Multi-Cavity Compression Molding

C & M Rubber Co. produced this silicone rubber encapsulated ultrasonic sensor assembly for a customer in the manufacturing/packaging industry. This project presented two unique challenges. First, the face thickness of the rubber sensor body needed to be held to a tight ± .003″ tolerance to minimize distortion of the ultrasonic frequencies. Second, to maintain the high sheen required on the face of the rubber part, no mold release agent could be used.

Working with customer specifications, our engineers developed precision tooling that would keep the part within the tight dimensional tolerances and have the lubricity to release it with no sticking. Utilizing a 25-ton hydraulic press and silicon rubber with a 30±2 Duro Shore A hardness, we executed a multi-cavity compression molding process to encapsulate the heater and sensor assembly. A manual deflash and inspection process verified that desired high gloss finish was achieved and the tolerances were within specification.

At C & M Rubber, we manufacture this part on an ongoing basis within a 1-2 week turnaround and deliver stock just-in-time to the customer. For more information on this project or to learn how our encapsulation molding expertise can improve your application, request a quote today.

Multi-Cavity Compression Molding Project Highlights

Product Name
Sensor Encapsulate in Silicone Form
Product Description
This ultrasonic sensor is used on an assembly line to detect a host of programmed conditions.
Capabilities Applied/Processes
Primary: Multi-Cavity Compression Molding
Secondary: Manual De-Flashing at Parting Line
Equipment Used to Manufacture Part
Standard 25 Ton Hydraulic Press
Overall Part Dimensions
Width: 24" Height: 2" to 7" O.D.: ø24"
30 ± 2 Duro Shore A
Tightest Tolerances
± .003 on Face Thickness
Material Used
Rubber Silicone
Material Finish
High Gloss on Face of Part
In Process Testing/Inspection Performed
Inspection of High Gloss Surface and Face Thickness
  • Thermo-Resistant Ribbon
  • Cord Heater Assemblies
  • Insert Built to Withstand Clamping Pressures During Molding Processes
  • Color Matching (Choice of Different Colors)
Industry for Use
Manufacturing & Packaging
5000 Pcs./Yr. (Approx.)
Delivery/Turnaround Time
1-2 Weeks ARO - Stock Held for Customer
Delivery Location
USA - Ohio
Standards Met
Customer Specifications
2D CAD Drawing