Category Archives: Waxes

UnderstandingofInvestmentCastingWaxes

Investment Casting Waxes

Pattern Waxes:
In investment casting waxes are widely used as a pattern material with few exceptions. As the ultimate quality of castings in this process depends primarily on quality of wax patterns, so it is necessary to understand how best performance of wax – blend can be achieved. For the purpose, we will understand basics of wax moulding process.

Process of pattern – making needs either gravity pouring of molten wax or injection moulding of wax under pressure.

Gravity pouring is practiced when it is not possible to exert pressure on the mould (or only nominal pressure is permitted). In this case pouring is at comparatively high temperature to ensure proper fluidity. Mould material must be specially formulated to achieve low shrinkage values and cavitation to account for this high temperature.

Injection moulding in general, is preferred with semi-liquid or paste form of wax. To replicate the die for wax pattern, it should be filled at as low a temperature as possible to contract minimum on solidification.

Although for special requirements, billet injection is carried out by pressurizing solid blocks in to die, practically, considering mechanical set-up requirement etc. semi-liquid or the paste form is the best choice.

Selection of a wax blend for pattern – making must consider below mentioned points,

  • Should be suitable for injection and other processes in current plant set-up
  • Quality requirement of castings should be fulfilled by pattern performance on injection

While understanding the waxes we should know how the wax will perform in the shop floor condition and what is required to achieve its optimum performance, so it is very important to understand the nature of formulation of pattern – waxes.

Straight, Resin-filled & Water Emulsified Waxes

Normal straight formulation of pattern – wax is prepared from constituents, each of them
melting and forming a homogeneous melt.

When molten wax solidifies, it sets with dimensional shrink and cavitation or dishing effect, to reduce shrinking effects, a component may be added which is called filler and it does not melt but remains in the fine particulate suspension in the wax melt. Filler reduces the tendency to shrink of liquid wax thereby reducing the shrinkage percentage.

For this application, several natural or synthetic chemical entities have been tried in past. But research have resulted in the choice of synthetic resins, often styrene based homo or copolymers till date.
Water emulsified waxes are prepared by making slightly changes in normal straight formulation of pattern waxes so that with suitable emulsifiers, water added in the molten wax forms emulsion in the melt and fine droplets remain dispersed throughout the wax volume.

Water reduces the proportion of liquid which solidifies, reducing the shrinkage by that ratio hence it act as filler also these waxes are also called resin-filled waxes.
Due to function of water as a fillers in water emulsified waxes we can eliminate high initial cost of resin filler and later filler replenishment cost in subsequent cycles for reuse of wax after dewaxing.

Concept of Wax Conditioning:
Homogeneity of wax melt is very important to get good patterns.
The process to achieve the thoroughly homogenized phase of wax is called as ‘conditioning’ Need of wax conditioning arises due to poor thermal conductivity of waxes.
Total wax mass must attain the same physical form viz. semi-liquid, paste etc. and throughout maintain the same temperature. Generally, it is attained by slowly cooling wax molten at higher temperature under continuous agitation. Care must be taken to prevent air entrapment in the process of conditioning.
Conditioning is a very slow process and should be carried out before feeding into injection machine.

For achieving pattern quality is depend on function of injection conditions, wax conditioning, die design considerations, dedicated shop floor practice and very important quality of waxes, We, Saffroshine Organics Pvt,Ltd. is a leading investment casting wax manufacturer our waxes are available in the world market like India, Taiwan, China, Turkey, Germany, USA and other leading countries.

LostWaxInvestmentCastingAdvantages

Lost Wax Investment Casting

Lost Wax Casting:
Lost wax casting is also called as investment casting and is one of the oldest technique carried out to obtain precision casting. Today it is widely used in each and every sector of casting so as to reduce machining cost and obtain fine surface finish because of many impactful advantages and few are listed below:

Design Advantage:

  • Lost Wax investment casting helps to form intricate forms even forms with undercut.
  • Production of wide variety of products across different industries is only possible in lost wax investment casting. (Examples are like a larger-sized product that can be made using investment casting is turbine blades with complex shapes for power generation industries, Blades can be single-crystal, directionally solidified, or conventional equated blades and another example is The firearm industry where investment casting is used for smaller precision parts like firearm receivers, triggers, and hammers.

ACCURACY ADVANTAGE:

  • The accuracy of lost wax investment casting is second to none,
  • Parts with the highest precision can be cast with little to no machining or detailing required.
  • superior surface finish on the castings ( 120 to 150) RMS. Grater alloy selection
  • Helps to enhance performance of casted part.
  • Close tolerances of ± .005” (This is not possible with other types of casting processes.

Cost Reduction Advantage:

  • Lost wax investment casting provides exact shapes which leads to lower material cost.
  • Lost wax investment casting reduces the expensive machining operations that reduces initial tooling cost

The most impactful advantage of lost wax investment casting is environment friendly as it is produced from wax patterns which in most cases can be reclaimed and used again. Because of wax pattern one can eliminate expensive revisions and reducing metal scrap as we can see our part before it get casted.

Now it is very essential to use lost wax in investment casting industry to save environmental changes. We, Saffroshine organics Pvt,Ltd. are leading manufacturer of pattern wax, Our wide range of waxes are economically friendly as they can be used 3 to 5 times without losing any of their properties. and are easiest recyclable wax available in the world market like India, Taiwan, China, Turkey, Germany, USA and other leading countries.

WhatistheLostWaxInvestmentCastingProcess

Lost Wax Casting:
Lost wax casting is also called as investment casting and is one of the oldest technique carried out to obtain precision casting.
Today lost wax casting is widely used in each and every sector of casting so as to reduce machining cost and obtain fine surface finish.

What is The Process of Lost Wax Casting?
In lost – wax casting process wax pattern is coated with refractory ceramic material and ceramic material is hardened its internal geometry which takes the shape of the casting after that wax is melted out and molten metal is poured in the cavity.
The lost wax casting is divided in below mentioned departments for process control of castings.

  • Die/Mold making
  • Wax Pattern making
  • Wax pattern tree
  • Shell building
  • De-waxing
  • Shell firing
  • Casting
  • Refractory ceramic removal
  • Finishing

Die/Mold Making:-For making die it is very important to get perfect drawings of the specimen to get perfect die cavity as per norms

Wax Pattern Making :-After we get a correct die with perfect dimensions wax is injected in the die making is the replica of the final piece which is going to be casted.

Wax Pattern Tree:- Wax patterns dimensions are properly checked using Vernier caliper and are mounted on runner systems using sticky wax and finally it looks like wax pattern tree.

Shell Building :- After the wax pattern are completely stick on the runners they are properly inspected and then are dipped in refractory ceramic material and coated with zircon sand kept for drying and after a cycle of dipping coating and drying a thick layer is formed on the wax patterns which is called ceramic shell

Dewaxing:-After the shell is fully dried they are placed on shell stand and inserted in autoclave dewaxing machine and the wax is taken out from the shell at about 175°C which leaves the same cavity as the wax pattern inside the shell.

Shell Firing :- When the wax is removed from the shell. shell firing is done to remove the remains of the wax and increase the permeability of the shell.

Casting:- As the shell achieves a certain temperature in shell firing furnace the shell is taken out and placed on a sand bed and then the metal is poured in the cavity of the shell.

Refractory Ceramic Removal :- As the metal is cooled down after pouring in shell the shell is set to knocking machine to remove the refractory ceramic and get the final casted parts

Finishing :- the final castings are separated from the runner bars and further taken in machining department where finishing work like fettling, finishing is done of the casted parts. If needed certain heat treatments and surface treatments are given.

What are the Other Uses of Lost Wax Investment Casting Process?
Foundry-men and artists to make intricate sculptures, ornaments and automobiles widely uses the lost-wax casting process from decades. This process is also used for making casting brooches, jewelry, buckles and other small parts used in various industries.

What are the Advantages of the Lost wax Casting Process?
Despite modern ways of casting, foundry-men and artists still prefer the traditional methods of casting. Some of the advantages include –

  • The lost-wax casting process can be used on any material that can melt burn and evaporate to leave behind a mould cavity.
  • The duplicate model will reproduce even minute details of the original sculpture.
  • Allows for unique shapes of casting that would be impossible in other methods.
  • Near net shape castings are produced with high productivity and competitive price.

Hence, the lost wax investment casting process is a seasoned method for the reproduction of various objects.

However, the procedure does have its disadvantages such as the initial cost, need for large machinery and the particularity of holes in the mould. Therefore, it is important to look for expertise, design, performance and cost to get the best quality at the best price.

ComparisonofFilledandUnfilledPatternWaxes

Comparison of Filled and Unfilled Pattern Waxes

Filled and Unfilled Pattern Waxes:
Wax blends have been used for pattern making in Investment Casting process from decades. Initially the wax blends were unfilled or straight Pattern Waxes and they are blend of Paraffin Wax, Micro Crystalline Wax, Natural Waxes like Carnauba and resins, These waxes tends to shrink while solidification due to a pure wax blend.

The shrinkage of the Unfilled Wax is depend on wax temperature, tooling temperature, wax solidification rate and wax injection pressure.

To avoid the shrinkage of the heavy or thick cross section of wax patterns, wax chills are generally used, Wax chills are placed in to the wax cavity before wax pattern injection. These chills should be injected previously of the wax patterns and after Wax Pattern Production, there are chances of occurring chill marks on the wax pattern surface.

Filled Pattern Waxes are having different types of filler materials mixed in the base to avoid surface shrinkage defect also to accelerate the solidification.

Filler materials are solid cross linked polymer are in free-flowing powder condition and mix homogeneously with the base pattern wax.

While solidification of the wax patterns, Filled Patterns solidify fast compared to Wax Patterns produced by Unfilled Pattern Wax because it remain in solid form in the molten wax.

Filler Waxes are preferred for high productivity, better consistency and improved pattern quality and it has limitations of recycling.

Below mentioned are comparison of unfilled and filled pattern waxes,

Criteria Unfilled Pattern Wax Filled Pattern Wax
Simplicity in wax Pattern Production Proper wax conditioning must be done for proper wax pattern production Can be work with wide range of injection temperature
Productivity Unfilled waxes have low productivity because of higher cycle time Filled waxes have better productivity because of low cycle time and solid filler material content
Surface Sink / Dishing Chills must be used for thick cross sections to avoid surface sink / dashing Chills are not required for wide range of thickness as well
Flow Lines Flow lines / Non fill problems may occur due to minor changes in wax temperature No flow lines / Non fill problem and surface quality of wax pattern is good
Ovality and Shape sustaining Chances of ovality, Bending of wax patterns and variation in dimensions may occurs because of uneven cooling rates in variation of cross section Ovality, bending and variation in dimensions avoids due to 30 % to 40% of filler content, solidification of wax pattern mostly complete in the cavity during injection takes place
Process Control Close injection parameters, frequent inspection, process controlled and skilled operator required Wide range of inspection parameters, semi skilled operator, better reliability in dimensional consistency and quality required
Dewaxing and Burnt Out Maximum wax removal is possible while dewaxing and easy / fast burnt out while shell sintering Some quantity of wax tends to remain in the shell cavity after dewaxing also high temperature and longer time required for total burnt out
Recycling Recycling is easy after proper settling, filtration and centrifuge: ash content of used wax can be effectively removed Filled waxes could not be filtered or centrifuged due to filler content and There are limitations for ash removal (Only way to minimize ash content is by settling the wax at controlled temperature)

Considering all above features, Filled Pattern waxes are widely used in Investment Casting Industries, multi cavity dies and tooling can be easily used with Filled Pattern wax and it can be used for small wax pattern to large wax patterns.
Whereas Unfilled Pattern Waxes are used for small to medium size wax patterns.

Saffroshine Pvt. Ltd. is the leading manufacturer and supplier of water soluble waxes in across the world. Please connect with our wax expert for getting customized consulting solutions for your requirement at sales@saffroshine.com or call us at +91-217-2357272.

WhatAreWaterSolubleWaxes?

Water-Soluble-Waxes

Water Soluble Waxes:

Water Soluble Waxes are widely used in investment casting industry and are used to achieve internal cavity in a casting and perfectly suited for making hollow items.

General Properties

  • Water soluble wax is special product used for manufacturing of soluble cores to create critical internal shapes
  • Water soluble waxes can be used for any type of core configuration
  • Water soluble fibers contained formulations can increase strength and resistance to cracking

Advantages of water soluble waxes

  • Water soluble waxes are ease to inject like any other waxes
  • They have good surface finish
  • They have ability to produce many types and shapes of cores dimensions
  • They have excellent dimensional stability.
  • They can be easily leached from the patterns.

How to use water soluble waxes

Water soluble waxes are different to other wax products. They are high in viscosity and have different melting characteristics. Here are some points below which will help you in using a water soluble wax-

 1. Melting of wax.

  •  Melt the wax in a tank till it gets thick liquid
  • While melting the wax should be continuously aggregated or stirred using mixing tools
  • Entrap of air should be avoided while aggregating the wax
  1. Producing of water soluble cores: Use of water soluble cores should be done with care
  •  Care must be taken while filling injection tank and avoid air trap in tank while filling.
  • Injection temperature should be perfectly set to achieve good surface finish of cores
  • Die chilling is very important to increase productivity and avoid shrinkage of cores.
  • For better die release of the core, oil base die release agents or Greece can be used.
  • Injected Water-Soluble Cores must be stored properly avoiding contact with heat and Moisture.
  • Finished Water Soluble Cores can be used for Wax Pattern Production by placing the Soluble Core in to the tooling before injecting the wax.
  • Injected Wax Patterns should be allowed for complete solidification.
  • Water-soluble core should be leached out from the wax pattern with the help of mild acidic water. When the core material comes in contact with acid, dispersing of the core is started. To accelerate this process there should be light stirring of the acid bath. Also the acid should be replaced once it lost its strength.
  • After complete leaching of the core, wax patterns should be inspected properly and used for the production.

 

DISPOSAL:

  • Cores can be removed by immersion in a 10% solution of hydrochloric acid
  • Citric acid may be substituted but this will increase the wax removal time
  • A separate technical advice sheet is available on leaching of water soluble wax products
  • Wash patterns in clean water after removal from tank
  • To prevent deterioration of surface patterns should be stored in an airtight container
  • Any residues should be neutralized with a suitable material and then disposed of with normal foundry waste

Saffroshine Pvt. Ltd. is the leading manufacturer and supplier of water soluble waxes in across the world. Please connect with our wax expert for getting customized consulting solutions for your requirement at sales@saffroshine.com or call us at +91-217-2357272.

TypesofWaxUsedinInvestmentCasting

Types of Wax Used in Investment Casting

Types of Wax:
Investment casting is an oldest manufacturing. It is the proven technology to economically produce metal forms with low tolerance parts, complex geometries and superior surface finish, for achieving these it is very important to use superior waxes at every stages of casting.

It has been used in various forms from decades; earlier beeswax was used to form patterns necessary for the casting process. Today, more advanced waxes are used which are as follows,

  • Filled Pattern waxes
  • Un-filled or Non-filled Pattern waxes
  • Runner waxes
  • Water-soluble waxes
  • Repair Waxes
  • Sticky waxes

 

Filled Pattern Waxes:

Filled pattern waxes are having excellent flow properties and consistent dimensional stability with superior surface finish.

It is suitable for manual as well as automatic production system. It is designed for big to small wax pattern production, It makes special for wax pattern production of Aerospace Parts, Automobile Components, Valve and Impeller Components, General Engineering and other industries.

There are different products which are highly efficient in this category, namely:

  • Filled pattern wax FPWE.30 (Colour: Green)
  • Filled pattern wax FPW.E40 (Colour: Green)

 

Unfilled / Non – Filled Pattern Waxes:

Unfilled pattern waxes are the blends used in filling even the most complex dies, producing sharply defined patterns. And they are used in automotive, golf club and hardware applications like gears, decorative castings.

This waxes have exceptional flow properties, hence the wax is suitable for critical and precision applications. It works perfectly on both manual and automatic production systems. Also it has dimensional consistency which makes this wax suitable for mass production.

Speciality of this wax is simplicity in recycling and sustaining physical properties after dewaxing, these waxes are widely used in automotive, golf club and hardware applications like gears, decorative castings and other industries.

There are different products which are highly efficient in this category, namely:

  • Non Filled pattern wax NFPW.B200 (Colour: Blue)
  • Non Filled pattern wax UPW-E145 (Colour : Green)

 

Runner Waxes:

Runner waxes have excellent mechanical strength, low viscosity and melting point which ease use in assembly of pattern wax.

While dewaxing lower melting helps runner melt first and drain out of the ceramic mould and passage for the thermal expansion of the Wax Patterns which results in cracks free moulds. It has Good operational Soldering strength for avoiding part broken while handling the assemblies and shells.

There are different products which are highly efficient in this category, namely:

  • Runner Waxes UVERCON (Colour: Olive Green)

 

Water Soluble Waxes:

Water Soluble waxes are widely used for making internal intricate cores of the wax patterns. These cores should be placed in wax pattern die. After wax pattern injection, these soluble cores should be dissolved in acid and water solution bath. Surface finish and productivity of these soluble cores is very good.

These waxes are leached before assembling of pattern on runners. There are different products which are highly efficient in this category, namely:

  • SOLCAST

Note: It is an improvised version of regular soluble wax and is fortified with the solubility busters, these special type of accelerating molecules improves the solubility of the wax. This wax has proven  better results when used with water mixed with mild acids.

 

 Repair Waxes:

Repair waxes are paste type wax used to cover the surface defects of the wax patterns. This wax is widely used for repairing the surface defects of the wax pattern, like cavitations, flow lines and non-fills.

There are different products which are highly efficient in this category, namely:

  • REPAIR WAX (Colour: Red)

 

Sticky Waxes:

This is a glue type wax. Sticky Wax provides a very strong joint which reduces the assembly time and makes the process hassle free.

There are different products which are highly efficient in this category, namely:

  • STICKY WAX (Colour: Pale Yellow)

 

Saffroshine Pvt. Ltd. is the leading manufacturer and supplier of pattern wax in India. If you are looking for waxes for your any investment casting solutions, please reach us to our wax expert for getting customised solutions as per your requirement.

 

 

MeasuringtheMeltingPointOfWaxesUsedinInvestmentCasting

The melting point of wax is important to both the wax supplier and the investment casting foundry.

Wax manufacturers run tests as a part of quality control and wax development; foundries run tests on incoming waxes to determine melting time injection temperature and autoclave.

Various organizations have testing methods that are applicable to the investment casting industry such as ASTM1 {American Society for Testing Materials), and ICl2 (Investment Casting Institute). One problem that arises, however, is that melting point means different things to different people.

The melting point is usual1y defined as the temperature at which a substance makes a transition from the solid or semisolid state to the liquid state. In the investment casting industry, there are other terms that are sometimes used synonymously, including congealing point, dropping point, drop melting point, and softening point. Each of these terms, however, has a very specific definition.

The congealing point is defined by the ASTM D938 method as “the temperature at which molten petroleum wax, when allowed to cool under prescribed conditions, ceases to flow.”

The dropping point is defined by ASTMD566 as “the temperature at which the wax passes from a solid to a liquid state.”

The drop melting point is defined by AS”TM 0127 as “the temperature at which material becomes sufficiently fluid to drop from the thermometer.” and lastly, the softening point is defined by ASTM E_8 as “the temperature at which a disk of the sample held within a horizontal ring is forced downward a distance of 1 inch, under the weight of a steel ball as the sample IS heated at st> C (9t>F’) per minute:” The Investment Casting Institute’s Determination of a Softening Point has a similar definition with the exception that it specifies the heating rate of 4° F per minute.

Compounding the problem of determining melting point is the fact that a wax can have many “melting points,” depending on which test method is used.

For this reason, an experiment has been conducted to compare some of the different test methods currently available for determining melting points. Goals of the experiment were to determine which test gave the most reproducible results, which test methods were most applicable, and to compare the results of one test with those of another.

Saffroshine is a 25-year young company, manufacturing Pattern Waxes for Investment Casting Industry. Inert and Stable compositions compatible with various production and dewaxing processes. Better dimensional consistency and consistency of the Pattern Waxes. We are an Indian Manufacturing Company supplying to various Investment Casting Foundries in India and Overseas.