Mould Lubricants

There is persisting interest in nylon-RIM materials as alternatives to polyurethane-RIM. Advantages of the nylon materials are the better shelf life and lower viscosity of the reaction components, ability to mould thick-walled articles, absence of a need for mould lubrication and the ability to avoid using isocyanates with their associated hazards. The main disadvantages of nylon-RIM are the need to have heated storage tanks and elevated temperature reactions, difficulties in catalyst handling and the high water absorption of the product. Possible markets include exterior car body components and appliance and business machine components. 

Other ingredients may be added to prevent sticking to moulds (lubricants), to promote the curing reaction (accelerators), to improve the flow properties (plasticisers) and to colour the product (pigments). 

Glycerin, glycerol. A thick, syrupy, sweetish liquid used as a plasticiser, a mould lubricant and as a raw material for the manufacture of glyptal resins. 

Jargon term for mould lubricant or mould release agent. 

Another term for mould lubricant but generally applied only to liquids particularly those based on silicones. 

Flow cracks. Incorrect shape and size of blank, incomplete mould flow high viscosity stock and excessive mould lubricant. Modify the shape, reduce temperature, modify curing system, peptize and pre warm the stock. 

Sticking to mould. Dirty mould, inadequate lubricant and undercure. Frequent cleaning and proper maintenance of moulds and proper application of mould lubricant. 

Copper/Constantan 400-62QK tol = 0.0041 T-2731K 1073 5566 10741 food processing, stack gases, plastic moulding, lubricating oils, producer gas plants. 

Curing reactions Vulcanisation reactions Isothermal ageing Product stability Thermal degradation Identification of processing aids Plasticisers Mould lubricants Blowing agents Antioxidants Flame retardants Safety concerns... 

Water 20-30 Mould lubricant (release agent), tool lubricant, rubber lubricant, electrically conducting coating... 

The moulding lubricant in the ABS resin should act in two ways to aid processing. First, it should lower the viscosity of the resin and thereby facilitate moulding and second, the mould lubricant should serve as a mould release agent as a result of being more concentrated on the plastic surface while solidifying in the mould [58]. 

DSC has been used in the determination of an internal moulding lubricant (low-MW PE) in a polyphenylene oxide (PPQ) based resin, where the area under the melting peak is proportional to the amount of PE [82]. De et al. [83] have used thermal analysis methods (DSC, TG) for characterisation of polyurethane-mica composites DSC of TPU-mica was carried out to determine the Tg of composites. Examination of Tg by DSC reveals the plasticising effect of small molecules on the glass transition behaviour of polymers. The addition of plasticisers lowers Tg of NBR [84]. The plasticiser content in... 

Some more specific polymer chemistry applications for TG-FTIR are solvent and water retention, curing and vulcanisation reactions, isothermal ageing, product stability, identification of base polymer type and additives (plasticisers, mould lubricants, blowing agents, antioxidants, flame retardants, processing aids, etc.) and safety concerns (processing, product safety, product liability, fire hazards) [357]. A wide variety of polymers and elastomers has been studied by TG-FTIR [353,358,359]. The potential applications of an integrated TG-FTIR system were discussed by various authors [346,357]. 

Pleshkova et al. [1031] have used TD-MS to determine the composition of a number of commercial bisphenol A-based polycarbonates. PhOH, p-t-butylphenol, and p-isooctylphenol were determined as the main chain-transfer agents for these polycarbonates. Up to 10 additives with concentrations exceeding 0.05% could be determined in a sample. Mould lubricants of various chemical nature were the main additives found. 

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