1 Plastic Joining Processes Enoch McDowell Gary Evans December 1, 2000

2 Introduction Introduce different plastic joining techniques Provide links to suppliers Provide links to online materials at the BYU Library Call numbers of handbooks

3 Types of Plastic Joining Hot Plate Lazar IRAM Ultrasonic Assembly Linear Vibration Orbital Vibration Spin Welding

4 Hot Plate Welding Hot plate welding utilizes a temperature controlled heat platen assembly which is introduced between the two parts to be assembled. All item are brought together, and the melting cycle is started. The parts are melted for a pre-set time to displace enough plastic for surface preparation and to properly heat the subsurface of the joint area. The parts are then separated, and the heat platen is withdrawn. Both halves of the holding fixtures are brought together against stops for the proper amount of seal time and seal depth.

5 Lazar IRAM Laser IRAM is based on the idea of passing light/laser radiation through one plastic component and designing the second component to absorb the laser light. This absorption results in heating and melting of the interface and with the application of a controlled clamp force, the parts are joined. The major breakthrough of IRAM technology is the ability to heat the entire welding surface simultaneously as compared to heating a single spot and moving the IR spot across the welding zone.

6 Ultrasonic Assembly Ultrasonic assembly utilizes an acoustic tool called a horn to transfer vibratory energy through the part to the joint area, where it is converted to heat through friction that melts the plastic. Ultrasonics can be used to join not only rigid thermoplastics, but fabrics and films as well. If your interested in the textile marketplace, you may want to check out the site of the Industrial Fabrics Association (IFAI), which represents the international industrial and technical fabrics and textile marketplace.

7 Linear Vibration Linear vibration welding employs frictional heat at the joint interface of two mated parts. The heat is generated by moving one part against the other under pressure through a linear displacement in the plane of the joint or amplitude. When a molten state is reached at the joint interface, vibration is stopped. Clamping pressure is maintained briefly while the molten plastic solidifies to form a bond.

8 Orbital Vibration Orbital vibration welding is a frictional process that uses an electromagnetic drive to create relative motion between two thermoplastic parts. This constant velocity motion generates heat, which raises the material temperature at the joint to its melting point. The motion is stopped after sufficient material is melted. The plastic then solidifies and forms a permanent bond.

9 Spin Welding Spin welding is a process that joins circular thermoplastic parts by bringing the part interfaces together, under pressure, with a circular, spinning motion. One part is held stationary in a fixture, while the other is rotated against it under pressure. The frictional heat that is generated causes the part interfaces to melt and fuse together, creating a strong, hermetic seal.

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17 Links to online materials at the BYU library Journal of Applied Polymer Science www3.interscience.wiley.com/cgibin/jtoc?ID=30035 Journal of Polymer Science Part A: Polymer Chemistry www3.interscience.wiley.com/cgi-bin/jtoc?ID=36444 Journal of Polymer Science Part B: Polymer Physics www3.interscience.wiley.com/cgi-bin/jtoc?ID=36698

18 Journal of Applied Polymer Science

19 Journal of Polymer Science Part A: Polymer Chemistry

20 Journal of Polymer Science Part B: Polymer Physics

21 Handbooks Welding Handbook TS 227.w387 Concise Encyclopedia of Polymer Science and Engineering TP 1087.c66

22 Conclusion There are numerous ways to join plastics This presentation has links to suppliers web pages Links to Journals are provided Handbook reference numbers are provided