The Benefits of Omyacarb in Rigid and Flexible PVC 17/06/2013 Gil Morieras Director Marketing Asia Pacific Group Marketing Plastics Oftringen, Switzerland
Table of Contents CaCO3 Basics Thailand Product Portfolio Advantages of Omyacarb in Rigid and plasticized PVC o How to improve gloss and Impact? A special case study Optimized Compounding Process 2
Calcium Carbonate Basics
Origin of Omyacarb Natural source The history of CaCO 3 Rocks (summary): - CaCO 3 rocks formation: CO 2 + Ca 2+ + H 2 O Bioactivity Shells of CaCO 3 Deposits of Shells on Sea-floor Sediments Compaction Chalk Weak Porous Compaction & Cementation Limestone Marble Quarry hard low porosity Transformation under: High T & P Metamorphic stone high purity no porosity very hard Erosion
Calcium Carbonate (CaCO 3 ) Different Types Crystalshape Needle like Cigar like Cube like
Wt-% finer than Selection criteria to find the right product CaCO 3 Most Important Properties Surface Treatment Dispersion Flowability Adsorption Purity Carbonate content Contamination Insolubles Particle Size Distribution Particle size / µm Particle Size Particle Size Distr. Top Cut Median PS Specific Surface
Selection criteria to find the right product Surface treatment Reducing surface tension > better dispersion in the polymer melt > better wetting through polymer melt > reduced adsorption of water > reduced adsorption of processing aids Lower friction of the polymer melt > advantage of stabilisation Improvement of free flowing properties > better conveying behaviour
Thailand Product Portfolio
Thailand Product Portfolio Very Fine treated CaCO3 Omyacarb 95T - LR PVC Profile High Requirements Glossy PVC Pipe Omyacarb 1T - LR PVC Rigid and Soft PVC Flexible Omyacarb 2T - LR PVC Rigid and soft Cost Effectiveness 9
Advantages of Omyacarb in Rigid PVC
Advantages of Omyacarb in rigid PVC Processing properties Mechanical Properties Optical Properties Thermal Conductivity
Omyacarb in Rigid PVC Processing properties affects affects melt homogenisation melt strength viscosity, rheology torque & melt pressure Calcium Carbonate affects time of gelation processability of formulation
Omyacarb in Rigid PVC Mechanical properties Stiffness Impact strength affects Calcium Carbonate
E-Modulus (N/mm 2 ) E-Modulus (N/mm 2 ) Grade evaluation Stiffness Stiffness Stiffness (Youngs Modulus) is mainly affected by the Omyacarb loading increasing loadings of Omyacarb will increase stiffness Youngs Modulus in Rigid PVC with CC 4000 3800 3600 3400 3200 3000 2800 2600 2400 2200 2000 0 5 10 15 20 25 30 35 40 CaCO 3 content (phr) Youngs Modulus in PVC with CC 3400 3200 3000 2800 2600 2400 Stiffness data was obtained at same loading for all tested Omyacarb 2200 Youngs Modulus 15 phr 2000 0 1 2 3 4 5 6 Particle size d50% (microns)
Grade evaluation Impact property Omyacarb 1T to improve impact resistance
Omyacarb in Rigid PVC Optical properties (gloss 60 ) Particle size
Surface finishing of PVC profiles Omyacarb in Rigid PVC The finer the CaCO 3 the better the gloss
Product Comparison a special case study
A special case study - Formulations Chemical characterization Quantity (phr) PVC Resin KW 66 100 Acrylic Impact Modifier 6 Ca/Zn Stabilizer 4.3 12- hydroxy stearic acid 0.2 Polyethylen wax 0.15 Titanium dioxide 3.5 Omyacarb 95 T LR 10/20 Omyacarb 1 T - LR 10/20 Omyacarb 2 T - LR 10/20
A special case study - Gloss
A special case study - Impact
A special case study - impact
Summary Advantages using Omyacarb Increase stiffness Improved impact strength Homogenisation of the PVC melt, optimisation of pigment distribution Reduce die build up / plate out Superior chemical purity Increase output Cost reduction of the formulation - Replacement of PVC resin with Omyacarb - Higher loading lower cost
Optimized Compounding Process
PVC S Porosity
Trial 1 30 phr Omyacarb Trial 1 The components were all added together and mixed for 3 min. The temperature rose to 40 C. SEM (x250) 100 µm Some of the filler and additive particles are on the surface of the PVC particles but many are separate not combined at all. Such a mixture is not homogeneous and will lead to separation during conveying and poor output from the extruder as well as irregular flow.
Trial 2 The mixing time was greatly increased and the final temperature reached 120 C The higher final temperature and the longer mixing time greatly improved the quality of the dry blend. The additive and filler particles were largely in the pores or on the surface of the PVC particles. There was almost no dusting.
Trial 3 The stabilisers and lubricants were added when the temperature of the PVC had reached 50 C i.e. after the pores had opened. The filler was then added at a temperature of 90 C. SEM (x250) 100 µm By adding the stabilisers and lubricants at 50 C, they entered into the pores of the PVC particles. Adding the filler subsequently resulted in almost all of the particles adhering to the surface of the PVC particles or being absorbed into the pores.
Trial 4 The lubricants, which melt at the lowest temperatures, were added at 50 C, followed by the stabilisers at 70 C and finally the fillers at 90 C. The mixing time was 1 minute longer than in the previous trial. SEM (x250) 100 µm This was the best of all. Some white particles are visible on the surface of the PVC particles but the pores have opened sufficiently to admit most of the filler. The bulk density was the highest of all the trials and the flowability of the dry blend overall the highest. The conclusion is that at higher filler levels the mixing time, temperatures and order of addition of the various components play an important role in achieving the best possible dry blend.
Optimized Rigid PVC compounding process Put the PVC powder into the mixer Mix at 30 m / s Add the lubricants at 50 C. Add the stabiliser at 70 C to the mixture mix without speed reduction Mix at 30 m / s Drop the produced dry blend into the cooling chamber at between 120 C and 130 C Add fillers and pigments at 90 C. Mix at 30 m / s Discharge the dry blend from the cooling chamber at 50 C. Manufacturing of PVC-U
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