Machining and finishing of aluminium - BWB

SURFACE TREATMENT ENgINEERINg FOR 

ARCHITECTURE & DESIgN 

Machining and finishing of aluminium

02_ ANODISINg bY bwb 

THE ADVANTAgES OF 

ANODISINg

The BWB anodising procedures (electrolytic oxidation) combine the advantages 

of the electrochemically produced aluminium oxide layer with the aesthetic 

virtues of coloured aluminium in architecture and design. With the BWB anodising 

and colouration techniques, the aluminium retains its metallic nature. 

Corrosion resistance 

Anodising the aluminium produces a resilient 

and corrosionresistant protective layer. This 

ensures that components retain their value 

over decades. 

Colour retention 

With the BWB colouration techniques, the dye 

sits inside the pores of the anodised layer. 

Unique to the “Permalux” procedure, the 

colour effect is achieved by means of the integral 

layer structure. In the subsequent sealing 

process, all pores are closed. This results in 

extraordinarily high colourfastness. 

Light resistance 

The lightfastness of the dyes used is considerably 

higher than the highest value on the 

“Blue Scale” as per ISO 21352010 and complies 

with the EURAS guidelines. 

All colours exhibit excellent light resistance. 

Investment in the future 

The mechanical strength of anodised aluminium 

is very high. Even during slightly 

abrasive cleaning of the aluminium, the surface 

is not damaged. 

With proper maintenance, anodised aluminium 

parts retain their decorative value 

and metallic nature for decades. 

Ecology / recycling 

Comprehensive evaluation of economic and 

ecological aspects speaks in favour of the 

use of anodised aluminium as a material in 

architecture. 

Anodised aluminium also stands out due to 

lowemission colouration techniques, the high 

degree of recyclability and the very high stability 

of value.

04 _ SURFACE CONVERSION pROCEDURES 

SURFACE CONVERSION 

pROCEDURES 

FOR ARCHITECTURE AND DESIgN

BWB carries out a very wide range of surface conversion procedures on components 

for architecture and design, in order to satisfy a variety of requirements 

regarding function, aesthetics and corrosion protection. 

Anodising 

Electrolytic oxidation – also known as anodising 

– is an electrochemical process: the surface 

of the aluminium is converted into aluminium 

oxide from the inside out. This oxide 

layer is solidly attached to the base material; 

to use a metaphor, it “gets under its skin”. 

An accurate topographical copy of the original 

structure is created, and the surface retains 

its metallic look. 

With the multitude of anodising procedures 

offered by BWB, it is possible to produce oxide 

layers with very different properties. Thus, 

procedurespecific oxide layers with different 

thicknesses and colours can be manufactured 

to satisfy the respective requirements. 

Sealing 

With electrochemically produced oxide layers, 

the pores of the oxide layer are closed in a 

subsequent operation. This makes it very difficult 

for foreign matter, such as dust or dirt, to 

adhere to the surface, and causes the surface 

to become tackfree. Before sealing, adsorbed 

chromophoric materials are embedded and 

fixed within the oxide layer. The wellsealed 

oxide layer is enormously important for a topquality 

surface on the work piece (weather 

resistance, etc.). For this reason, sealing is 

monitored in a correspondingly strict manner. 

BWB offers the following electrolytic 

surface conversion procedures for 

architecture and design: 

• Anodising / electrolytic oxidation 

• Permalux colour hard anodising 

• Colouration 

– Sanodal 

– Bronze 

– Sandalor 

– Colinal 

– Spectrocolor

06 _ pRE-TREATMENTS AND pOST-TREATMENTS FOR ANODISINg 

pRE-TREATMENTS AND 

pOST-TREATMENTS 

FOR ANODISINg – ALL FROM A SINgLE SOURCE

A clean surface on the work piece is a precondition for an even and stable 

surface finish. BWB offers competent advice, for optimal fulfilment of the customer’s 

wishes and ideas. 

Mechanical pre-treatments 

A mechanical pretreatment is recommended 

in the event of damage, faults or irregularities 

in a surface. However, it is also used in order 

to achieve a special finish and implemented 

with the following surface processing procedures. 

The surface thus becomes matt or polished, 

depending on the selected procedure: 

• E1 grinding* 

(light grinding for matt etching) 

• E2 brushing* 

(light grinding and brushing) 

• E3 polishing* 

(polishing) 

• E4 grinding and brushing* 

(clean grinding and brushing) 

• E5 grinding and polishing* 

(clean grinding and polishing) 

Chemical pre-treatments 

Chemical or electrochemical finishing of 

aluminium surfaces requires a suitable 

pretreatment. Contamination, corrosion or 

minor processing marks must be treated or 

concealed in a chemical pretreatment. Here, 

BWB offers the following procedures: 

• E0 degreasing and deoxidising* 

(industry anodising) 

• E6 etching* 

(matt etching) 

Post-treatments 

BWB offers the following posttreatment 

methods for components: 

• Antinoise coatings 

• Film coating 

Q labels 

• EGR7S 

• QUALANOD 

• British Standard 

• SSG Structural Glazing 

* See glossary on page 11

08_ YOUR pARTNER FOR SURFACE TREATMENT ENgINEERINg 

YOUR pARTNER FOR 

SURFACE TREATMENT 

ENgINEERINg 

COMpETENT, RELIAbLE, EXpERIENCED

As a designer or planner, your requirements vary. Whether for purely functional 

aspects, for aesthetic criteria, or both combined: BWB offers you comprehensive 

advice on material, colour, machining and structural design. 

Material selection 

BWB has longstanding expertise in the selection 

and procurement of the right material 

for demanding projects in architecture and 

design. We advise you when selecting material. 

For decorative applications, aluminium 

alloys of anodising quality must be used. 

Structural design advice 

Early integration of BWB experts into the 

project guarantees a more successful implementation 

of surface finishing. This enables 

typical peculiarities of the respective procedures 

to be accounted for in the structural 

design and integrated into the project in 

good time. 

The bath sizes limit the dimensions of the 

work pieces to be finished. The BWB sales 

team provides you with competent advice in 

this regard. Special attention is also paid to 

welded structures. 

Special effects 

With the interplay of mechanical and chemical 

pretreatments and the different anodising 

procedures, various special effects are 

achieved. The BWB advisors are happy to 

help you. 

Sampling 

The colour chart on the next page can be 

used for initial selection of the colour tone. In 

order to determine the exact colour tone, a 

standard hand sample may be necessary. 

For object sampling, it is advisable to define 

not only the mechanical and chemical pretreatment, 

but also the anodising and colouration 

with the original material.

BWB Natural Colour 

colourless) 

• Layer thicknesses 10, 15, 20, 25 µm 

• Costefficient, environmentally friendly procedure 

BWB Permalux* Integral colouration procedure 

BWB Spectrocolor* 

• Maximum durability, colourplay/lightplay, no chalking 

• The Permalux colours are created during the oxidation 

process and are extraordinarily hard, durable and 

corrosionresistant. 

BWB Colinal Electrolytic colouration procedure 

BWB Sandalor Basis* 

BWB Sandalor Combi* 

BWB Sanodal 

BWB Bronze 

10 _ ALUMINIUM COLOUR CHART 

• Very good colour equality, no chalking 

Adsorptive colouration procedure 

• Bright colours, no chalking 

A combined electrolytic-adsorptive 

colouration procedure 

• Distinctive colours, no chalking 

Adsorptive colouration procedure 

• No chalking 

Combined electrolytic-adsorptive 

colouration procedure 

• Distinctive colours, no chalking 

Interference (colouration procedure) 

• Bright colours, colourplay/lightplay, no chalking 

Natural Colour (colourless) 

EV1 

BWB Permalux P1 BWB Permalux P2 BWB Permalux P3 

BWB Colinal 3115 

( ≈ Euras C 31) 

BWB Spectrocolor 


( ≈ Euras C 32) 

BWB Sandalor C60 1 BWB Sandalor C62 1 


( ≈ Euras C 33) 

BWB Sandalor 

C60 2 C60 3 C60 4 C62 2 C62 3 C62 4 

BWB Argentan 2 BWB Brass 2.5 BWB Gold 3 

BWB Bronze 3 BWB Bronze 4 BWB Bronze 5 

Interference effect 

With the interference colouration procedure Spectrocolor, aluminium surfaces can be given many colours with dazzling lightplay. Surfaces 

with this finish can be used both indoors and outdoors. In order to determine the exact colouring, comprehensive object sampling with 

original material must be carried out. 

* Manufacture in Altenrhein only

BWB Permalux P4 

BWB Colinal 3175 BWB Colinal 3178 

( ≈ Euras C 34) 


( ≈ Euras C 35) 

BWB Sandalor C63 1 BWB Sandalor C64 1 BWB Sandalor C66 1 BWB Sandalor C671 

BWB Argentan 6 BWB Argentan 7 BWB Brass 8 

The colour samples shown in this colour chart 

serve only as orientation. For technical reasons, 

it is impossible to print an exact reproduction of 

how the material appears after anodising and 

colouration of the aluminium. For sampling of 

aluminium components for architecture, contact 

our customer service team. Please note that the 

appearance of metal sheets and profiles can 

vary, even with the same treatment and dye. In 

addition, we refer to the guidelines and quality 

regulations 41.06 for anodised aluminium facade 

components, from the Swiss Centre for Windows 

and Facades (SZFF), as well as DIN 17611. 

BWB Sandalor 

C63 2 C63 3 C63 4 C64 2 C64 3 C66 2 C66 3 C66 4 C67 2 C67 3 C67 4 

BWB Bronze 21 

Glossary 

DIN 17611 

Anodised products of wrought 

aluminium alloys – technical 

conditions for delivery 

E0 

Degreasing 

and deoxidising 

BWB terminology Industry 

anodising 

E1 

Grinding 

Light grinding 

for matt etching 

E2 

Brushing 

Light grinding 

and brushing 

BWB Gold 9 

E3 

Polishing 

E4 

Grinding and 

brushing 

Polishing Clean grinding 

and brushing 

Colour selection 

For architecture, the BWB Group offers you a 

broad palette of colours to choose from, as 

shown on this page. However, in order to evaluate 

colours correctly, we recommend that you 

get us to carry out sampling with original parts 

and with the designated aluminium alloy. 

Do you have any questions? 

You will find answers at www.bwbgroup.com 

by selecting a site under “Contact details” 

and clicking on “Range of services”. 

E5 

Grinding and 

polishing 

Clean grinding 

and polishing 

E6 

Etching 

Matt etching

12 _ www.bwb-gROUp.COM 

BWB Group 

www.bwb-group.com 

YOUR CONTACT p ARTNERS 

BWB is happy to advise you on material selection and procedures 

The BWB Group is your partner for the machining 

and finishing of aluminium 

Due to our wealth of experience in surface treatment engineering, we offer economical 

allinone solutions for architecture, industry and design – from competent 

advice, to material procurement, right through to implementation, delivery and 

assembly. With our production sites, we have good regional support and are always 

where you need us. 

Büren Bätterkinden 

Niederwangen 

StansOberdorf 

BWB-Bürox AG 

Industriestrasse 15 

CH3294 Büren a.A. 

T +41 32 352 04 40 

F +41 32 352 04 49 

bueren@bwbgroup.com 

Schlieren 

Altenrhein 

Gregor Kern 

Sales Manager 

BWB-Altenrhein AG 

I & G Park 

CH9423 Altenrhein 

T +41 71 858 61 46 

F +41 71 858 61 71 

gregor.kern@bwbgroup.com 

concept by www.stier.ch 092.11EN

Machining and finishing of aluminium - BWB

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