RRIM development

Automotive manufacturers are evaluating hang-on RRIM body panels, e.g. boot lids, bonnets, door panels, and wings, and as already mentioned a production car is already available. Detroit has been the impetus behind RRIM and the high mod urethanes that are expected to successfully compete with steel. Since Detroit has dominated the development of RRIM, 

---

The reinforced reaction injection moulding (RRIM) process is a development of RIM in which reinforcing fillers such as glass fibres are incorporated into the polymer. One advantage of such a system is to reduce the coefficient of thermal expansion, and with a 40-50% glass fibre content the coefficient is brought into line with those of metals. 

An area of RIM which very rapidly advanced through machinery and equipment developments is the so called REINTORDCSD RIM or (RR3M) technology now an accepted and proven carmercial process after only several years of intense machine development (16). The kinds of solid additives which in reality can be processed on RRIM equipment are fillers not reinforcing agents, due to their low asp>ect ratio. 

Data summarizing raw material usage and cost development 1s provided 1n "Table III". Raw material usage 1s based upon part weight, material waste, and production demand. Today, body panels of PU-RRIM and PC alloy are molded at thicknesses of. 125 Inch. 

Newer developments include also RIM and RRIM machines for the processing of polyamide and epoxy formulations. 

The necessity to lower the weight of automobiles in order to meet the 1985 government CAFE requirements of 27.5 mpg. has spawned the development of high modulus RIM polyurethanes and reinforced RIM (RRIM) to replace metal in fenders, door panels, trunk lids, etc. The RRIM polyurethanes are well suited for the external body panel application where structural requirements are at a minimum. In addition to significantly lighter weight in comparison to steel, the RRIM panels eliminate corrosion problems and improve resistance to damage. 

At this point in time in the development of RRIM technology, it is difficult to predict the future market and the resultant impact on the polyurethane raw material market. 

Based on the tremendous momentum that has built in the polyurethane industry for development of RRIM technology, it can be confidently expected that significant improvements... 

The development of non-automotive RIM and RRIM applications will be slow unless considerably more effort is expended in this direction by the polyurethane industry. It has been predicted that by 1983 the non-automotive R IM and RRIM polyurethane elastomers will be approximately 6 M lbs.JJiJL. 

There is no single method for treating polymethane (PUR) waste, due to the different quantities, qualities, mixes, and cleanliness. It is estimated that some 125,000 t of RIM polyurethane is used worldwide, 85% in automotive parts, mainly in bumper fascias. Current technologies for physical recycling of PURs are mainly directed towards flexible and rigid foams, but systems have also been developed for recycling reinforced reaction injection molded (RRIM) PURs, on the... 

Structural reaction injection molded (SRIM) sandwich panel composites incorporating recycled RRIM granulate have been developed in Europe, comprising two layers of glass reinforcement on either side of a core layer of granulated RRIM. The filling can be composed of either painted or unpainted material and can be preformed to shape before resin injection. 

With PUR, a chemical reaction between the mixed liquid components, polyol chain extender, and isocyanate takes place inside the mold after each shot, enabling the properties of the moldings to be predetermined and controlled. Depending on the mix, the cycle times can be reduced. In the past ten years, cycle times for typical PUR-RIM or PUR-RRIM have been reduced from 3 min. to about 30 s because of the development of a faster reaction speed (glycol chain extenders were replaced by amine chain extenders). 

The following is a preliminary report on reinforced reaction injection moulding (RRIM), The process is in a state of rapid development and as yet there are no UK applications, although several companies are considering RRIM automotive parts. 

RRIM is a development of the RIM process (reaction injection moulding). The essential feature of an RIM system is a 2-component liquid resin system which reacts rapidly when the two components mix, to form a fully developed polymer inside the mould. Usually these systems are polyurethanes, although others, especially nylon-based systems, are under development. 

Redland Tiles Ltd, 65 Reinforced reaction injection moulding (RRIM), 127-32 advantages, 131 development, 129 limitations, 132 process, 130... 

The growth rate of pol5airethane RIM/RRIM parts is slowed to only about 1% because of the need to develop products with easier recycling routes, but RRIM-based composite pickup-truck boxes weighing up to 115 kg are currently produced using two separate RRIM molding processes. This trend may positively influence the future growth rate of polyurethane parts. In 1998 RIM/RRIM consumption in Europe was 8935 kt/a, while in the United States, 39,900 kt/a was consumed. The Asian market amounted to 8205 kt/a. 

The first major growth of RIM processing, as noted earlier in this section, occurred in the United States with the development of automobile bumpers designed to meet Congressionally mandated safety standards in a 5-mph impact. Polyurethane fascia (a term applied to both the front and rear bumpers, as well as fenders and other automobile parts) were designed to cover steel beams mounted on shock absorbers. Later, glass-reinforced RIM (RRIM) products were introduced and applied to some fender and body parts. In 1987, about 150 million pounds (67, 500 metric tons) of material were used for the manufacture of RIM products in the United States. About half of this total is polyether polyol, and about half was used in automobiles. 

---