Trial report Demonstration trials for washing and drying …edge.rit.edu/edge/P16702/public/Phase 3 Subsystems Design... · Washing and drying the mixed, contaminated material without

Trial report

Demonstration trials for washing

and drying contaminated textiles

Report of a trial to assess the value of washing and drying textiles which are highly contaminated, sourced from comingled kerbside collections (Trial 1)

Project code: MPD007-004

Research date: January to April 2012 Date: June 2012

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Document reference: [e.g. WRAP, 2006, Report Name (WRAP Project TYR009-19. Report prepared by…..Banbury, WRAP]

Written by: Hannah Burke, Jane Gardner, Liz Morrish and Beth Ripper

Front cover: Kannegiesser laundry equipment used at Professional Linen Services

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Demonstration trials for washing and drying contaminated textiles 3

Executive summary

WRAP commissioned Axion Consulting to investigate and assess the economic benefits and likely carbon and water impacts associated with washing and drying contaminated textiles for sale to reuse and recycling markets. The project research was delivered through a series of demonstration trials, assessing textiles that had been collected from a specific domestic source with varying levels of contamination, as shown below.

Table 1 Summary of washing and drying trials

Trial Sub-trial

Details Trial partners

1 Medium to high contamination - visible stains or wet with high odour

1a Washing and drying the mixed, contaminated material without any pre-sorting.

Axion, I&G Cohen and PLS

1b Pre-sorting the mixed, contaminated material by colour and by weight as well as into ‘delicates1’; then washing and drying the material.

2 Low contamination - low odour, cleaned using a steam cleaner

Not applicable. Axion and I&G Cohen

3 Damp and contaminated clothing



3b Pre-sorting the mixed, contaminated material by colour and by weight as well as into ‘delicates’; then washing and drying the material.

4 Drying only – wet textiles, no odour

4a Drying the mixed, wet material without any pre-sorting. Axion, I&G Cohen and PLS 4b

Pre-sorting the mixed, wet material to separate items by weight into heavyweight and lightweight clothing.

An individual report was produced for each of the trials as well as an overall summary report, comparing the results from each of the trials and investigating the commercial and environmental impacts associated with each option. This report details the methodology and findings from Trial 1. Trial 1 aimed to assess the viability of washing and drying textiles of medium to high contamination, with visible stains and high odour. The textiles were sourced from Shanks Materials Recovery Facility (MRF) in Glasgow and originated from comingled kerbside collections in North Lanarkshire. Before the washing and drying trials, all of the material collected would have been categorised as waste, with no resale value. The trial was divided into two sub-trials to investigate whether separating coloured clothing prior to washing adds value to the washed and dried textiles. A 1,500kg sample was obtained for the trial and sorted by I&G Cohen staff at their facility in Salford, Greater Manchester. This pre-sort aimed to separate intact clothing suitable for washing and drying from damaged textiles. Approximately 50% of the material in the sample, 758kg, was judged to be suitable for the washing and drying trial due to the high

1 A delicate item can be described as an item that is made out of silk, chiffon, lace or another type of fine material. It may also

have embellishments attached or embroidered decoration.


proportion of severely damaged or heavily contaminated items. The majority of damaged items had been cut by wire used during the baling process implemented at the MRF. This sample was divided into the following sub-samples:

365kg of textiles of mixed weight and colour for Trial 1a; and

393kg of textiles separated by weight and colour for Trial 1b.

The textiles were washed and dried in 40kg batches at PLS, using a Kannegiesser Continuous Batch Washer PT 50 -9 (CBW) at 71⁰ C for 27 minutes per batch. Following washing, batches identified as lightweight textiles were dried for 14 minutes and heavyweight items were dried for 16 minutes. Both drying programmes included a 2 minute cool down period so that the textiles were cool enough for operatives to handle. Once the material was washed and dried it was returned to I&G Cohen for grading and valuation experienced sorting staff (see Table 6 for details of material grading used). Table 2 below summarises results of the grading process after the washing and drying trials.

Table 2 Grading of material following washing and drying trial

Trial Trial 1a: Mixed, contaminated material

Trial 1b: Contaminated material, pre-sorted by colour and by weight as well as into ‘delicates’ for separate washing and drying

Grade Sample

weight (kg) Composition

(%) Sample weight (kg)

Composition (%)

Premier grade 23.4 6.5% 18.4 5.1%

Vintage/retro grade 0.0 0.0% 0.0 0.0%

Lightweight clothing 104.9 28.9% 123.8 34.2%

Heavyweight clothing 89.3 24.6% 47.0 13.0%

Lightweight recycling 54.2 14.9% 103.2 28.5%

Heavyweight recycling 89.3 24.6% 69.2 19.1%

Waste 1.6 0.4% 0.4 0.1%

Total 362.7 100% 362.0 100%

The key conclusions from this washing and drying trial are:

Approximately 50% of the bulk sample of textiles from comingled collections provided

intact clothing suitable for washing and drying. The remaining fraction was unsuitable

and destined for landfill;

After being washed in batches of mixed colour and weight (Trial 1a), 99.6% of the sample

was upgraded to either a reuse or recycling grade;

After being washed separated by weight and into colours/whites (Trial 1b), 99.9% of the

sample was upgraded to either a reuse or recycling grade;

The trials demonstrated that there was no added value in separating the material into

colours/whites or by weight prior to washing and drying compared to washing and drying

the clothing in mixed batches;

Should more complex grading systems be used, such as systems including ‘cream grades’,

this may impact the categorisation of processed textiles and resulting valuation;

The potential for maximising value from this textiles stream is heavily impacted by the

initial yield. Only 50% of feed material collected for this trial was considered suitable for


processing. If this yield could be increased, the quantity of reusable and recyclable

textiles could also be increased; and

The proportion of material suitable for processing could be maximised though a range of

supply chain improvements, such as educating MRF operators to undertake simple pre-

sorting at source, working with MRF operators to change procedures that could negatively

impact the value of the textiles stream (such as baling) and improving material storage

and handling to reduce damage through damp and mould.


Contents

1.0 Background ................................................................................................................................. 8 2.0 Trial information ......................................................................................................................... 9

2.1 Objective of trial ................................................................................................................. 9 2.2 Trial hosts and roles ............................................................................................................ 9 2.3 Trial equipment ................................................................................................................... 9 2.4 Feedstock for the trial ........................................................................................................ 10 2.5 Trial methodology ............................................................................................................. 12

2.5.1 Sample preparation ............................................................................................... 12 2.5.2 Washing and drying the textiles ............................................................................. 13 2.5.3 Material grading .................................................................................................... 15

3.0 Results and discussion ............................................................................................................. 17 3.1 Trial 1a: Composition of sample after washing and drying .................................................... 17 3.2 Trial 1b: Composition of sample after washing and drying.................................................... 21 3.3 Comparison of Trial 1a and Trial 1 b ................................................................................... 22

4.0 Conclusions ..................................................................................................................................... 26

List of Figures

Figure 1 Stock images of Kannegiesser equipment as set up at PLS ................................................................ 9 Figure 2 Bulk sample of the material used for Trials 1a and 1b ..................................................................... 11 Figure 3 Example of ripped and torn clothing found in the source material .................................................... 11 Figure 4 Preparation of sample material ..................................................................................................... 12 Figure 5 Contaminated textiles on loading conveyor prior to washing ............................................................ 14 Figure 6 Washed and dried material ready for packing ................................................................................. 15 Figure 7 Composition of washed and dried textiles in Trial 1a ....................................................................... 17 Figure 8 Lightweight clothing prior to washing and drying ............................................................................ 17 Figure 9 Lightweight clothing following washing and drying ......................................................................... 18 Figure 10 Heavyweight clothing classed as waste prior to washing and drying ............................................... 18 Figure 11 Heavyweight clothing after washing, suitable for sale in Eastern Europe and Asia............................ 19 Figure 12 Jeans and shirts classed as waste before being washed ................................................................ 19 Figure 13 Clothing classed as Premier grade after being washed .................................................................. 20 Figure 14 Clothing still stained after washing but suitable for sale as wiping cloths and rags ........................... 20 Figure 15 Examples of knitwear damaged in the washing process ................................................................ 21 Figure 16 Composition of washed and dried textiles in Trial 1b ..................................................................... 22 Figure 17 Trial 1a: Lightweight whites washed mixed with other colours, after processing .............................. 22 Figure 18 Trial 1b: Lightweight whites separated prior to washing, after processing ....................................... 23 Figure 19 Comparison of sample composition by reuse and recycling grades after washing and drying ............ 24

List of Tables

Table 1 Summary of washing and drying trials .............................................................................................. 3 Table 2 Grading of material following washing and drying trial ........................................................................ 4 Table 3 Summary of washing and drying trials .............................................................................................. 8 Table 4 Material requested by North Lanarkshire Council .............................................................................. 10 Table 5 Running order of batches in Trial 1 ................................................................................................. 13 Table 6 Textile material grading ................................................................................................................. 15 Table 7 Final sample composition for Trial 1a and Trial 1b ............................................................................ 23


Acknowledgements

Axion Consulting and WRAP would like to thank I&G Cohen and Profession Linen Services for their time and cooperation in delivering this trial. We would also like to thank Shanks for providing sample material for the trial.


1.0 Background WRAP commissioned Axion Consulting to investigate and assess the economic benefits and likely carbon and water impacts associated with washing and drying contaminated textiles for sale to reuse and recycling markets. For the purpose of this project, textiles are defined as clothing, footwear and sheet products, such as towels, bed linen and blankets. All of these product items have a reuse or recycling market, enabling their value to be quantified. The project research was delivered through a series of demonstration trials, assessing textiles that had been collected from a specific domestic source with varying levels of contamination, as shown below.

Table 3 Summary of washing and drying trials

Trial Sub-trial

Details Trial partners

1 Medium to high contamination - visible stains or wet with high odour



1b Pre-sorting the mixed, contaminated material by colour and by weight as well as into ‘delicates2’; then washing and drying the material.

2 Low contamination - low odour, cleaned using a steam cleaner

Not applicable. Axion and I&G Cohen

3 Damp and contaminated clothing



3b Pre-sorting the mixed, contaminated material by colour and by weight as well as into ‘delicates’; then washing and drying the material.

4 Drying only - wet textiles, no odour

4a Drying the mixed, wet material without any pre-sorting. Axion, I&G Cohen and PLS 4b

Pre-sorting the mixed, wet material to separate items by weight into heavyweight and lightweight clothing.

The demonstration trials investigated and assessed the economic and environmental impacts that washing and drying of contaminated textiles may have on the quality and subsequent value of those textiles for reuse and recycling markets. An individual report was produced for each of the trials as well as an overall summary report, comparing the results from each of the trials and investigating the commercial and environmental impacts associated with each option. This report summarises findings from Trial 1. Trial 1 aimed to assess the viability of washing and drying textiles of medium to high contamination, with visible stains and high odour. The textiles were sourced from the Shanks Materials Recovery Facility (MRF) in Glasgow and originated from comingled kerbside collections in North Lanarkshire. The trial was divided into two sub-trials to investigate whether separating coloured clothing prior to washing adds value to the washed and dried textiles.

2 A delicate item can be described as an item that is made out of silk, chiffon, lace or another type of fine material. It may also

have embellishments attached or embroidered decoration.


2.0 Trial information 2.1 Objective of trial The key objectives of the trial were to:

Establish the impact of washing and drying contaminated textiles on the quality and

subsequent value of those textiles within reuse and recycling markets; and

Determine the commercial viability of laundering heavily contaminated textiles which

would otherwise be landfilled.

2.2 Trial hosts and roles The trial was managed by Axion Consulting and delivered in partnership with I&G Cohen and PLS. I&G Cohen is one of the UK’s leading textile recyclers based in Salford, Greater Manchester. They collect textiles from a variety of sources including textile banks, door to door charity donations and school donations. Textiles are sorted and bulked for sale to markets within the UK, Eastern Europe, East and West Africa and the Middle East. PLS is a commercial laundry, based in Bonnyrigg, Edinburgh, specialising in laundering towels, bed and table linen for hotels and hospitals, along with simple items of clothing such as hospital scrubs and chef uniforms. Sample material was prepared and packed by I&G Cohen at their Salford facility in Greater Manchester on 13th February 2012. Washing and drying of textiles was undertaken at the PLS facility in Edinburgh on 15th February 2012. Material was returned to I&G Cohen for final grading and valuation on 28th February 2012. 2.3 Trial equipment The following equipment was used for the trial:

Kannegiesser 4 stage incline conveyor;

Kannegiesser Powertrans Continuous Batch Washer PT 50 -9 (50 kg batch 9

compartments);

Kannegiesser Power Press;

Kannegiesser Lift Shuttle; and

3 Kannegiesser D120 GWU 100 kg (2 x 50 kg batch) dryers each with InfraTouch and

Energy Air Control (EAC).

Figure 1 Stock images of Kannegiesser equipment as set up at PLS

Left to right: (1) Incline conveyor, (2) Powertrans Continuous Batch Washer PT 50-9, (3) Power Press, (4) Lift

Shuttle and (5) D120 GWU 100kg dryer.


2.4 Feedstock for the trial The textiles were sourced from the Shanks MRF in Glasgow and originated from fortnightly comingled kerbside collections in North Lanarkshire. In North Lanarkshire, textiles are placed in bins by householders comingled with other materials such as newsprint and magazines, food and drinks cans, cartons, plastic bottles, plastic pots and tubs, as well as plastic food trays. Table 4 shows the materials that are collected by North Lanarkshire Council as part of their blue bin collection service. Residents are asked not to use plastic bags for material placed into blue bins.

Table 4 Material requested by North Lanarkshire Council3

Material Action required

Newsprint, magazines, junk mail, telephone directories

Clean cardboard (all types) Please flatten (if possible)

Clean food and drinks cans Please rinse out

Aerosol cans Need to be empty

Drinks cartons (Tetra Pak type material) Please rinse out and flatten (if possible)

Clean plastic bottles Please rinse out and flatten (if possible)

Clean plastic pots and tubs Please rinse out and flatten (if possible)

Clean plastic food trays Please rinse out

Textiles (clothes, towels etc.)

The comingled material is then collected in a compactor vehicle and transported to the Shanks MRF in Glasgow. At the MRF, the mixed materials are passed through a trommel, before textiles are handpicked from the picking line and baled for onward transport. The clothing obtained from this source was very badly stained and many items were damp with high odour.

3 NLC (2010), Improvements to Kerbside Recycling Service, http://www.northlanarkshire.gov.uk/index.aspx?articleid=7534

http://www.northlanarkshire.gov.uk/index.aspx?articleid=7534


Figure 2 shows the feedstock used for this trial.


Figure 2 Bulk sample of the material used for Trials 1a and 1b

A large of proportion of the material was badly damaged, ripped and torn as shown in Figure 3 below.

Figure 3 Example of ripped and torn clothing found in the source material

Normally, all of this material would be classed as waste, with no resale value. The material could not be used for low grade recycling, such as wiping cloths or rags, as it was too heavily soiled. Instead, this material would be sent for landfill disposal, representing a significant cost to the MRF operator.


2.5 Trial methodology 2.5.1 Sample preparation Five bales of textiles, each weighing approximately 400kg were obtained for the trial, providing a 2,000kg bulk sample. The bales were broken open and samples of material obtained from each of the bales for inclusion within the trial, to ensure a representative mix. The mixed sample of approximately 1,500kg was then pre-sorted by I&G Cohen staff at their facility in Salford, Greater Manchester. This pre-sort aimed to find intact clothing suitable for washing and drying. Only 50% of the material, 758kg, was judged to be suitable for the washing and drying trial due to the high proportion of severely damaged or heavily contaminated items. The majority of damaged items had been cut during the baling process implemented at the MRF.

Suitable material was divided into the following sub-samples:

Trial 1a: 365kg - all the contaminated material to be washed and dried mixed together;

Trial 1b: 393kg - material separated into the following categories prior to washing:

Lightweight clothing - whites;

Heavyweight clothing - whites;

Lightweight clothing - colours; and

Heavyweight clothing - colours.

To comply with manual handling procedures at PLS, the material was weighed and placed into sacks containing approximately 20kg each. Once filled, each sack was clearly labelled with the trial number and description of contents, as shown in Figure 4. Each sack was also given a number that corresponded with the order in which the material would be processed through the PLS laundry system. After labelling, the sacks were loaded onto a lorry for transportation to PLS in Scotland.

Figure 4 Preparation of sample material


2.5.2 Washing and drying the textiles The washing and drying stage of the trial was carried out during at PLS between 15:00 and 23:00 on 15th February 2012. The washing and drying process was supervised by two PLS staff members.

To meet the washer capacity, material was washed in 40kg batches at 71⁰C for 27 minutes per batch. Following washing, batches identified as lightweight textiles were dried for 14 minutes and heavyweight items were dried for 16 minutes. Both drying programmes included a 2 minute cool down period so that the textiles were cool enough for operatives to handle. As it was important to wash and dry the samples for Trial 1a and Trial 1b in separate batches, some of the batches were only 20kg. The quality of water in the Kannegiesser Powertrans Continuous Batch Washer (CBW) is regularly monitored by experienced operatives via visual inspection; water is recirculated back into the washing process until it is considered too dirty to be used for further washing. Material for Trial 1a and 1b was processed along with material from Trial 3a and 3b (see separate trial report), to ensure that white textiles were washed at the beginning of the process when the water was cleaner. Table 5 shows the running order, description and weight of each batch processed.

Table 5 Running order of batches in Trial 1

Batch number Trial code Description Weight of batch (kg)

3 1b Lightweight – Whites 41

4 1b Lightweight – Whites 21

5 1b Heavyweight – Whites 43

6 1b Heavyweight – Whites 23

33 1b Lightweight – Darks 40




37 1b Heavyweight – Darks 42



40 1a Mixed 43

41 1a Mixed 40

42 1a Mixed 40

43 1a Mixed 40

44 1a Mixed 41

45 1a Mixed 41

46 1a Mixed 41

47 1a Mixed 39

48 1a Mixed 40


The washing and drying procedure was as follows:

A batch of textiles was placed into the loading conveyer which moved it towards the nine

chamber CBW, as shown in Figure 5;

The material was dropped into chamber 1 of the CBW. Water and the following

detergents were added:

Ecolab Silex 3000 (6ml/kg)

Ecolab Elpa Soft (6ml/kg)

Ecolab Setin (2ml/kg)

Hydrogen Peroxide (3ml/kg);

Chamber 1 oscillated from side to side for 3 minutes. After 3 minutes the chamber

rotated fully, dropping the wet material and the water from chamber 1 into chamber 2.

This was a continuous process and once a batch entered chamber 2 a fresh batch was

dropped into chamber 1;

This process continued along the CBW until chamber 9 where after 3 minutes the material

in that chamber was rotated and was dropped out into a press;

The press used high pressure to squeeze excess water out of the material. For the

purpose of this trial the pressure was decreased to reduce damage to buttons, zips and

other closures. The press was set at 30 bar for 30 seconds for the heavyweight batches

and 25 bar for 20 seconds for the lightweight batches.

From the press the clothes were moved by shuttle lift to one of three dryers;

Heavyweight and mixed weight batches were dried for 16 minutes and lightweight

batches were dried for 14 minutes, after which the textiles were dropped onto a conveyer

and moved towards a final hopper for packing, as show in Figure 6; and

The processed material was packed into clean 20kg sacks to meet manual handling

procedures and labelled clearly with the trial number and a description of the contents

ready for onward transport and material grading.

Figure 5 Contaminated textiles on loading conveyor prior to washing


Figure 6 Washed and dried material ready for packing

2.5.3 Material grading Once washed and dried, the material was transported back to I&G Cohen’s facility in Salford, Greater Manchester for valuation. The textiles were hand sorted into the material categories listed in Table 6. Each grade was determined by the likely end market for the material. Material sorting was conducted by experienced I&G Cohen staff, able to determine the value of the material taking into account issues such as levels of contamination and odour.

Table 6 Textile material grading

Grade Sorting criteria

Reuse grades

Premier grade

Best modern clothing suitable for sale in

shops in the UK and abroad, fitting with

current fashion trends, designer labels, etc.

High quality items with no contamination or odour.

Vintage/retro grade

Best quality pre-1990s clothing suitable for

sale in shops in the UK and abroad.

Items may have a musty odour, but no rips/tears. Items may still be categorised

as vintage with small areas of very light staining, potentially washable.

Mixed lightweight clothing

Clothing suitable for sale in West and East Africa.

These items may have very light contamination, such as light food stains that were potentially washable. Items

may have light odours, such as perfume

or smoke, which may be removed through washing. No strong odours or

heavy contamination.

Heavyweight clothing

Clothing suitable for

sale in Eastern Europe and Asia.


Grade Sorting criteria

Recycling grades

Lightweight recycling

Material suitable for

rags and wiping clothes

These items may have heavier odours or contamination, such as dark food stains,

mud, or some animal hairs. Items

contaminated with minimal paint stains may be acceptable in this category. No

heavy staining from paints or oils. Heavyweight recycling

Material suitable for re-pulling and flocking

Waste

Wet/dirty material and

waste

Heavily contaminated or damaged material,

odd socks, tights, etc.

Items with high odour and/or irremovable contamination, such as heavy paint/oil

staining, large numbers of ingrained animal hairs. No reuse or resale value.

Branded items Branded items to be shredded

Items with large, irremovable corporate branding.

Plastic bags Waste plastic bags

Other

Shoes

Other items with potential reuse/recycling value. Items with minor damage may be accepted within this category. Single shoes still

accepted as they may be paired with similar shoes or the

component parts recycled.

Bags

Belts

Other Accessories

Toys

Books

Other

Body Armour

Each item was carefully inspected for rips, tears, small marks and labels to determine the grade and value. The total weight of items in each grade was recorded and supporting photographs taken. The value of the material was then determined based on the total weight and current market price for each grade of material.


3.0 Results and discussion 3.1 Trial 1a: Composition of sample after washing and drying Prior to washing and drying, all of the sample material from Trial 1a was graded as waste and would have been destined for landfill disposal. Figure 7 shows the composition of the mixed weight and colour sample after being washed and dried.

Figure 7 Composition of washed and dried textiles in Trial 1a

In Trial 1a, only 0.4% of washed and dried material was categorised as waste after processing. 60.0% of sample material was considered suitable for reuse, categorised as premier grade, lightweight clothing or heavyweight clothing. The remaining 39.6% was considered suitable for recycling, including lightweight and heavyweight grades. Examples of the different items within each grade before and after washing are given below. Figure 8 shows lightweight clothing classified as waste before being washed and dried.

Figure 8 Lightweight clothing prior to washing and drying


Figure 9 shows lightweight clothing suitable for sale in East and West Africa after being washed and dried. This grade included items such as lightweight trousers, t-shirts and shirts.

Figure 9 Lightweight clothing following washing and drying

Figure 10 shows heavyweight clothing classed as waste before being washed and dried and


Figure 11 shows heavyweight clothing suitable for sale in Eastern Europe and Asia after being washed and dried. This grade made up 24.6% of the total sample and included items such as coats, jumpers and skirts in good condition.

Figure 10 Heavyweight clothing classed as waste prior to washing and drying


Figure 11 Heavyweight clothing after washing, suitable for sale in Eastern Europe and Asia

Figure 12 shows jeans and shirts classed as waste before being washed and dried. Figure 13 shows jeans and shirts classed as premier grade clothing after being washed and dried. Premier grade clothing fits with current fashion trends and can be sold in shops in the UK and Eastern Europe. Items found in this sample included modern blouses, shirts and fashionable children’s clothes.

Figure 12 Jeans and shirts classed as waste before being washed


Figure 13 Clothing classed as Premier grade after being washed

Immediately after washing and drying, the textiles still had a faint musty odour. However this smell was no longer present a few days later when the clothes were graded by I&G Cohen staff at their facility in Salford, Greater Manchester. After washing and drying, the clothing was noticeably cleaner. Staining such as paint, deep-set food stains and rust from baling wire did remain on some items. However, this material could still be upgraded from waste to a recycling grade. Figure 14 shows several items which remained stained after washing but are suitable for sale as wiping cloths (lightweight recycling). It also shows a football shirt with a logo which had been melted in the drying process.

Figure 14 Clothing still stained after washing but suitable for sale as wiping cloths and rags


The nature of the washing and drying process meant that in some cases, items were damaged. For example, some embellishments, such and sequins and beads, became detached during processing and fixings, such as zips and buttons, were damaged. Many knitwear items felted or stretched during the washing and drying process, as shown in Figure 15.

Figure 15 Examples of knitwear damaged in the washing process

3.2 Trial 1b: Composition of sample after washing and drying For Trial 1b a total of 393kg was prepared for washing and drying. A 362kg sample was graded and valued after processing, indicating that 31kg were lost during the washing and drying process. This variation could be attributed to a range of factors, including moisture and contaminant losses from the dirty textiles, losses of embellishments, buttons and zips during the washing and drying process and item losses during transport. Different weighing scales were also used at each of the sites, with accuracies of +/- 2%, introducing a minor source of error. Assessments have been made based on the final recorded weights following processing. Before washing and drying, all of the sample material for Trial 1b was graded as waste and would have been destined for landfill disposal.


Figure 16 shows the composition of the sample after being washed and dried. The sample had been sorted by weight and by colour prior to washing and drying.


Figure 16 Composition of washed and dried textiles in Trial 1b

In Trial 1b, only 0.1% of washed and dried material was categorised as waste after processing. 52.3% of sample material was considered suitable for reuse, categorised as premier grade, lightweight clothing or heavyweight clothing. The remaining 47.6% was considered suitable for recycling, including lightweight and heavyweight grades. 3.3 Comparison of Trial 1a and Trial 1 b The purpose of sub-dividing the trial was to investigate whether separating colours and heavyweight clothing prior to washing further retains value to the washed and dried textiles. In Trial 1a, material was mixed, whereas in Trial 1b, material had been separated by colour and by weight prior to washing and drying. In Trial 1a, light coloured clothing that had been washed in mixed batches with coloured items had a greyish tint to them after washing and drying. In Trial 1b, where textiles had been pre-sorted by colour and weight, the resulting white clothes appeared whiter in comparison; however, this did not have a substantial effect on how materials were graded and subsequently valued. Figure 17 and Figure 18 show whites that were washed and dried during Trials 1a and 1b.

Figure 17 Trial 1a: Lightweight whites washed mixed with other colours, after processing


Figure 18 Trial 1b: Lightweight whites separated prior to washing, after processing

Table 7 provides a full breakdown of final sample weights and gradings.

Table 7 Final sample composition for Trial 1a and Trial 1b

Trial Trial 1a: Mixed, contaminated material

Trial 1b: Contaminated material, pre-sorted by colour and by weight as well as into ‘delicates’ for separate washing and drying

Grade Sample weight

(kg) Composition

(%) Sample weight

(kg) Composition

(%)

Premier grade 23.4 6.5% 18.4 5.1%

Vintage/retro grade 0.0 0.0% 0.0 0.0%

Lightweight clothing 104.9 28.9% 123.8 34.2%

Heavyweight clothing 89.3 24.6% 47.0 13.0%

Lightweight recycling 54.2 14.9% 103.2 28.5%

Heavyweight recycling 89.3 24.6% 69.2 19.1%

Wet 0.0 0.0% 0.0 0.0%

Waste 1.6 0.4% 0.4 0.1%

Total 362.7 100% 362.0 100%

Both samples contained a relatively high proportion of lightweight clothing. This may be due to the timing of the trials, which were conducted in February. No vintage clothing was found in either sample. In both samples, a very small proportion of material was categorised as waste following the washing and drying process.


Figure 19 compares the proportion of clothing in the sample that was considered suitable for reuse or recycling after the washing and drying process for Trial 1a and Trial 1b.


Figure 19 Comparison of sample composition by reuse and recycling grades after washing and drying

After the washing and drying process in Trial 1a, where the mixed material was processed without any prior sorting, 60.0% of the material was considered suitable for reuse, with 39.6% suitable for recycling and 0.4% classed as waste. In Trial 1b, in which the material was pre-sorted into colours and by weight prior to washing and drying, 52.3 % was considered suitable for reuse, with 47.6% suitable for recycling and 0.1% classed as waste. The difference in composition between the two samples was not significant and it is likely that the differences can be attributed predominantly to inherent variation in the sample composition rather than being a consequence of the pre-sorting that took place before washing and drying in Trial 1b. This indicates that there was unlikely to be any major benefit in pre-sorting the textiles prior to washing. Washing white colours separately from dark colours did lead to whiter whites, but did not have a substantial effect on how the material was graded and subsequently valued. Should more complex grading systems be used, such as systems including ‘cream grades’, this factor may impact the categorisation of processed textiles and resulting valuation. The trial results demonstrated that following washing and drying, virtually all of the selected fraction could be upgraded to either a reuse or recycling grade. It must be acknowledged, however, that the potential for maximising value from this textiles stream is heavily impacted by the initial yield. Only 50% of feed material collected for this trial was considered suitable for processing. If this yield could be increased, the quantity of reusable and recyclable textiles and resulting revenues could also be increased. The proportion of material suitable for processing could be maximised though a range of supply chain improvements:

Working with MRF operators to change operating procedures that reduce the value of the

textiles. For example, many high quality items that could have been classed as premier

or clothing grade were damaged by the baling process used at the MRF. Opting to

transport the material in bulk or using a lighter baling pressure may help to reduce

damage to the clothing and improve the yield.


An element of pre-sorting could occur at the MRF to improve the quality of material

collected, by training MRF operators not to select severely damaged items for processing.

However, detailed sorting into textile grades should be undertaken by experienced textiles

recyclers and the demands placed on MRF operators to sort textiles should be minimised.

Improving material storage and handling; for example, some quality material may become

damp and mouldy in storage, reducing the resulting material quality and value. More

efficient transfer of the textiles to the textiles recycler could reduce the volume of material

that is unsuitable for processing.


4.0 Conclusions The key conclusions from this washing and drying trial are:

Approximately 50% of the bulk sample of textiles from comingled collections provided

intact clothing suitable for washing and drying. The remaining fraction was unsuitable

and destined for landfill;

Before the washing and drying, all of the sample material was categorised as waste and

was destined for disposal to landfill;

After being washed in batches of mixed colour and weight (Trial 1a), 99.6% of the sample

was upgraded to either a reuse or recycling grade;

After being washed separated by weight and into colours/whites (Trial 1b), 99.9% of the

sample was upgraded to either a reuse or recycling grade;

The trials demonstrated that there was no added value in separating the material into

colours/whites or by weight prior to washing and drying compared to washing and drying

the clothing in mixed batches unless more complex grading systems are used by textiles

recycler, including ‘cream grades’;

The potential for maximising value from this textiles stream is heavily impacted by the

initial yield. Only 50% of feed material collected for this trial was considered suitable for

processing. If this yield could be increased, the quantity of reusable and recyclable

textiles could also be increased; and

The proportion of material suitable for processing could be maximised though a range of

supply chain improvements, such as educating MRF operators to undertake simple pre-

sorting at source, working with MRF operators to change procedures that could negatively

impact the value of the textiles stream (such as baling) and improving material storage

and handling to reduce damage through damp and mould.

www.wrap.org.uk/textiles

Documents

Trial report Demonstration trials for washing and drying …edge.rit.edu/edge/P16702/public/Phase 3 Subsystems Design... · Washing and drying the mixed, contaminated material without