Stack mold & molding
In a few decades, Stack mold in the packaging products and many other small parts production growth continued access to new development. Innovative mold design is to stack the mold of traditional markets a variety of colors and a variety of materials forming ability. Stack mold now are seizing the large-tonnage molding machines to produce opportunities for large industrial components.
The usual stack mold design because of their productivity than ordinary single-sided mold is known. They are mostly used for very small, shallow stretch packaging products and other disposable products, and few other products used in addition. But in the past few years introduced a number of new mold broadened the concept of stacked die capabilities, including multi-material molding and large industrial parts, such as car headlights and the side of the modified prism pieces. Means that large parts forming the first application of laminated mold in more than 1000 t of molding machine.
The pace of innovation in multi-component molding has been quite active. The usual mold of the typical single multi-component molding method is injection mold half of a kind of material into the cavity, and then injecting the second material into the mold of another half-plane. In a cycle, the horizontal axis rotary templates, make the mold upside down. Laminated mold can be used to double the mold surface, allows the mold surface forming with the respective materials. This new design has a vertical axis rotation in the center of the template. Depends on the system, the center or the template can have two or four side, when mold is open rotation 90o or 180o.
The concept of the four mold parts so that mass production of multi-component approach to commercialization. The structure of such a new mold, including Engel's rotating template design, the center of the template has two faces, each cycle of rotation 180o. Ferromatik Milacron Europe by the German mold maker Foboha companies to develop a rotating stack mold surface of the center of the four templates, which each cycle of rotation 90o. Gram Technology of Denmark rotating laminated (Spin Stack) method as many as four side next to the center of the small side laminated structure, each of the four face again, and each cycle of rotation 90o. Another unique structure, called the low-inertia Technology (LIT) from Caco-Pacific Corporation. In this relatively simple design, with two core groups of the rotation pole connected to the side of each mold, rather than the design in other settings as a separate.
These new designs are being asked laminated better feel for the soft touch applications. Such applications include, for example, toothbrush, resistance through packaging applications, with a molded lining of hats and caps, multi-color cell phone case, and from different materials like PVC composition PP and medical components.
An example is the Foboha company with PET (40g) resistance through the layer of HDPE (70g) toothpaste-style bottle shoulder mold design capability 1 billion. The company has two processing methods and product patents. The new 4x64 Rotating Laminated (Turning Stack) system spit out a 8.4s cycle of 64 double parts. Production is estimated at 175 million a year, it will use the six production systems. This scale of production would normally require 21 sets of conventional stack molds and machines. Special injection quantity control device allows the device to run in regulating the thickness of PET layer, and can help reduce the weight of 43% of the parts.
Consumer goods more and more popular, for example, soft touch feel good toothbrush and shaving characteristics hilt, the strength requirement will push their volume needs the most appropriate level stack mold. Ferromatik Milacron Europe and Foboha 50-60 sets of rotating stack mold company is running, of which up to 20 units in North America. Multi-component parts of the company forecast 10% annual market share.
"At present, the multi-component parts and components market and is in prosperous condition," an Austrian supplier of packaging products, mold, so far Gram's hat and cap the only patented rotating laminated technology business, the company's general manager Claus Ziegler said. "Five years ago, we sold the mold about 1% of applications for multi-component, multi-component application is our business volume has reached 15% -20%," Ziegler said. KTW company has 8 to 10 sets of rotating laminated mold in the test or working condition.
Method of rotating laminated
With the usual rotation for multi-component molding template comparison, this new type of rotating laminated mold due to the rotation part of the mass was smaller, so much faster translocation. Gram's rotation in the laminated mold and Caco-Pacific's low-inertia system, particularly evident in the quality decreases. "Typically you could save 20% to 30% of the cycle time, special circumstances can save up to 50% to 80%," KTW's Ziegler said.
Gram's system has additional advantages, it allows rotating stack mold the minimum required to open away from the mold. Manager Jes Gram said that to make the system switch position, a two-component mold simply open the lid of 100mm. Is developing a new ejector design allows the template to open from the reduced to 60mm.
"The concept of rotating laminated on the market is the most flexible," Gram added. "Rotating body, hydraulic equipment and all components included in the mold itself, so it allows the technology
For any conventional molding machine. "The second material can be used in the machine next to a modular injection device to supplement supply, for example, by Windsor's new PlugExpress system that in the U.S. by its sister company Sandretto sales.
Gram company will expand its rotation stacking technology to injection mold called double two systems. Toothpaste designed for two-component bottle shoulder mold, with four sub-surface and two pairs of each of the four rotating laminated surface, each side has 24 cores, a total of 384 core and 192-type cavity. Cycle time is shorter than 7 s, its production capacity of 1.15 million / d, or 390 million / a.
Gram said that the two injection process on the thickness of a single material forming parts is also good. This method can use the same supply of hot runner injection of the second layer of the same material. Gram said, as long as each injection small volume injection and cooling the melt, which reduces the possibility of shrinkage marks produced.
Rotating laminated method is not used for forming the center stack of the (second and fourth) surface can be used to assemble documents or cooling components, and will not increase the cycle time. Gram company recently obtained a new patent ejector system, it will be the top products to the machine's side. The ejector hydraulic system installed in the mold frame. Additional use of laminated surfaces another method is a kind of three injection molding products. Gram company creates a pipeline for the production of medical connector mold, the first injection of PVC, the second injection of thermoplastic elastomer (TPE), the third time injection of PVC, with some overlapping molding TPE. The products of the three stations forming, and from the top of the fourth station. Demonstrate operation in a 88t of Demag machines on the company, the cycle time less than 15s. This 8 +8 +8 cavity mold for the industrial companies in Denmark Carmo more than 46,000 parts per day.
Ferromatik Milacron Europe and Foboha jointly developed rotating stack mold in last year's K 2001 exhibition debut, shows that the system used to date the largest number of cavities. The 4x64 system cube in the center of each side of its four side cores 64, and for each of the two materials used in the cavity 64. This application is the introduction of the toothpaste bottle shoulder.
Although the original model rotating stack system has two central plane and 180 ° rotation position, the new model has a location 90 ° increments to convert the center cube, can allow for cooling or non-forming side of the insert with. A hydraulic motor with programmed acceleration / deceleration curve so that central part of the change in the 1.3s in position.
This rotating laminated system only in Ferromatik's K-Tec machine production line running. These devices have a standardized adaptation laminated mold can choose sets of components, providing a longer lever to increase the shut height, provide a more solid machine bed to support the central part can be rotated. The second injection unit is located next to the rotary table, and the machine vertically.
In the K2001 exhibition, Engel has introduced their system of rotating laminated by a Duo's dual-molding machine and a set of templates has a 180 ° turn-bit central template composed of two materials laminated mold. Engel Duo's company only in its spin machine to provide laminated mold, this is because of its shorter clamping device that allows the template in the opposite movable second injection unit installed. That system greatly simplifies the design flow. Translocation speed of 1.5s or less.
So far, Engel has an Austrian company High Tech Plastics manufacturing of this type of presentation with the mold. It shows that the multi-component laminated mold in automotive applications is the emergence of new opportunities. In the K2001 exhibition, Engel about the company before the big shade produced by the transparent polycarbonate (PC) and the border of a black PC frame composition.
And other technical differences, Caco-Pacific's multiple injection techniques can be applied to the normal rotation of the center is not part of the stack mold design. All low-inertia servo-driven technology system will be the main mold core and mold to separate them fixed in the installation of a mold surface rotation in the level of poles. Two cores installed on the pole - a group of up, the other down. This bar with a rail connection to a half of the mold. In the molding process, core flush with the mold surface. A material is injected into the cavity above a row, while the second material while filling the cavity into the row below, using two American Caco-Pacific hot runner. When the clamping device open, core rod from sliding away from the mold surface, to allow cores rotating rod 180o. An ejection lever finished products will be forming a group of cores from below the top out, then slide the bar back to the surface of die and mold closed.
The quality of rotary core rod relatively light, installed by the end of a small servo motor to rotate. Rotation process is shorter than 0.5s, sales and marketing vice president John Thirlwell said. He pointed out that if you want, the system allows the second injection, and fully covered the first injection of material.
Caco-Pacific company in less than two years, several low-inertia within the manufacturing technology mold. All of these are single-sided mold. But now can order a laminated mold. So far the largest application is a 16 +16 a single mold for the production of the overlap with the soft feel of the whole coated plastic barrel. 32 +32 a kind of two materials are laminated mold design. Thirlwell said that because of its low inertia technology applicable to all electric drive clean room, so medical market attracted great interest.
Skills in a variety of resin
Gram companies and Ferromatik company / Foboha companies both said rotatable laminated mold so that they develop a number of unusual applications. One is the thermoplastic / thermosetting plastics, or "hot / cold" molding. Molding, a material needs to be a hot mold plastics, and other materials needed to cure a cold mold. Gram company has designed a 2 +2 cavity rotating stack mold, used to process silicon rubber gasket with internal nylon for auto parts. Although the nylon / silicone molding aim is to achieve good adhesion between the two, Gram companies and Ferromatik company / Foboha companies use a four rotating laminated components to achieve the opposite effect. If the first injection in the overlapping products thoroughly before enough cooling, and the final products made of two components to slide freely relative to each other.
Gram companies use this method Demo forming a valve, one of the parts in the other parts within the slide. Another example is forming a triangle on top of the juice box with the nozzle used in the screw cap. First, the PP copolymer forming juice box cover, rotating the core, and LDPE using a new type of nozzle core within the cover molding. Cover a long time because of an extra cooling cycle, and the second injection of the LDPE melting temperature is lower, cap and nozzle will not stick together.
To break the size barrier
Stack mold technology for the first time breaking barriers, access to more than 1000 t in forming the machine large parts applications. Plastcoat company is using a surface of a cavity in each of the Husky's double stack mold, the Ford XLT truck while the production around the rotary-type lights. Another 1 +1 tandem mold is for Toyota's Camry production line manufacturing arm. Each of these parts a few feet (ft) long (1ft = 0.30 m), using 300 g of the thermoplastic polyolefin (TPO). This part in the Husky's 2200 t EWLL (widening, lengthening) on the two-plate molding machine.
"The main advantage of stacking is to save die area," shaping operations manager Rebecca Branca said. Cycle time normally speak with the same tonnage of capacity in two different machines running the mold in line, she said.
This mold has a unique operation in the mold following injection Road bar (sprue-bar). It will melt assigned to the stack mold tray. A bracket to
Two die material for hot runner system unique. Husky-designed so that the melt flow channel system is always in equilibrium, even if the A side and B side of the different parts, forming the maintenance department manager Roy Zinner said.
When the mold is open, note Road bar is divided into two and a half and half to connect to a fixed template, the other half connected to the laminated mold tray. A "coordinated" bar pulled all the parts of mold to Stack molding together. This rod can be adjusted to suit the different sides of the mold height. Plastcoat company about the production of each work shift 600 parts.
