Page 36 - Plastics News February 2021

FeAtures

Manually actuated: Operator-dependent position control; In some cases, solution applicators are also needed. A
manual sheet-thickness reading to determine gap; optional liquid solution is used as the medium to transfer anti-fog
encoder feedback for display only; adjustable only under additives to the sheet surfaces. Applicators can range in
reduced pressure. design from the lower-value flood-coating types to higher-
value models capable of application at a micron level,
Gear motor: Operator-initiated position change; encoder
feedback; position control; adjustable under full load. such as those used on PET applications.
Once formed, PPE sheet can either be wound on a fixed-
Hands-free: Servo-hydraulic precision roll-position control;
linear transducer resolution of 1 micron; closed-loop force station, turret-style winder for thinner material, or cut
to length and stacked for thicker gauges. Winders, if not
automated, should include accumulators to allow for safe
cut and transfer of the web from a full to empty core.
It’s important to have your machine builder come to your
plant and do an on-site evaluation of existing capabilities
and propose potential upgrades or line additions. For
new sheet systems, defining the resins and application
specifications helps the OEM properly size extruders, dies
and rolls. We also encourage you to take advantage of
any laboratory or trial opportunities offered by the OEM
to test capabilities.

(Courtesy : PT)
control; displays actual force and force-limit capability.

In addition, roll-stand systems can be equipped with a
variety of features to support processing. These include
individual roll drive, protective masking, edge trim, India second-largest producer of
solution applicator, and gauging. New systems come PPE kits
standard with individual roll drive, individual roll-
temperature control, and various edge-trim capabilities.
PE kits are the first line of defence for health workers
Whether on new or existing equipment, roll-temperature
control is critical to proper sheet formation. In additional, Pagainst infectious diseases like Covid-19. Their
roll-temperature ranges vary widely according to the production was ramped up in March amid growing demand
material to be processed, and the TCU will need the ability for them as the Covid-19 pandemic worsened. Gradually
to achieve and maintain the recommended setpoints listed India was producing 10 million PPEs per month, on the
in Table 3. Some resins and thickness ranges will require specs that were demanded by the Central government to
high-temperature synthetic fluid systems to achieve fight the coronavirus pandemic. The Central government
proper performance. had placed an order for 22 million PPEs in March to meet
the demand for health workers. The government had also
A required option in RPET production is protective
masking equipment to allow application of a protective faced severe criticism for not being able to provide enough
film to the sheet in order to deliver it damage-free to the coveralls for essential workers. In June, the ministry
customer. The type of laminate applied will dictate the allowed the export of 500,000 PPE kits monthly. In July,
required options for the let-off machinery. Dual stations India exported 2,300,000 PPE kits to five countries. The
are recommended to allow for smooth changeover of government allowed the PPE exports amid demands from
laminate rolls as well as side-lay adjustment to ensure the industry as it started producing surplus kits. The PPE
proper alignment with the sheet being produced. Quality production came as a boost for the industry as it faced
tension control is essential and can be accomplished with nearly 84% fall in apparel sales and an acute shortage of
a range of options, from air-clutch resistance to inverter labour due to the pandemic in the first quarter.
drive control.

Plastics News Februar y 2021 36