Sikafloor®-31 PurCem LP
Sikafloor®-31 PurCem LP is a three part, solvent free, high build, coloured, matt finish, polyurethane modified, cement and aggregate coating with excellent chemical resistance and very good resistance to abrasion and mechanical damage.
Typically applied in two coats for a total of 0.2 - 0.25 mm.
- Excellent chemical resistance. Resists a wide range of organic and inorganic acids, alkalis, amines, salts and solvents.
- Allows use of severe cleaning regimes in the Food and Beverage industry. Please refer to the Chemical Resistance Chart or consult your local Technical Dept.
- Very low VOC emissions
- Water based Odourless formulation.
- Excellent long term wear resistance from a two coat application
- Rapid one step application. Normally, no concrete primer required
- Economical and easy to apply
- Good hiding power
- Tolerant to substrate moisture. Can be applied on to 7 to 10 day old concrete after adequate preparation and with a tensile bond strength in excess of 1.5 N/mm2 (218 psi).
- Bio-static surface. Does not contribute to the growth and development of bacteria or fungi.
- Wide range of application temperatures +10°C - +35°C
Usage
Sikafloor®-31 PurCem LP is designed to be used as:- Stand alone, high build coating or as a seal coat for covings and details performed with Sikafloor®-29 PurCem LP or other products in the Sikafloor®- PurCem range
- To provide an improved aesthetic finish to the products in the broadcast texture range of Sikafloor®-PurCem
- Suitable for concrete protection providing physical resistance (Principle 5, method 5.1 of EN 1504-9)
- Suitable for concrete protection providing chemical resistance (Principle 6, method 6.1 of EN 1504-9)
- Food processing plants, in wet or dry process areas, freezers and coolers
- Pharmaceutical plants
- Containment areas
- Chemical process areas
Advantages
- Excellent chemical resistance. Resists a wide range of organic and inorganic acids, alkalis, amines, salts and solvents.
- Allows use of severe cleaning regimes in the Food and Beverage industry. Please refer to the Chemical Resistance Chart or consult your local Technical Dept.
- Very low VOC emissions
- Water based Odourless formulation.
- Excellent long term wear resistance from a two coat application
- Rapid one step application. Normally, no concrete primer required
- Economical and easy to apply
- Good hiding power
- Tolerant to substrate moisture. Can be applied on to 7 to 10 day old concrete after adequate preparation and with a tensile bond strength in excess of 1.5 N/mm2 (218 psi).
- Bio-static surface. Does not contribute to the growth and development of bacteria or fungi.
- Wide range of application temperatures +10°C - +35°C
Packaging
Part A : 1.60 kg plastic drum
Part B : 1.40 kg plastic jerrycan
Part C : 1.70 kg plastic bags
Part A+B+C : 4.7 kg ready to mix units
Colour
Part A pre-tinted : Coloured liquid
Part B : Brown liquid
Part C : Natural grey powder
Available colours: Cream , Light Grey, Grey, Green, Red
Custom colour matching is available upon request. Minimum order quantities apply.
Please consult the producer for required lead times.
Colour uniformity cannot be completely guaranteed from batch to batch. Do not mix batch numbers in a single area.
Product Details
APPROVALS / STANDARDS
Polyurethane screed for concrete protection according to the requirements of EN 1504-2 for principles 5 (PR) and 6 (CR) as a Coating (C) and Conforms to the requirements of EN 13813: 2002. All other values indicated are internal test results.
Chemical Base
Part A : Water borne polyol and pigments
Part B : Isocyanate
Part C : Aggregates, cement and active fillers
Shelf Life
Part A : 12 months from date of production. Protect from freezing.
Part B : 12 months from date of production. Protect from freezing
Part C : 6 months from date of production. Must be protected from humidity
Storage Conditions
Stored properly in original, unopened and undamaged sealed packaging, in dry If stored properly in original, unopened and undamaged sealed packaging, in dry conditions at temperatures between +20 °C and +30 °C.
Density
| Part A : | ~1.07 kg/L |
| Part B : | ~1.24 kg/L |
| Part C : | ~1.05 kg/L |
Shore D Hardness
| ~80 | (ASTM D 2240) |
Tensile Adhesion Strength
| > 2.0 N/mm2 (failure in concrete) | (EN 1542) |
(1.5 N/mm2 is the minimum pull out strength of the recommended concrete substrate)
Bond Strength after Thermal Shock Resistance Test
| 4.93 ± 0.42 N/mm2 | (EN 1542) |
Reaction to Fire
| Class B(fl) S1 |
Chemical Resistance
Resistant to many chemicals. Please ask for a detailed chemical resistance table.
Permeability to Water Vapour
| To Water Vapour: 0.260 g/h/m2 | (ASTM E-96) |
Thermal Resistance
When applied over Sikafloor®-20 PurCem in 9 mm thickness, Sikafloor®-31 PurCem LP will withstand thermal shock caused by steam cleaning if application is done within 12 hours of application of the screed layer.
Not suitable for steam cleaning or thermal shock exposure as standalone coating.
Skid / Slip Resistance
| Substrate | SRV Dry | SRV Wet |
| Sikafloor®-29 PurCem LP overcoated with Sikafloor®-31 PurCem LP | 65 | 40 |
| Sikafloor®-31 PurCem LP over Sikafloor®-21 PurCem® | 60 - 65 | 35 - 40 |
TRRL Pendulum, Rapra 4S Slider
Application
Mixing Ratio
Part A : B : C = 1 : 1: 1.40 (packaging size = 1.50 : 1.50 : 2.10 ) by weight
Ambient Air Temperature
+10 °C min / +35 °C
Layer Thickness
As Top Coat : 70 microns min. / 140 microns max.
As stand alone coating : 140 microns min. / 275 microns max.
Relative Air Humidity
85 % max.
Dew Point
Beware of condensation!
The substrate and uncured floor must be at least 3 °C above dew point to reduce the risk of condensation or blooming on the floor finish.
Substrate Temperature
+10 °C min / +35 °C
Substrate Moisture Content
The substrate can be dry or damp with no free standing water (saturated surface dry or SSD).
If any moisture is detectable according to ASTM D 4263 (Polyethylene sheet test) for the thin screeds (-21, -22) and the coating (-31), additional tests must be done to quantify actual relative moisture content amount or vapour drive.
Refer to System Structure and options for substrate priming.
Pot Life
| Temperature | Time |
| +10 °C | ~40 - 50 min |
| +20 °C | ~25 - 30 min |
| +30 °C | ~15 - 20 min |
| +35 °C | ~10 - 15 min |
Curing Time
| Substrate | Foot Traffic | Light Traffic | Full Cure |
| +10 °C | ~42 h | ~78 h | ~7 d |
| +20 °C | ~18 h | ~60 h | ~6 d |
| +30 °C | ~12 h | ~48 h | ~4 d |
| +35 °C | ~12 h | ~48 h | ~4 d |
Note: Times are approximate and will be affected by changing ambient and substrate conditions.
Consumption
As seal coat :
Over Sikafloor®-20/21/29PurCem, 0.1 - 0.2 kg/m2 in one coat.
As stand-alone coating:
Over an adequately prepared mineral substrate, 0.1 - 0.2 kg/m2 per coat in two coats.
As integral finish coating:
Over Sikafloor®-21 PurCem, 0.25 - 0.35 kg/m2 for the 45 mesh (355 μm), 0.20 – 0.30 kg/m2 for the 60 mesh (250 μm) and 0.15 – 0.25 kg/m2 for the 80 mesh (180 μm).
These figures are theoretical and do not allow for any additional material due to surface porosity, surface profile, variations in level or wastage etc.
Make sure the substrate is trowelled smooth to prevent any pores from appearing on the surface of Sikafloor®-31 PurCem LP.
MIXING
Material and ambient temperature will affect the mixing process.If necessary, condition the materials for best use to 15°C – 25°C
Homogenise part A with a low speed electric stirrer and then add part B and premix part A and B separately for 30 seconds. Make sure all pigment is uniformly distributed.
Use a double paddle (axis) mixer for best results and gradually add part C (aggregate) to the mixed resin parts over a period of 15 seconds. DON’T DUMP!
Allow part C to blend for further 2 minutes minimum, to ensure complete mixing and a uniform moist mix is obtained. During the operations, scrape down the sides and bottom of the container with a flat or straight edge trowel at least once (parts A+B+C) to ensure complete mixing. Mix full units only.
When adding aggregate to prepare a patching / levelling mortar, gradually add the 6 kg of 2 - 3 mm dry quartz sand immediately after mixing the full set.
Start the pan mixer and gradually add part C (aggregate) to the mixed resin parts over a period of 15 seconds. DON’T DUMP!
Integral finish mixing instructions
When mixing the integral finish system, add the corresponding Silicon Carbide in 5 % by weight of the full set after the rest of the components have been mixed to a homogeneous consistency, and mix for an additional 10 seconds.
Mixing Tools
A low speed electric stirrer (300-400 r.p.m.) and an Exomixer-type mixing paddle (recommended) suited to the size of the mixing container to minimise the air entrapment.
APPLICATION
Prior to application, confirm substrate moisture content, r.h. and dew point.
Application as seal coat on smooth screeds or stand-alone coating.
Apply the mixed Sikafloor®-31 PurCem LP onto the substrate using a short or medium nap roller directly from a paint tray. Push the resin well into the surface, making sure that the coating fully wets the surface, and then pulling back lightly with the roller to the required thickness.
Apply at least two coats when using as stand-alone coating.
When overcoating previously laid Sikafloor®- PurCem screeds a single coat application generally provides sufficient coverage.
Application as seal coat onto broadcast screeds
The most efficient way to apply the seal coat(s) onto broadcast screeds is to pour the material and spread it using a squeegee and then back-roll the excess using a medium knap roller.
Application can also be done with long knap rollers (20 mm).
A slip resistant texture can also be attained by seeding the first coat of Sikafloor®-31 PurCem LP with selected mineral aggregates and then sealing with a second coat.
Application of the integral texture finish.
Decant the mix into a tray and apply from there. Do not pour directly onto the floor as the shadow of the pour will remain. Keep agitating the material in the tray with the roller to avoid settling of the aggregate.
Waiting Time / Overcoatability
Before applying Sikafloor®-31 PurCem LP on Sikafloor®-20 or -21 or -29 PurCem LP allow:
| Substrate | Minimum | Maximum |
| +10 °C | ~24 h | ~72 h |
| +20 °C | ~18 h | ~48 h |
| +30 °C | ~8 h | ~24 h |
| +35 °C | ~6 h | ~24 h |
Times are approximate and will be affected be changing ambient and substrate conditions, particularly temperature and relative humidity.
Always overcoat products which share the same type of part B hardener, as colour differences exist between standard and LP versions
CLEANING OF TOOLS
Clean all tools and application equipment with Thinner C immediately after use.
Hardened / cured material can only be mechanically removed.
CLEANING
To maintain the appearance of the floor after application, Sikafloor®-31 PurCem LP must have all spillages removed immediately and must be regularly cleaned using rotary brushes, mechanical scrubbers, scrubber dryers, high pressure washers, wash and vacuum techniques, etc., using suitable detergents and waxes.