Heat Staking

Manufacturing operations currently use many different combinations of attachment methods to keep components together.  Common fasteners such as bolts, screws, and rivets can be used to form permanent attachments, but there are attachment methods that don’t require secondary hardware.  One of those methods is heat staking, which doesn’t require additional fasteners.  Here’s why we offer heat staking as an attachment method for our turn-key operations

Heat staking is the process to attach two separate components together by melting the base plastic material into a shape that will hold the secondary component.  It’s a permanent attachment method that does not require any additional material such as an adhesive or a solvent to make the permanent bond.  The only addition is the heat applied to melt the plastic and a tool to shape the plastic to form the mechanical connection.

Types of Heat Staking

• Standard Flared Stake – With a standard flare, the end result is a mushroom of plastic that covers the secondary component and attaches it to the base plastic firmly. The plastic mushroom has a slight dimple in the center.
• Spherical Stake – A spherical stake starts with a tower of plastic and a pointed end. This plastic is melted to form a rounded button-head shape.
• Hollow Stake – A hollow stake starts with a hollow boss of plastic that appears to be a cylindrical shape. The exterior walls of the cylinder are melted and folded over the edge of the secondary component to form the mechanical attachment.  The open center of the original hollow boss shape stays open and doesn’t fill in.  A benefit to using the hollow boss is that it produces a large and strong connection without the need to melt a large amount of base material. The hollow stake also avoids sink mark on the opposite side of the component and enables the parts to be reassembled with self-tapping screws should repair and disassembly be necessary.
• Knurled Stake – A knurled stake should be used where appearance is not a critical design feature. The knurled stake is best used in high volume production as alignment isn’t critical for the function of the attachment.  Knurled tips are available in varying levels of fine, medium and coarse shapes.
• Flush Stake – The flush stake is used in applications that require a flush surface after the plastic is melted and operation is complete. The flush stake necessitates that the retained secondary component has sufficient thickness for a chamfer or counter-bore connection point. The melted plastic resides inside the counter-bore and fills it with plastic to make the final mechanical connection.

SEA-LECT Plastics offers heat staking as an attachment method to reduce costs while increasing strength and quality.  Heat staking can be done with a precise and rapid operation that also offers repeatable results every cycle.  Manufacturing machine can be developed to complete multiple heat staking operations at once to decrease cycle time.  The stakes don’t have to be parallel which makes the design options limitless.

Heat staking is a great option that is comparable in strength and durability to other operations involving secondary fasteners without extra cost.  These connections can also resist corrosion in harsh environments.

Here are other benefits and reasons we employ heat staking in our turnkey solutions:

• No extra materials are needed, such as solvents, adhesives, or mechanical fasteners. That can reduce the assembly line set-up time, minimize process costs, and contribute to a clean work area.
• The heat staking operation can be completed in seconds, and it can be automated to reduce cycle time.
• Heat staking equipment is easy to maintain without an extensive maintenance program. Assembly personnel can use a simple TPM schedule to keep the process efficient and optimized.
• Heat staking will not contaminate the final product and leaves a clean assembly when finished. The staked areas should not need additional work, which allows parts t flow efficiently in an assembly operation.

At SEA-LECT Plastics we use many fastening methods for assembly, including heat staking.  Our customer and in-house designed and assembled products range from military grade assemblies to the outdoor industry.  Our experts can advise you on what may be the best option for your new product idea or how to change your current product to reduce cost, increase productivity, and also increase quality.

When you’re ready to work with our elite team on your next design concept, call (425) 339-0288 or email us at mattp@sealectplastics.com.