On-line production technology of automotive fiberglass molding

Most large European automotive groups that use D-LFT compression molded parts originally used compression molded GMT to produce compression molded parts, and now they are used in both technologies. D-LFT molded parts often use the same mold as GMT parts. BERNDWULF, High Performance Plastics and Composites Center, RIETER Automotive, Switzerland, said, "We produce high quality, low cost parts, and D-LFT technology is a major factor in increasing market share." RIETER already has two Years of experience in D-LFT operations on two DIEFFENBACHERs, plans to install two more production lines soon.

BERSTORFF produces a continuous production facility similar to GMT materials. A twin-screw extruder was modified to separate the continuous rovings with a pair of rolls and heat them, which were wetted with the melt before being pulled into the twin screw.

BERSTORFF has produced two compound extruders capable of processing D-LFT, although none of them used molds, one of them in the laboratory of BERSTORFF in Germany and the other one in Switzerland, QUADRANT, which is used to produce low cost. The GMT film is sold to the compression molding manufacturer. Interestingly, QUADRANT uses this technology to combat competition from D-LFT compression molding.

The United States Composite Products Company (CPI) developed the first D-LFT compression molding process in 1989 and commercialized it in 1991. CPI uses two single-screw extruders on the production line, one for the melting of PP and the other with a low-shear screw to preheat the chopped fibers and gently mix them with the melt, then Transfer it to a compression molding die.

CPI has three D-LFT production lines and has been producing the lower dashboard of the 3 x 5 foot DODGERAM excavator cab for 7 years. Recently, JEEPWRANGLER has also produced door peripheral parts and front gears, and will soon produce activity boards for TIERONE automotive suppliers. CPI is building its fourth D-LFT system, which will use a new long glass fiber process called WOODSHED to coat the melt onto the roving with a wire-coated handpiece. The inventor of this process, RONHAWLEY, calls this latest process "pultrusion", which eliminates the need for collectors and plugs and can be filled with standard injection molds.

In 1995, Swedish VOLVO licensed CPI's D-LFT compression molding process. VOLVO requires long fiber products, but the price is lower than GMT. VOLVO compression molded car body dashboards and boxes in the front and truck cabs.

VOLVO gave its D-LFT compression molding business to POLYTEC Materials Sweden, a German automotive GMT molder. POLYTEC's new D-LFT project includes the VOLVE engine cover. The POLYTEC and VOLVO trials competed with SMC with a 30 mm long glass fiber filled nylon. POLYTEC is also developing a shredder that shreds rovings next to the D-LFT equipment instead of buying expensive shredded glass. POLYTEC does not want to use an extruder to chop the glass, as the extruder chopped the glass to produce more random glass length (this is also a debate among twin-screw extruder manufacturers).

The CPI process has recently been licensed to DECOMA International, which will begin D-LFT compression molding later this year.

American Composites Technology (CTC) received the plasticizing equipment technology of the former ROSE Extruder Company in 1993 and began to research its own D-LFT compounding technology, which was patented in 1994. This technique uses a reciprocating single screw extruder having a length to diameter ratio of 34 to chop the glass fibers into a compression molding die. CTC currently operates eight D-LFT compression molding lines, producing a range of non-automotive composites with trimmed glass fiber mats and TPO recycled from automotive bumpers, and also produces backboards and carriers for basketball boards for HUFFYSPORTS. . CTC License C. A. LAWTON uses its plasticizing equipment and is also testing users for LAWTON. CTC also recently sold a system to a US user that will be delivered later this year.

W&P has been supplying the co-rotating twin-screw compounding equipment and injection unit for D-LFT. Currently, 12 sets of compounding equipment are used to supply roving for D-LFT compression molding, 7 of which are DIEFFENBACHERGMT presses. Transformed. An extruder generally feeds two molds. The compounding equipment to be installed in RANGERPLAST, Italy, will soon be fed to three molds.

RKT is the largest user of W&P's D-LFT compounding equipment, with five systems in operation in Germany, Brazil, Spain and Mexico. The production line in Mexico began producing parts for Volkswagen in Mexico six months ago. RKT hopes to install the D-LFT compression molding line in its AKSIS in the next few years. RKT molding products such as body panel, baffle and front end carrier, the length of the fiber in the molded product is 2 ~ 25MM, but most of the length is 8 ~ 10MM.

Hydraulic Diaphragm Metering Pumps

As the name suggests, Diaphragm Metering Pump using a special design and processing of flexible diaphragm instead of the piston, under the action of the drive mechanism to achieve reciprocating motion, complete the suction - discharge process. Due to the segregation of the diaphragm, the isolation between the metering fluid and the driving lubrication mechanism is realized in the structure. High-tech structural design and the selection of new materials has greatly improved the service life of the diaphragm, coupled with excellent corrosion resistance of composite materials, diaphragm metering pumps become the main application of fluid measurement pump type.

In the diaphragm-type metering pump family members, the hydraulic diaphragm metering pump/refineries hydraulic metering pump/Hydraulic Diaphragm Metering Pumps as a result of the use of hydraulic oil evenly drive the diaphragm, to overcome the mechanical direct drive mode under the pump diaphragm too concentrated shortcomings, to enhance the diaphragm life and working pressure ceiling. In order to overcome the single diaphragm metering pump may occur due to damage caused by the diaphragm damage, and some metering pumps equipped with a diaphragm breakage sensor to achieve the diaphragm when the automatic chain protection; with double diaphragm structure of the pump head to further improve its safety Sex, suitable for security protection is particularly sensitive to the application.