The process of recycling plastic bottles
An IELTS Academic Writing Task 1 process diagram showing how plastic bottles are recycled into new products, with a band 9 model answer, a plan, and notes on how it meets each marking criterion, including the passive and sequencing language a process needs.
Write your answer
Do this before you scroll. The model answer below will make sense as a comparison and not much use as a template.
Task 1 Academic · 20 minutes · at least 150 words
The diagram below shows how plastic bottles are recycled. Summarise the information by selecting and reporting the main features, and make comparisons where relevant.
A circular process diagram with nine labelled stages joined by arrows. Stage 1: used bottles are put in recycling bins by consumers. Stage 2: a lorry collects the bins and takes them to a recycling centre. Stage 3: bottles are sorted by hand and by machine into plastic types and non-plastic waste is removed. Stage 4: sorted bottles are compressed into large blocks. Stage 5: the blocks are crushed and washed. Stage 6: the washed plastic is shredded into small flakes. Stage 7: the flakes are melted and formed into pellets. Stage 8: the pellets are sold to manufacturers, who use them to make new products such as clothing, containers and new bottles. Stage 9: the products are bought and used by consumers, and the cycle returns to stage 1.
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How to plan this one
- 1A process has no trends. The overview states how many stages there are, where it begins and ends, and whether it is linear or a cycle. This one is a cycle, and that is the main feature.
- 2Split the stages into two natural halves for the two body paragraphs: collection and preparation (stages 1 to 5), then transformation and reuse (6 to 9).
- 3Use the passive for what is done to the bottles and sequencing language for the order. Every stage on the diagram should be mentioned, briefly.
- 4Do not add technical detail the diagram does not show. Report the labels; do not explain how a shredder works.
Model answer
Written at the top of the band. Read it for the moves it makes, not the opinions it holds: a memorised essay on this topic will not fit the prompt you actually get.
The diagram illustrates the stages by which used plastic bottles are collected, processed and turned into new products, and shows that the process is a continuous cycle.
Overall, there are nine stages, beginning with consumers disposing of bottles and ending with new products made from the recycled plastic being bought and used, at which point the cycle begins again. The first half of the process prepares the bottles for recycling, while the second half transforms them into raw material and then into goods.
The process starts when used bottles are placed in recycling bins by households. These bins are collected by lorry and delivered to a recycling centre, where the bottles are sorted, both by hand and by machine, into different types of plastic, and any non-plastic waste is removed. Once sorted, the bottles are compressed into large blocks for easier handling, and these blocks are then crushed and washed to remove labels, dirt and residue.
In the second half of the cycle, the clean plastic is shredded into small flakes, which are heated until they melt and are formed into pellets. These pellets are the finished raw material, and they are sold to manufacturers, who use them to make a range of new products, including clothing, containers and new plastic bottles. Finally, these products reach consumers, and when they are eventually discarded into recycling bins the whole process is repeated.
Why it scores, criterion by criterion
Task Achievement
The overview gives the stage count, the start and end points, and the cyclical nature, which are the main features of a process. Every stage on the diagram is reported in order, at the level of the labels, without invented technical detail. The division into two halves is stated in the overview and then used to organise the body.
Coherence and Cohesion
Sequence is carried by a varied set of markers ("starts when", "once sorted", "then", "in the second half", "finally") and by relative clauses that chain stages ("where the bottles are sorted", "which are heated"). The last sentence closes the loop back to the first, which mirrors the diagram.
Lexical Resource
Process vocabulary used precisely: "disposing of", "compressed", "crushed", "residue", "shredded", "flakes", "pellets", "raw material", "discarded". Paraphrase of the prompt ("collected, processed and turned into", "a continuous cycle"). Nothing is repeated where a synonym exists.
Grammatical Range and Accuracy
The passive is used throughout for what is done to the material ("are placed", "are collected", "is shredded", "are formed"), with agents added only where the diagram names them ("by households", "by lorry", "by manufacturers, who ..."). Participle clauses ("once sorted") and relative clauses vary the structure. Present simple for a general process; no errors.
Language worth stealing
Each of these carries a trap as well as a use, so the note matters as much as the phrase.
- Overall, there are N stages, beginning with ... and ending with ..., at which point the cycle begins again
- The overview formula for a cyclical process. For a linear one, replace the last clause with what the final output is.
- The process starts when X is/are ... by ...
- A first-stage opener that puts the material in subject position and the agent in a by-phrase. The passive is the natural voice for a process.
- Once sorted, the bottles are ...
- A participle clause that sequences without "after that". The subject of the main clause must be the thing that was sorted, or the participle dangles.
- These pellets are the finished raw material, and they are sold to ...
- A sentence that marks the transition from processing to use. Naming the product of a half of the process is what shows you understood the diagram's shape.
More Task 1 Academic practice
Last updated 18 September 2026.