Connected to a cleanroom, Aptar Radolfzell produces an innovative multiple dosing system for the administration of eye drops. The dosing system is microbiologically sealed and does not require any preservatives. In production, high precision needs to be combined with efficiency. For series production, ENGEL supplied two new production cells, each consisting of e-victory injection moulding machines and integrated easix articulated robots.
In Germany alone, millions of applicators for eye drops are used. The symptoms for which liquid medications are dripped into patients' eyes are manifold. What all eye drops used to have in common was unavoidable contact with bacteria after opening. The systems commonly seen on the market are therefore often single applicators whose contents can only be used for a few hours after opening. Aptar Radolfzell, an Aptar Group Inc. company, produces a sustainable alternative: a multiple-use dosing system with bottles of 5 and 10 ml capacities. As a self-contained system, it provides the necessary protection against microbiological contamination that reliably prevents premature expiration of the drug. "Our applicator delivers the drug drop by drop and is free from preservatives. That is the added value of the system," says Ingo Korherr, production manager at Aptar Pharma, summing up. "The advantages here are that this is not a one-off application, which is not ecological and produces a lot of waste. The multiple dosage system can be used for several weeks, and it is more ergonomic to apply at the same time," adds Ralf Fichtner, the site manager at Aptar Pharma in Eigeltingen in southern Germany.
In ophthalmology, one of the Aptar Group's product lines, the strategy of manufacturing all plastic parts in-house, has been successfully implemented. This has largely been achieved with ENGEL manufacturing systems.
Tie bar-less clamping unit ensures high-precision moulding
The ophthalmic squeeze dispenser (OSD) consists of a total of seven plastic parts with varying degrees of complexity and one metal part. To produce the applicator and the spray pins, capital was invested in two new production cells for the Eigeltingen location; this is Aptar Radolfzell’s second production location in addition to Radolfzell.
The applicator with a diameter of 15 millimetres is produced from polypropylene (PP) in a 32-cavity mould equipped with a partial hot runner on an ENGEL e-victory 740/220 injection moulding machine with a clamping force of 220 tonnes. The total shot weight is 30.5 grams. An ENGEL e-victory 50/90 with a clamping force of 90 tonnes produces the spray pin from TPE with a total shot weight of 1.97 grams in a 16-cavity full hot runner mould. Both parts are product-carriers, i.e., they come into contact with the medication. With a view to microbiological purity, both production cells have been encapsulated in cleanroom-compatible production units in compliance with ISO 7 requirements. Further ENGEL injection moulding machines with an identical configuration operate in the greyroom.
Where the plastic parts are highly filigree, complex at the same time, and are also produced in a multi-cavity mould, hybrid e-victory injection moulding machines with an electric injection unit and servo-hydraulic clamping unit often offer benefits. The reason for this is the tie-bar-less clamping unit, which provides sufficient space for large multi-cavity moulds even on machines with comparatively low clamping forces. The excellent parallelism of the mould mounting platens is also maintained during clamping force build-up and injection. Patented force dividers distribute the clamping force evenly across the mould mounting platens, ensuring consistently high moulding precision across all cavities. These were the factors that tipped the scales at Aptar in favour of capital expenditure on machines from the e-victory series. As ENGEL sales representative Jürgen Fridrich adds: "What was required up front was very high repeatability, shot for shot, and very high availability of the entire production cell in each case."
"Let's not forget the very strict demands on the mould and the part, which necessitate a high level of precision – requirements which the e-victory series meets in full. The servo-hydraulic clamping unit side from ENGEL runs like clockwork," says Andreas Gräber, manager Injection Moulding Services at Aptar Pharma.
Ralf Fichtner adds: "We process polyolefins, especially PP and PE. There are certainly more dimensionally stable plastics. The tolerance range with two decimal places in which we manufacture our parts, requires very high precision of the mould, the injection moulding machine, and the entire process. Polyolefins with this precision are certainly not standard, and this is exactly what we specialise in. The challenge is to achieve this precision in a cost-effective way in multi-cavity moulding with a high level of process stability."
Integrated control unit facilitates change to articulated robot
The production process is fully automated and 100% monitored. SPC checks of the parts are also an integral part of the process. After completing the respective injection moulding cycle, the parts are removed by ENGEL easix articulated robots, including separation of the cavities, which is important for traceability. In other applications at Aptar, ENGEL linear robots – vipers and a few older ERC robots – handle the parts. Due to the limited space available in production, the two new production cells were equipped with easix articulated robots. But it was also the production process that necessitated the articulated robots. Different depositing positions are implemented. NOK parts are separated from good parts. For permanent quality control, cleaning and other process steps, the robot needs to approach several positions in a programmed routine.
The fact that the control unit for the ENGEL robots is fully integrated into the control CC300 control unit of the ENGEL injection moulding machines, made the change to articulated robots particularly easy for Aptar. The integrated production cell ensures uniform control logic and the same look-and-feel for the machine and the robot. "One major advantage is that I can see everything on the machine display and do not have to walk around the machine. Of course, I have the hand-held unit for the process settings and teach-in, but that is a one-off thing, otherwise I can control everything from the machine, and it is very easy. The employees are familiar with the user interface and do not have to readjust or learn anything new, but can apply what they know 1:1," says Andreas Gräber, summing up.
In Eigeltingen, this accelerated the start-up process of the new easix robots and ensures an effective approach to work. The manual robot panel and the smart ENGEL CC300 control unit access one and the same database. Another benefit is that both systems coordinate their motion sequences with each other. This reduces the handling time in some applications.
500 million dosing units a year
As an expert for innovative medication delivery systems and packaging solutions, Aptar pursues a two-supplier strategy in-house. Of the total of 85 injection moulding machines with clamping forces of 35 to 250 tonnes, ENGEL machines account for more than 60 percent. Some 850 employees produce more than 500 dosing units annually at both locations. With several global good manufacturing practice (GMP) production sites, Aptar Pharma ensures both a reliable supply chain and local support for its customers. The division of the company, which is headquartered in Radolfzell, Germany, focuses on injection moulding technology. "We buy in other processing technologies strategically," explains Ralf Fichtner: "The answer to the question as to what we do in-house, and what we don't, is driven by the complexity of the parts to be produced." After all, the company name, Aptar, is derived from the Latin word aptare. And that means to adapt, which reflects to the company's philosophy in practice.