Form-In-Place Gaskets Superior accuracy and reliability for even the most intricate gasket designs
What is Form-In-Place?
Form-in-place (FIP) gaskets are thick liquids dispensed on top of substrates to create a strong, durable seal between two surfaces like metal, glass, or plastics. FIP seals offer good compressibility and low compression set, ensuring years of effective EMI shielding and environmental sealing performance.
A three-axis gasket application process dispenses precisely positioned, conformable gaskets in a variety of cross-sections with an infinite number of layouts. This automated process offers the additional benefit of allowing for the batch to batch part variations without any tooling changes.
This is favorable for manufacturers as many gasketing applications provide the lowest total installed cost. FIP gaskets can reduce installed costs up to 60% over other gasketing solutions. Thus helping save on materials, reducing the space needed, and avoiding expensive gasket production tooling costs.
For EMI shielding applications, a variety of electrically conductive particles can be added to the gasketing compound allowing for shielding effectiveness ranges from 60 dB to more than 100 dB+ at 200 MHz to 12 GHz.
FIP Gasketing from Parker Chomerics
Form In Place Basics
What are two types of form in place gaskets?
There are two types of form in place gaskets. The first is a gasket that is placed in a mold and then removed. The second is a gasket that is placed in a mold and then cured.
What are the advantages of the form in place gaskets?
The advantages of the form in place gaskets are that they are easy to install and they are very durable.
What is the purpose of using seals and gaskets?
Seals and gaskets are used to prevent the leakage of fluids and gases.
The many benefits of FIP gasketing includes:
- Up to 60% space saved
- Up to 100 dB shielding effectiveness 200 MHz to 12 GHz with very small gasket beads.
- Highly compressible gaskets, ideal for applications with limited available deflection force.
- Can be dispensed in complex layouts with short lead times and minimal tooling cost.
- Quick turn-around of prototypes and samples. Fast and low-cost gasket design changes.
Our Automated CNC Multi-Axis Robotic Application Process offers:
1. Turnkey gasket adhesion to metal, glass, or plastics
2. Very small beads with 100 Db shielding
3. Complex layouts with short lead times and minimal tooling
Applications for FIP gasketing
Form-in-place gasketing is a versatile manufacturing technique with applications across a wide range of industries, including:
- Military and defense work demanding a high level of accuracy and low-weight design
- Commercial and military aerospace applications
- Medical devices, including automated external defibrillators (AEDs) and CPAP machines
- Test and measurement applications, including 5G test equipment where EMI shielding is crucial
Placement of the gasket is done by multiple-axes robotic dispensing, driven by a CAD drawing of the part. This process ensures reliable sealing against environmental variables.
This application method also allows us to meet varying height requirements and compensate for uneven surfaces in molded parts and castings to provide consistent, highly reliable seals.
There are several combinations of elastomers and particles that provide a range of desired properties including, compression force, deflection range, electrical conductivity, shielding effectiveness, galvanic corrosion resistance, adhesion and cure options.
Through this process, small seals can be accurately placed in complex patterns to meet the increasing demands of electronic enclosure designs.
These durable, highly conductive seals and gaskets offer years of effective mechanical performance and EMI shielding*.
*With our precise instrumentations, spaces as narrow as .030 inches (0.76 mm) can be accommodated for gasket application, allowing more real estate for components.
KRA Fab is an authorized converter of Parker Chomerics materials
We use the same procedures to apply FIP materials as Chomerics. Finished products are certified by an authorized distributor. This type of certification is important for some customers with higher standards for quality, especially in the medical and aerospace industries.
Chomerics CHOFORM 5513
Two-component, thermal cure silicone system, which requires a minimum cure of 30 minutes at 140°C (284°F). The Ag/Cu particle filler makes 5513 a > 70 dB shielding material while also having the best adhesion to chromate coated aluminum and most other substrates.
Chomerics CHOFORM 5528
One-component, room temperature, moisture cure silicone system, which requires a full cure of 24 hours at 50% relative humidity. The Ag/Cu filler makes 5528 a >70 dB shielding material, while providing a soft, low closure force gasket.
Chomerics CHOFORM 5560
One-component, thermal cure silicone system, which requires a minimum cure of 30 minutes at 150°C (302°F). The Ni/Al filler makes 5560 a very good >90 dB shielding material while also providing the best galvanic corrosion-resistant gasket when mated with aluminum for even the harshest salt/spray fog environments.
Many electronic devices are subject to a variety of not only environmental conditions but electromagnetic/radio frequency interference.
In densely populated electronics packaging, particularly where intercompartmental isolation is required to separate processing and signal generating functions, conductive form-in-place gaskets provide excellent electrical contact to mating conductive surfaces including printed circuit board traces.
Design Limitations and Considerations
- Substrate dimensional considerations
- Substrate surface quality considerations
- Gasket adhesion
- Gasket aspect ratios
- Published specs versus real world results
The most common problems that occur when a product is in-transit can be mitigated through proper packaging. There are four key areas to focus on in order to decrease damage when wrapping, packaging, and shipping FIP gaskets. The first is proximity; the longer the distance, the greater the chance for damage. The next is manufacturer-controlled shipping. Placing control in the manufacturer’s hands can decrease overhead costs. The third area is stretch wrapping as improper wrapping can make a load much more unsafe and unstable. The last key area is on-site box fabrication. For items that are rarely ordered, custom boxes are not necessary.
This continual search for the best ways to help our customers means communicating with our customers about a part, including how it’s unpacked and assembled. Considering these factors allows us to optimally serve customers in the packaging and delivery process.
Gasketing Material Selection
There are several combinations of elastomer compounds and particle fillers that provide a range of desired gasket properties.
Material choices are available for optimization of the material for best shielding, compressibility or available compression, galvanic corrosion, environmental sealing or chemical resistance. In some cases, two materials may be used to create a dual bead gasket that addresses multiple areas of concern.
With a wide variety of gasketing materials, IC packages and EMI Shielding , KraFAB supplies custom materials that have the capabilities beyond the standard EMI shielding and gasketing. Our custom fabricated materials are developed specifically to meet the demands in a variety of industries.
Our skilled team can help with the selection of a FIP compound to best meet your gasket design requirements and limitations, addressing not only the factor listed above but allowable gasket envelope, available deflection ranges, and substrate properties as well.
FIP Gasketing Process Quality Control
Our robust and mature ISO 9001 certified quality system plays a key role in ensuring that each customer’s needs for high performing and repeatable gasket solutions are always met.
Each batch of customer supplied FIP substrates is checked for suitability for gasketing, including its cleanliness, uniformity, and damage.
Substrates are inspected during the gasketing process as well.
We have the capability to perform automated dimensional verification of gasket bead placement and height for statistical process control, using a fully programmable optical coordinate measuring technology and vision systems. Electrical resistance of cured gasket material is tested using a 4-probe multimeter capable of measuring to 0.001 ohm in conjunction with custom apparatus designed for testing shielding gaskets. Typical Cp and Cpk values for most FIP gasket application processes are approximately 1.5.
Since this installation is dependent primarily on software and programming, it permits rapid and inexpensive prototyping, production scale-up and design changes. It works well for batch runs or continuous production, from ten to ten million parts.
Through our latest generation form-in-place gasket application, metal, plastic, and glass surfaces and enclosures are sealed against moisture, air, dust, liquids, gaseous substances, dirt and EMI/RFI interference. By implementing in-line curing of the gaskets, production times are cut and turn-arounds are increased.
We can further reduce production and sourcing costs by adding secondary EMI products, thermal interface materials, PSA’s, damping foams, labelling, marking, protective films and packaging to create a turnkey production solution.
FIP gasketing has become a widely accepted sealing and shielding solution over the past 2 decades across all manufacturing industries. Its unique value proposition of low cost and high performance has made it one of the first choices for engineers looking for shielding and sealing solutions.
It has been used in telecom, military, aerospace, industrial, transportation, life sciences and commercial EMI shielding and sealing applications to replace molded, extruded, die-cut gaskets and RTV sealants for decades.
What are the benefits of FIP gasketing over molded or die-cut gaskets?
Form-in-place gaskets are another choice besides molded gaskets or die-cut gaskets. This unique type of gasket is able to fill in any irregular spaces or gaps on the substrate. Pre-formed gaskets are not always able to adequately fill those gaps, which can make form-in-place gaskets an ideal alternative.
We program the dispensing system, which means there’s no need to create a mold or steel die. The robotic system also makes it much easier to change from one design to another very quickly and cheaply.
Form-in-place gaskets are cured at room temperature or by oven and are ideal for applications that involve opening and closing the door or component. This versatile process can be used on plastics, glass, electronics, and more.
These seamless poured in place gaskets adhere to one side of the surface. By contrast, with cure-in-place gaskets, the corresponding part is attached and the gasket fills all voids for permanent assembly.
K.R. Anderson was one of the first companies to offer automated form-in-place (FIP) gasketing technology back in 1997. Today, our company has installed FIP gasket solutions for customers across the globe in almost every industry imaginable.
Our automated form-in-place gasketing system is ideal for EMI shielding, environmental sealing applications, or both simultaneously.
Our precision application works on almost any substrate design and construction. It can be applied directly on castings, machined metal or plastic, providing turnkey assembly.