Optional Activity 3.3.1f – Plastic Fasteners & Bonding Classification

Purpose Many products today are made from plastic. How can plastic parts be fastened and bonded securely so that the product stays together even under daily usage? Take a cell phone, for instance. What material is the case? If it is a flip phone, how is it hinged? Have you ever dropped your cell phone? Did it survive the impact? What if the hinge broke after a month of use? As you can see, choosing the correct fastener and bonding techniques is crucial to the life of a product and its success.

Today’s product designers must understand and be able to apply effective plastic fastening and bonding techniques. The information you gain from this activity will be important to use during the design of a product and during the remainder of this lesson.

Equipment  Samples of fasteners used in plastic assembly each labeled with a unique letter. o Snap fits: Cantilever, Torsion, Annular. o Mechanical Fasteners: Threaded Metal Insert, Self-tapping Screw, Stamped Sheet Metal Fasteners, Metal Rivets. o Plastic Assemblies: Press Fit, Living Hinge, Boss.  Examples of plastic bonding each labeled only with a unique letter. o Bonding: Solvent, Adhesive.  Pencil  Engineer’s notebook

Procedure: In this activity, you will complete the Plastic Fasteners and Bonding Classification Worksheet by classifying various fasteners and bonding techniques based on their characteristics for plastic products. You may wish to refer to the Plastic Fasteners, Welding & Bonding PowerPoint. Take notes as you learn about the fasteners and welding and bonding techniques. When finished, submit your completed worksheet to your teacher for assessment.

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Plastic Fasteners & Bonding Classification Activity

DIRECTIONS: Analyze the sample fasteners and bonded examples provided and then match the letter labeled for each sample to the list. Place your answers in the space provided.

SNAP-FITS MECHANICAL FASTENERS

____ Cantilever ____ Threaded metal insert

____ Torsion ____ Self-tapping screw

____ Annular ____ Stamped sheet metal fasteners

____ Metal rivets

PLASTIC ASSEMBLIES BONDING

____ Press fit ____ Solvent

____ Living hinge ____ Adhesive

____ Boss

Conclusion: 1. How is a fastener or bonding technique for a plastic product chosen? What factors are considered?

2. What is the difference between a solvent and an adhesive?

Project Lead The Way, Inc. Copyright 2007 IED – Unit 3 – Lesson 3.3 – Optional Activity 3.3.1f – Plastic Fasteners & Bonding Classification – Page 2 3. How do fasteners designed for plastic differ from fasteners designed for metal or wood applications?

4. Which fasteners would make a plastic product easy to disassemble?

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