Page 51 - November-December-2020

50

Production

COVID-19 rapid

test devices

possible thanks

to innovative

printing process

SPGPrints

Due to the immense pressure COVID-19 puts on technique to print the film with the level of precision
societies worldwide, pharmaceutical companies that is required for these test strips.
strive to make rapid test devices available to the
public as soon as possible. However, to do so, The creation of COVID-19 rapid test devices
innovative techniques have to be used to meet the For this exact reason, SPGPrints was invited by an
necessary medical requirements. Due to their international pharmaceutical company to be involved
experience with biosensors and their reputation of in the production of COVID-19 rapid test strips. The
creating foolproof, reliable systems, SPGPrints was goal was to produce a diagnostic test system that —
asked to be involved in the development and delivery with use of a patient’s saliva — could quickly indicate
of several production lines to produce COVID-19 if a patient suffered from COVID-19 or not. In this
rapid test strips. Millions of test strips are expected to international cooperation, it was up to SPGPrints to
be produced on both production lines, in which way develop a process for printing on film. In the printing
SPGPrints contributes to a solution for the increased process, high levels of accuracy were crucial since
global demand for more test capacity. the newly developed chemical reagent could only
function properly under optimal conditions.
The use of biosensors in rapid medical testing
Hank Guitjens, Commercial Manager Label & The collaboration turned out to be very successful.
Industrial printing at SPGPrints explains that the Within less than a year, SPGPrints managed to
usage of biosensors around the world is not new. For develop, produce and deliver a custom-made system
over 30 years, biosensors are a quick tool for analyz- for their pharmaceutical partner. Despite it being a
ing diseases, using just a strip and body fluids. A new, custom-made system, the startup phase was
common application of biosensors in the medical very successful, and a yield was achieved above
industry are the glucose test strips for diabetes expectation within weeks. On top of that, newly hired
patients. They use these strips to test if their blood operators needed limited training due to the
sugar levels are deviating from normal. user-friendliness of the system. Which means the
partner could start producing directly. This enabled
These biosensor test strips contain an advanced the pharmaceutical partner to reach their ideal
piece of technology. The film used for the test strips production levels within weeks after the new system
must be printed in such a way that it can absorb the had been delivered. Due to a close collaboration
body fluid and provide the optimal conditions for this between SPGPrints and the client, millions of test
reagent to react with the body fluid. SPGPrints strips are expected to be produced in the upcoming
specializes in and holds the correct innovative months.

November/December 2020

means of an integrated light barrier, resulting in actual tension being applied. (IDF 1 break draft 1.0).
perfect synchronisation between card and IDF. The The second diagram illustrates that IDF 2 and IDF 1
levelled loop permits high change speeds. This both have the same trend, i.e. that the yarn strength
ensures a higher efficiency at the card, especially decreases with increasing total draft. Compared to
when using small rotor cans. IDF 1, IDF 2 shows overall strength at a higher level.
This confirms the statement that the use of only one
drafting zone has a positive effect on the yarn
properties.
Development of the IDF 2
The IDF 2 has been established on the market for
seven years. The advantages of the system are now
recognised by the entire professional community,
competitors and customers. Initially, the shortened
process was only used with 100 percent cotton –
preferably from the recycling sector – but today it is

The combination of Truetzschler cards with IDF 2
gives customers an advantage, because they
produce a thin, stable web which is perfectly suited
to be drawn directly to the desired sliver count – at
highest production rates and lowest drafts. If cards
produce a heavier web, the use of low drafts is not
possible at all, as, for example, from 12 ktex to 5 ktex
a draft of 2.4 is applied.

One versus two drafting zones – technological no longer limited to this. The system is successfully
advantages applied in the processing of 100 percent raw cotton
In order to show the influence of the distribution of and other materials. It thus offers an answer to the
drafts on main draft and break draft as opposed to requirements of our customers with regard to
only one draft zone, a yarn of 100 percent raw cotton increasing and necessary flexibility in the production
(Mato Grosso) with Ne27 was spun in the direct process.
spinning process with a card production of 170kg/h.
With IDF 1, break drafts of 1.0, 1.05 and 1.16 with The handling of the IDF has also been improved. For
different main drafts were combined. The IDF 2 was example, there is now a retention lock that prevents
run with drafts of 1.2 to 1.95. The tests showed the the cover of the IDF from always having to be
trend across all parameters that IDF 2 with its 1-zone opened completely during the piecing process.
drafting system has clear advantages over IDF 1. Similarly, the use of maintenance-free deep groove
ball bearings entirely eliminates the need for
The first diagram shows the influence on yarn relubrication at the delivery rollers: The number of
evenness for a total draft of 1.7. There is clear lubrication points is thus reduced to four. The
evidence that the break draft in the IDF has a
negative influence on yarn parameters. It is self-adjusting lap monitoring of the top rollers,
noteworthy that for all quality parameters, the already known from the draw frames, has now also
presence of the first drafting zone in the IDF 1 alone found its way to the IDF. There is no need to readjust
has a negative effect on the results, without any after grinding intervals and changed settings.