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Describe The Process Of Harvesting And Ginning Of Cotton Fiber Pdf

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Our finished products go through an extensive purification process at our cotton processing plant before they ever end up in the hands of consumers. Raw cotton arrives initially in densely packed bales, and these bales are subjected to a series of steps over time, ultimately undergoing a dramatic change.

Cotton Processing

Index Search Home Table of Contents. Kenaf Harvesting and Processing Charles L. Bledsoe, and Robert E. Kenaf Hibiscus cannabinus L. As the commercial use of kenaf continues to diversify from its historical role as a cordage crop rope, twine, and sackcloth to various new applications including paper products, building materials, absorbents, and livestock feed, choices will continue to increase and involve issues ranging from basic agricultural production methods to marketing of kenaf products.

Management decisions will require an understanding of the many different facets of kenaf and reliance on a systems approach that will integrate the production, harvesting, processing, and utilization of kenaf. The purpose of this review is to provide a greater understanding of kenaf harvesting and processing systems, with a goal to increase the potential use of kenaf and its products. This review includes an introduction to the crop, a short history, an overview of harvesting and processing systems, and a profile of plant components and their uses.

Kenaf has been used as a cordage crop to produce twine, rope, and sackcloth for over six millennia Dempsey Kenaf was first domesticated and used in northern Africa. India has produced and used kenaf for the last years, while Russia started producing kenaf in and introduced the crop to China in Dempsey In the United States, kenaf research and production began during World War II to supply cordage material for the war effort Wilson et al.

The war not only interrupted fiber supplies from countries such as the Philippines, but the war effort also increased the use of these fibers by the US. Once it was determined that kenaf was a suitable crop for US production, research was initiated to maximize US kenaf yields. As a result, scientists successfully developed high-yielding anthracnose-resistant cultivars, cultural practices, and harvesting machinery that increased fiber yields Nieschlag et al. Then in the s and early s, as USDA researchers were evaluating various plant species to fulfill future fiber demands in the US, it was determined that kenaf was an excellent cellulose fiber source for a large range of paper products newsprint, bond paper, and corrugated liner board White et al.

It was also determined that pulping kenaf required less energy and chemical for processing than standard wood sources Nelson et al. The evaluation of procedures for harvesting kenaf continues to be an important aspect of commercialization. The harvest method depends on the production location, the equipment availability, processing method, and final product use.

Over the last years, since its first domestication, kenaf has consistently been hand-harvested for use as a cordage crop rope, twine, and sackcloth Dempsey The bast fiber strands, located in the kenaf bark, are the source for these cordage products.

When hand-harvested, the tall, cylindrical-shaped stalks were cut at or near ground level with a curved blade or machete Dempsey Usually plants were still actively growing, nearing or already flowering at the time of harvest. The hand-harvested plants were then prepared for the retting process. Retting is the process, usually involving moisture with bacteria or chemicals, to remove the unwanted bark material from the kenaf fiber strands within the bark.

Kenaf was retted by natural processes that use primarily aerobic air loving bacteria, unlike water-retting of flax that is carried out primarily by anaerobic bacteria and various fungi. The plant material status prior to retting influences the water-retting efficiency for kenaf. Removing the upper, non-fibrous portion of the plant, prior to the retting process increases the retting rate by decreasing the amount of leaf and plant material to be digested.

This highly nutrient-laden portion of the plant can be either used as a high quality livestock feed or returned to the soil to maintain fertility. Even if the upper portion of the plant is not removed, the retting process can be increased if the plants are allowed to dry for 24 to 48 hr after harvesting to promote defoliation. Removal of the bark from the stalk also makes the retting process more efficient.

The ease of separating the bark from the core material is enhanced by the physiological makeup of the plant. The bark, which contains the bast fiber phloem tissues , and the core that contains the core fibers xylem tissues , are separated by meristematic tissue, the vascular cambium. The vascular cambium is responsible for secondary growth, increase in girth, by generating new phloem tissue sieve tubes outwardly and new xylem tissues core fibers inwardly. The phloem cells transport food materials products of photosynthesis and the xylem vessels transport water within the plant.

The mature, dead xylem cells become lignified xylem fibers, which then serve as structural support for the plant. The presence of the vascular cambium interface between the kenaf bark and core results in easy separation between these two plant components as long as the plant has been recently harvested or is not fully dried.

Once drying has occurred, the bark will adhere more aggressively to the stalk core and bast fibers will also be more difficult to separate from the non-fibrous material in the bark. In addition, drying the bark while either attached to or separated from the stalk will impede the water-retting process. Although the natural water-retting bacterial process is still used throughout many portions of the world, newer chemical retting processes have been studied, developed, and implemented to produce fibers of greater chemical and physical uniformity Dempsey ; Chen et al.

The USDA, universities, and private industry have developed an assortment of mechanical harvesters and post-harvest equipment to separate the bark from the core material, and the bast fibers from the core fibers. This machine harvested green plants, removed the leafy, low fiber top portion of the plant, ribboned the bark, bundled the ribbons, and tied the ribbon bundles Dempsey Ribboning is the process of removing the bark from the core material. The same process is also referred to as decorticating, the removal of the core from the bark.

The objective is no longer to harvest only bark ribbons, but to separate and harvest the core material for other uses Chen et al. The development of these whole-stalk harvesters has taken two major approaches; sugarcane-type harvesters and forage-type harvesters.

In both approaches scientists and industry have concentrated on using or adapting existing equipment, rather than developing a totally unique kenaf harvester. Sugarcane-type Harvesters.

The unmodified or slightly modified sugarcane harvesters use rotating knives or circular cutting blades to sever the base of the kenaf stalk and to cut off the low fiber, high foliage, top portion of the plants. These long stalks then pass through the equipment in an upright fashion soldier-type harvester and then are laid down in long windrow piles to field-dry.

Once these stalks have been field-dried on the ground other sugarcane equipment with articulating claws can be used to pick up the kenaf stalks and place then in sugarcane wagons. This type of system can be used to harvest both live and dead kenaf stalks. If the kenaf stalks are already dry at harvest, the harvesting system can be reconfigured to immediately transfer the long cut stalks to in-field wagons traveling with the harvesting equipment or existing sugarcane harvesters could be adapted to cut the kenaf stalks in smaller segments e.

One important consideration for all harvesting and processing systems is the moisture content of the kenaf plant material. Sugarcane-type harvesters encounter an easier cutting process with growing, high moisture kenaf plants, but allowances must be made in the harvesting and processing systems for either drying the plant material or handling and storing high moisture material.

If dry, dead kenaf stalks are harvested, the harvesting equipment will encounter tougher stalks with a greater likelihood that the long, twine-like, fiber strands in the bark will wrap around rotating equipment parts. Another important consideration is the density of the kenaf plant material and the potential limitations and disadvantages that low bulk density plant material may have on storage and transportation.

Drawbacks of the sugarcane-type harvesting systems include the transport and storage of the low density stalks or stalk segments. This limitation is often mentioned as requiring the growing and processing the kenaf to occur within a limited geographical location, for example within a 50 to km range of the processing facility, such as a pulp mill.

Forage-type Harvesters and Baling Equipment. Forage-type harvesting and baling systems have been widely evaluated for use in kenaf production, harvesting, and processing systems. It has been demonstrated that standard forage cutting Fig. Kenaf can be baled in both small and large square bales or large round bales. In cotton growing regions, cotton modules Fig.

Compressing of kenaf in cotton modules or baling kenaf serves to increase the bulk density of the kenaf for storage and transportation purposes. A dry kenaf stalk without leaves is a lightweight material with a low density, 0. Chopped uncompressed kenaf fiber will have an even lower density of approximately 0. The low bulk density of either the individual kenaf stalk or the chopped kenaf stalk will affect management decisions concerning the economic transportation and storage of the kenaf material.

Industry and the USDA have cooperated to develop methods to increase the density of the kenaf material for increased transportation and storage efficiency. They produced kenaf pellets over a range of 0. The same researchers successfully cubed bast fibers to a density of 0. Although these kenaf pellet and cube densities refer to average densities of the items produced rather than total bulk densities, the advantages of compressing the kenaf material would also translate into advantages in bulk transportation or storage of these materials compared to unprocessed kenaf stalks or non-compressed chopped kenaf.

Whole stalk kenaf compressed into small pellets right , range pellets center , and square cubes left. It may be economically advantageous to use available commercial harvesting and processing equipment rather than investing in the development and production of kenaf-specific equipment. Appropriate harvesting, pelletizing, and cubing equipment is readily available throughout the United States.

When harvesting kenaf for fiber use, moisture content and equipment availability are important considerations.

Kenaf can be harvested for fiber when it is dead, due to a killing frost or herbicides, or when it is actively growing. The dry standing kenaf can be cut and then chopped, baled, or transported as full-length stalks. If the kenaf drying and defoliation process is dependent on a killing frost, the harvest date will vary according to the environmental conditions of the area, including the time of the killing frost and the time required for the kenaf to dry.

Soil type and seasonal weather may delay harvesting and drying, especially on high clay soils in areas that receive excessive rainfall during harvest. Actively growing kenaf can be cut and then allowed to dry in the field. Once dried, the kenaf can then be chopped, baled, or transported as full-length stalks. Initial processing methods and equipment will be dependent on many factors, including the production location, equipment availability, the economic variables involved, and the available commercial markets.

One of the first processing decisions is whether the whole stalk, either as an unmodified stalk or as a chopped stalk, will be separated into its bast and fiber components or left unseparated for use as a combined fiber source. For example, kenaf used in some paper products or processes can be pulped using a mixed fiber supply unseparated bast and core , while certain processing applications involve separating the bast and core components.

Several existing commercial kenaf facilities mechanically separate the two fiber components by different methods with distinct processing efficiencies, using a range of equipment with varying rates of throughput resulting in varying degrees of fiber separation.

Each separation system also has unique economic ramifications based on their integrated production, harvesting, processing, and utilization systems. One method of fiber separation adapts unused cotton gin facilities, which are scattered throughout the southern region of the United States, to process the kenaf fibers. The modified gin equipment and facilities provide excellent machinery for separating the kenaf core material from the bast fibers, similar to the method that cotton gins process separates cottonseed from cotton fibers.

Since the number of active cotton gin facilities is decreasing with the decline in cotton production, unused gin facilities are available for converting to kenaf separation facilities. The diversity and usefulness of kenaf plant components provides both a wide spectrum of potential commercial products and the necessity to understand the distinct and diverse harvesting and processing options to produce these products.

Depending on the component under discussion it may contain such useful substances as bast and core fibers, proteins, and essential oils.

Research has evaluated the components of the kenaf plant and the composition of these components. The bark of the kenaf stalk contains a long fiber called bast fiber, while the woody core contains short core fibers.

Whole stalk kenaf bast and core fibers has been identified as a promising fiber source for paper pulp Nieschlag et al. The kenaf fibers, bast, and core, can be pulped as a whole stalk or separated and pulped individually Kaldor et al.

Whole Stalk. Whole stalk kenaf can be pulped by kraft, soda, neutral-sulfite, sulfate, mechanical, chemimechanical, thermomechanical, and chemithermomechanical processes Clark and Wolff ; Bagby Whole stalk kenaf pulps have been processed into high quality bond, surface sized, coated rawstock, and newsprint papers Clark et al.

The Journey of Cotton: An Introduction

The Handbook of Texas is free-to-use thanks to the support of readers like you. Support the Handbook today. No thank you, I am not interested in joining. Cotton was first grown in Texas by Spanish missionaries. A report of the missions at San Antonio in indicates that several thousand pounds of cotton were produced annually, then spun and woven by mission craftsmen. Cotton cultivation was begun by Anglo-American colonists in In a census of the cotton production of the state reported 58, bales pounds each.

Cotton is a soft, fluffy staple fiber that grows in a boll , or protective case, around the seeds of the cotton plants of the genus Gossypium in the mallow family Malvaceae. The fiber is almost pure cellulose. Under natural conditions, the cotton bolls will increase the dispersal of the seeds. The plant is a shrub native to tropical and subtropical regions around the world, including the Americas, Africa, Egypt and India. The greatest diversity of wild cotton species is found in Mexico, followed by Australia and Africa.

Chapter 8. Cotton is an important fiber crop grown under varying climatic conditions in more than or machine harvested. Of these methods, manual harvesting of seed cotton case of handpicked cotton described in preceding section.

Kenaf Harvesting and Processing

To kick off this new series, we wanted to give brief overviews of each processing step. These overviews only scratch the surface, so this seven-part series will dig deeper into each specific step with more detail. Early each spring, cotton is planted in the southern half of the United States from California to Virginia. Heat and water allow the seed to emerge from the soil around 10 days after planting. The average growing season is to days from planting until harvest, and during that time the farmer uses good practices to make sure the cotton is free of weeds, grass, and insects that could potentially harm the plants.

Cotton is a shrubby plant that is a member of the Mallow family. Its name refers to the cream-colored fluffy fibers surrounding small cottonseeds called a boll. The small, sticky seeds must be separated from the wool in order to process the cotton for spinning and weaving.

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Index Search Home Table of Contents. Kenaf Harvesting and Processing Charles L.

Еще несколько сантиметров, подумал Джабба. Работа заняла намного больше времени, чем он рассчитывал. Когда он поднес раскаленный конец паяльника к последнему контакту, раздался резкий звонок мобильного телефона.

Organic cotton processing

 - Личный помощник директора.

Компьютерные вирусы столь же разнообразны, как и те, что поражают человека. Подобно своим природным аналогам они преследуют одну цель - внедриться в организм и начать размножаться. В данном случае организмом является ТРАНСТЕКСТ. Чатрукьяна всегда изумляло, что АНБ никогда прежде не сталкивалось с проблемой вирусов. Сквозь строй - надежная система, но ведь АНБ - ненасытный пожиратель информации, высасывающий ее из разнообразнейших источников по всему миру.

 Сьюзан, - тихо сказал Стратмор, - с этим сначала будет трудно свыкнуться, но все же послушай меня хоть минутку.  - Он прикусил губу.

Коды, с которыми столкнулось агентство, больше не были шифрами, что разгадывают с помощью карандаша и листка бумаги в клетку, - теперь это были компьютеризированные функции запутывания, основанные на теории хаоса и использующие множественные символические алфавиты, чтобы преобразовать сообщение в абсолютно хаотичный набор знаков. Сначала используемые пароли были довольно короткими, что давало возможность компьютерам АНБ их угадывать. Если искомый пароль содержал десять знаков, то компьютер программировался так, чтобы перебирать все комбинации от 0000000000 до 9999999999, и рано или поздно находил нужное сочетание цифр. Этот метод проб и ошибок был известен как применение грубой силы. На это уходило много времени, но математически гарантировало успех.


Renae H. 10.06.2021 at 01:36

ginning, a micro-gin was used to gently process seed-cotton samples. The resulting fiber small farms with manual cropping and harvesting. The results of the fiber quality characterization on bale samples describe the combined effect​.

Domiciano M. 11.06.2021 at 20:53

Cotton is a seed fiber, meaning the fiber grows from seeds.

MichГЁle A. 14.06.2021 at 09:04

By: Edward Menezes.