Innovative technologies secure the sustainability of a company. Here we provide some information on the technologies we use - a brief overview:
Gas injection technology (GIT)
In using the gas injection, a gas (usually nitrogen) is injected in the still movable melt after the cavity has been filled. There various different sorts of procedures ranging from partial fillings to fillings up to 100%, before the gas is injected.
Using a partial filling, the gas transports the melt to the end of the flow path and thereby creates a tubular part. The moment in which the machine filling switches to gas may cause surface blemishes.
Using the 100%-filling, a distinction is made between applications of the subsidiary cavity procedures and thin-walled applications, which are used to compensate the volume contraction (volume shrinkages). Using the subsidiary cavity procedures, we can achieve relatively controlled wall-thickness by controlling the dwell pressure of the machine, before injecting the gas in order to push the liquid plastic melt into a now open subsidiary cavity. A lot more common are applications that are only used to compensate the volume contraction. Here usually those gas passageways are defined in the non-visible area, which offer ground potential for holding pressure effects with gas. The results are low-tension components due to more regular holding pressure effects. The injector leaves an opening that needs to be sealed in case it is perturbing.
External gas moulding (EGM)
As one can tell by the name, the gas acts externally on the component in order to compensate the volume contraction. The non-visible side is chosen for EGM, because the compensation of the volume contraction usually leaves visible sink marks on the respective side, while the visible side is reproduced perfectly (also when using high gloss polish). As the respective part of the tool needs to be sealed, internal slides are to be avoided, round ejectors are permissible. This procedure is particularly suitable for extensive, box-shaped lid geometries. The components are producible with very little pressure and therefore have low strain and low distortion.
Gas cooling technique
In case oval bent handle profiles need to be produced, in spite of the gas injection, wall-thickness accumulations may happen, which in turn may cause distortions. This in turn can be compensated by gas cooling. The interior cavity is tempered by the gas, while outside the heat energy is discharged by conventional temperature regulation.
Gas valve system (GaNaSys)
With a special valve gate nozzle system, the system enables the gassing via the valve in the valve gate nozzle system. With this procedure, closed hollow parts can be produced that are with a defined medium under defined pressure.
Water injection technology (WIT)
The water injection technology is mainly used for the production of plastic components with tube profiles. Generally, a distinction is made between gas injections with subsidiary cavity procedures or in combination with partial fillings, when the injected water pushes the liquid melt to the end of the flow path. In a cooperation project, the water injection into a closed blind hole has been realised in a way that not more than a drop of water remains at the component when the component is demoulded. It is important to note that the volume contraction (volume shrinkages) cannot be compensated when using water.
We learn from mistakes. Therefore, the number of mistakes also stands for experience we have made. It is useful to archive mistakes and to document the solutions so that we don’t have to make all the mistakes for ourselves and if possible don’t repeat the mistakes. So we are available for getting potential problems under control quickly and at reasonable cost. We mention just a few problems which might arise in the manufacture of plastic components: Diesel effect; burners; streaks; distortion; sink marks; stringing; adverse gate definition or wrong gate position; cold slug; missing sprues; deformation while demoulding; formation of coats on the tool; visible or not robust weld-lines; jetting; burst integral hinge; gas bubbles in the component; black clouds; dull patches; haloing; differences in luster; insufficient temperature regulation of the tools; gramophone effect; ridge; visible ejector marks; stress whitening; cold cracks; air pockets; vacuole; demoulding grooves.
Let us analyse your mistake, let us show you the best possible solution, and, if you wish, let us solve the problem in cooperation with you or our network partners. We will document the mistake and its cause so that it will not be repeated.
Your problem is our job.
We - A QIM - are at your disposal at any time to answer your questions.
3 x R = Reliance, Responsibility, and Reliability – all the more so during difficult times!