| 摘要 |
<p>The invention relates to apparatus for use in the production of mouldings of a plastics material which initially consists of at least two liquid components which have to be intimately mixed before introduction into a mould. In a known form such apparatus comprises a mixing head, and for each component to be mixed, a reservoir tank, a pump for supplying the component from the reservoir tank to the mixing head, and a valve at the mixing head operable to direct the component either into the mixing head or back to the tank. In such apparatus and according to this invention the valves are arranged within the housing of the mixing head, the reservoir tanks, the pumps and the mixing head are mounted on a metal block in good thermal contact therewith, and the metal block and the housing of the mixing head are formed with ducts through which the liquid components flow. The metal block and/or the reservoir tanks, and if necessary the pumps, may be provided with thermostatically controlled electric heating elements to ensure that these parts are each maintained at the required operating temperature and by running the pumps for a time before a mixing operation uniformity of temperature of each liquid component throughout the system is ensured.</p> |
