CL Series: Compression Limiters for Plastic Applications
Compression limiters are commonly used in applications where a compressive load is applied to a plastic assembly. The compression limiter strengthens the plastic and resists/carries the load that is applied when a bolt is tightened in the assembly. The integrity of the plastic is not compromised by the load that is applied.
Because of the amount of variables involved, compression limiters are made on a custom basis to meet your individual specifications. Various lengths and sizes can be manufactured to accommodate inch and metric bolts. Below you will see some common design options to consider when choosing a compression limiter for your application.
In order to quote your requirement we need either a detailed drawing or the following information needs to be completed to one of the forms provided for each design type:
- Design Type
- Part Length
- Inside Diameter (I.D.)
- Outside Diameter (O.D.)
- Installation Method
- Plating or Finish if required
Common Design Types:
Full Diamond Knurl
Designed for mold-in installation only. The diamond knurled design allows the plastic to fill in the peaks and valleys to lock the insert in place. This style also resists tensile loads and also provides added torque resistance compared to non-knurled styles. The part is symmetrical and requires no orientation.
Non-Knurled Symmetrical Mold-In
Designed for mold-in installation only. The undercut feature allows for plastic fill, therefore providing resistance to tensile loads. If any rotational torque loads are present consider a knurled design for added resistance. The part is symmetrical and requires no orientation.
Common Installation Methods:
Listed below are the most common installation methods used to install compression limiters.
Press In: This method assumes that no melting of the plastic takes place. The insert (compression limiter) is pressed in place with a pre-determined amount of interference to the hole.
Mold In: This method assumes the part will be placed onto a core pin in the mold and the plastic will be molded around the part.
Thermal Insertion: During this process the insert (compression limiter) is placed into a molded or drilled hole that is slightly smaller than the main diameter of the insert. A heated probe then contacts the insert, causing the plastic to melt in a localized area around the insert. The insert is driven to the required depth or slightly below to allow for a slight withdrawal that may occur. The probe is then removed and the plastic re-solidifies around the insert. This process provides similar results when compared to ultrasonic insertion but utilizes “heat” rather than ultrasonic energy to melt the plastic.
Ultrasonic Insertion: During this process an insert is placed into a molded or drilled hole that is slightly smaller than the main diameter of the insert. Ultrasonic energy is applied to the insert with the use of an ultrasonic welder and a hardened steel or titanium horn. The ultrasonic energy develops frictional heat at the interface of the insert and plastic. This causes localized melting of the plastic while the insert is driven to the required depth. The plastic then re-solidifies, and the insert is secured in place.
Finishes & Platings:
Commercial finishes are available upon request. Please specify if a particular finish is required so that it can be included in your design and quote.