Tag Archive for: chromefree

Visit AD Chemicals at the Eurofinish exhibition in Leuven, Belgium (15-16 May 2019). Eurofinish is the largest surface treatment exhibition for the Belgian market. AD Chemicals will be highlighting you all new chromium(VI)-free pre-treatments and passivation products.

Want to register for a free visit? Use our link in combination with registration code: 300432

https://lnkd.in/gjZaGV8

 

AD Chemicals chromefree innovations eurofinish leuven

AD Chemicals will highlight the latest developments in coating and pretreatment at the Surface Campus, 14-11-2018, Brabanthallen Den Bosch, the Netherlands. See the program below:

Register for this seminar for free at: https://surfacecampus.nl/2018/10/10/innovatie-in-coatingproces-voor-opdrachtgevers-chemicalien-en-lakleveranciers/

 

Locatie Conferentieruimte A
Thema Voorbehandeling
Zaalvoorzitter Roland van Meer
13.30 – 14.00 uur Low temperature zinc phosphate: An innovative concept reduces process costs and saves money (Engels)
(meer informatie)
dr. Ulrich Hönig
(Kluthe Benelux)
14.00 – 15.00 uur Combipresentatie: (meer informatie)
Hollandia: Innovatie binnen de conservering van staalconstructies
Wim van ‘t Hof en Nardo Hoogendijk
(Hollandia Infra)
Game changer voor oppervlaktepreparatie voorafgaand aan coatingproces
ing. Roland van Meer
(AD Chemicals)
Blik op innovatie staalconservering vanuit de lakleverancier
Anita Snoeren
(Powder Supply)

Comprehensive congress programme

SURFACE Campus will offer around 75 different lectures in hall 4. Let the stories inspire you. Take master classes to put theory into practice. And present your issues to experts during one of the consultation moments. The congress hall is where you’ll be the first to hear about the latest developments. So be there, if you want to stay up-to-date.

AD Chemicals, together with steel construction company Hollandia Infra have been nominated for the ION Borghardt 2018 award.

The ION Borghardt Award is the acknowledgement for innovation and sustainability. Once every two years, the Ministry of Economic Affairs awards one company that shows how vital sustainability and innovation are in the surface treatment industry.

An independent jury, selected by Stichting Borghardt examines the entries and nominates the ten best ideas to be exhibited at the trade show. The winner will be announced on Tuesday, 13 November 2018. The award show marks the kick-off of SURFACE Campus.

 

ad precoat innovation award

(image copyrights, ION, Netherlands)

 

 

PreCoat Z31 for galvanized steel: First in Europe

AD Chemicals (chemical supplier) and Weert Group (galvanizer and powder coating applicator) are introducing an innovative chromium (VI)- free pretreatment system prior to powder coating on galvanized steel (Duplex-system). Weert Group is the first galvanizer in Europe to implement this new technology that complies with both the GSB and Qualicoat (Approval No. A-119) standard.

For making this innovation possible, there has been a joint research and development trajectory of more than 8 years. The uniqueness of the PreCoat Z31 pretreatment lies in the fact that it is a 1-on-1 replacement for chromium (VI), meaning that all the qualitative properties are sustained (corrosion protection, paint adhesion, passivation). This results in a corrosion protection and paint adhesion of more than 2000 hours of NSS, a performance to be proud of. The expectation of AD Chemicals and Weert Group is that this new system will become the (global) market standard in chromium (VI) free pretreatments on galvanized steel.

 

More innovations from AD Chemicals: PreCoat F31/20 and Z31/20 for grit blasting

AD Chemicals launches a revolutionary new product on the global grit/sand blasting market. Namely, PreCoat F31/20 suitable for treatment of steel and PreCoat Z31/20 for aluminum and galvanized steel. PreCoat is a chemical treatment applied directly after grit/sand blasting or metallization(also referred to as metal spraying). It has two main benefits; by applying the product directly after blasting, a conversion layer is created that substantially improves the adhesion of the painting system (suitable for wet painting and powder coating) and significantly enhances the corrosion-protection resistance properties of the paint system as a whole. The application procedure of PreCoat is very easy and can be integrated in every business process. Furthermore it is developed in compliancy with the Qualisteelcoat, Qualicoat and GSB quality standards. The innovative aspect is that it combines the worlds of mechanical and chemical pre-treatment, enabling a longer product lifetime.

 

Abstract

It is well known now that some well described Qualicoat pretreatment procedures are very critical in obtaining good adhesion of powder coating and sufficient corrosion protection.

Proper etching/pickling to remove the most sensitive Aluminium top layer and sufficient rinsing are two of these important pretreatment steps.

Even though job coaters are following Qualicoat procedures most of the time when adhesion or corrosion issues occur the failure can be found in the pretreatment steps and not in the conversion bath or in the powder coating cycle. It seems that the newly developed Cr (VI) free conversion coatings are less forgiving than former chromate conversion coatings.

AD Chemicals and her customers are working closely together to determine the critical pretreatment steps. Pickling, racking and rinsing procedures can be optimized to guarantee the best performance possible with Cr(VI) free conversion coatings.

In this presentation we will discuss some factors that might influence the quality of your powder coated aluminium.

 

Introduction

Each powder coating line has it´s own challenges. You have to be aware of the best processes prior to the painting of Aluminium objects. Companies often think that it is an easy step to switch their traditional Chromating process to a Chrome (VI) free process. Unfortunately this thought is a big misunderstanding. The starting point must be that a pretreatment line with chromium (VI) is not the same as a chromium (VI) free pretreatment line.

Our opinion is that previous pretreatment lines based on Chromium (VI) had possible processing problems, but the reactivity of the Chromating process had the ability to eliminate the possible defects that occur. The whole pretreatment industry is convinced that Chromium hexavalent has unique properties. Properties like self-healing, corrosion characteristics (For example filiform corrosion) will belong to the past after the sunset date for Chromium (VI) applications in 2017. This radical change requires a different view to the pretreatement lines and it’s chemicals products. “The struggle for pretreatments between raw aluminium and paint”.

The ultimate goal is to work with Chromium (VI) free pretreatments while maintaining the quality properties between Aluminium and paints. Also to meet the required specifications of Qualicoat.

First let’s focus on the variables of the pretreatment line and the quality of the Aluminium.

Concerning the quality of the Aluminium, an assessment of the quality is essential. However, jobcoaters have no influence on this question. They are depending of the Aluminium quality which they received from their sources. The only thing the jobcoater can do is to ask for a quality certificate of the Aluminium or a certificate of analysis of the formation of the Aluminium. Only the structure of the pretreatment line and the chemicals is in control of the jobcoater.

For example: Structure of a Pretreatment line(spraying), chromium (VI) free application

  1. Degreasing /Acid pickling >1.0 g/m2
  2. Rinse
  3. Rinse
  4. D.I. Rinse
  5. Chromium (VI) free pretreatment

 

Stage 1: Pretreatment tunnel, Pickling phase

Due to the increasing demands from Qualicoat (for example, sea-side > 2 g/m2), the pickling rate (etching-rate) has to be increased in the pickling (etching) phase. This means that you have to increase the aggresivity of the chemicals in the pickling phase. Important note is that when there is a stop in the line speed aluminium profile will be exposed by wet pickling solution and aggressive acid vapor. This “pollution” can dehydrate on the Aluminium surface. It is highly recommended to use a water curtain in case of an outage, as this will prevent acid drying effects. Experience has shown that dried-acid residues on the aluminum surface will not be removed totally in the rinsing phases. Residues can be a possible influence for the chromium (VI) free pretreatment. The formulation of the acid pickling is also a factor to prevent acid drying problems. AD Chemicals monitors it’s formulation at costumers to prevent undesirable effects. Other important items to prevent undesirable effects are good maintenance of the spraying nozzles, temperature, spraying pressure, contact time and the build up of the Aluminium content in the pickling solution.

Stage 2 and 3: Pretreatment tunnel, 2x normal rinse (tapwater)

The both rinsing phases are very important. The difficulty in these phases is that the rinsing water reaches all shapes and surfaces. Especially the seams of insulated profiles have to be rinsed well. In the seams acid residues stick and the rinse water flows over the pollution, this effect results in a minimum mixture with rinse water. The temperature of the rinse water is recommended to 18- 20oC, lower temperatures of the rinse water result in more viscous water and the rinsing effect will be less. The quality of the rinse water will be controlled by pH and conductivity.

Stage 4: Pretreatment tunnel, D.I. rinse water

The best rinsing quality will be if the conductivity is < 30µS and with a pH between 4,5 and 6,0.

At these parameters the risk of contaminations on top of the aluminium surface is minimized. This phase is highly important because any pollution can influence the last phase, the chromium (VI) free pretreatment phase.

 

Stage 5: Pretreatment tunnel, Chromium (VI) free pretreatment

The chromium (VI) free preatreatments of AD Chemicals are based on a precipitation reaction, where the conversion layer will be made. This layer is a cross linking layer for organic coatings. The thickness of this layer is very important. A layer that is too thick, results to bad adhesion and will be humidity sensitive.

A layer that is too thin, influences the adhesion at the bending tests. By guaranteeing the parameters like conductivity, pH and concentration, the chromium (VI) free layer can be assured. There are several types of chromium (VI) free pretreatments available for Aluminium. The most common types are based on the reactive groups titanium/zirconium (marked named by chromium free pretreatments) and chromium (III). All those Chromium (VI) replacements confirm the 1000hours Salt Acid Spray, corrosion resistance test requirements of Qualicoat.

 

One very important question bothers AD Chemicals:

“Is the requirement of 1000 hours corrosion resistance which Qualicoat prescribes enough?”

AD Chemicals doubts this statement of Qualicoat. When you only focus on the 1000 hours corrosion resistance, that has been described in the past, Qualicoat is right. However, the corrosion resistance of chromium (VI) based pretreatments fulfills the 2500 hours. This was a fair value for Chromium (VI) based pretreatments on Aluminium. AD Chemicals has investigated their chromium-free systems on the corrosion resistance of 2500 hours and compared it with the traditional chromium(VI) systems.

Internal research shows that the chrome free pretreatment of AD Chemicals precoat CR-FREE A-021, that has been approved since 2003, achieved a corrosion resistance of 2500-3000 hours.

Recently, the latest products of AD Chemicals (Precoat TVL & Precoat COLOR) also achieved the 2500-3000 hours corrosion resistance.

So AD Chemicals goes for long corrosion resistance!!

By proper process optimizations and pursuing the parameters and variables with fine chemicals, Chromium (VI) free pretreatments are perfect replacements of Chromium(VI) based pretreatments.

 

It is well known now that some well described Qualicoat pretreatment procedures are very critical in obtaining good adhesion of powder coating and sufficient corrosion protection.

Proper etching/pickling to remove the most sensitive Aluminium top layer and sufficient rinsing are two of these important pretreatment steps.

Even though job coaters are following Qualicoat procedures most of the time when adhesion or corrosion issues occur the failure can be found in the pretreatment steps and not in the conversion bath or in the powder coating cycle. It seems that the newly developed Cr (VI) free conversion coatings are less forgiving than former chromate conversion coatings.

AD Chemicals and her customers are working closely together to determine the critical pretreatment steps. Pickling, racking and rinsing procedures can be optimized to guarantee the best performance possible with Cr(VI) free conversion coatings.

In this presentation we will discuss some factors

that might influence the quality of your powder coated aluminium.

Introduction

Each powder coating line has it´s own challenges. You have to be aware of the best processes prior to the painting of Aluminium objects. The starting point must be that a

The ultimate goal is to work with Chromium (VI) free pretreatments while maintaining the quality properties between Aluminium and paints. Also to meet the required specifications of Qualicoat.

First let’s focus on the variables of the pretreatment line and the quality of the Aluminium.

Concerning the quality of the Aluminium, an assessment of the quality is essential. However, jobcoaters have no influence on this question. They are depending of the Aluminium quality which they received from their sources. The only thing the jobcoater can do is to ask for a quality certificate of the Aluminium or a certificate of analysis of the formation of the Aluminium. Only the structure of the pretreatment line and the chemicals is in control of the jobcoater.

For example: Structure of a Pretreatment line(spraying), chromium (VI) free application

  1. Degreasing /Acid pickling >1.0 g/m2
  2. Rinse
  3. Rinse
  4. D.I. Rinse
  5. Chromium (VI) free pretreatment

 

Stage 1: Pretreatment tunnel, Pickling phase

Due to the increasing demands from Qualicoat (for example, sea-side > 2 g/m2), the pickling rate (etching-rate) has to be increased in the pickling (etching) phase. This means that you have to increase the aggresivity of the chemicals in the pickling phase. Important note is that when there is a stop in the line speed aluminium profile will be exposed by wet pickling solution and aggressive acid vapor. This “pollution” can dehydrate on the Aluminium surface. It is highly recommended to use a water curtain in case of an outage, as this will prevent acid drying effects. Experience has shown that dried-acid residues on the aluminum surface will not be removed totally in the rinsing phases. Residues can be a possible influence for the chromium (VI) free pretreatment. The formulation of the acid pickling is also a factor to prevent acid drying problems. AD Chemicals monitors it’s formulation at costumers to prevent undesirable effects. Other important items to prevent undesirable effects are good maintenance of the spraying nozzles, temperature, spraying pressure, contact time and the build up of the Aluminium content in the pickling solution.

Stage 2 and 3: Pretreatment tunnel, 2x normal rinse (tapwater)

The both rinsing phases are very important. The difficulty in these phases is that the rinsing water reaches all shapes and surfaces. Especially the seams of insulated profiles have to be rinsed well. In the seams acid residues stick and the rinse water flows over the pollution, this effect results in a minimum mixture with rinse water. The temperature of the rinse water is recommended to 18- 20oC, lower temperatures of the rinse water result in more viscous water and the rinsing effect will be less. The quality of the rinse water will be controlled by pH and conductivity.

Stage 4: Pretreatment tunnel, D.I. rinse water

The best rinsing quality will be if the conductivity is < 30µS and with a pH between 4,5 and 6,0.

At these parameters the risk of contaminations on top of the aluminium surface is minimized. This phase is highly important because any pollution can influence the last phase, the chromium (VI) free pretreatment phase.

 

Stage 5: Pretreatment tunnel, Chromium (VI) free pretreatment

The chromium (VI) free preatreatments of AD Chemicals are based on a precipitation reaction, where the conversion layer will be made. This layer is a cross linking layer for organic coatings. The thickness of this layer is very important. A layer that is too thick, results to bad adhesion and will be humidity sensitive.

A layer that is too thin, influences the adhesion at the bending tests. By guaranteeing the parameters like conductivity, pH and concentration, the chromium (VI) free layer can be assured. There are several types of chromium (VI) free pretreatments available for Aluminium. The most common types are based on the reactive groups titanium/zirconium (marked named by chromium free pretreatments) and chromium (III). All those Chromium (VI) replacements confirm the 1000hours Salt Acid Spray, corrosion resistance test requirements of Qualicoat.

 

One very important question bothers AD Chemicals:

“Is the requirement of 1000 hours corrosion resistance which Qualicoat prescribes enough?”

AD Chemicals doubts this statement of Qualicoat. When you only focus on the 1000 hours corrosion resistance, that has been described in the past, Qualicoat is right. However, the corrosion resistance of chromium (VI) based pretreatments fulfills the 2500 hours. This was a fair value for Chromium (VI) based pretreatments on Aluminium. AD Chemicals has investigated their chromium-free systems on the corrosion resistance of 2500 hours and compared it with the traditional chromium(VI) systems.

 

Internal research shows that the chrome free pretreatment of AD Chemicals precoat CR-FREE A-021, that has been approved since 2003, achieved a corrosion resistance of 2500-3000 hours.

 

The following reaction takes place on the surface:

When there is a good etching in the way that all the oxides are removed of the surface and the alloys are complexed then the layer is ready for the interaction with our PRECOAT CR-FREE. So there will be a interface bonding between our precoat and paint.

By proper process optimizations and pursuing the parameters and variables with fine chemicals, Chromium (VI) free pretreatments are perfect replacements of Chromium(VI) based pretreatments.

precoat chrome free pretreatment qualicoat