Hapco, Inc. https://hapcoincorporated.com Formulating the Future™ Tue, 13 Jun 2017 13:47:49 +0000 en-US hourly 1 https://hapcoincorporated.com/wp-content/uploads/2016/07/cropped-SquareLogoH_BlueBG-32x32.jpg Hapco, Inc. https://hapcoincorporated.com 32 32 Casting a Clear Sculpture Using Hapco Materials, Equipment, and Expertise – Part 2 https://hapcoincorporated.com/casting-a-clear-sculpture-using-hapco-materials-equipment-and-expertise-part-2/ Wed, 14 Dec 2016 15:22:54 +0000 http://hapcoincorporated.com/?p=2282 Part 2: Casting the Unicorn

Hapsil Mold with Ultraclear UnicornIn part 1 of this how-to guide, we showed you how we created the silicone mold using Hapsil™ 360. In part 2, we will go through the steps and materials needed to cast a water clear part out of Ultraclear™ 480N-40, using Hapco’s X-80 Molding Chamber and X-Vac™ Chamber.

Measuring the UltraclearUltraclear™ 480N-40 is weighed out and poured into plastic containers. The B side is then added to the A side container.

Mixing UltraclearThe Ultraclear™ 480N-40 is mixed thoroughly for 2-3 minutes. It is a good idea to periodically scrape the sides and bottom of the container. Pouring into a second container and re-mixing is also recommended.

X-Vac Vacuum ChamberThe mixed resin is placed into the X-Vac™ Chamber and degassed, removing air and moisture from the mixture.

Filling MoldThe mold is placed upright in the X-Vac™ Chamber and the Ultraclear™ is slowly poured into the mold, leaving about 1/2” from the top of the mold.

Degassing MoldThe vacuum is turned on and the mold is watched carefully to avoid any material rising over the edge of the mold. One hand is kept on the valve to avoid any mishaps.

Pressure Cast Ultraclear ResinThe mold box is placed on the X-80 Molding Chamber shelf and topped off with Ultraclear™.

Close Pressure Pot DoorClose the chamber door and tighten the clamps in a crisscross pattern. Slowly open the valve until the tank reaches the desired pressure. We recommend between 70-80 PSI.

Remove the MoldThe following day, the chamber is depressurized. Once relieved of pressure, the C clamps are loosened and the mold is removed.

Remove Mold from FrameThe wooden frame is disassembled and the silicone mold is removed.

Remove Cast Part from MoldThe silicone mold is laid flat on the bench and the two halves are carefully pulled apart.

The flash and vents are trimmed off. There will be a slight visible line where the parting line was. This can be buffed and polished after the piece is post cured.

Post Cure CastingThe piece is placed in an oven at 80˚C for 8 hours to speed up the cure time and to strengthen it.

Hapsil Mold with Ultraclear UnicornIf you have any questions regarding this tutorial, or any of Hapco’s products or equipment, please feel free to call us toll free at: (877) 729-4272
















Casting a Clear Sculpture Using Hapco Materials, Equipment, and Expertise – Part 1 https://hapcoincorporated.com/casting-a-clear-sculpture-using-hapco-materials-equipment-and-expertise-part-1/ Mon, 14 Nov 2016 20:49:05 +0000 http://hapcoincorporated.com/?p=1959 Part 1 – Making the MoldFinished Unicorn Mold

In this article, we show you step by step, how to duplicate a complex pattern using Hapco’s high performance materials and equipment.

Unicorn Pattern After taking measurements of the pattern and creating a drawing to outline our plan, we constructed a mold box using medium density overlay.

Pattern in Mold FrameOrient the pattern inside the mold frame in a manner that will maximize the flow of material and minimize the amount of air that could get trapped. The paper represents cutouts that will reduce waste and save on material costs.

unicornmold2Pieces of cardboard were cut and layered to follow the shape and contours of the unicorn. This creates a foundation for a layer of clay that will represent the parting line for the two mold halves.

Clay Parting LineThe clay is carefully smoothed out up to the halfway point to raise the part from the board and create a parting line along the middle.

Mixing Hapsil 360 Silicone for Unicorn MoldHapsil™ 360 is mixed thoroughly and degassed in an X-Vac™ Chamber to remove any trapped air before pouring.

Pouring Hapsil 360 SiliconeHapsil™ 360 is slowly poured over the pattern until it reaches the top of the mold box.

Cured first half of the moldThe silicone is left to cure overnight at room temperature.

Remove Mold Half

Once the silicone has cured, the cardboard and clay are removed. The cured silicone mold half is temporarily removed from the frame for easier cleaning.

Clean and Release Mold

The pattern is temporarily removed allowing the mold to be cleaned thoroughly with isopropyl alcohol. Grease-It™ 5 release agent is also sprayed on the mold.

Release the Mold with Grease-It 5Once the unicorn pattern and mold are placed back in the frame, a final coat of Grease-It™ 5 is evenly applied over the surface.

Pouring Hapsil 360 Step 5 is repeated and the Hapsil™ 360 is poured evenly over the part in a thin, steady stream. It is best to pour from one side to allow the air to escape as it’s filling.

moldhalfflippedThe uncured silicone is allowed to cure at room temperature overnight.

Clean Two Mold HalvesThe silicone is removed from the frame and separated. Once the pattern is demolded, the silicone is cleaned thoroughly with isopropyl alcohol.

Cutting Vents in the Silicone MoldIt is important to understand how the mold will be oriented and to consider where air may get trapped. Vents are carved out of one mold half to give air bubbles a path to escape.

Post Curing Silicone MoldThe two mold halves are separated and placed in an oven at 125°F for 8 hrs. It is important to separate the mold halves to allow any oils or
residue to flash off.

Cutting Mold BoxA hole is cut where the material will be poured into. This represents the top of the mold.

Finished Mold BoxThe silicone rubber is completely supported by the wooden box. The two side pieces are screwed into place and the mold is rotated so that the hole is on the top. It is now ready for casting.

To learn how we cast a clear part using Ultraclear™ 480N-40, view Part 2- Casting the Unicorn.


















A Helpful Guide to Processing High Viscosity Resins https://hapcoincorporated.com/a-helpful-guide-to-processing-high-viscosity-resins/ Thu, 13 Oct 2016 15:30:17 +0000 http://hapcoincorporated.com/?p=1912 High Viscosity Epoxy

The term “viscosity” refers to the thickness or flow-ability of a liquid. Viscosity numbers range from 1 (water) to millions of centipoise (cP) or pascal seconds (Pa.s), 1cP = 0.001 Pa.s. Refer to our viscosity comparison chart here.

Urethane and epoxy resins with viscosities ranging from <100cP to 1,000cP are ideal for most generic casting applications. They de-air very well on their own and flow easily into closed molds, whether mixed ad poured by hand or dispensed using meter-mixing equipment. However, there are many specialty materials, such as, Hapco’s Steralloy™, Filterbond™ and Hapflex™ resins that are formulated for highly-engineered applications, and because of their unique chemistries, they have a thicker viscosity than other products, making them a bit trickier to process.

Vacuum Degassing

When mixing and pouring by hand, Hapco always recommends vacuum degassing the mixed resin prior to pouring. With viscous materials, it can be helpful to add a few drops of a surfactant, such as Hapco’s Anti-Air™ product, which reduces surface tension and allows the resin to degas more easily. However, vacuum degassing alone does not always alleviate air bubbles due to cavitation of the material as it flows through the mold. It may also be necessary to cure your parts under pressure using a pressure-pot or molding chamber, like Hapco’s unique X-Series Molding Chambers.

X-11 Molding Chamber by Hapco, Inc.

When using meter-mix dispensing, Hapco recommends designing a mold that fills from the bottom up. A general rule in this case is to design the mold so that the output opening(s) equals 2-4 times that of the input. In simple terms, if you have a 0.50” diameter input, your out-put should equal 1”-2” in diameter. This enables a “pressure drop,” which minimizes any back-pressure build-up caused by shooting a viscous material into a closed mold.

Filling Mold

When dealing with complex mold geometry, it may be beneficial to use a two-step degassing process. After initially degassing the resin mix, fill the molds and place them under vacuum again for an additional few minutes. This not only helps to release trapped air caused by material cavitation, but it will also “pull” the viscous material into the cavity to ensure a complete fill, especially if your mold has thin walls or complex geometry. While degassing the molds, the material inside will not swell up as it did during the initial degassing step, however, it may continue to “boil” somewhat. Therefore, it is advisable to fabricate a small “chimney” around the top of your mold to prevent material from spilling out. You can do this easily with wax, putty, or a simple strip of packaging/duct tape wrapped around the top of the mold. After secondary degassing you may find the need to top off the molds to ensure they are filled to proper height, in which case you should be able to do so without the need for further degassing

Vacuum and Pressure

Other suggestions for thinning higher viscosity materials are as follows: Pre-heat the resin to 80° – 110°F. It is really only necessary to pre-heat the thicker component which is typically the Part A for most materials. As a general rule, for every 10° you heat the material above room temperature, the material viscosity is cut in half. Bear in mind though, that heat will also cause the material to gel faster, thereby reducing your overall work time. In lieu of pre-heating the resin, you can pre-heat the molds instead. This will maintain work time for mixing, and still thin the resin viscosity as it flows into the warm molds. Another suggestion would be to add a small amount of solvent, such as, isopropyl alcohol or acetone into the resin mix. Solvents will cut the viscosity without impacting curing or material properties in most cases, as they will flash off quickly once the material starts its exothermic reaction.
The bottom line is that you will need to incorporate the proper equipment and techniques into your process in order accommodate using viscous materials. Water-thin materials require very little in the way of specialized equipment and they certainly make things easier. However, limiting your material offerings can also limit your opportunities for getting more of those “high-dollar” projects. My advice for expanding your business opportunities is to think “outside of the mold-box,” and have enough flexibility in your process to take on those jobs that nobody else wants!

A Helpful Guide to Casting Clear Resins https://hapcoincorporated.com/a-helpful-guide-to-casting-clear-resins/ https://hapcoincorporated.com/a-helpful-guide-to-casting-clear-resins/#comments Fri, 08 May 2015 14:15:32 +0000 http://hapcoweb.wordpress.com/?p=10 Hapsil Mold with Ultraclear Unicorn

Achieving optically clear parts using thermoset liquid molding is not impossible. But as anyone with experience will tell you it’s not a slam dunk either, especially if the cast possesses complex detail. So unlike the days of old, today’s materials and methods allow manufacturers and model-makers alike to attain water-clear parts without excessive rejects. It just takes the right combination of process and resins.

Ultraclear 480. The sample on the right was cast at 70 PSI while the sample on the left was cast at ambient pressure.

 Vacuum degassing and pressure casting are perhaps the most popular if not the most efficient methods employed to create clear, void-free and bubble-free castings. Additional time and energy are required, and rejects are still possible.

Pulling a vacuum on liquid resin will remove air. Pressurizing will squeeze it down to invisible sizes while the part cures.

Heating resin and vibrating the mold is another method of choice for casting clears (or any thermoset resin). This procedure helps relieve surface tension and allows air bubbles to more easily escape while filling the mold. Ultimately, heating/vibrating can yield better results, but it is not a failsafe.

Vibrating Table

A mold is secured to a vibrating table to help air move to the surface while filling.

Regardless of the process, cast and mold material must be compatible for water-clear casts. For instance, some mold materials and release agents are not compatible with aliphatic urethanes(clears).

Cure Inhibition

A medical component cast in an silicone mold that wasn’t post cured. This was left with a tacky surface and many tiny bubbles which were exacerbated due to not being pressure cast.

Choosing the correct release agent (and applying it correctly) is important to avoid tackiness and surface defects. Silicone-based release agents tend to react poorly with clear resins, causing cure-inhibition and other defects. This is why many molders will opt for a silicone mold to avoid the releasing process altogether, but it brings its own set of challenges to casting clear resins.

Grease-IT 2 is an example of a PVA release agent.

Grease-IT 2 is an example of a PVA release agent.

The only release agent that can be considered a fail safe is Polyvinyl Alcohol(PVA). This one part liquid, which can be sprayed or brushed on, dries to form a non-reactive film over the part.

Hapsil 360 Group

RTV Silicone rubber, be it tin- or platinum-based, are most often the choice of liquid molders because of their self-releasing properties and flexibility. The major issue with casting clear resins in silicone molds is the fact that the surface of the part can be tacky or uncured upon de-molding. This phenomenon, often referred to as cure inhibition, is a major challenge with very limited solutions. Post-curing the silicone mold before use is essential in flashing off some of the natural oils and acids on the surface. Those substances are the major reason why many clear resins have trouble fully curing. Unfortunately, post-curing is not always possible when molds are exceptionally large.

Polishing the finished piece is almost always necessary, especially when considering that upon de-molding most parts have parting lines, gates and vents that require removal. This can be achieved with a bench top buffing machine or done by hand. Either method will require a polishing compound. This can add a considerable amount of time and energy depending on the size and complexity of the piece.

Ultimately, success when casting crystal clear resins is best achieved when process (this includes the equipment) and materials come together to provide the best outcome.

Related Links:

Ultraclear™ is Hapco’s series of water clear casting resins. They are a 1:1 ratio by weight and volume and very low viscosity to make mixing and pouring easy. They are also 100% mercury free unlike most clear resins on the market.

Hapsil™ 360 is Hapco’s RTV silicone rubber that was designed to be compatible with aliphatic casting resins and not inhibit the cure.

The X-Series Molding Chambers allow the user to control the pressure and temperature of parts during the curing process. They come in 4 sizes.

This article is helpful for anyone who is getting ready to do resin casting.

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Expertise + Collaboration = Successful Partnership https://hapcoincorporated.com/expertise-collaboration-successful-partnership/ https://hapcoincorporated.com/expertise-collaboration-successful-partnership/#comments Mon, 06 Apr 2015 17:21:32 +0000 http://hapcoweb.wordpress.com/?p=1 Moldmaking Technical Support HapcoThermoset prototypes and molds are used in nearly every manufacturing industry and a broad set of chemicals and formulations are used in prototyping and production.

Given the wide range of both needs and solutions, how do you know you are taking the best approach to advancing your next creation? It’s no trivial question. After all, this is where new ideas often make their first three-dimensional impression, or where they prove their financial advantage.

Many manufacturers are small but novel businesses, or have limited R & D resources. A thermoset supplier capable of sharing their expertise can make the difference between go and no-go, profit and loss. Partnering with the right company does more than provide mold materials—a collaborative approach helps manufacturers discover otherwise unattainable solutions. It’s a classic application of “two minds are better than one”.

Think about it. Your company knows your market, your design team is expert at defining the end product, and your accountants know the cost constraints. Dimensions and dollars are defined down to multiple decimal places. How do you apply this kind of focus and detail to potential thermoset needs? You simply cannot.

Partner with an expert. Find a thermoset supplier that opens their doors and knowledge to you. Some have a yeoman’s offering of materials that meet manufacturing needs of all kinds. Others are more niche-oriented. Ultimately, one that adds its full capabilities to yours gives you the greatest chance for success.

Does the thermoset supplier have material and manufacturing expertise? Do they provide a laboratory to incubate and test manufacturing concepts? With which manufacturers have they collaborated?

The answers to these questions may lead you to a new source of thermoset expertise, a collaborative relationship and a successful partnership.

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Choosing the Best Epoxy or Urethane for Electrical Applications https://hapcoincorporated.com/choosing-the-best-epoxy-or-urethane-for-electrical-applications/ Sat, 28 Mar 2015 20:31:39 +0000 http://hapcoincorporated.com/?p=487 In our previous post, we discussed the application of potting and encapsulating using urethanes and epoxies. When choosing the proper urethane or epoxy for an electrical application, there are some important considerations to keep in mind. In this article, we will discuss those considerations and how they apply to the world of urethanes and epoxies.

Potting Electronics with Epoxy

Here some examples of electrical applications using urethanes and epoxies:

Di-Pak R-Series Group

The 3 most commonly sought after resins for electrical applications can be classified as electrically conductive, electrically insulative, and statically dissipative.


Electrically conductive materials have a low electric resistance and electrons flow easily across the surface or bulk of the material. Charges go to ground or to another conductive object that the material contacts. These materials have a surface resistivity less than 1 x10^5 Ohm/sq or a volume resistivity less than 1 x 10^4 Ohm-cm. Electrically conductive resins are typically filled with metallic or conductive particles.


Electrically insulative materials prevent or limit the flow of electrons across their surface or through their volume. Insulative materials are difficult to ground and have a high electrical resistance. Static charges remain in place on these materials for a very long time. These materials are defined as having a surface resistivity of at least 1 x 10^12 Ohm/sq or a volume resistivity of at least 1 x 10^11 Ohm-cm.

Di-Pak E-Series Group

Statically dissipative materials have a surface resistivity equal to or greater than 1 x 10^5 Ohm/sq but less than 1 x 10^12 W/sq. They have a volume resistivity equal to or greater than 1 x 10^4 Ohm-cm but less than 1 x 10^11 Ohm-cm. For these materials, the charges flow to ground more slowly and in a somewhat more controlled manner than with conductive materials.


RoHS Compliance https://hapcoincorporated.com/rohs-compliance/ Sat, 21 Feb 2015 19:01:30 +0000 http://hapcoincorporated.com/?p=452 What is RoHS Compliance?

The European Union set forth the RoHS (Restriction of Hazardous Substances) Directive to establish environmental guidelines and legislation to reduce the presence of six (6) materials deemed hazardous to the environment. To comply, products entering the EU must not have a homogeneous presence of these materials above the following levels by weight percentage:

Lead (Pb) < 0.1%

Mercury (Hg) < 0.1%

Cadmium (Cd) < 0.01%

Hexavalent Chromium (CrVI) < 0.1%

Polybrominated Biphenyls (PBB) < 0.1%

Polybrominated Diphenyl Esters (PBDE) < 0.1%

Currently, all of Hapco’s products are RoHS compliant. We certify that PART’s A, B, and C (if applicable) of Hapco products are considered raw materials in compliance with RoHS 2 Directive 2011/65/ EU, as it applies to EEE applications and non-EEE uses. These raw material parts, either separately or when combined according to Hapco’s literature, do not contain Hazardous Substances in excess of RoHS standards.

If you require a material certification for a specific Hapco product please contact us.

Using Polyurethanes in Medical Device Applications https://hapcoincorporated.com/using-polyurethanes-in-medical-device-applications/ Wed, 07 Jan 2015 14:34:39 +0000 http://hapcoincorporated.com/?p=457 Steralloy R-Series Group

Medical Device Manufacture encompasses a wide range of health care products that are used to diagnose, monitor or treat a disease or condition that affects humans. Medical technology extends and improves life. It can help alleviate pain, injury and handicap. The endless improvement of medical technology enhances the quality and effectiveness of care and is essential in the healthcare industry.

What are the advantages of using polyurethanes in this industry?

The high strength and ease of processing of polyurethane elastomers makes them the material of choice for soft durometer applications, such as, instrument grips, gaskets, seals, implants, etc. Silicone, for example, another common polymer used in low durometer applications, is difficult to extrude and does not bond easily to other device components made of non-silicone materials. Polyurethanes eliminate the problems associated with other materials such as PVC, where the dangers of leachable plasticizers become a concern. Liquid rubbers also retain their elastomeric characteristics even at low temperatures where PVC becomes brittle.Steralloy E-Series Group

Rigid polyurethanes also have applications in injection molded devices as component parts or for potting and encapsulating electronics. They are also commonly used for short term implants.

What organization regulates medical device applications?

The United States Food and Drug Administration’s Center for Devices and Radiological Health or “FDA” regulates medical devices.


Are there any polyurethanes that are approved for medical device applications?

Raw materials and component parts are not individually approved by the FDA. The FDA will evaluate the safety and effectiveness of a device for its intended use, and approvals are granted to the final product based on these considerations. In reality, the majority of medical devices entering the market haven’t been FDA approved. In this case, the device manufacturer must file a PMA (Pre Market Approval) on the new device.

Who is ultimately responsible for ensuring Medical Device compliance?

It is always the responsibility of the manufacturer to determine the suitability of all the component parts and raw materials that are used in the finished product.

What influence does raw material supplier test data have on FDA acceptance?

If a polyurethane supplier already has relevant toxicology data about its formulation, it can make that data available for review by the device manufacturer. The importance or desirability of certain toxicological characteristics will vary based on the intended use of the device. For example, the use of a material to make an implant requires more toxicology data than if the same material was used for a device that doesn’t contact living tissue.




Hapco’s Vacuum Chamber Video Demo https://hapcoincorporated.com/hapcos-vacuum-chamber-video-demo/ Thu, 25 Dec 2014 17:51:29 +0000 http://hapcoincorporated.com/?p=447 Watch as Fred DeSimone discusses the features of Hapco’s vacuum chamber, the X-Vac™.

Toxics Use Reduction Act https://hapcoincorporated.com/toxics-use-reduction-act/ Mon, 17 Nov 2014 18:10:55 +0000 http://hapcoincorporated.com/?p=445 Enacted in 1989 and amended most recently in 2006, The Toxics Use Reduction Act(TURA) requires Massachusetts companies that use large quantities of specific toxic chemicals to evaluate and plan for pollution prevention opportunities, implement them if practical, and annually measure and report the results. Learn more.

TURA Reporting & Fees

Each company considered a Large Quantity Toxics User is required to file an annual toxics use report for every listed chemical it manufactures, processes or otherwise uses above applicable thresholds.

TURA Planning Requirements

A Toxics Use Reduction (TUR) Plan is a document that provides both economic and technical evaluations of the toxics use reduction opportunities available to a company, and identifies those methods, if any, that the company intends to implement.

Hapco’s Status

Under the requirements of the Massachusetts Toxics Use Reduction Act (TURA), HAPCO INC. has been submitting annual chemical use reporting forms for di-isocyanates. As part of this TURA compliance program, HAPCO INC. expects to prepare a Toxics Use Reduction Plan update by July 1, 2014 aimed at reducing the use of our reportable chemicals. This TURA Plan must address the location and performance of our process equipment, and the Plan must be certified by a certified Massachusetts Toxics Use Reduction Planner to assure that it demonstrates a good faith effort to identify toxic use reduction options and it meets the requirements of the Massachusetts Department of Environmental Protection.