The growing importance of rapid prototyping and rapid tooling is a prominent theme of the recent annual meeting and design competition of the SPI Structural Plastics Department.
Held in CharlotteC.
The meeting showed a brand
New ways to make molds faster and cheaper using a method similar to Fast
The prototype method of establishing the model with thin slices.
Also worth noting is an article on how to choose fast
Provides useful similar prototype materials for the physical performance of the production parts. Gas-
Auxiliary molding is also a hot topic.
Of the 62 parts participating in the design competition, 10 were using gas AIDS.
A conference spokesman to a well-known
Auxiliary technology, and proposed more costs
An effective alternative.
In addition, the biggest feature of the part design competition is the glass
The filled nylon part was once injection molded and two large structural parts containing recycled materials.
Another winner showed more
Over-forming of materials. New rapid-
Using a new laminating process called Fast-it is possible to make a mold that is cheaper 10%, faster 20%
Form from Fast4M tools
As of January 2003, the company has been developing for seven years and has been commercializedThe form is laser
Based on this technology, thin layers of flat steel plates are laminated to establish core, cavity and other mold parts.
A variant of this process can also be used to make low aluminum tools
Mark Manuel, president of Fast4M, said pressure applications like RIM.
This process is achieved by placing a Fiat piece High.
The speed laser cutting machine
, which follows the pattern generated from the CAD file.
Slice of CAD model of drawing pattern representation tool--
Similar to the program used in rapid prototyping. Sheets are 0. 030 to 0. 250 in. thick.
After cutting, place each piece of metal plate in the positioning device.
To ensure tolerance, the paper is measured separately there.
Then glue the steel plate together with a patentpending high-
Thin layer of Eli (0. 0002 in. )
Copper as adhesive.
According to Manuel,
The step-by-step bonding process not only changes the performance of copper, but also forces it into the surface irregularities in the steel plate, resulting in mechanical bonding.
The result is a composite tool with a tensile strength of 92% to 94% of the steel. For low-
Pressure mold, aluminum plate bonded with epoxy resin and interlocked in patent
A pending method for increasing the mechanical strength of the tool and allowing it to withstand temperatures up to 450 F.
Using CNC machining and conventional molds, steel or aluminum tools are processed into final tolerances
Finishing Techniques such as potty and finishing eyes.
It is said that the tool size is as accurate as standard CNC machining.
Fast4M has developed proprietary software to manage and automate the entire process from laser cutting to finishing and to monitor and maintain set tool tolerances.
The production tools are made of 410 stainless steel and 13 H steel and 6061 T-6 aluminum. Cold-
Prototype molds have been made using rolled steel.
The Fast4M has been built with molds up to 4x6 ft sizes.
At the beginning of last year, the first steel tool was put into production.
It is said that the cost of laminating process is particularly high
Effective for large molds, in large molds, purchasing large pieces of steel will increase the delivery time. Fast-
It is reported that Form can produce large tools in a few days, not weeks.
Manuel said that the cost savings from the use of laminated tools may exceed the cost that may be saved by overseas discounted tools.
In addition to saving time in tool manufacturing, Fast-
The advantage of the Form is the ability to combine shape-preserving cooling and \"flood\" cooling channels, as well as wide ventilation at low cost, as they are in relation to the core/cavity geometry.
Shape preservation and flood cooling channels are closer to the geometry of the part than the straight gun
Shape preservation and flood cooling are said to produce faster cycles, lower part stress and reduced warping.
Prototype materials for rapid prototypingprototyping (RP)
Technology provides a useful preview of the appearance of the production parts, and RP materials provide little or no information about the mechanical and thermal properties of the intended application.
Tom Mueller, partner of RP prototype supplier Express Pattern, said that none of the RP systems currently available can be used to make parts that are exactly the same as the production materials.
After studying this issue, the Express mode determines that the RP part does not need to meet every performance feature of the application in order for the designer to understand the performance of the actual part.
\"In almost all test cases, the performance of the part is determined by the performance of relatively few critical materials,\" Mueller said . \".
Therefore, RP materials only need to provide a reasonable match with the production materials in these key performance areas.
Express patterns developed a method to help select RP materials based on how well they match key performance standards.
The main step is to determine which material properties are really important and how close the RP material properties must be to the material properties at the end
To give a useful indication of performance, use the material.
The result of this analysis is a chart showing the drop position of the RP material relative to the required performance criteria for the part.
To prove the practicality of the method, Express Tool provides two working examples: in the first case, Express Tool is interested in load
The carrying capacity of the prototype
The company produced a chart showing the bending strength and stiffness of several RP materials as well as the actual endsuse material--
A common ABS resin.
Next, the Express Tool determines that the stiffness of the prototype material should be within 20% of the bending modulus of the production material, and that the bending strength of the prototype must be slightly higher than half of the bending strength of the production plastic.
As shown in the chart on p.
56, any RP material belonging to an acceptable stiffness/strength area should provide useful performance data.
\"For some prototyping situations and materials, there is no RP material that can be close enough to the production of the resin,\" Miller said . \".
He shows an example in which no RP material can approach the impact strength of the applied resin.
Mueller also pointed out that many parts will have several functional requirements and may need to use several prototypes of different RP materials to fully test the adequacy of the design.
In addition, material performance may not be the only consideration when selecting the RP process.
Features such as dimensional accuracy and surface finish may be critical, and the RP system may vary significantly at these points.
In addition, the material properties in the polymer change with section thickness, loading rate and other factors, which makes it more difficult for them to replicate in the prototype.
Mueller warned, \"in key applications, it may still be necessary to validate the design with the molded parts of the production material.
\"Testing RP parts is also unlikely to predict the life of the production parts.
Overflow cavity in gas
Assisted injection molding, the method of receiving resin replaced by gas using an overflow well or cavity has been in use for many years.
In fact, this may be over-used and unnecessary, and will increase tool costs and cycle times, says Paul Deere, a sales and technical expert at gas supplier Bauer plastic technology group.
\"Using an overflow cavity can increase the tool cost by 10%, and an overflow cavity using a hydraulic pin can increase the cost by 20%,\" Dier said . \".
The overflow cavity may require the tool manufacturer to use a larger mold base, which also increases the cost.
The cycle time can be extended because the resin quality in the overflow cavity must be cooled before the parts are demoulded.
Dier added that the excess material in the overflow channel, whether it is unused scrap or re-processed, will increase the cost.
The overflow cavity leaves an extra hole on the part, and if the overflow cavity is not designed properly, it can let the gas escape instead of the resin.
More importantly, Dier said, the use of overflow cavities may result in high licensing fees because they are covered by several patents.
One way to eliminate the overflow cavity is to adopt precise timing control and gas pressure lifting during the injection process.
Bauer provided a ramp.
Control function as its gas standard
Auxiliary controller, not ladder pressure distribution used with other systems.
\"It is able to inject gas and melt at the same time, while other systems do not provide this overlapping function,\" Dier said . \".
He warned that it was necessary to wait until the resin injection stopped before leaving a sign of hesitation on the surface of the part.
Steadily increase the gas pressure to promote melting, while reducing the possibility of melting when the gas is first introduced.
When the gas is introduced, increasing the gas pressure also reduces the chance of star burst marking on the surface of the part.
It is said that the ramp profile method is especially suitable for forming thick-wall parts.
With power\'s controller, model will be short.
Shoot the mold, but the material put in the cavity is usually more than the thin part.
Thick parts are usually formed by completely filling the mold with resin before introducing gas to eliminate the hesitation line.
Bauer\'s system also has a vent.
Control valves capable of providing more exhaust control.
\"This is a benefit, because if the gas is discharged too quickly, it creates a vacuum that sucks volatile substances and/or materials into the gate and blocks the gate,\" said Dier.
Power\'s system releases gas into the atmosphere while bringing volatile substances into the container.
It is said that this is the largest glass injection molding product in history.
Filled with nylon, the top cover of the Mercury Marine outboard engine gets the structural plastic Div.
Conference Awards, People\'s Choice Awards and leisure entertainment awards.
Cast by Bemis Manufacturing Company
, Cowl weight 11.
3 lbs, 20% lbs or 3 lbs less than previous versions of heat sleeve SMC compression molding.
The overall size is 33x23. x 16. 25 in. deep.
The hood of the John Deere 7000 series tractor won the single part Award, and the engine casing won the agriculture/lawn and garden award.
Both of these products are manufactured and formed by Bemis, which is said to be co-injected in recycled engineering materials (ABS)
Used in the core.
The housing is PC/pbx alloy.
The core of recycling reduces the overall cost.
Both parts have walls of 6 to 8mm thick and contain recycled ABS of 9 to 20 lbs.
One of the most beautiful designs in the competition for structural plastic ports is the new Eleganzia series service products of Tupperware Corp. , Orlando, Fla.
Win the retail/consumer goods awards.
The product is molded from two colors of polycarbonate, which partially overlap to produce a third color.
Morder is a Tupperware in France. A.
Need to know more?
For more information, please enter the PT direct code at www.
Bauer plastic technology group, Clinton Township, Michigan. (586)286-
0360, PT Direct: 418AV Express mode, sick at Buffalo Grove. (847)215-
0001, PT Direct: 388UR Fast4M Tools Co. , Ltd. , Rochester Mountain, Michigan. (248)457-