Medical Rubber Molding for Custom Dental Grips

Designed specifically for the medical industry, these transfer molded custom dental grips help reduce fatigue when handling dental utensils. Qualiform Custom Rubber Molding is your source for custom medical rubber molding design and development of medical industry products. Qualiform has superior experience working with non-staining and non-conductive specifications and upholding critical medical standards.

Custom Dental Grips from Our Transfer Molding Process

For this medical rubber molding project, Qualiform worked with the customer to satisfy specific requests for comfort. We formulated a special compound that met the characteristics required in that industry, good grip combined with comfort.

This comfort rubber compound is a special FDA white-listed ingredient. This compound met out customer’s application and need. These transfer-molded custom dental grips are available in a variety of colors.

Types of Medical Rubber Molding Processes

Rubber injection molding is an ideal process to produce precision medical rubber molded components and rubber-to-metal bonded products.  This process is selected for rubber parts that require high volumes, tight tolerances, over-molding or precision applications. Rubber injection molding delivers speed and precision not found in other rubber manufacturing processes.  Furthermore, medical rubber injection molding is an optimal manufacturing process for products specified with rubber compounds that have quicker rubber cure times. Efficiency is gained by a higher level of automation, strict control over flash and reduced waste from scrap parts.

Rely on Qualiform’s technical staff’s experience with rubber injection molding to help our customers determine if injection molding is the correct process for their product application and material property requirements.

Rubber Injection Molding Process Description

The process of injection molding rubber starts with bulk mixing the rubber compounds, aka stock.  The stock is then stripped into continuous strips approximately 1.25″ wide & .375″. The strips of uncured rubber stock are then fed from a hopper into the rubber molding injection equipment via a conveyance channel.

A large auger type screw moves the stock into a barrel that holds a specific amount of rubber stock.  As it turns and moves through the channel into the injection unit, the material is heated.  As the rubber stock is heated, it plasticizes to a target temperature.  The plasticized rubber material is then injected into a heated mold cavity held under high-pressure.  A runner and gate system is used similarly to the plastic injection molding process.  The temperature and pressure activate the cure of the rubber compound, vulcanizing it.  Once the rubber reaches and required level of cure, it is allowed to cool and reach a solid state within the mold. The molds open and parts are removed or ejected ready for the next cycle.

Medical rubber injection molding began in the mid-1960s as a spin-off from the plastic injection molding process.  The difference in the processes is that rubber is cured under significantly more pressure per square inch of molds cavity surface.

Advantages of the Rubber Injection Molding

  • A highly efficient process
  • Can be fully automated with automatic material feeding
  • Provide high precision rubber molded products
  • Superior process for consistency and repeatability
  • Allows for molding of complex geometry
  • Ideal over-molding of inserts, overmolded components and rubber to metal bonding
  • Eliminate preforms and preform labor cost
  • Flashless molding / flashless tooling / eliminating secondary trimming
  • Rapid cavity filling
  • Reduced cycle time
  • Minimal material waste

Disadvantages of Rubber Injection Molding

  • Higher start-up/shutdown costs
  • Suited for high volume applications
  • Not all elastomers are suitable

Utilizing the medical rubber molding process for rubber to metal bonding is the most effective way to adhere rubber to metal parts.  Qualiform is the leader of all rubber to metal bonding companies producing the largest, most complex parts in the industry.  We offer unparalleled experience in this process and are more than happy to consult on your medical rubber to metal bonding application.  Questions on rubber to metal bonding? Contact our technical staff at (330) 336-6777 or CLICK HERE to send us a drawing.

The Rubber to Metal Bonding Process

The rubber to metal bonding process provides a superior mechanical bond of rubber to metal parts or inserts.  Integral to the process is a two-step preparation of the metal for rubber molding.  First, the metal must be degreased, similar to metal coating or paint preparation, and cleaned of any contaminants.   Next, a special, heat-activated adhesive is uniformly sprayed onto the metal parts.

Ready for rubber overmolding, the prepared metal parts are inserted into the mold cavity.  Held in place by special magnets or chaplet pins, the mold is closed and the rubber molding process begins.  The heat required to cure the rubber, activates the adhesive forming a mechanical bonding of rubber to metal.

Rubber insert molding completely encapsulates the metal part with rubber by suspending the metal insert in the mold cavity.  Rubber can also be molded to a specific area of metal parts.   Mechanically adhering rubber to metal can enhance the stability of metal parts with the flexible characteristics of rubber.  Metal parts with molded rubber can improve part properties such as seals to NEMA standards, electrical conductivity, noise and vibration isolation, wear and impact resistance, chemical and corrosion resistance and more.

Steel, brass, aluminum, exotics, engineered resins and plastics can all be overmolded with rubber.

Medical rubber to metal bonded parts range in size from small inserts to large transportation components.  Overmolded rubber metal parts are utilized across a broad range of applications, shapes and sizes such as bumpers, shafts, rollers and isolaters.

Rubber compression molding is ideal for low to medium volume production of rubber products.  The medical rubber compression molding process can produce a diverse range of precision rubber molded components.  The compression molding process allows for the affordable production of large, intricate products. It is often used to produce environmental seal products such as rubber o-rings, seals and gaskets.

The Rubber Compression Molding Process

The rubber compression molding process uses a preformed piece of uncured rubber that is placed in an open mold cavity.  The mold is preheated to an elevated temperature.  As the mold closes, the material is compressed and flows to fill the rubber mold cavity.  A combination of high-pressure and elevated temperatures activates the curing of the rubber compound, aka vulcanization.  The optimal level of cure is achieved, the part hardens and cools then the mold is opened and part removed.  The cycle repeats with the next rubber preform inserted into the rubber mold.

The Benefits of the Compression Molding Process

  • Economical process
  • Low-cost tooling compared to rubber injection molding
  • Maximized cavity count
  • Ideal for large parts that require a long cure time
  • Can process most elastomers and cure systems

Disadvantages of Compression Molding

  • Longer cycle times
  • Mid-range precision and consistency
  • Labor intensive

Applications of compression molding range from simple drive belts to complex large diameter diaphragms.

The medical transfer molding process can be used to produce both solid rubber parts and parts that require bonding rubber to a metal or non-metallic component. Examples of parts manufactured with transfer molding include vibration isolators and shock absorbers.

The Rubber Transfer Molding Process

Similar to compression molding, transfer molding requires raw material preparation into pellets and/or pre-forms.  Rather than placing the preform in the mold cavity, the preformed material is placed in a “pot” located between the top plate and a plunger.  In the pot, the material is compressed by the heated plunger and forced (transferred) through sprues into the cavity below.  The plunger is kept in place until the preform takes on the shape of the mold and the cure is reached, vulcanized.  The part is allowed to harden, cool, then is ejected. The cull pad, any cured rubber left in the pot, is removed, mold cavities are cleaned and the next molding cycle begins.

When used for rubber to metal bonding, the transfer molding process requires the components are loaded into a heated mold either by hand or using a loading fixture.  Material is loaded into the well pot of the transfer mold.  The mold closes and the heated rubber is then transferred through the runner and gate sprues into the mold cavities.  Under pressure and elevated temperatures, the rubber cures/vulcanizes and parts are removed.

The rubber transfer mold consists of a piston, well pot, sprue plate, cavity plate, and a base plate with a knock-out system used to eject the parts after molding.

The Benefits of the Transfer Molding Process

  • Economical process with high cavity count per mold per cycle
  • Cost effective tooling
  • Allows for rubber to metal bonding
  • Allows for rubber overmolding
  • Tighter dimensional tolerances than compression molding
  • Ideal for large parts that require a long cure time
  • Can process most elastomers and cure systems

Disadvantages of Rubber Transfer Molding

  • Longer cycle times
  • Mid-range precision and consistency
  • Labor intensive
  • Increased flash and waste

Medical transfer molding is an ideal process to not only produce precision molded rubber products, but also products that require rubber bonded to metal surfaces.

Medical Rubber Molding Services

The medical industry has high quality standards and specifications. Qualiform is able to deliver consistently and meet the strict demands of the medical industry. We are equipped to respond quickly to unpredictable medical industry demands.

Services Offered:

Medical Rubber Molding | Rubber Compound Molding | Custom Dental Grips

Medical Rubber Molding Materials

Other Idustries We Serve

  • Medical Industry
  • Automotive Industry
  • Lawn & Garden Industry
  • Electronic Industry
  • Transportation Industry
  • Material Handling Industry
  • Home Application Industry
Medical Rubber Molding | Rubber Compound Molding | Custom Dental Grips
Our technical staff is ready to assist you with all your custom medical rubber molding needs.
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