Smooth-On PMC-serie poly-urethaan elastomeren zijn een begrip in de industriele verwerking van beton en gips
PMC-744 has been used for years by mold making professionals to cast plaster, concrete, resins, etc. It is excellent for making molds that are strong, durable and dimensionally stable. Low viscosity ensures fine detail reproduction.
- PMC-744 is ideal for making ceramic case molds and plaster block molds, reproducing ornamental plaster, making molds for casting concrete, casting a variety of Smooth-On urethane resins, casting wax and making a variety of mechanical rubber parts.
Technical Bulletin
PMC-746 was developed to make molds for casting gypsum plasters. Like PMC-744, this product is well suited for use as a rubber case mold – especially large case molds where extra rigidity is required. Shore hardness is 60 A.
- Because of its durability and moisture resistant properties PMC-746 is also used by zoos and museums for a variety of mold-making, display and exhibit applications. It features a convenient mix ratio (2:1 by weight or volume), and contains no mercury.
- Other applications include making plaster block molds, reproducing ornamental plaster (architectural restoration), pre-cast concrete molds, casting waxes, Smooth-On rigid polyurethanes and epoxies and also for making a variety of special effects for movies and theatres.
Technical Bulletin
PMC ® -770 wordt gemengd twee delen A tegen een deel -B per gewichtsdeel, PMC ® -770 giet gemakkelijk en hardt uit bij kamertemperatuur tot een solide Shore 70A rubberen elke uitzonderlijke kwaliteit en vormvastheid bezit. Het is toepasbaar voor de productie gieting van schurende materialen zoals beton (prefab beton, zoals beton stempels, etc.) en gips die hoge exothermische uitharding hebben. Het is also toepasbaar voor rubber mechanische onderdelen van uiteenlopende configuraties (pakkingen, wielen, katrollen) en kogelmolen liners en trillingen / dempingselementen.
PMC ® -770 - Shore 70A Hardheid
PMC ® -780 Urethaan Rubber
PMC ® -780 is een eersteklas urethaan rubber dat uitzonderlijke sterk, duurzaamheid en slijtvastheid is. Wordt gemengd in twee delen A naar een deel B-gedeelte op gewicht of volume. PMC ® -780 giet gemakkelijk en hardt uit bij kamertemperatuur met verwaarloosbare krimp. Kies degene die het meest geschikt is voor uw toepassing: De Originele PMC ® -780 Dry die geen olie afscheid. PMC-780 WET bevat een ingebouwd lossingmiddel om te helpen bij de lossing van betonnen vormen. Beide worden in de hele wereld gebruikt voor het gieten van abrasieve materialen zoals beton (prefab beton, waardoor beton stampen pads, etc.) en gips met hoge exothermische hitteafstoot. PMC ® -780 Dry wordt ook vaak gebruikt om rubber mechanische onderdelen van verschillende configuraties (pakkingen, wielen, katrollen) evenals kogelmolen liners en trillingen / schokken pads maken.
PMC ® -780 DRY en PMC ® -780 WET - Shore 80A hardheid
PMC®-780 Dry is also commonly used to make rubber mechanical parts of varying configurations (gaskets, wheels, pulleys) as well as ball mill liners and vibration/shock pads. PMC®-780 Dry does not exude an oil.
PMC®-780 is a premium performance urethane rubber that offers exceptional strength, durability and abrasion resistance.
Shore 80A hardness
mixed two parts A to one part B by weight
negligible shrinkage
PMC ® -790 Urethaan Rubber
PMC ® -790 is een industriële urethaan rubber die is ontworpen om aan de strengste eisen van de industriële productie toepassingen te voldoen. Het is een zeer harde rubber die superieure scheur-en treksterkte evenals slijtage weerstand biedt. PMC ® -790 is ook geschikt voor een verscheidenheid aan industriële toepassingen, waaronder het maken van beton stempels, moulagevullers en mallen voor het gieten van beton. PMC ® -790 is ook goed voor het maken van kogelmolen liners, industriële rollen en riemen, rubberen mechanische onderdelen.
PMC ® -790 - Shore 90A hardheid
PMC | A:B mixing ratio | Demold Time | Elongation at Break | Mixed Viscosity | Pot Life | Shore A Hardness | Tear Strength | Specific Gravity kg/lt |
744 | 2:1 weight/ volume | 16 hrs | 400 % | 3400 cps | 15 min | 44 A | 90 pli | 1,000 |
746 | 2:1 weight/ volume | 16 hrs | 650 % | 1200 cps | 15 min | 60 A | 100 pli | 1,000 |
770 | 2:1 by weight | 16 hrs | 600% | 3000 cps | 35 min | 70 A | 160 pli | 1,015 |
780 | 2:1 weight/ volume | 48 hrs | 700% | 2000 cps | 25 min | 80 A | 200 pli | 1,015 |
790 | 2:1 weight/ volume | 48 hrs | 600 % | 3000 cps | 20 min | 90 A | 300 pli | 1,068 |
Preparation - Materials should be stored and used in at room (73°F/23°C). Humidity should be low. These products have a limited shelf life and should be used as soon as possible. Wear safety glasses, long sleeves and rubber gloves to minimize contamination risk. Good ventilation (room size) is necessary.
Some Materials Must Be Sealed - To prevent adhesion between the rubber and model surface, models made of porous materials (gypsum plasters, concrete, wood, stone, etc.) must be sealed prior to applying a release agent. SuperSeal® or One Step® (available from Smooth-On) are fast drying sealers suitable for sealing porous surfaces without interfering with surface detail. Shellac is suitable for rough contours. A high quality Shellac is suitable for sealing modeling clays that contain sulfur or moisture (water based). Thermoplastics (polystyrene) must also be sealed with shellac or PVA.
In all cases, the sealing agent should be applied and allowed to completely dry prior to applying a release agent.
Non-Porous Surfaces - Metal, glass, hard plastics, sulfur free clays, etc. require only a release agent.
Applying A Release Agent - A release agent is necessary to facilitate demolding when casting into or over most surfaces. Use a release agent made specifically for mold making (Universal® Mold Release). A liberal coat of release agent should be applied onto all surfaces that will contact the rubber.
IMPORTANT: To ensure thorough coverage, lightly brush the release agent with a soft brush over all surfaces of the model. Follow with a light mist coating and let dry for 30 minutes.
Because no two applications are quite the same, a small test application to determine suitability for your project is recommended if performance of this material is in question.
IMPORTANT: Shelf life of product is reduced after opening. Remaining product should be used as soon as possible. Immediately replacing the lids on both containers after dispensing product will help prolong the shelf life of the unused product. XTEND-IT® Dry Gas Blanket (available from Smooth-On) will significantly prolong the shelf life of unused liquid urethane products.
MEASURING & MIXING - Liquid urethanes are moisture sensitive and will absorb atmospheric moisture. Mixing tools and containers should be clean and made of metal, glass or plastic. Materials should be stored and used in a warm environment (73°F/23°C).
IMPORTANT: Pre Mix the Part B before using. After dispensing equal amounts of Parts A and B into mixing container, mix thoroughly for at least 3 minutes making sure that you scrape the sides and bottom of the mixing container several times.
If Mixing Large Quantities (16 lbs./7 kg. or more) at one time, use a mechanical mixer (i.e. Squirrel Mixer or equal) for 3 minutes followed by careful hand mixing for one minute as directed above. Then, pour entire quantity into a new, clean mixing container and do it all over again.
Although this product is formulated to minimize air bubbles in the cured rubber, vacuum degassing will further reduce entrapped air. A pressure casting technique using a pressure chamber can yield totally bubble free castings. Contact Smooth-On or your distributor for further information about vacuum degassing or pressure casting.
Pouring - For best results, pour your mixture in a single spot at the lowest point of the containment field. Let the rubber seek its level up and over the model. A uniform flow will help minimize entrapped air. The liquid rubber should level off at least 1/2” (1.3 cm) over the highest point of the model surface.
Curing - Allow rubber to cure overnight (at least 16 hours) at room temperature (73°F/23°C) before demolding. Cure time can be reduced with mild heat or by adding Smooth-On “Kick-It®” Cure Accelerator. Do not cure rubber where temperature is less than 65°F/18°C.
Post Curing - After rubber has cured at room temperature, heating the rubber to 150°F (65°C) for 4 to 8 hours will increase physical properties and performance.
Using The Mold - If using as a mold material, a release agent should be applied to the mold before each casting. The type of release agent to use depends on the material being cast. The proper release agent for wax, liquid rubber or thermosetting materials (i.e. Smooth-On liquid plastics) is a spray release made specifically for mold making (available from Smooth-On or your distributor). Prior to casting gypsum plaster materials, sponge the mold with a soap solution for better plaster flow and easy release. In & Out® II Water Based Release Concentrate (available from Smooth-On) is recommended for releasing abrasive materials like concrete.
Performance & Storage - Fully cured rubber is tough, durable and will perform if properly used and stored. The physical life of the rubber depends on how you use it. Shrinkage will be higher with wet vs. dry rubbers. Contact Smooth-On directly with questions about this material relative to your application.
Hier vindt u onze produkten gerangschikt naar diverse toepassingsmogelijkheden, zoals: Lifecasting, boetseren, afvormen, gieten, make-up, stuntwerk, dentaalwerk en studie.