Method

Continuous Molding

Molded Joint

Precision Vulcanization

Standard Vulcanization

Relative Cost

$$$$$$

$$$$

$$$

$$

Tooling Cost

Depends on CS

N/A

N/A

N/A

Typical Lead Time

5-12 Weeks

2-8 Weeks

1-21 Days

1-21 Days

Not Actual Example Images - Exaggerated Oversized Renderings

Method

Continuous Molding

Molded Joint

Precision Vulcanization

Standard Vulcanization

Advantages

-Best option for high performance, dynamic, gas, pressure and vacuum applications over 35” Diameter

-Performance similar to fully molded

-Proprietary method yields consistent quality

-No mold/tool cost 

-option for prototyping and basic applications with > 15% compression-squeeze

-Performance can be similar to fully molded

-Best value for prototyping and basic applications

-Proprietary method yields consistent quality

-Angled joint increases bond surface area and strength

-Rubber based  adhesive

-Flexible compressible joint

-Angled or Straight joint depending on material and thickness

-Only for basic static, low pressure,  short term applications

Disadvantages

-Highest cost due to time and scrap rate

-Longer lead times

-Best option for high performance, dynamic, gas and vacuum applications

-Inconsistent quality

-Occasional slight under-fill or over-fill at joint increases leak potential

-Parting line and flash can be misaligned and buffed at joint

-Multiple joints can be required

-Not recommended for vacuum or high pressure

-Higher cost than standard vulc

-Lead times can be longer than standard vulc

-Potential for slight excess adhesive, misalignment and buffing at joint

-Not recommended for vacuum, high pressure or dynamic seals

-Inconsistent quality

-Angled or Straight joint depends on material and thickness

-Potential excessive

adhesive at joint

-Potential misalignment

-Only for basic static, low pressure,  short term applications

Continuous Molding
Proprietary molding method that typically results in nearly same quality as traditional fully molded techniques with almost undetectable joints.  Investing in continuously molded method will increase the consistency of higher performance sealing applications.  Best option for large and critical applications like in Vacuum, LCD, Solar equipment manufacturing with low seal compression force.  Possible slight parting line and flash misalignment and variable surface finish at the mold transfer points.  ID dimensional tolerances per quote.
(Exaggerated Renderings to describe potential issues)

Molded Joint
Partially cured molded cord is joined and molded under pressure and high temperature in a tool/fixture. Depending on size multiple joints could be used.  The finished seal is then placed in a high temperature post cure oven to complete the cure.  After the o-ring is fully cured, it is de-flashed and buffed if required.  ID dimensional tolerances per quote.
   1  Potential slight over-fill at joint (Exaggerated Renderings to describe potential issues)

   2  Potential slight under-fill at joint could lead to leaks in some applications

   3  Parting line and flash can be misaligned at joint

   4  Buffing at the joint can yield variable surface finish from the rest of the part

Precision Spliced and Vulcanized
Fully cured extruded cord is typically cut to length with a 45 degree angle scarf cut ends.  A proprietary process is performed to bond the ends with a rubber and adhesive mixture that results in a much cleaner joint than Standard methods.  The consistently cleaner joint allows for better sealing with less leak potential which can be used in higher performance applications.  Good joint tensile strength can be achieved with Buna-N, Neoprene and EPDM, reasonably good with Viton and only fair strength can be expected with Silicone.  Great for prototyping before migrating to Continuous Molding method.  ID dimensional tolerances per RMA Table 18, S1 Precision or better.

   1  Potential for slight adhesive excess at joint (Exaggerated Renderings to describe potential issues)

   2  Potential slight misalignment

   3  Buffing at the joint can yield variable surface finish from the rest of the part

Standard Spliced and Vulcanized
Fully cured extruded cord is typically cut to length with a straight 90 degree or 45 degree angle scarf cut ends depending on the material type and thickness.  The ends are treated with a mixture of uncured rubber and adhesive and placed in a tool fixture to heat and cure the joint.  Once removed from the fixture the joint might be buffed but imperfections could remain that can cause leaking in some applications thus recommended for very basic short term non-critical applications.  Joint quality can vary as they are produced by hand.  Good joint tensile strength can be achieved with Buna-N, Neoprene and EPDM, reasonably good with Viton and only fair strength can be expected with Silicone.  ID dimensional tolerances per RMA Table 18, S2 Commercial or better.

   1  Potential excessive adhesive at joint (Exaggerated Renderings to describe potential issues)

   2  Potential misalignment

   3  Buffing at the joint can yield variable surface finish from the rest of the part