Technology Profile

Laser welding DuPont Engineering

Helping You Get the Most from Laser Welding DuPont engineering and know-how can help you gain the How laser welding works... benefits of laser welding in cost- Clamping Laser welding can join parts made pressure effective assembly solutions. from the same or very similar poly- mers. One part must absorb laser light, and the other part must be at Key capabilities and benefits least partially laser-transparent. of laser welding include: In making a weld, the laser beam ■ Assembly of sensitive parts passes through the laser-trans- parent part to reach the laser- - No relative motion of parts Laser- absorbing part. Absorption being welded. transparent of the laser’s energy produces part - Little or no heating beyond heat, melting the material in the weld area the localized absorption area. The adjacent surface of the ■ Excellent aesthetics: no visible laser-transparent part is melted Melt zone scars or flash on exposed by the conduction of heat from Laser- surfaces. the laser-absorbing part. When absorbing part ■ High precision: tight control of the laser beam is removed or Welding direction relative part location. relocated, the molten surfaces cool and bond together. ■ Wide latitude in molding related materials, e.g. PA66 to high- performance polyamide (HTN). Clamping ■ Versatility: suitable for a wide pressure range of part designs and sizes. ■ Low cost: usually competitive with alternative welding methods, In automotive door lock (left) and sometimes less expensive. and fuel vapor canister (below), covers made of natural, laser-transparent Application Ideas PA66 are welded to black, Automotive: Sensors, door lock laser-absorbing PA66 and gearshift housings, headlights, housings. Both materials are ™ ® taillights, fuel and air filters, fuel DuPont resins. injectors, actuators, reservoirs for clutch and brake fluids. Electronics: Instruments, keyless entry devices, connectors, housings, Medical products: containers, keyboards, mobile phones, watches. syringes, connectors Microtechnology: Biochips, pumps, Design idea: rigid structural motors, valves, manifolds, contain- parts with flexible seals. Do it ers, test plates. by welding Hytrel¨ thermoplas- Office equipment: containers, tic polyester elastomer to cartridges for toner, ink, etc. Crastin¨ PBT thermoplastic Packaging: sterile containers for polyester resin. Think how pharmaceuticals or medical products, other hard-soft structures can food packages. be used in your products. Do it with DuPont PET thermoplastic polyesters and but have sufficient laser transparency Hytrel¨ thermoplastic polyester for successful welding. Laser-transpar- DuPont Engineering Polymers offers elastomers. Special grades of Crastin¨ ent colors permit strong welds to laser- a wide range of suitable materials for PBT and Rynite¨ PET with enhanced absorbing colors. laser welding and a wealth of laser transparency provide greater expertise in the technology. For evaluation purposes, we can supply latitude in part thickness and welding laser-transparent colors of Delrin¨, It’s quite easy to produce strong process conditions. Zytel¨, Crastin¨ PBT, Rynite¨ PET or welds with Delrin¨ acetal, Zytel¨ Laser transparent components. Hytrel¨. nylon (including PA66, PA6 and Most natural (uncolored) grades are PA612 types) and Zytel¨ HTN high Laser-absorbing parts. Standard black sufficiently transparent to laser light performance polyamide. With and some standard colored grades of the to permit strong welds. Colored laser- somewhat tighter limitations on wall resins cited above are suitable for laser- transparent components can be made thickness and part design, strong absorbent components of welded from materials that are opaque to welds are also feasible with Vespel¨ assemblies. visible light - i.e., to the naked eye - TP parts, Crastin¨ PBT and Rynite¨

Design Guidelines for Successful Laser Welding Zytel® Nylon Thickness limit*, transparent part (mm)

10

Narrowing process latitude Delrin® Acetal Wide process latitude Rynite® PET (GR)

Hytrel® Crastin® PBT (GR) TPE 5

0 STANDARD ENHANCED STANDARD ENHANCED GR UNREINFORCED TRANSMISSION TRANSMISSION

*The thickness of injection molded parts does not typically exceed 4 mm.

Let’s go forward together The data listed herein fall within the normal range of properties, but they should not be used to establish specification limits nor used alone as the basis of design.The DuPont Company We’re geared up to support customers like assumes no obligations or liability for any advice furnished or for any results obtained with you in developing laser welding applica- respect to this information. All such advice is given and accepted at the buyer’s risk. The disclosure of information herein is not a license to operate under, or a recommendation to tions with good business potential. Contact infringe, any patent of DuPont or others. DuPont warrants that the use or sale of any material your local DuPont representative or the that is described herein and is offered for sale by DuPont does not infringe any patent covering nearest contact point listed below: the material itself, but does not warrant against infringement by reason of the use thereof in combination with other materials or in the operation of any process. It is the recommendation North America of DuPont that you carefully survey the patent literature to determine, in advance, whether Tel: 1-800-441-0575 uses such as that which you have in mind may create infringement of any patent. DuPont does E-mail: enggpoly@usa..com not warrant and is not in a position to state that your intended use is free of patent infringe- ment. You should independently consult counsel of your own choice in order to make such Asia-Pacific legal determinations. DuPont does not suggest, induce or recommend infringement of any Tel: +81-3-5434-6935 patent held by others by providing these sample materials. CAUTION: Do not use in medical applications involving permanent implantation in the human E-mail: [email protected] body. For other medical applications, see “DuPont Medical Caution Statement,” H-50102. Europe The DuPont Oval Logo, DuPont™, The miracles of science™, Crastin®, Delrin®, Hytrel®, Rynite®, Vespel® and Zytel® are trademarks or registered trademarks of E.I. du Pont de Nemours and Company. Tel: +41-22-717-6693 Copyright © 2003, E.I. du Pont de Nemours and Company. All rights reserved. E-mail: [email protected] plastics.dupont.com

H-99299 (06/03)