaitu Pre - Treatment (PT). Zona PT mempunyai area pencelupan dan semprotan dan biasanya terdiri dari beberapa kolam yaitu :


"From PA on if OK with hand wipe & jig set is lifted to the next process in Pre Treatment (PT). PT zone has dipping area and spray, usually consist of several pool such as : "
  • Pre Degreasing
Pada tahap ini bodi disemprot oleh air + Fine Cleaner HA dan bertujuan membersihkan awal dari bodi dari kotoran-kotoran yg ada (spidol, gram, oli).


"In this step, body is sprayed by water and has purpose pre cleaning body from impurities."

  • Degreasing
Pencelupan ke air + Fine Cleaner HB dg volume kolam 7000 L yg bertujuan menghilangkan kotoran seperti oli, serpihan logam (gram), lemak dll dan juga utk menjaga wet ability di permukaan logam


"Dipping into water with pool volume is 7000 L and has purpose to remove impurities such as oil, metal flake (gram), grease and also to keep wet ability in the metal surface."
  • Water Rinse 1 (WR 1)
Penyemprotan dan pencelupan oleh air reverse osmosis (RO water) kemudian dicelupkan ke kolam dg volume 69100 L yg bertujuan utk membersihkan permukaan logam dari sisa larutan degreasing, disini dibuat overflow utk mengurangi kadar kontaminasi di tanki akibat pengotor dari degreasing.


"Spraying and dipping by reverse osmosis water then it is dipped in the pool with volume is 69100 L which has purpose to clean metal surface from residue degreasing solution, here made overflow to reduce contaminant degree in the tank that caused by impurities from degreasing."
  • Surface Condition
Pencelupan ke air + larutan Prepalene (PLX - HG) dg volume 69100 L yg bertujuan utk mengkondisikan permukaan logam agar terbentuk lapisan sempurna dan merata di proses selanjutnya dan menutup pori - pori bodi, penggantian larutan dan air setiap hari.


"Dipping into water + Prepalene solution with volume is 69100 L which has purpose to arrange metal surface so will be formed perfect layer and smooth to the next process and close the body pore, substitution of solution and water every day."
  • Phospating
Pencelupan ke larutan Palbond dan terjadi reaksi kimia antara logam dan larutan phospat yg menghasilkan kristal phospate coating (lapisan anti karat).

"Dipping into Palbond solution and happen chemical reaction between metal and phospate solution which produce crystal phospate coating (anti corrosion layer)."
  • Water Rinse 2 (WR 2)
Penyemprotan dan pencelupan ke air bertujuan utk membersihkan permukaan logam dari sisa larutan phospate.



“Spraying and dipping into water has purpose to clean metal surface from residue of phospate solution”
  • Water Rinse 3 (WR 3)
Tujuan sama dengan  WR 2 dan bertujuan utk menyempurnakan pembersihan.


“The purpose like WR 2 and has purpose to perfect cleaning”

  • Demineralized Ion Water (DI Water)
Penyemprotan menggunakan air yg sudah dihilangkan kandungan logamnya utk membersihkan kontaminasi dan ion yg ada pada lapisan phospate di permukaan logam.


“Spraying using water that already removed of metal content to clean contaminations and ions of phospate layer in the metal surface”

  • Electro Deposite (ED)
Pencelupan dg menggunakan larutan Epoxy Polyamide / Powernic dg volume 144000 L dan proses Catodic Electro Deposite (CED) dan dijaga suhu sekitar 28 C, tegangan max 310 - 350 V dan arus max 1000 A. Di tahap ini terjadi reaksi elektrolisis shg larutan akan menempel pada bodi mobil dan melindungi dari karat.


"Dipping using Epoxy Polyamide / Powernic solution with volume is 144000 L and process Catodic Electro Deposite (CED) and keep temperature approximately 28 oC, maximum voltage is 310 - 350 V and maximum intensity is 1000 A. In this step happen electrolite reaction so that solution will patch at body and protect from corrosion."
  • Ultra Filtration (UF) 1 dan 2
Pada tahapan ini bodi yg mengandung larutan ED dibersihkan dg cara dicelup dan larutan disaring ulang dan dikembalikan ke ED, jadi fungsi adalah cleaning and recycle larutan ED


“In this step, car body that contain ED solution will be cleaned with dipped and solution is refiltered and return into ED, so function is cleaning and recycling ED solution”

  • Water Rinse ED
Pencelupan ke DI water utk membersihkan bodi dari larutan sisa ED


“Dipping into DI water to clean car body from residue of ED solution”

  • Pengeringan - Lift Down - Spray Air Cleaning
Sesudah bodi dikeringkan sesaat maka akan turun dari hanggar, dibersihkan menggunakan udara bertekanan dan jalan ke tahap selanjutnya.


“After car body is dried so will drop down from handle, cleaned using compress air and run in the next step”

3.  Electro Deposit Oven (ED Oven)
Memanaskan bodi yang telah mengalami pelapisan di ED agar menempel lebih sempurna dan memberi lapisan yg bagus dan oven dikondisikan 190 C selama 40 menit, diakhir setiap oven selalu ada Air Cooling dari Chiller utk mendinginkan bodi yg keluar.



"Heating body which suffering ED layer so can patch more perfect and give a good layer and condition in the oven 190 oC during 40 minutes, in the end every oven always there is Air Cooling from Chiller to cooling out body."

4.  Sealing (Sealer & Melt Sheet - PVC Side Seal - PVC Under Body)
Dilakukan pemberian lapisan penutup seperti cat (sering disebut Sealer) dan bahan dg nama dagang khusus, dilekatkan pada bagian bodi yg renggang (sekat antara part dg part) utk mencegah kebocoran. Selanjutnya pemberian Melt Sheet yaitu lembaran hitam terbuat dari aspal yang mudah merekat pada bodi mobil utk menahan getaran saat mobil berjalan. Biasanya dipasang pada atas bagian interior (dalam mobil, atas roda mobil dan bagian depan). PVC Side Seal dan PVC Under Body adalah pelapisan menggunakan bahan khusus untuk melindungi area bawah mobil dari benturan benda asing shg bisa terkelupas dan berpotensi karat. Biasanya dipasang pada eksterior roda mobil dan bawah bodi mobil.

"Done given close layer like paint (often called Sealer) and material with specific popular name, patched in the gap of body to prevent leakage. Then giving Melt Sheet, black sheet which is made from asphalt, easy patch to car body to hold vibration while car run. Usually put in the interior car. PVC Side Seal and PVC Under Body is layer using specific material to protect below car body from collision strange material so that can be peeled and has potential corrosion. Usually put in the exterior car body." 

5.  Inspection Sealer - PVC Oven - Final Inspection Sealer
Pengecekan hasil sealing di Inspection Sealer apakah sudah OK, kalau belum diselesaikan terlebih dahulu dan kalau OK lanjut ke PVC Oven utk merekatkan lebih lanjut Sealer agar menempel kuat. Oven dikondisikan 151 C selama 15 menit. Kemudian keluar di cek lagi di Final Inspection Sealer apakah sesudah dipanaskan ada perubahan yg tidak diinginkan dan kalau sudah OK lanjut ke proses selanjutnya.


"Inspection the result of sealing in the Inspection sealer, what is OK, if not yet so will be finished and if OK then to PVC Oven to continue adhesive sealer so strong patch. Oven is kept 151 oC during 15 minutes. Then out and checked if OK then to the next process."

6.  Inspection & Repair Deform - Dry sanding ED - Spray Sanding - Final Dry Sanding
Pengelapan bodi dg lap yg dibasahi wash bensin utk meratakan sealer yg tdk teratur, pengamplasan tepi bodi yg masih kasar dan pengecekan cacat seperti penyok pada bodi dan diperbaiki menggunakan martil di Repair Deform, kemudian kalau sudah OK dilakukan pengamplasan secara manual di Dry sanding ED dg tangan menggunakan kertas amplas dan yg parah menggunakan mesin amplas kemudian dilakukan pembersihan debu sisa amplasan di Spray Sanding. Kemudian dilakukan lagi pengamplasan kecil bodi hasil pemanasan di oven dan penambalan lagi selaer pada daerah yg renggang (menggunakan semprot tangan manual) di Final Dry Sanding.

"Wiping body with lap which is wetted by wash benzene to smooth sealer, sanding of hard edge body and inspection deform and repaired using hammer in the Repair Deform, then if OK done manual sanding in the Dry Sanding ED with manual using sand paper and if not overcame it so using sanding machine then done cleaning residue dust sanding in the Spray Sanding. Then done again small sanding the result of heating in the oven and repair again in the gap area (using manual spray) in the Final Dry Sanding."

7.  Primer / Surfacer Coat (Eksterior Robot - Manual Interior & Eksterior) - Surfacer Oven
Pemberian pelapisan dasar bodi di Primer / Surfacer Coat. Disini terdapat robot yg bertugas menyemprot bagian eksterior bodi kemudian dilanjutkan dengan penyemprotan manual utk bagian eksterior & interior utk menyelesaikan tugas yg tidak bisa dijangkau robot dan dilakukan pemanasan agar pemberian lapisan benar-benar menempel bodi di Surfacer Oven dan oven dikondisikan 170 C selama 30 menit.

"Giving layer in the under body. There is robot has assignment spraying exterior body then continued with manual spraying for exterior and interior to finishing assignment which can't be holded by robot and done heating with purpose layer can patch in the body, oven is conditioned 170 oC during 30 minutes."

8.  Inspection Deform & Sealer - Dry Sanding Primer - Blowing Air Cleaning
Pengecekan cacat penyok yg mungkin masih kelolosan dan penambahan selaer di area yg dibutuhkan di Inspection Deform. Pengamplasan bodi keseluruhan dari cacat, bintik luka dll menggunakan manual dan mesin amplas di Dry sanding Primer kemudian dilakukan pembersihan dari sisa debu amplasan di Blowing Air Cleaning.


"Inspection deform which maybe still through and adding sealer in the area that it is needed. Sanding complete body from deform, pin spot etc using manual and sanding machine then cleaning from residue dust sanding."

9.  Base Coat (Interior Manual - Eksterior Robot Coat - Eksterior & Interior Manual)
Dilakukan penyemprotan bagian interior mobil yg tdk mungkin dijangkau robot dengan manual selanjutnya menyemprot dg robot utk coating bagian eksterior (atap, samping, depan dan belakang bodi mobil) kemudian dilakukan manual menyemprot bodi eksterior dan interior yg mugkin masih belum dijangkau oleh proses sebelumnya. Tujuan dari Base Coat memberikan warna bodi mobil sesuai keinginan, jadi disinilah sebenarnya warna yg kita liat sehari-hari.



"Spraying in interior body which not hold by robot using manual then for eksterior body (roof, side, front, rear body car) using robot and then with manual for interior and exterior body which it is not hold by robot. The purpose of Base Coat is giving color of body according to necessity, so here actual color that we see every day."


10. Clear Coat (Eksterior Robot Coat - Eksterior & Interior Manual - Top Coat Oven)
Pada bagian ini bertujuan utk memberi keindahan pada cat bodi shg tampak mengkilat. Pada bagian ini pengerjaan menggunakan manual utk interior sebelum robot coating dan eksterior dg robot selanjutnya disempurnakan manual utk bagian interior & eksterior yg mungkin masih belum dijangkau proses sebelumnya. Kemudian masuk ke Top Coat Oven utk pengeringan dan mendapat hasil yg bagus, oven dikondisikan 177,5 C selama 30 menit dan diakhir proses sebelum keluar dilengkapi Air Cooling dari Chiller agar bodi yg keluar tdk panas.


"In this area has purpose to give esthetic at the car body so glossy look. Doing using manual for interior before robot coating and exterior with robot and then perfected manually in the interior and exterior which still not hold by last process. Then entering in the Top Coat Oven to drying and get a good result, oven is conditioned 177,5 oC during 30 minutes and in the end process is completed by Air Cooling from Chiller to prevent hot out body."


11.  Inspection Top Coat
Hasil dari top coat diperiksa cacat, baret, dan di ruang ini kalau ada cacat di sanding dan di benerin, dilapisi cairan pengkilat dan keluar terbagi cabang 2 yaitu jika cacat parah masuk ke Big Repair dan jika OK langsung ke Inner Wax


“The result from top coat then be inspection likes deform, scratch etc and this room if there is deform the treatment is sanding then coated with clear coat and out run divided into 2 likes big deform enter into big repair and if OK run into Inner Wax”


12.  Big Repair (Repair Booth - Repair Inspection)
Cacat yg parah masuk ke Repair Booth utk dilakukan perbaikan kemudian masuk ke Repair Inspection utk dilakukan inspeksi dan kalau sudah OK masuk ke Inner Wax


“Big deform run into repair booth to repair then run into repair inspection and if OK run into inner wax”


13.  Inner Wax & Painting Body Stock (PBS)
Pertama ditanbahi Sash Door Tape (pelapisan Tape pada bagian sash door utk keindahan). Bagian yg berlubang dan diperkirakan mudah tergenang air diberikan cairan wax supaya tidak terjadi karat dan kemudian masuk ke PBS utk ditampung sebelum masuk ke proses selanjutnya yaitu Assembling Frame (PA off)


“The first added sash door tape (layering tape in sash door for beauty). Hole part and estimate easy place of collect water then given wax liquid so that no corrosion and then run into PBS for collected into next process assembling frame (PA off)”

Referensi : Pengalaman pribadi manufacturing Japan Automotive Karawang

Previous
« Prev Post
Next
Next Post »

Subscribe to: Post Comments (Atom)