Specialized Binder Systems and Additives for

Complex Foundry Applications

2nd South African Metal Casting Conference P. GröningWFO Technical Forum 2017

Agenda

Introduction

Modern Cold-Box Systems

Special Properties – Elasticity / Deformation

Emissions – Gas / Smell / Fume

Additives

Conclusion

2

General Requirements – Foundry Industry

Technical Growing complexity, increased

core intensity Reduction of casting weight Casting walls becoming thinner Low dimensional tolerances

3

Political / Developments Environmental legislation Decreasing acceptance of

residents Printing cores and metal! E-Mobility

Application Requirements

4

Advanced Cold-Box binder

Inorganic core sand additive

Thin coating layer

Source : Eisenwerk Brühl Germany

Modern Cold-Box Systems - Profile

Standard Properties

High strength level

High productivity

5

Special Needs Low gas evolution

Low Emissions

Elasticity

High thermal stability

Problem of modern Binder & Production Technology

Source : Eisenwerk Brühl Germany

Common assembly technologies Screwing Glueing Staple Gun (Tacker)

6

Elasticity Cold-Box Generations

7

Gen 1 Gen 2 Gen 3 Gen 4

Aliphatic SolventsSilicatic Solvents

Matrix Elasticity / Flexibility

8

Very strong but not flexible

Very strong and flexible

Not flexible and not strong

Flexible but not strong

Force

Way

Source : Jung Instruments

Comparison Cold-Box Binder Type

9

0

20

40

60

80

100

120

140

160

0 0,2 0,4 0,6 0,8 1 1,2

Forc

e in

N

Way in mm

Bio 0,8/0,8

Bio 0,8/0,8

Silikat 0,8/0,8

Silikat 0,8/0,8

Elasticity Aliphatic

Aliphatic

Silicatic

Silicatic

Elasticity Modification Cold-Box System

10

0

20

40

60

80

100

120

140

160

0 0,2 0,4 0,6 0,8 1

Forc

e in

N

Way in mm

1 WM 10 / 2WM 10

1 WM 10 / 2WM 10

1 WM 12/ 2WM 12

1 WM 12/ 2WM 12modified

unmodified

modified

unmodified

unmodified

Cold-Box Process - Sipurid

New generation Cold Box - Properties1. OH groups reduced

> Viscosity of the base resin is reduced> Less solvent required – 50%

2. Increased molecular mass> Amount of isocyanate can be reduced

3. Silicate embedded in resin matrix – chemical bond> Improved thermal stability> Less organic in the resin / system> Less emission (gas, odour, condensates)

11

Sipurid – CB System

12

0%10%20%30%40%50%60%70%80%90%

100%

Cold-Box Standard P 1 Cold-Box Standard P 2 Cold-Box Sipurid P 1 Cold-Box Sipuriud P 2

Base Base + TEOS Solvents aromatic/aliphatic Solvents TEOS Additives

Examination Thermal Deformation

13

Measuring device outside heating oven

Source : IFG Düsseldorf

Thermal Deformation – Results

14

0,00000

0,00010

0,00020

0,00030

0,00040

0,00050

0,00060

0,00070

0,00080

0,00090

0,00

0,50

1,00

1,50

2,00

2,50

3,00

3,50

4,00

0 100 200 300 400 500

Eong

atio

n[%

]

Tens

ile S

tress

[N/m

m²]

Temperature [°C]

CB Standard System

Tensile stress Elongation

0

0,0001

0,0002

0,0003

0,0004

0,0005

0,0006

0,0007

0,0008

0,0009

0,00

0,50

1,00

1,50

2,00

2,50

3,00

3,50

4,00

0 100 200 300 400 500

Elon

gatio

n [%

]

Tens

ileSt

ress

[N/m

m²]

Temperatur [°C]

CB deformation reduced System

Tensile Stress Elongation

Casting Examination – Deformation Behaviour

15

Very important property for fragile and complex cores

Standard Cold-Box System Special Cold-Box System

Casting trialAlloy: AluminiumCasting temperature: 750 °CCasting weight: 8 kgCore: Cold-BoxCore dimension: 5,5 mm

Gas Evolution – Binder Systems

16

Gas evolution @ 720°C Gas evolution @ 900°CStandard CB System 183 280gas reduced CB System 1 149 164gas reduced CB System 2 144 124

0

50

100

150

200

250

300m

l

Gas Evolution100 % Silica Sand0,7 % Part 1 0,7 % Part 2

BTX Emissions

17

BTX 900°C aliphatic System 334silicatic System 275silicatic Sipurid System 216

0

50

100

150

200

250

300

350

400m

g/kg

BTX Emissions 100 % Silica Sand0,7 % Part 1 0,7 % Part 2

100 % Silica Sand0,9 % Part 1 Sipurid0,5 % Part 2 Sipurid

Smell and Fume

18

Engine V8 Cold-Box Silicatic-Process

Measuring HoodCasting

Core package

Additives

19

Additives

Organic

Sealed wood or plant based

Carbon basis

Starch - based

Hybrid forms Inorganic

Minerals with a low melting point

Substances with high thermal conduction

Substances with a low expansion

behaviour

Additives

20

Properties inorganic additives No additional gas evolution

No additional pollutant emissions

Controlled sintering behaviour

Uncoated application possible

Addition rate 2-5%

Conclusion

For the succesfull production of complex castings the used binder systemsand additives have to be chosen accordingly

Modern binder systems with low gas evolution and small emission footprint

Additives with controlled sintering properties and low gas evolution

21

Thank You !