1. Insect resist and
mite protection
finishes
insect resist finishes, including
protection against dust mites.
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2. Introduction
• Insect resist finishes are chemical treatments that
protect wool and other animal fibres from attack
by
• the larvae of certain moths
• and beetles. Only keratincontaining
• fibres are damaged by these insects.
• Dust mites cause health problems, such as
• allergy,
• asthma
• and neurodermitis.
• Mites are not insects, they belong to the
• spider group of animals.
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3. INTRODUCTION
• Keratin-digesting pests include
• the clothes moth (Tineola bissiella),
• brown house moth (Hofmannophilia pseudoprettella),
• carpet beetle (Anthrenus flavipes)
• and fur beetle (Attagenus pellio).
• Moth populations can increase
dramatically in a relatively short time. Each
female moth lays
• about 150 eggs
• and four to five generations per year can be
produced.
• Various chemicals have been used to
control damage from larval attack on wool 3

4. INTRODUCTION
• Annually, about 2 million pounds weight (about
900 000 kg) of insect resist finishes are used
• with wool products.
• The most important market for insect resist
finishes is the carpet industry.
• More than two-thirds of these finishes are used with floor
coverings and wall hangings.
• Other significant markets include
• home furnishing
• and upholstery fabrics,
• Blankets,
• uniforms,
• apparel and furs.
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5. Mechanisms of insect resist
finishes
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6. Mechanisms of insect resist finishes
• Insect resist finishes fall into two types,
• poisons
• Poisons interfere with the keratin digesting
process of the
• larvae
• and nerve poisons that have been specifically
formulated from agricultural pesticides for textile
applications.
• digestion-affecting poisons are more species
specific, killing the feeding larvae by
• blocking enzymes needed for digestion.
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7. Mechanisms of insect resist finishes
• Nerve poisons are more general control agents, affecting a
broader range of insects. Both types are considered to enter
through the larvae‘s digestive tract
• because insect resist treated wool only kills insects that ingest the
fibre
• Each category has distinct advantages and disadvantages.
• Digestive poisons present a lower environmental hazard than nerve
poisons, but are not as effective against some pests such as
• the brown house moth.
• Nerve poisons are usually more rapidly biodegraded than
• digestive poisons, but also exhibit less durability.
• The usual application level of insect resist finishes varies
• from 0.1 to 1.5 % on weight of goods
• depending on the
1. final product,
2. the specific finish
3. and the performance requirements. 7

8. Chemistry of insect resist
finishes
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9. Chemistry of insect resist finishes
• Digestive poisons were the first
durable insect resist finishes to
be commercialised.
• Early products were based on
• chlorinated tri- phenyl-methanes
• And chlor-phenylids
• a Later, sul-cofe-nurons
• and flu-cofe-nurons were
introduced.
• These compounds could, for the
most part, exhaust
• To wool under acidic conditions
and have reasonable fastness 9
properties.

10. Chemistry of insect resist finishes
• Agricultural pesticides were
found to be effective insect
resist agents when applied
in emulsion form to wool
dyebaths.
• Dieldrin (Fig. 16.2a), one
of the original nerve
poisons, is also highly toxic
to mammals and aquatic
life and its use has been
banned in most countries.
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11. Chemistry of insect resist finishes
• Products based on
permethrin (Fig. 16.2b), a
• synthetic pyrethroid, are
very effective against moth
larvae,
• but have less effect on
Anthrenus beetles.
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12. • To overcome this disadvantage,
combination products of
• permethrin and hexahydropyrimidine
derivatives (Fig. 16.2c) have been
introduced.
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13. Application of insect resist finishes
Insect resist finishes are most commonly applied during dyeing.
The best light fastness and wet fastness properties are obtained when the finish is
able to fully penetrate the fibres.
When applying insect resist finishes to wool/nylon blends,
care must be taken in the choice of the particular finish used.
Chlorphenylid derivatives exhaust preferentially to nylon, leaving the wool fibres
unprotected,
whereas permethrin-based products distribute themselves more uniformly between
the two fibre types.
Application of insect resist finishes during scouring is also possible when wool
yarns for carpets are scoured in hank form or when fabrics for blankets, apparel and
upholstery are prepared as piece goods. Finishes applied during scouring do not
completely penetrate the fibres owing to the lower temperatures and shorter
treatment times in the scouring process, so fastness properties are not as durable as
with finishes applied during dyeing. 13

14. Application of insect resist finishes
A third approach to the application of insect resist finishes is to combine
the finish with spinning lubricants
and then to apply the combination to loose wool
prior to spinning.
This method of finish application produces yarns with only a
superficial treatment with much lower fastness than applications made during
dyeing or scouring.
Chemical cleaning of wool textiles as
smaller carpets,
wall hangings, upholstery fabrics,
furs or uniforms can easily be combined with the
application of insect resist finishes.
Dip and cautious spray application is used for the protection of wool
and silk textile exhibits
in museums.
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15. The efficiency of insect resist
finishes can be determined by
tests that measure the
weight loss of the treated
fabrics and/or the weight of
insect excrement after
exposure to insects under
Evaluation of controlled conditions.
insect resist The direct examination of
finishes exposed fabrics by
microscopic methods to
Standard methods observe fibre damage is also
for evaluating fabrics with insect useful.
resist finishes are given in AATCC
Test Method The typical half round bite
traces of the moth larvae are
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observable.
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16. Troubleshooting for insect resist finishes
• Exposure to light as well as mild washing, dry
cleaning and shampooing can reduce the
effectiveness of insect resist finishes significantly.
• The durability requirements of the final product
must be carefully considered during product
development.
• Finish baths that are not completely depleted of
insect resist finishes must be
• disposed of in accordance with local, state and
federal regulations.
• Special care must be taken to prevent
accidental release of these insect poisons to the
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environment

17. elements
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