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Die Casting News

NADCA's Congress West Returns! Spotlights Die Casting Lubricant

Posted by Hill and Griffith Company on Dec 13, 2017 2:01:52 PM

Room Block Closes December 21 - Register Today!

From the Dec 13, 2017 Newsletter: 

NADCA is excited to announce the return of Die Casting Congress West on January 11-12, 2018 at the Hilton Long Beach. The Congress will feature technology highlights of our Congress in Atlanta earlier this fall. The event will kick off with a cocktail reception on January 11 and lead into a full day of presentations on January 12.  Presentations to include: 

Session: State of the Industry
An update on the current state of the die casting industry.
Paul Brancaleon, North American Die Casting Association 

Session: Structural
The ability of the die casting industry to improve cast component performance will help die casting continue to be a relevant manufacturing process. Structural die castings have been identified as having the potential to expand markets for die castings by providing improved mechanical properties. Higher strengths and elongations allow die castings to be used as structural, or even crash-worthy, components on automobiles. Research on alloys and heat treatments used in structural die castings will be presented during this session.
Paul Brancaleon, North American Die Casting Association 
 
Session: Die Coatings  
Die casting is a harsh environment for dies and tooling. Heat checking, soldering and wash-out are all issues that die cast tooling faces. Research is being performed on the use of coatings to not only protect the tooling, but also reduce the amount of die spray needed. Protecting the surface of the die, as well as the shot sleeve inner diameter, will extend the life of the die and sleeve, which in turn leads to better quality castings.
Steve Midson, The Midson Group
 
Session: Computer Modeling
To make higher quality die castings the die casting process needs to be understood on a fundamental level. Transforming the basic principles of die casting into mathematical equations, the process can be simulated on a computer. Advances in computer simulation lead to process improvements, improved tooling, and optimum utilization of new alloys.
Al Miller, The Ohio State University

Session: Advanced Technology    
Customers are constantly looking for higher quality parts at lower costs with shorter lead times. There are limits to the benefits of improving process control. Eventually, new technology is required to meet the demands of new products or stricter quality and functional requirements. This session will look at some of those new technologies and how they can be utilized to improve die castings.  
Beau Glim, North American Die Casting Association

The Congress is sponsored by a limited number of Suppliers that attendees will be able to meet with to learn more about products and services available to the die casting industry.

Sponsors Include: 
Thermtronix Corp
BuhlerPrince Inc
Visi-Trak Worldwide, LLC
Frech USA Inc
B&L Information Systems Inc
Oerlikon Balzers
MAGMA Foundry Technologies Inc
Hill and Griffith Co
Hildreth Manufacturing LLC
Midland Technologies, Inc
Anviloy By Astaras Inc
HPM North America Corporation

The cost is just $20 for NADCA Members and $50 for Non-Members (note that registration includes access to the cocktail hour as well as breakfast and lunch on January 12).  In addition, if you will be sending 5 or more people we are offering special pricing.  

Information and registration can be found herePlease note that the housing block closes December 21, so make your reservations right away! If you have any questions please feel free to contact Melisa Ryzner, CMP at mryzner@diecasting.org or 847.808.3161.


A Short History of the Die Casting Lubricant

Die casting has progressed over the last sixty years from small parts of lower melting metals and alloys such as zinc, to castings of large parts, such as tailgates and engine blocks with high-melting alloys of aluminum or magnesium.

The metals are injected into a mold very quickly and under high pressure. The pressure is maintained until solidification, which produces accurate parts with good surface finish. Depending on the alloys, it's possible to obtain a variety of physical and mechanical properties over a range of sizes and weights.

As die casting conditions grow more severe with higher temperatures, pressure and increased part size. Higher performance die casting lubricants are needed to enhance the process, as long as they don’t negatively affect the quality of the casting.

The Hill and Griffith Company is dedicated to providing high performance die casting lubricants, application and management technologies to continue to increase the size, quality and strength of diecast parts and assemblies.


Die Casting Process in Google News:

The global aluminum casting market is projected to reach USD 97.36 billion by 2025

Die Casting Machine Market 2022 | Industry Outlook, Growth, Trends and Forecast in Europe


Hill and Griffith Customer Service

We're known for our hands on approach. Let us visit your plant, offer die casting technical support and recommend release agents, lubricants, plunger lubricants and permanent mold lubricants that suit your needs. Products that represent the latest in technology and ongoing research that enhance competitiveness and increase productivity. 

Read More

Tags: Die Casting, Metal Casting, diecasting, Aluminum Die Casting Process, die casting release agent, die casting lubricant, Die Casting Technical Support, Aluminum Die Casting, Die Casting Tooling Coatings

Application of die casting lubricant

Posted by Hill and Griffith Company on Dec 6, 2017 3:49:04 PM

Proper die casting lubricant and its application ensure that parts eject easily and without defects.

Also called mold release or die spray a precise amount of it is sprayed onto the steel mold before each shot. It evaporates when it comes in contact with the hot steel leaving just the right amount of lubricated coating and required temperature of the mold.

If it cannot evaporate fast enough or if the tool cools too quickly, the molten metal may become more porous. Porosity is always caused by the die casting process. Proper component design, draft, overflows and venting can reduce porosity; as well as specially formulated die release agents.

If there is not enough, the component may stick in the die and cause defects. The larger the draft; the less mold release required. 

Die lubricants are formulated specifically for zinc, aluminum or magnesium and the complexity of the die casting. 

Water-based lubricants provide a release agent and die cooling. Oil-based lubricants may be more appropriate for painted or plated components. It doesn’t provide the same cooling as water-based. Oil-based allows for an increased temperature which may be required for high-quality finishes.


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Tags: Die Casting, Metal Casting, diecasting, Aluminum Die Casting Process, die casting release agent, die casting lubricant, Die Casting Technical Support, Aluminum Die Casting, Die Casting Tooling Coatings

NADCA News: Die Casting Tooling Coatings & Congress West

Posted by Hill and Griffith Company on Nov 29, 2017 3:20:39 PM

Video News Update: Coatings for Die Castings: Conventional Coating Processes

From the November 29, 2017 Newsletter: 

Video News Update: Coatings for Die Castings: Conventional Coating Processes



The material presented in this video are some highlights from NADCA’s online webinar - Coatings for Die Castings: Conventional Coating Processes - presented by Stephen Midson of The Midson Group. Conventional coatings (nitriding, carbonitriding) have been used for some time on die casting dies. This introductory webinar will review these processes, and describe die failure mechanisms (soldering, erosion) they are used to address.

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Tags: Die Casting, Metal Casting, diecasting, Aluminum Die Casting Process, die casting release agent, die casting lubricant, Die Casting Technical Support, Aluminum Die Casting, Die Casting Tooling Coatings

NADCA Video News Update: Die Casting Process Modeling

Posted by Hill and Griffith Company on Nov 22, 2017 12:10:22 PM

The material presented in this video are some highlights from NADCA’s online webinar - Modeling: Die Casting Modeling Capabilities - presented by Charlie Monroe.

From the November 22, 2017 Newsletter

In this course capabilities of die casting process modeling will be reviewed from the current NADCA literature. Common modeling approaches and typical results will be discussed. Topics include: What is simulation, the hows of simulation, and more.

Click here for information.

For information on purchasing a downloadable copy of this webinar in its entirety, please visit: www.diecasting.org/store/detail.aspx?id=WEB072

From the highlight:

 "Once you have a project description and a clear objective for that simulation, the next question is always how detailed do I need to get on those geometries that I need to simulate. The statement at the top basically is saying without the "right" geometry, as produced on the shop floor, you can't expect to get comparable results

I have, let's say, an expected geometry on the top line, and then I have three different options for simulation on the bottom. Everyone may laugh and say the geometry representation on the left is not very good, but if all I'm interested in the solidification time, for instance, perhaps that core doesn't really, or that slide doesn't really take up much of the solidification heat, and so my simplified block is sufficient to give me the overall solidification time, so I know how long the duration is. That would be one option.

Then in the middle section, you can see that I've removed all the draft, and I have included a slide in this case. In that case, maybe the draft didn't influence my results. If I'm not interested in the filling, if I'm only interested in where is the hot spot in this part, that geometry in the center may be sufficient to answer the question.

Then, on the right, I have probably the most faithful representation of that geometry, but again, maybe I'm missing the parting line, or this may give me more inclination about what the fill might be, what is the finished section on the part, but it still might be missing some different pieces. Again, even from this perspective, you can see that with particular forms of the geometry, I can answer questions, but certainly, if I had a question of whether the draft is sufficient, the two cases on the left is not going to be able to answer those problems for me. I have to make sure that I've included the right pieces of the geometry, the drafting, the correct holes if those are actually cast in holes or removed. Those are all questions that need to be answered as you're going through your model.
This is just giving some additional examples of things that could happen. I certainly ran across many of these when I was working with Caterpillar.



When we're asked to, for instance, quote a geometry or think about it, knowing which of those features are the machined features and what additional stock might need to be added if it is a machined feature may be a missing part of the geometry. Certainly, missing features or unanticipated features that are in there can be a problem for getting a realistic answer to the simulation.

The incorrect runner system from what happens on the die versus what happens in our 3D modeling is a problem.

Any lack of venting or thermal lines are all examples of ways we need to reconcile our geometries with the simulation.

In the process of talking to at least one simulation company about their service group, and when you contract service with them, what was the biggest problem that they saw with the simulations and the setups that they were getting, they quoted a number that was fairly high, that it was about 80% of all the problems with non-comparable to simulation results came from the wrong geometry or the wrong mesh that they had.

Again, these are not problems generally. I know I never go into a project where I'm intentionally trying to not simulate the right geometry, but then in the process of ... Normally our simulations are run earlier, and then later we go back, and we have an actual process, going back and validating that what happens in the shop practice versus what happens in our simulation world, it's very important to reconcile so that we can diagnose future problems that we'd end up having.

To purchase access to this course, visit the NADCA Marketplace at www.diecasting.org/store. Purchasing a course through the online education system grants you one year of access to the recording, presentation, support material, and test when applicable.


Die Casting Process in Google News:

Die Casting Machine Market with Geographic Segmentation, Statistical Forecast and Competitive Analysis Report to ...

New Report of Die Casting Machine Market Overview ...


Hill and Griffith Customer Service

We're known for our hands on approach. Let us visit your plant, offer die casting technical support and recommend release agents, lubricants, plunger lubricants and permanent mold lubricants that suit your needs. Products that represent the latest in technology and ongoing research that enhance competitiveness and increase productivity. 

Read More

Tags: Die Casting, Metal Casting, diecast, diecasting, Aluminum Die Casting Process, die casting release agent, die casting lubricant, Die Casting Technical Support, Aluminum Die Casting, Die Casting Process Modeling

Die Casting Release Video of Application by Kawasaki Robotics

Posted by Hill and Griffith Company on Nov 15, 2017 7:19:12 PM

Video shows Kawasaki robots extracting die casting and applying release agent to mold

 

This application shows a Kawasaki F-Series FS45N Robot extracting aluminum parts from a mold. A second Kawasaki F-Series FS10N Robot is utilized to spray mold release agent on the die surfaces. The automated process ensures operators will not be exposed to hazardous emissions or be in harms way of moving machinery.

View die casting release video in YouTube "Mold Extraction with Release Agent Spray - Kawasaki Robotics.Download video link.

"The hot steam and hazardous emissions from die casting machines have been a cause of problems in the aluminum casting process. Kawasaki Robotics offers a viable solution to these serious hazards. First, the Kawasaki FS10N robot sprays the mold with release lubricant prior to start of the casting process. The FS10N robot effectively and completely sprays the entire surface of the casting with release agent. This coating process accurately dispenses a proper amount of release fluid, and the robot ensures that is applied evenly, to only those areas that require lubricant, resulting in a reduction in waste and significant cost savings. 

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Tags: Die Casting, Metal Casting, diecast, diecasting, Aluminum Die Casting Process, die casting release agent, die casting lubricant, Die Casting Technical Support, Aluminum Die Casting

Process Simulation and Optimizing Die Casting Lubricant Spray Patterns

Posted by Hill and Griffith Company on Nov 8, 2017 12:09:05 PM

Learn the Benefits and Limitations of Die Casting Process Modeling and Simulation, including die casting lubricant spray patterns

This series of three NADCA webinars is a brief overview of issues related to modeling and simulation of the die casting process. Emphasis is placed on making a distinction between modeling and simulation and understanding where simplifications necessary to successfully implement simulation software require special attention by the end user.


Part 1 - Background -

The first of three sessions addressing die casting modeling and simulation issues covers basic background material. The relationships between simulation and modeling is introduced with emphasis on the fact that simulation always requires modeling, but modeling does not necessarily require simulation. The concept of simulation is introduced as the numerical solution of models developed from basic models developed primarily from fundamental conservation laws. Modeling issues discussed include definition of problem boundaries, approximation of geometry, restriction of the phenomena (e.g. thermal, flow, stress, etc.) of interest, and the importance of boundary conditions. The special problems presented by widely varying spatial and temporal analysis scales are also introduced.
Date: November 14, 2017



Part 2 - Selected Technical Details -

The basic equations of physics do not change from one simulation package to another, but the solution procedures may vary. Some of the key differences of finite element, finite volume, and finite difference are briefly illustrated and the pros and cons of each are reviewed. Specialized elements available in many general-purpose CAE packages, but generally not available in casting packages, are also illustrated to help understand why questions need to be asked to fully understand how a casting simulation package is generating certain types of results. Geometry and meshing issues and the impact on the solution are considered. Some of the problems inherent in comparing simulation results with casting results are illustrated including the fact that nearly all such comparisons are qualitative. The session concludes with an overview of typical solution rendering techniques and their pros and cons. 
Date: November 15, 2017


Part 3 - Limitations -

This session is a review of the range of modeling simplifications that are used to make simulation tractable, but then require careful interpretation of the results. Included are time-scale issues and transient versus steady state results including temperature creep; modeling of spray; selection of heat transfer coefficients; technical issues modeling heat loss during fill; cooling line performance, and venting performance. The benefits of special purpose models to provide engineering insight to supplement simulation results in select cases is also illustrated. 
Date: November 16, 2017

Purchase a single webinar
Part 1: Die Casting Process Modeling and Simulation – Background
Part 2: Die Casting Process Modeling and Simulation - Selected Technical Details
Part 3: Die Casting Process Modeling and Simulation – Limitations



Purchase access to the entire webinar series
Die Casting Process Modeling and Simulation Webinar Series

These webinars will take place at 1pm CDT on the dates listed. The cost per webinar is $69 for Corporate Members, $99 for Individual Members or $119 for Non-Corporate Members. Please note that registering for a webinar grants you access to the live broadcast on the given date. No recordings or pdfs of the presentation will be issued.

Headquartered in Arlington Heights, IL, the North American Die Casting Association (NADCA) represents the voice of the die casting industry, representing more than 3,100 individual and some 300 corporate members in the United States, Canada and Mexico. NADCA is committed to promoting industry awareness, domestic growth in the global marketplace and member exposure.


Die Casting Process in Google News:

Aluminum Casting Market Size Worth $97.36 Billion by 2025 | CAGR: 7.8%: Grand View Research, Inc.

Global Brazil Automotive Parts Die-Casting Market Outlook, Growth, Demand, Forecast 2017-2022


Hill and Griffith Customer Service

We're known for our hands on approach. Let us visit your plant, offer die casting technical support and recommend release agents, lubricants, plunger lubricants and permanent mold lubricants that suit your needs. Products that represent the latest in technology and ongoing research that enhance competitiveness and increase productivity. 

Read More

Tags: Die Casting, Metal Casting, diecast, diecasting, Aluminum Die Casting Process, die casting release agent, die casting lubricant, Die Casting Technical Support, Aluminum Die Casting

Aluminum Die Casting Fan Housing Performance Requirements

Posted by Hill and Griffith Company on Nov 1, 2017 2:28:27 PM

Today's post is a review of a NADCA presentation titled, "A Study in Aluminum Die Casting Housing for a Thermo-Electric Fan." You can find the entire presentation here.

The Requirement

  • In cold climates, military personnel need warm shelter for protection from the elements. In tents, sheds, and buildings without central heating, the shelters use individual space heaters to provide warmth.
  • In such uninsulated structures, the hot air from the heaters rapidly rises to the ceiling without warming the actual living space.
  • The comfort level in these shelters is markedly improved if the warm air is directly circulated throughout the shelter, as compared to natural convection conditions.
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Tags: Die Casting, Metal Casting, diecast, diecasting, Aluminum Die Casting Process, die casting release agent, die casting lubricant, Die Casting Technical Support, Aluminum Die Casting

Die Casting Lubricant Flash Point and Flammability

Posted by Hill and Griffith Company on Oct 25, 2017 5:18:52 PM

There has been much discussion between the technical staff and customers concerning the application of release agents.

One thing that seems to always seems to be a concern for a customer is the flammability of a product and how flammable our products are compared to the competition. One of the most basic forms of testing the flammability of a product is the flash point.

The die casting lubricant flash point is the lowest temperature at which vapors above a volatile combustible substance will ignite in air when exposed to a flame and is expressed in either Fahrenheit or Centigrade. The test procedure entails filling a prescribed container with the liquid, gradually heating the product and passing a flame over the top of the liquid surface. At such time when the flame causes an immediate flash of fire to occur, the temperature is recorded and is determined to be the flash point. If the material was allowed to continue to heat and a source of ignition was present, the material would eventually ignite and remain on fire until external forces were used to extinguish the fire. This temperature would be titled the fire point. In both cases, a source of ignition is required to cause combustion.

Three types of testing procedures are outlined by the ASTM. The Tag Closed Cup (T.C.C.), the Penske-Martin Closed Cup (P.M.C.C.) and the Cleveland Open Cup (C.O.C.) are all standard test methods. All three will give slightly different results in the temperature of the first flash. In order of lowest temperature flash to highest temperature flash, they would be 1)Penske-Martin 2) Tag and 3) Cleveland Open Cup.

Taking this test information and using it in real-world application is not as difficult as it would seem. The flash point of a material will basically express whether a material will burn or flash at or above a specific temperature. For example, gasoline has a flash point of -36 degrees F. T.C.C. This means that at any temperature above -36 degrees the material will flash or burn. Contrasting, Heptane has a flash point of 25 degrees F. In both instances, the two materials will burn if exposed to an ignition source at room temperature. The bottom line is that it doesn't really matter how low the flash point is for a material, if the operating environment is greater than the flash point, the possibility for ignition will always be present.


The material in this part is extracted from Chapter 1 – Operations – of the book Plant Design and Operations.

This book contains many discussions to do with the control of flammable and combustible materials. The terminology used for this topic — which can be confusing — is explained below.

Flammable Range

Fires require the presence of fuel and air (oxygen) along with a source of ignition. These criteria are often referred to as the fire triangle.

The fuel always has to be in the form of a vapor (liquids and solids do not burn directly — the fire generates flammable vapors at their surface and it is the vapors that actually burn). Moreover, not all fuel vapor/oxygen mixtures will burn — the concentrations have to lie inside the flammable range, which has upper and lower limits for the concentrations of the fuel in the vapor space. The flammability limits vary according to many factors, of which some of the most important are: the pressure and temperature of the mixture and the presence of inert components such as steam, carbon dioxide or nitrogen.

Flammable Limits

The flammable range for a fuel is defined by the Lower Flammable Limit (LFL) and the Upper Flammable Limit (UFL). These terms are also referred to as the Upper and Lower Explosive Limits. Below the Lower Flammable Limit (LFL) there is insufficient flammable material for a fire to occur — the mixture is ‘too lean’. It is the lowest concentration of a flammable vapor in air capable of producing a fire in the presence of an ignition source.

The UFL is similar to the LFL except that there is too high a concentration of vapor for a fire to occur — the mixture is said to be ‘too rich’.

For most flammable hydrocarbons the LFL is around 2 – 5%. For simple alkanes, such as methane and ethane, the UFL is in the 10 – 15% range. Some chemicals, such as hydrogen, ethylene oxide and acetylene, have much higher values for UFL. Values for flammable limit ranges for many flammable materials are provided by NFPA 704 — Standard System for the Identification of the Hazards of Materials for Emergency Response.

Flash Point

The flash point of a flammable material is defined as the temperature at which a vapor that is inside its flammable range that can be ignited. An ignition source such as a flame or spark is needed to make the material actually burn. It is important to recognize that an ignition source is required. The flash point is not the same as the auto-ignition temperature.

The flash point is determined by heating the liquid in test equipment and measuring the temperature at which a flash will be obtained when a small flame is introduced into the vapor zone above the surface of the liquid.

Figure 1.1 illustrates the concepts of ignition temperatures and flashpoints and flammable limits

Figure 1.1
Flammability and Ignition Limits

Before a flammable mixture will burn its temperature must be at or above the flashpoint. If the temperature is below this point then the vapor mixture will not burn, even if a source of ignition exists. The left line in Figure 1.1 is the flashpoint line.

Even if the material is above its flashpoint, the ignition source must be of sufficiently high temperature and must contain sufficient energy to ignite the fuel. The minimum energy varies with type of gas and concentration; for hydrocarbon vapors it is low, for high flash point liquids, such as diesel and fuel oil, it is much higher — usually in the form of an existing fire. This is why low energy flashes (such as might be created by a mobile phone or a digital camera) may not ignite a flammable mixture.

If a flammable mixture is heated to a high enough temperature it will spontaneously ignite; an ignition source such as a flame or spark is not needed. Spontaneous ignition occurs at the auto-ignition temperature (AIT), which is also shown in Figure 1.1.


If you liked this post you may also like:

Preventing Dust Explosions and Fires in the Die Casting Industry

 


Hill and Griffith Customer Service

We're known for our hands on approach. Let us visit your plant, offer die casting technical support and recommend release agents, lubricants, plunger lubricants and permanent mold lubricants that suit your needs. Products that represent the latest in technology and ongoing research that enhance competitiveness and increase productivity. 

Read More

Tags: Die Casting, Metal Casting, diecast, diecasting, Aluminum Die Casting Process, die casting release agent, die casting lubricant, Die Casting Technical Support

Die Casting Machine Lubrication Tips

Posted by Hill and Griffith Company on Oct 18, 2017 3:04:45 PM

NADCA Video News Update - Mechanical Maintenance & Evaluation of Die Cast Machines: DCM Primary Mechanical Structures - Highlight

The material presented in this video are some highlights from NADCA’s online webinar - Mechanical Maintenance & Evaluation of Die Cast Machines: Die Casting Machine Primary Mechanical Structures - presented by Jerald Brevick. The first in the Mechanical Maintenance & Evaluation of Die Cast Machines series covers topics related to the major mechanical support structures of die casting machines; the machine base, rails, platen supports, wear pads, die carriers, tie bars and bushings.

Click here to view the sample of the complete video.

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Tags: Die Casting, Metal Casting, diecast, diecasting, Aluminum Die Casting Process, die casting release agent, die casting lubricant, Die Casting Technical Support

Die Lubricant Biofilms -  How They Impact the Die Casting Process

Posted by Hill and Griffith Company on Oct 11, 2017 4:56:31 PM

Presentation by Tim Cowell, Technical Director Die Casting & Metal Working Fluids, The Hill and Griffith Company.

In the picture above Tim Cowell is presenting this Formal Presentation, "Die Lubricant Biofilms -  How They Impact the Die Casting Process," at the XVI Simposium 2017 in Queretara, Mexico

Die Lubricants

Within the die casting process, where molten metal is injected into a steel die, a release/lubricant agent is applied to the die to allow for proper release. These release agents are often referred to as die lubricants.

Die Lubricants provide three major functions that are vital to the die casting process.

  • Release of the Casting
  • Lubrication of the moving parts of the Die
  • Surface cooling of the Die

Die Lubricant Central Systems

These products are typically water dilutable and are diluted between the range of 50:1 to 100:1 in a central mixing system.  

The die lubricant is delivered through a network of piping connected to the die cast machines and ultimately to the die surface by spray nozzles. Below is a simple diagram of this type of set up.

Die Lubricant Spray Nozzles

An important key to assuring that the die is evenly coated with the die lubricant is to make sure that all spray nozzles are working and there is nothing that would obstruct the flow to and from these nozzles.

Filtration

To insure this, a series of filters are placed at various locations in the die lubricant supply system.

An example of a steel reinforced wire mesh filter used in Die Lubrication supply systems. Often steel reinforced filters are used to keep the filters from collapsing.

The purpose of these filters is to keep the fluid clean so that foreign materials will not plug up the spray nozzles.

Biofilms: Filters

Inline filters are used to keep the lubricant flow clean and protect the Spray nozzles from clogging up.

Biofilms often clog these filters reducing the amount of release agent being supplied to the spray nozzle and reducing the effectiveness of the atomization.

An example of an inline screen filter just pulled out of the line. This screen filter was given to the die lubricant manufacturer for further evaluation.

However, these filters often become contaminated with a slime (biofilms) resulting in a reduction of die lubricant flow to the spray nozzles and sometimes completely shut off.

Biofilms

All water dilutable die release formulations share the common problem of susceptibility to microbial attack.

This is not all bad news since we need the used dilute fluid to be biodegradable for waste treatment purposes. 

The challenge for both formulators and die casters using water-based release agents is to minimize the adverse economic impact of uncontrolled microbial contamination in the die casting operations.

Biofilms are a real problem in maintaining a clean die lubricant system.

In order to address this problem, the following questions need to be answered:

What are Biofilms?
  • How do Biofilms Form and Reproduce?
  • What can be done to remove Biofilms?
  • What can be done to prevent Biofilms?

What are Biofilms?

Biofilms are collections of microorganisms and the extracellular polymers they secrete, attached to either inert or living substrata.

Two types of microorganisms contaminate die release fluids: bacteria and fungi. Four factors predominate in controlling microbial life:
  • Energy Source – Obtained by breakdown of organic compounds
  • Nutrients – Water Source (minerals)
  • Warm Thermal Conditions
  • pH conditions – between 7-9.0

Microorganisms create "micro-environments“ called Biofilms in which conditions may be very different than they are in the bulk fluid.

A biofilm is an aggregate of microorganisms in which cells adhere to each other on a surface. These adherent cells are frequently embedded within a self-produced matrix of extracellular polymeric substance (EPS). Biofilm EPS, which is also referred to as slime

These Biofilms are protected from changes in diluted release agent temperature, chemistry and pH by the slime that the microbial population produces.

In terms of pH, this means that even though a diluted release agent may be maintained at pH 8.5-9.0, the pH within the microenvironment may be below 7.0. PH control often affects symptoms rather than the underlying problem of microbial growth.

Biofilms: Central Systems and Piping

Die Casting Systems and Biofilms

What can be done to remove Biofilms?

Biofilms are difficult to remove, especially the mature colonies. Typically, removal involves a two-step process.

  • Chemical Treatment
  • Physical Removal

Biofilms: Treatment

Chemical Treatment

A residual level of biocide is essential to help control biofilms, but biocide alone cannot penetrate or dissolve a biofilm mass. Incorporating the use of specially formulated cleaners/disinfectants assist in dissolving the EPS allowing the biocide to effective kill the microbes. It also removes byproducts, such as Nitrogen (Ammonia) that promote the growth of the bacteria in the biofilm.

Normally, the system being cleaned is filled with the cleaner/disinfectant and allowed to sit for a period of 8 to 24 hours before being flushed with water (preferably hot). This allows for plenty of contact time for the surfactants of the cleaner to break down the EPS and allow the disinfectant to do its work.

Physical Removal

Physical methods can be effective, especially in addressing “mature,” well-developed biofilms.  Flushing hot water through pipes at high velocities, for example, can help remove biofilms from smooth pipe interiors, such as PVC. 

Biofilms may be more difficult to address in pipes with rough interior surfaces.  In those cases more aggressive physical methods are used to scour pipe interiors.  Pushing a flexible swab with an abrasive outer coating through a pipe by means of hydraulic pressure is one of the most common methods employed to physically remove scale and biofilm.

If the buildup is too much, then the pipe should be replaced with PVC if possible.

Biofilms: Prevention

What can be done to prevent Biofilms?

Biofilms are heterogeneous, inherently patchy, and colonized with diverse microbial communities — qualities that make biofilm control challenging for any die lubricant supply system. The keys are a monitoring system, a treatment system, and a preventative maintenance program. 

A. Monitor the Microbes within the System

With the understanding that the microbes (bacteria and fungi) are present where water and food sources are present, it is unrealistic to think that the microbes can be eradicated. However, monitoring the number of microbes within the bulk fluid allows for a die caster / fluid manager to determine when hit the system with a kill dosage of biocide / fungicide.

The simplest way of monitoring them is by bio dip slides.

These slides allow for the both the die caster / fluid manager to determine the concentration of microbes present in the bulk fluid.

If the bacteria are greater than 104 in the bulk fluid, then the system should be treated with a dose of biocide.

If fungus shows up in greater amounts of two colonies, then a fungicide should be added. These are typically added to the diluted die lubricant reservoir.

B. Reduce the free number of bacteria by using small dosages of biocide / fungicide

There are products that keep the number of both bacteria and fungi minimal by introducing low maintenance dosages into the system throughout the week. The focus is keeping the number of microbes minimal before they begin to create biofilms.

C. Perform Preventative Maintenance every six months.

Every six months, the system should be shut down and cleaned using the specially formulated cleaner / disinfectant.

This will keep the bacteria and biofilms to a minimum before they create problems for production.

Summary

Die lubricant spray is vital to the successful production of castings within the die casting industry.

Biofilms, without the proper treatment program, can create a real problem in this area.

Die casters must have a monitoring system and a scheduled preventative program in place to assure a clean and consistent source of die lubricant supply to the die.


Hill and Griffith Customer Service

We're known for our hands on approach. Let us visit your plant, offer die casting technical support and recommend release agents, lubricants, plunger lubricants and permanent mold lubricants that suit your needs. Products that represent the latest in technology and ongoing research that enhance competitiveness and increase productivity. 

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Tags: Die Casting, Metal Casting, diecast, diecasting, Aluminum Die Casting Process, die casting release agent, die casting lubricant, Die Casting Technical Support

 


Hill and Griffith Customer Service

We're known for our hands on approach. Let us visit your plant and recommend release agents, lubricants, plunger lubricants and permanent mold lubricants that suit your needs. Products that represent the latest in technology and ongoing research that enhance competitiveness and increase productivity. 

Hill and Griffith Samples

Product Samples

We are pleased to provide samples in quantities large enough to allow you to "try before you buy." Die Casting and Squeeze Lubricants- Diluco®, Permanent Mold Coatings- Concote™, Plunger Lube™- Graphite and non-graphite oils and pastes with excellent anti-wear properties, Casting Operations Products: Start-up lubes, Ladle coatings, Anti-soldering pastes, Water glycol, Trim press lubricants, Surface protection for casting storage, Corrosion protection for die storage, Cleaners for machines and dies, Corrosion protection for machines, Heat treatment quenchants, and Heat-transfer fluids. Also, Industrial Lubricants Griflube®, Hydraulic fluids with fire-resistant and anti-wear properties, Bio-Syn natural ester-based hydraulic fluid, Way oil knuckle lubes and Metalworking Fluids- Grifcut™

Contact us for Product Samples

Hill and Griffith Customer Service

Technical Services & Support

On-site process surveys, Casting defect investigations, Product testing, Tooling start-ups and Statistical process controls and much more. Also, lab facilities are available to provide testing upon request. 

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