Presented by: Joshua Bush Michael Goetz Michel McCluskey Insert Molding Presented by: Joshua Bush Michael Goetz Michel McCluskey

Introduction Inserts Provide: Anchorage / Reinforcement Bearing Surfaces / Shafts Internal / External Threaded Sections Thermal or Electrical Conductivity Positioning Nameplates / Lettering Hinging

Background and Theory An insert is an integral part of a plastic molding consisting of metal or other material which may be molded into position or may be pressed into the part after it is molded

Basic Operation Types of Inserts Two general types: Molded-In inserts Post Molded inserts

Basic Operation (cont.) Molded-In Inserts Typically for internal threads / studs Metal Inserts Usually Undercut or knurled so they stay in the part

Basic Operation (cont.) Post Molded Inserts Uses Molded-in Hole Press Fit / Ultrasonically Fit / Self- Tapping Used for Internal Threads usually

Basic Operation (cont.) Other Types of Inserts Blind-Hole Inserts Through-Hole Threaded Inserts Protruding Thread Inserts Shoulder-Type Inserts

Basic Operation (cont.) Other Types of Inserts (cont.) Pressed-in Inserts Expansion Inserts Self-Tapping Screws Flat-type

Equipment Injection molding machine Hand/Pneumatic press (for post molded inserts) Specialized Molds Pockets to place the insert Magnetic Insert Holders Robots / other mechanical ways of putting inserts into molds.

Advantages Provide metal threading in a plastic part Provide for bearing surfaces Good for anchoring parts in an assembly Electrical Contacts in a plastic part

Disadvantages Floating Crushing Flow of Material Into an Open Hole Through The Inserts Flow of Material Into Blind-hole Inserts Protruding Inserts

Plastic Part Design Standards Dimensions/Tolerances: Thread dimensions critical. Exterior Dimensions/Knurling not as Critical. Tolerances: Length +/- 0.010 in. Diameters +/- 0.002 in. Angular +/- 1 degree max.

Minimum Wall Thickness Around Inserts Dependant Upon Shrinkage of Plastic Coefficient of Expansion (plastic and inserts) Temperature Range of Inserts Moisture Sensitivity of Plastic Resin Design of Insert

Minimum Wall Thickness Around Inserts (cont.) Try To Keep Wall Thickness Around Inserts Nominal Put Inserts in Bosses or Gussets

Mold Design Suggestions Ejectors on the Inserts Post Inside the Mold to Hold Inserts Magnetic Insert Holders

Selection of Metal For Inserts Refer to Data Sheets from Material Supplier Essential Due To Coefficient of Expansion Must Be The Same

Materials Used For Inserts Aluminum Brass Copper Carbon Steel Alloy Steel Stainless Steel Silver and Other Precious Metals

Insert Illustrations

Conclusions Through the use of inserts, a plastic part can be used in applications where once only metal could be used. Good thread, pin, and bushing properties can now be obtained in plastic parts through the use of inserts.

? ? ? ? ? ? ? ? ? ? ? ? Questions ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?

THANK YOU