Attaching Metal Grilles and Screens to Plastic

For many years, metal grilles and screens have been attached to plastic housings and frames by the use of additional fasteners. These fasteners may be screws, clips, rivets, hot-melt glue or adhesive. Each of these processes cost money, require inventory and are subject to fluctuating degrees of consistency in quality.

In recent years, many manufacturers have designed or redesigned their products to incorporate heat staking or swaging process. This can typically be done with minimal expense to new or existing injection molding tools. In many cases, the final product, when staked or swaged, becomes much stronger and robust than its predecessor that required hardware for attachment.

Besides the reduction in product cost by eliminating hardware, there are many advantages, as cited by our customers, for why switching to staking/swaging is such a benefit to many products. Listed below are just a few.

• Rattles from loose fasteners become non-existent.
• Screens or Grilles do not become loose over time.
• Products become tamper proof.
• Production rates increase with smaller workforce.

  

As shown in Examples #1 & #2, a heavy duty, construction grade screen is heat staked onto a plastic Vent Housing. The Housing has 16 heat stake posts equally spaced around the perimeter. A machine operator locates the housing into a part holding nest, and then places a precut screen over the surface with posts. Upon initiating the machine cycle, the parts become an assembly within 10 seconds.

  

As shown in Examples #3 & #4, a black painted grille is swaged into the rib of a plastic engine frame. The process of "swaging" is basically embedding the metal grille directly into the plastic. This process is much more difficult than straight forward heat staking as shown previously. In this application, the heat stake iron (tooling) must remain only a few degrees below the plastics actual melting point. Any point over will produce a stringy mess. With quality tooling and equipment, the iron temperature can be closely maintained to repeat this assembly with ease. Thermal Press International employs machine controls with precise tooling to make assemblies such as this routine.

Many other screen materials such as nylon, felt and fabric can be easily staked as well. To discuss your application and whether heat staking/swaging is a viable option for you, please contact a Thermal Press Engineer.

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Heat Staking of Antennas in Handheld Devices

As the world of electronic components continues to miniaturize, so do the electronic devices that contain them.

Many devices such as cell phones, PDAs, laptops and MP3 players are in great need of real estate within the products' enclosures to mount critical components and hardware. In the past, locating a component within .100" of another was considered close tolerance placement to allow the device to perform correctly. Now, the tolerances have shifted to a degree of .005 inches and smaller. This creates great challenges to the engineers involved in providing a manufacturing solution.

The performance of components such as an antenna can be greatly improved if their proximity to other live components can be controlled to within .005-.010 inches. The ability to do so can become expensive and difficult to maintain. If these obstacles can be achieved with proper tooling and equipment, the products success and reliability in the marketplace will be realized while profits are retained.

In the two (click pictures for close-ups) before and after examples shown, a cell phone antenna must be bent to conform to the curved shape of the housing they are to be attached to. By bending the antenna @.050" away from the PCB to be mounted directly above it, the distance between the two increases by almost 100%. This increase in distance is very significant in the performance of the antenna.

There are two ways to achieve this increase in distance. One, is to pre-bend the antenna from the antenna supplier. This is rather expensive and requires special packaging to eliminate damage during packaging and shipping. The other, is to invest in quality tooling and equipment to perform the bending during the assembly process. This investment is quickly realized in greater yields and savings of raw components.

Many heat stake machines and tooling sold on the market today do not provide the accuracy and repeatability to perform such precise heat staking needs. Their manufacturers feel that by offering an inexpensive piece of equipment, profits have been retained by their customer and all is well. The engineers at Thermal Press International do not feel that the savings end here. Nor do we feel that they even begin here. We feel that the real savings and educated investment involves not only the equipment and tooling cost, but the accumulated cost of simplified components, ease of assembly and reliability of the product itself.

In both of the examples shown, the manufacturers were able to purchase antennas at the lowest price available with shortest lead times. This is due to the fact that both antennas are flat and all bending is left to the tooling and the heat staking equipment. There was an investment of time by both parties to work with Thermal Press International engineers to establish proper product design. By designing the tooling from electronic part files, the Thermal Press engineers were able to calculate the degree of bending required and incorporate this into the heat stake tool as a feature. The success of this has been so great that this is now considered standard protocol for design of similar products.

To speak with, email one of our engineers, or visit our manufacturing facility go to Thermal Press International with maps and directions to our thermal press facility. View our heat stake equipment machine standards.

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Cell Phones Assembly Machines

When it comes to miniature plastic parts assembly such as cell phones and other products, a robust machine that can precisely control process parameters (Heat, Pressure, & Cycle time duration) for maximum assembly throughput with the highest yields possible is absolutely necessary.

The C & H Frame thermal presses built by Thermal Press International achieve these goals.

The C frame thermal press machine is one of the most versatile and popular models. Designed to allow the maximum flexibility for mounting on rotary tables, shuttle, or other custom designed tables, with extended arm capabilities for other types of products. Camera vision systems are an option for precise placement of LCDs on PCBs or other heat activated adhesive attachments. View LCD Heat Seal Rotary Table Vision System Close-up. Equipment can also be configured to include an automatic Interposer Dispensing System and be programmed to fit virtually any application. An automatic interposer dispensing system eliminates the possibility of operator error in material placement.

H frame units are also available. The H frame is designed to provide higher force applications than C models. Can be integrated into Bosch Pallet Transfer Conveyor Assembly Lines. This design is a closed format machine with side columns. The machines can be tooled for heatstaking and/or heatsealing, or additional applications.

When it comes to assembling RF shields and metal plates to plastics there is a need to precisely control the head heat & pressure for a side swage or plastic heat staked joint. Failure of the plastic joints will be the result, when using sub par equipment in the assembly process.

Certainly, less well built machines will not maintain the temperature consistently through an entire production run. This leads to cell phone failures in the field. Many companies have tried to build heatstaking & heatsealing machines out of less than optimum materials with substantially less than optimal production run results.

With the terrific amount of competition for cell phone manufactures through out the world, it behooves a company to verify what is claimed with the actual results.

At Thermal Press International we take pride in building the best machines possible for the most value for the investment. We can demonstrate the cost savings to an organization using our equipment to assemble your cell phones or other products.

As cell phone prototype designs change or a new production run begins it is important to be able to quickly come up to assembly line speed with equipment that can be easily configured with new tooling and/or be quickly changeable for other product designs.

Cell Phone Quick Change Fixture

Equipment longevity should be one of the criteria for any company looking to make a purchase of a heat staking machine. Costs analysis and not taking equipment longevity into account would be foolish indeed.

Take a look today, at how our Heat staking machines can achieve all that we say. Email, phone us, or stop by today. Visit our Heatstaking machinery manufacturing facility and view the results that we say.

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Plastics - Metal Parts Heat Staking & Heat Sealing News

Welcome to the press room of Thermal Press International news and information for the manufacturing and assembly industry.

Most items today require some form of plastics or metal parts assembly. Products applications examples include: automotive parts, cell phones, pcb connectors, disk drives, memory modules, lcd displays, and the whole array of consumer products such as laptop computers, PDA devices, pagers, wireless devices, cordless phones, GPS modules, DSL modems, and all types of electronic devices. applications gallery

Connecting Flat Panel LCD
Modules to Circuit Boards
Information Display Article

By controlling the exact heat and pressure applied to an assembly joint we can show you how to improve your production times while improving your throughput and increasing your yields.

Not all heat staking or heat sealing machines are equal.

Learn how Thermal Press International can help in the production of your plastic and metal assemblies today. Contact us by Email, phone, or if you are in the Livermore, California area stop by. Click link for maps, directions, and information to our thermal press manufacturing facility.

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