Thermoformed plastics

Thermoformed chassis and body panels are featured on the car. The products were made initially in the USA for assembly in China. The car will weigh less than 2000 lb (900 kg). Automotive Design Composites, Inc of San Antonio, TX, designed the vehicle to have body panels and trunk formed from coextruded sheet of ABS with an ASA cap layer that will hang on a pultruded composite frame. Ceramic tooling is used to thermoform plastic products. 

Phenolic resins. Resins such as those made from phenol and formaldehyde now account for about one third of the phenol consumed in the United States. They are widely used in construction related use such as plywood adhesives, foundry resins, thermoformed plastics, and surface coatings. 

Polyethylene Terephthalate (PET) A plastic resin of the polyester family and one of the most common thermoformed plastics. Plastic soda bottle are a common PET product. PET is also fully recyclable. 

This is another version of cold forming by utilizing a thermoformed plastic skin to impart an excellent surface and other characteristics (for weather resistance, etc.) to a cold-molded RP. For example, a TP sheet is placed in a matched mold cavity with an RP uncured material placed against the sheet. The mold is closed and the fast, room temperature curing plastic system hardens. The finished product has a smooth TP-formed sheet backed-up with RP. 

In 2003, Wilkinson Industries introduced NaturesPLAsticin, which says the company, was the first-ever thermoformed plastic food container made from NatureWorks PLA. NaturesPLAstic is completely recyclable under composting conditions in 45 days using commercial composting facilities. 

This may involve the collation of packages of similar or variable shapes. The most popular form uses either a direct shrink wrap (e.g. multi-packs) or a shallow tray which is usually made from corrugated board or solid board. Thermoformed plastic trays with a formed base (and/or a lid/cover) are also widely employed (e.g. bottles and aerosols). These systems offer restriction to pilferage and due to the see-through nature of the film may avoid the need for external labels. (Internal labels may be necessary if stock is controlled via a bar code.) Although LDPE has the major use, PVC may occasionally be used for its higher clarity. Gauges of 25 to 100 m are usually employed. 

Figure 5.21 Thermoformed plastic, used as the female mold, is backed up with sprayed RP...

Hand Layup (Contact Molding or Open Mold Process). The oldest and simplest technique is primarily manual. An open mold is waxed to lubricate it. The surface of the proposed product is applied to the mold, usually as an unreinforced gel coat or sometimes as a thermoformed plastic sheet. A layer of fabric is hand cut and hand laid into the mold. Catalyzed resin is poured over the fabric and worked into it with brush, roUer, and squeegee to eliminate air bubbles. Another layer of fabric is laid over this, often oriented in a specific direction to optimize properties. Again, catalyzed resin is poured over it and worked into it. The process is repeated as many times as required to build up the desired thickness and optimum orientation of the layers. If the cure reaction is inhibited by air, a wax may be dissolved in the resin it exudes to the surface and forms a barrier to exclude air and permit complete cure. The resin may be allowed to cure at room temperature, or the assembly may be heated to complete or hasten the cure reaction. 

Laminate sheet of polyflactic acid)-based resin arrd thermoformed plastic corrtain nucleating agent, rramely aliphatic carboxyhc acid arrride. ... 

Leaversuch, R., Close-Up on Technology— Thermoforming PPS Role Shapes Up in Thermoforming, Plastics Technology On-Line, August 2004. 

Comoform is an extension of the cold molding process which utilizes a thermoformed plastic skin to impart excellent surface to a cold molded laminate. 

Throne, J. L., and Kmetz, M. Computer-Aided Design in Thermoforming. Plastics Engineering, pp. 35-38, Sept. 1989. 

Fluoroplastics such as PVDF, FEP, PFA, and modified polytetrafluoroethylene can be thermoformedf ] by vacuum forming, pressure forming, and matched-die forming (Fig. 14.56). In all methods, a sheet of the fluoropolymer is heated until it reaches its gel point. It requires more soak (heat up) time than eonvention-ally thermoformed plastics due to its low thermal... 

Fig. 19.42. Basic thermoforming. Plastic sheet is clamped and heated. Vacuum beneath the sheet draws it down against the mold. The formed part cools against the mold and then is removed. (Courtesy Modern Plastics Encyclopedia, 1989-)...

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