What is Zanite®?
Zanite polymer composite is a blend of pure silicon dioxide ceramic (99.8%) quartz aggregate, specially formulated high strength epoxy resin and selected additives. The natural elliptical shape of quartz is ideal for casting intricate structures.
Zanite replaces traditional materials such as iron, aluminum, and steel used in the manufacture of many structural components. Castings are manufactured to tight finish tolerances, and the resulting base out-performs alternative material in many areas.
Zanite polymer composite is accepted by design engineers throughout the world as an alternative material due to its excellent design flexibility, mechanical properties, and short production time.
Bases are manufactured of Zanite, a proprietary polymer concrete material which is a blend of pure silicon dioxide, ceramic quartz aggregate and high strength epoxy resins. Our Zanite is continually enhanced and tested to insure BaseTek is associated with the best materials on the market today. Our properties are randomly tested for full compliance and exceed all published specifications.
More about Zanite®
Zanite polymer composite is a formulated composite material designed for casting foundations and other structural components. It is a combination of epoxy, quartz aggregate and selected additives. Zanite replaces traditional materials, such as iron, aluminum and steel, used in the manufacture of machine bases.
Zanite dampens vibration approximately 10 times better than cast iron and 45 times better than steel due to steel's higher dynamic stiffness. Reduction of vibration means improved system performance and tool life. Zanite also deadens sound.
Custom linear rails, hydraulic fluid tanks, threaded inserts, cutting fluid and conduit piping can all be integrated into the polymer base. Reduced assembly times are realized by incorporating multiple components into one casting. Zanite does not require a uniform wall thickness allowing for greater design flexibility of your base.
Zanite polymer bases can be cast and shipped within days of receiving an order providing shorter lead times than fabricated steel and cast iron. Plus, Zanite polymer bases reduce costly production time by arriving ready to assembly
Eliminating costly post-cast operations (machining, heat-treating, stress relieving and painting) means Zanite polymer bases cost significantly less than metallic castings. Inventory costs are significantly reduced and less work-in-process (WIP) is required. A competitive advantage to you.
Zanite is environmentally friendly. Zanite bases are created using a cold casting process requiring a minimal amount of energy consumption and are the only process which allows plastic and metal to merge in the same casting while providing excellent thermal stability.
Zanite is chemical and corrosion resistant. Zanite offers excellent strength and chemical resistance to most common solvents, acids, alkalis and cutting fluids. In addition, Zanite polymer bases do not require painting. Zanite polymer composite is accepted by design engineers throughout the world as an alternative material due to its excellent design flexibility, mechanical properties, and short production time.
Properties of Zanite®
|PROPERTIES||U.S. UNITS||S.I. (METRIC)|
|SPECIFIC HEAT||0.23BTU/Lb Degrees F||960J/kg Degrees C|
|COMPRESSIVE STRENGTH||20,000 psi||137 N/mm2|
|DENSITY||0.084 lb/in3||2.3 kg/dm3|
|FLEXURE STRENGTH||3,800 psi||26 N/mm2|
|MODULUS OF ELASTICITY||4.5 x 106 psi||31 KN/mm2|
|TEMPERATURE LIMITS||-50 Degrees F to
220 Degrees F
|-45 Degrees C to
104 Degrees C
|TENSILE STRENGTH||2,100 psi||14.5 N/mm2|
|THERMAL CONDUCTIVITY||11.09 Btu/(h.ft2.
|THERMAL EXPANSION||10.8 x 10-6 in/in Degrees F||2.0 x 10-5 / Degrees C|
|FLAME SPREAD INDEX||Class A (Class I) - 25 or under flame spread
per ASTM E84
Frequently Asked Questions
Zanite polymer composite is a formulation of a high strength epoxy, mixed with a blended quartz aggregate filler. In addition, the system includes chemical additives to improve the strength and durability of the composite.
Very good. The quartz aggregate offers excellent strength and chemical resistance. The epoxy formulation offers excellent resistance to most common solvents, acids, alkalis and cutting fluids.
Things to avoid are thin sections, back taper where tooling must be drawn against the part to be extracted, high tensile loading, shock loading, tapped holes too close to the edge and horizontal surfaces formed by the tooling, thus causing air to be trapped.
The standard Zanite mixture has aggregate up to 0.50" (12.7 mm) in size. The minimum section thickness should be at least two times the aggregate size or 1" (25.4 mm).
One of the major advantages of using Zanite castings is the ability to cast sections of varying thickness without causing internal stresses. Metallic castings require consistent cross section thickness to reduce internal stresses and distortions.
To utilize the Zanite formulation, the part needs to be at least as large as a bread box, about 80 lbs. (36.3 kg). The largest machine tool base we have cast weighed 70,000 lbs. (31.7 MT). The maximum size part is limited only by the ability to ship the part.
The average size part weighs between 800 and 2,000 lbs (363 kg and 907 kg). Smaller parts can be cast, but these are not the ideal type part for us to produce.
Part flatness, hole location, hole diameter and feature measurement are all measures of precision. The precision of the cast part is determined by mold design, mold construction and process variables.
Using a properly designed, high quality steel mold, parts can be cast with a flatness of 0.0025 in/ft (0.006 cm/m), and hole diameters of 0.001 in/ft (0.003 cm/m). When closer tolerances are required, or a low cost mold is to be used, tolerances can be achieved using secondary machining, lapping, grinding or grouting processes.
Casting to tolerance is highly desirable as it eliminates expensive secondary operations. By eliminating secondary operations, the delivery time is expedited, reducing work-in-process inventory and allowing quicker response to customer delivery requirements. Deliveries can be days, instead of months as is typical for metallic components.
In most cases the height of the part is held within +/- 0.25" (6.35 mm ). Parts are usually poured upside down, with the top of the mold open. This cast surface (the bottom of the part) is therefore very rough and not closely controlled.
Where the overall part height is of concern, or all surfaces must be finished, a secondary operation (post casting or machining) can be performed. This will add to the cost of the part.
Most machine tools are subject to compressive loading. Where parts have tensile loading the section thickness should be increased to accommodate the loading. If the section thickness must be kept small, internal reinforcements should be used. These internal reinforcements can be structural rebar, threaded rod, angle iron, fiberglass rebar or any other rigid structure.
Parts can be painted with any commercial paint, including new water base paints. Priming is not necessary as these parts can not rust. It is necessary to properly clean the surface to remove mold release from the part surface or the paint will not stick.
Most Zanite parts are not painted. Unlike metallic structures which rust or corrode, Zanite castings can not rust or corrode and are impervious to most common solvents.
Zanite castings are typically cast black, white or tan. It is possible to cast other colors, but this requires significant production volume and exact color matching is not possible. The part surface finish will exactly duplicate the mold surface, from high gloss, to matte to textured.
All materials creep. With proper part design Zanite parts has a low creep rate. Metallic parts not only creep, but also distort due to internal stresses.
It is important that the Zanite casting be properly designed and processed. Aggregate sizing and proper compaction is necessary to assure minimal air voids, along with solid aggregate contact, thus minimizing creep.
Zanite composite has a density of .082 lb./cu. in. (2.27 g/m? ), approximately the same as aluminum. Because the wall thickness will be greater than an aluminum casting, the part weight will be higher.
Part weight can be reduced by casting foam cores internally. This creates a closed box design that provides a stiffer design than open end cores used in metallic castings.
Weight reduction can also be achieved by using hollow structural forms such as steel box tubing. This not only reduces the weight of the part, but it also adds stiffness.
The density can be increased by using a high density filler, such as iron flakes, ceramic beads or iron ores.
Dowel pin holes are cast directly into the Zanite. The cast hole allows a perfect fit with a slight press fit.
The standard cure rate is 18 hours. For very complex or high precision parts, the cure rate is slowed to 24 hours.
Tapped holes are created by casting threaded inserts into position. These inserts are produced from steel, plated steel, stainless steel and brass.
Tapped hole locations are determined by the mold, which means once a mold is qualified, subsequent part inspection is minimized.
In most instances, the insert is strong enough to allow a grade 8 bolt to be tightened to the proper torque. For extreme bolt loading, the inserts can be anchored deeper into the casting.
The standard inserts have a hexagon external configuration, with a recessed center section to allow anchoring in the composite. Inserts should be kept at least one diameter from the part edge.
Zanite as cast cannot be tapped. If a tapped hole is required after casting, a hole is drilled and a insert is grouted into position using a template. If tapped holes need to be added during the assembly operation, steel pieces should be cast in the relative location.
Zanite castings can be ground using conventional aluminum oxide wheels and coolant to reduce the dust. The surface can also be machined using carbide cutting tools. Secondary machining is not desirable and should be avoided.
Although radiused edges are stronger, it is difficult to produce steel tooling that will result in radiused edges. Fiberglass molds can be used to produce radiused edges on castings.
Low heat transfer allows the base to resist heat transfer. In the case of machine tool bases, this means distortions due to heat build-up in one section, transferring to distort another section, will not occur. Transient heat loads due to outside doors being opened or sun light coming through a window, will have little effect on the base. Metallic structures tend to distort quickly due to minor heat loads.
Where heat transfer is required, vent holes or internal coolant lines can be cast in place.
Zanite is made from a thermal setting polymer, so it will not melt. Like any other common material, the strength decreases as the temperature increases. The strength is only slightly reduced up to 160˚ F (71˚ C). Parts can be used up to 250˚ F (121˚ C), where the strength will be approximately 50% of the room temperature strength.
The cost per pound is not comparable to metallic castings as Zanite parts are cast to finished tolerances, so the cost is for a finished part. Metallic castings are quoted on a cost per pound, but they require secondary machining so the delivered cost per pound is much higher.
Finished Zanite parts sell for $0.75/lb. to $100.00/lb ($1.65/ kg to $220.50/ kg).
PVC piping can be cast-in for wire ways, air venting or coolant flow. Oil lines can be cast-in. Cardboard tubes can be used to reduce weight. Low friction way surfaces can be integrally cast.
Mold cost includes mold design and mold production. Mold design is often supplied free, but can run between $2,500 and $4,500. The mold design belongs to the Zanite Division; the mold belongs to the customer. The mold design effects the part quality, production time and mold life. Polymer casting molds should only be designed by those experienced in the intricacies of the polymer casting technology.
A high quality steel mold typically costs between $6,000 and $90,000.
Molds can be produced from steel plates, aluminum plates, wood, sheet metal or fiberglass. Wood is used for prototype parts for quick delivery. Life expectancy is only one part, although with careful handling several parts can be produced. Tolerances cannot be held, so secondary machining or grouting is necessary to obtain precision.
Fiberglass molds are used for high volume, low precision parts.
Sheet steel molds are used for lower cost, high volume parts. Medium precision parts can be cast in a sheet steel mold, with the proper design.
Aluminum castings are used where the part has an intricate configuration and multiple molds are required.
High precision parts can only be cast using a heavy duty steel mold.
The mold life depends on the mold design, construction and handing. A good quality steel mold should last hundreds of parts, with only minor maintenance. Fiberglass molds will also produce hundreds of parts.
Draft is not necessary, but it can reduce production time. Cast parts can be produced with no draft, negative draft or recesses. High volume parts should be produced in a mold with draft. The tool construction cost is higher for molds with draft.
Draft should be 2∞per side. Molds that have no draft require complete disassembly to extract the part and therefore have a higher production cost.
The Zanite casting process uses much less energy than metallic castings. To produce a metallic casting, iron ore must be mined, smelted, melted for casting, and machined to tolerance. Zanite resins use very little energy to produce and the casting process is done at room temperature.