top of page

HOW TO MAKE NON-ASBESTOS CORRUGATED ROOFING SHEET

Writer: Haley Dang
Haley Dang
Nov 6, 2020
3 min read

Updated: Aug 24

Non-asbestos corrugated roofing sheet was made from cement, paper pulp, PVA fiber and other inorganic additives. Just with some simple raw materials but it is not easy to make good final sheet that requests exactly in proportion of raw materials, slurry and all process. So, how to make non-asbestos corrugated roofing sheet well?

To get the good final sheet, it has to go through eight basic stages.




Stage 1: Preparing raw material

Preparing materials in accordance with the ratio. PVA fiber (1 – 2 wt%), paper pulp (2 – 5 wt%), inorganic additives (5 – 10 wt%), cement (balance).


Stage 2: Pulp preparation

The first stage of the production is pulp preparation. Crushing kraft paper with water proportionally to convert to slurry.


Stage 3: PVA fiber preparation

After being pre-mixer, PVA fibers are fed into high-speed air stream to further separate single fibers to avoid clumping when mixed with the slurry. Then, the PVA fibers continue to be passed through pneumatic piping system and into the de-pressurizing chamber and then dropped into the vertical hydraulic mixer and dispersed into the slurry mix.


Stage 4: Two – component slurry preparation

Slurry - a component that is pumped quantitatively into the hydraulic vertical mixer. Here, water and cement are supplied quantitatively to create a two-component slurry. In this stage, the prepared additives silica fume and bentonite are also added according to the required material.


Stage 5: Three – component slurry preparation

Adding PVA to the two-component slurry to create a three-component slurry. After the homogeneity of the three-component slurry has been achieved, they are discharged into the turbo-mixer to continue mixing with the necessary additive components.


Stage 6: Green sheet forming process

The green sheet forming process is started from the rotary distributing mixer. Slurry mixture consists of paper pulp, PVA fiber, cement and together with a small percentage of additives to increase forming. All of this mixture is stored in the rotary distributing mixer to avoid any setting taking place and transferred into the green-sheet forming tank at a fixed rate at a certain time interval. The rotary distributing mixer will also add muddy water to the green-sheet forming tank to to maintain necessary water proportion in the mix. According to the principle of hydrostatic pressure and filtering a dilute suspension, the material is transferred on the cylindrical presses, one layered upon another. When the desired thickness is reached, the indicator light comes on, the worker uses the automatic cutter to detach the green sheet from the rotating cylinder sieve. The green sheet is then moved to the 1st conveyer belt, finishing the green sheet forming process.


Stage 7: Product forming process

After cutting the green sheet, it will be picked up and transferred into the 2nd conveyer belt. In these two conveyor belts, the green sheet will be cut by by the vertical and horizontal cutter. Once the specified size are achieved, the air-suction forming unit will picked-up and laid down onto the metal mould. At this point, the product forming process is over.


After the wave sheet is formed, it is moved to the steam curing chamber. The boiler will enhance the setting ability of the product. After 2.5 - 3 hours, the product reaches the required hardness and can be demoulded by automate stacker unit.

With only eight above basic stages, the fiber cement corrugated roofing sheet has been produced successfully. However, after that, the sheet should be properly cured to ensure the best quality, curing time should be 14 days before the day of loading.


Recent Posts

See All

644 Comments


Rose Kk
5 days ago

Confidence in communication develops through regular practice and a good understanding of basic English. I am working on my vocabulary, grammar, pronunciation, sentence formation, and listening skills to improve the way I speak. Spoken English Classes in Madurai gives me a chance to practise these areas through conversations and everyday speaking activities. Regular practice helps me notice my mistakes, speak with less hesitation, and express my thoughts more clearly in interviews, at work, and in daily conversations.


Like

kani
7 days ago

This article provides a clear overview of the growing role of Generative AI Course in Jaipur in modern technology. The explanation of its applications, practical benefits, and key concepts makes the topic easy to understand for both beginners and professionals. The focus on developing practical knowledge is particularly useful for anyone looking to strengthen their technical skills and explore opportunities in the evolving field of artificial intelligence.


Like

Kesavan Raj
7 days ago

A lot of everyday discomfort seems to come from repetitive routines and long periods without proper recovery. That’s why conversations around wellness and relaxation feel more relevant now than ever before. Many individuals exploring a Body Massage In Velachery appear to be looking for quiet spaces that support physical ease, flexibility, and a temporary pause from demanding schedules in a natural way.


Like

michael94897
7 days ago

The description of networking basics and how devices speak was very clearly described and useful. I found practical aspects of how to configure and solve network connectivity problems very useful. I'm trying to find ways in which I can further improve networking skills and the emphasis of practically applied learning felt useful. While searching the net for potential ways of improving, I saw FITA Academy among training providers and noticed their CCNA Course in Delhi, it aims to build practical knowledge.

Like

Sreenila
Sep 07

This is an insightful and well-structured post. The concepts are explained in a simple and clear manner, making it easy for readers to understand. For anyone aiming to build a career in Data Science, having a strong foundation is essential. A Data Science Course in Chennai offers practical exposure and helps learners tackle real-world testing challenges. Thanks for sharing such valuable information—looking forward to more updates!


Like
bottom of page