Views: 68 Author: Site Editor Publish Time: 2022-04-29 Origin: Site
Compared with foamed PS and foamed PE board sheets, foamed PP can be used in microwave ovens and is resistant to boiling water. Thermoformed plates have high enough impact strength at low temperature, can be used in cryogenic environment, and its surface feels comfortable and soft. For example, foamed PP sheets with a density of 0.1-0.5g/cm3 and a thickness of 1-3.5mm can be used for food or meat packaging, and can also be used to make thin shell products, various utensils (plates, dishes, bowls, boxes, etc. ). Foamed PP sheet with a density of 0.5～0.7g/cm3 and a thickness of 0.5～1.5mm is the raw material for the production of tableware (such as: plates, bowls), drink cups, etc. with high rigidity and good heat insulation. Foamed PP board with a density 0.2～ 0.5g/cm3 and a thickness of 1.0-3.5mm is used to produce meat packaging materials, tableware, or processed into pots and plates, and used for the packaging of low-acidity foods such as applesauce and yogurt in containers. In order to reduce the use of PS resin that is harmful to human body, most developed countries use polyolefin resin to make various lunch boxes. Previously, transparent PP sheets or extruded PP single layer foam sheets were used. Since May 2009, PP single-layer foam sheet has been officially used to make various tableware and containers that can be heated in microwave ovens. Because of its good safety and not easy to be affected by heat, it has been widely used in the manufacture of food packaging containers since 2008. . The United States, Austria, Denmark and other places have successively built production lines of foamed PP products for the production of food packaging boxes and trays and containers for microwave ovens.
German company Ofotec Folien, which produces foamed PP sheets, believes that PP foamed discs have a tendency to replace EPS molded discs, because users are interested in that PP foamed sheets can be directly fed from the take-up roll to forming-canning - sealing device, and the plate can be made steeper, so it occupies less shelf and is very popular with merchants. In addition, recyclable foamed PP molded trays are convenient for handling and shipping of fruits and other agricultural products. Due to the high heat resistance of PP, it is widely used abroad to replace PS foam sheets where the heat resistance cannot meet the requirements, such as thermal insulation materials for 90℃～120℃ heat carrier cycle batteries, engine rooms and workshops, thermal insulation jackets for heaters, and places in the car that must be insulated, such as sun visors, thermal insulation panels on instruments, and places where the temperature is likely to rise between the two doors. In short, foamed PP can be used in all parts where there is a heat resistance problem when using PE foamed materials.
PP foams for automotive parts have become increasingly important in recent years. In addition to the high heat resistance, high impact energy absorption, good resilience and thermoformability of PP foam, recyclability is also an important factor. This makes it possible to manufacture components entirely from PP, for example in instrument panels, with GMT or talc reinforced PP for the brackets, PP foam as a soft elastic middle layer, and a soft sealing film as the outer skin. With this solution, the plastic parts of the car can be dismantled, cleaned and re-granulated after the car is scrapped and reused for lower-grade product applications such as wheel arch linings. However, this process is limited due to the high cost and complexity of the process. All of these problems can be solved if foamed PP with a smooth surface is thermoformed and bonded to an injection-molded PP or ABS base. From this point of view, people continue to make efforts to use foamed PP as interior decoration materials such as automobile dashboards.
Extruded PP foam board sheets can be used to produce water barriers or sound insulation panels for car doors, rear engine compartments in luxury cars. Rigid PP foam panels reinforced with glass mats are used in the production of automotive engine guards, load-bearing floors and spare tire covers. At present, the foamed PP board with a density of about 0.6g/cm3 and a thickness of 2-6mm in the market can be processed into car covers, boxes, etc., and PP cross-linked foamed materials with a density of 0.035-0.085g/cm3 and a thickness of 1.5-6.0mm are used in the automotive industry as linings and damping materials.
Due to its good thermal weldability, foamed PP can be used for automotive roof panels. Due to its thermal processability, cross-linked foamed PP will be further used in components such as control boxes and shock-proof panels. Foamed PP sheet and PP, ABS and other inner layer materials, PVC and other surface materials are bonded by adhesives or heating, and vacuum forming can be used to make carpet support materials, sun visors, sound insulation panels, door linings and luggage racks, etc. Foamed PP can also be used to manufacture steering wheels, luggage compartment linings and baffles for air conditioning steam, side guards, energy-absorbing protection pads for door inner panels, cushions, headrests, tool boxes, etc. In these areas where higher operating temperatures are required, foamed PP has advantages over foamed PE, as the latter can only be used at temperatures below 80°C.
The PP foam board with center foaming and smooth surface, referred to as CD board, its surface does not need to be planed, and can be processed with wood processing tools and processing methods. Composite fabrics, metal sheets, films, wood grain sheets or films can be processed with recycled materials. The CD board is used as a building template, which does not absorb water, does not stick to cement, and has good air permeability, which is deeply used by foreign construction departments. For example, in order to welcome the Olympic Games, Australia specially introduced a low-pressure injection molding machine with an injection volume of 80kg from the Hettinga Company of the United States to produce CD boards and provide templates for the construction of Olympic venues. The CD board used as a template can be made of 100% recycled plastic, the price is completely competitive with plywood, and the CD board can be reused 50 times and has a lifespan of 10 times that of plywood. What's more valuable is that it can still be recycled after 50 times of use, there is no waste, and it will not pollute the environment, so it can be called a "green product". Low foaming PP sheet can be used as door panels, wall panels and roof panels of plastic camping houses, etc.