Rotomoulding
About Rotomoulding
What is Rotational Moulding ?
Rotational moulding process is a very simple process for manufacturing hollow, seamless products of all sizes and shapes. Due to its simple operation and relatively low cost moulds, this process has become very popular for manufacturing hollow items like water storage tanks.
Rotational moulding is a Four- Stage process.
Stage 1
Polymer powder is loaded in the mould manually and mould is closed.
Stage 2
The mould is then shifted to the heating oven. Here the mould is heated by forced hot air circulation. While the mould is heated it is also rotate about two perpendicular axes simultaneously. The polymer melts and forms a homogenous layer inside the mould.
Stage 3
The mould is shifted to a cooling station where forced air cools the mould.
Stage 4
The mould is open and finished part is taken out. Unlike injection and blow moulding, rotational moulding does not involve high pressures, hence the products are stress free and have uniform wall thickness. Accurate control of process is very important for producing quality products in rotational moulding.
What is Rotational Moulding ?
Rotational moulding process is a very simple process for manufacturing hollow, seamless products of all sizes and shapes. Due to its simple operation and relatively low cost moulds, this process has become very popular for manufacturing hollow items like water storage tanks.
Rotational moulding is a Four- Stage process.
Stage 1
Polymer powder is loaded in the mould manually and mould is closed.
Stage 2
The mould is then shifted to the heating oven. Here the mould is heated by forced hot air circulation. While the mould is heated it is also rotate about two perpendicular axes simultaneously. The polymer melts and forms a homogenous layer inside the mould.
Stage 3
The mould is shifted to a cooling station where forced air cools the mould.
Stage 4
The mould is open and finished part is taken out. Unlike injection and blow moulding, rotational moulding does not involve high pressures, hence the products are stress free and have uniform wall thickness. Accurate control of process is very important for producing quality products in rotational moulding.
Raw Materials
To obtain the desired end product, the choice of a quality powdered resin is essential in rotational molding. LLDPE (Li near Low Density Polyethylene) in its powdered form is most widely used raw material in Rotational moulding.
LLDPE Powder is generally recommended for:
- Overhead water tanks
- Storage bins
- Toys and traffic barriers
- Sanitation & Agriculture products
- Rotomoulding applications requiring outdoor exposure
In- house storage care:Bags should be stored in dry / closed conditions at temperatures below 5o•c and  protected from UV or  direct sunlight.Bags must be kept away from the furnace or any other imflamable objects.
Foaming in Rotational Moulding. PE foam increases rigidity and stiffness of rotational moulded parts while minimising weight. Insulating properties of foam may also have useful applications. Rotational Moulding with PE foam is very simple if machine is equipped with proper process controls. “Vinodrai” machines are highly suitable for making foam products and insulated water tanks.
Advantages of LLDPE Foam Tank.
- Keeps Water Temperature Normal.
- Higher Thickness and Rigid Tank.
- Value added product, better customer preference.
- Higher realization & better profits.
For other resources such as Powder Suppliers, Plastic Lid Suppliers, Books on Rotomoulding, Rotomoulding  Websites.
Machine Selection
Selection of a rotational moulding machine is based on the following considerations
• Capacity of tank which have max share in market
• Monthly expected production in terms of ltr.
• Range of tanks required in market (Loft, Roof, House hold, Horizontal )
• Running cost of production.
The machine must be selected from the point of view that it should produce the capacity of tank most economically which have max. share in market.
Machine must be able to produce required volume of tanks which are salable in market.
And finally running cost that matters and not capital cost. In the competitive world, running cost of production is the key to survival of a company. The running cost depends upon the selection of the machine. If you selected the machine which is unable to control the fuel, electricity consumption. Employing heavy maintenance and need skilled labor then such machines though are cheap but finely take away the entrepreneur towards the loss.
Therefore machine must be :-
- Fuel saver
- Less power consumable
- Must not be labor oriented
- Maintenance free and hence interruption free
- Essay to operate
- Productive and efficient

Applications
Rotational moulding is exceptionally versatile process that can produce a huge range of plastic products. Rotomoulded products are used in many key sectors like:
Process Comparison
Sr No. | Factors | Rotational Moulding | Blow Moulding |
---|---|---|---|
1 | Typical product volume range | 1,00,000 litres | 1,000 litres |
2 | Raw material used | • Linear Low Density Polyethylene (LLDPE) • Medium Density Polyethylene (MDPE) • High Density Polyethylene (HDPE) • Cross linking Polyethylene (XLPE) • Polyvinyl Chloride (PVC) • Polycarbonate • Nylon • Polypropylene (PP) • Several others | • Low Density Polyethylene (LDPE) • High Density Polyethylene (HDPE) • Polyethylene Terephthalate (PET) • Polypropylene (PP) • Polyvinyl Chloride (PVC) |
3 | Raw material form | Powder or Liquid | Pellets |
4 | Mould material | Steel/Aluminium | Steel/Aluminium |
5 | Mold pressure | Steel/Aluminium | Steel/Aluminium |
6 | Mould cost | Low | High |
7 | In-mould graphics | Yes | Yes |
8 | Labour Intensive | More | Less |
9 | Cycle time | Slow | Fast |
10 | Wall thickness | Uniformity possible | Tends to be non-uniform |
11 | Insert feasibility | Yes | Yes |
12 | Residual stress | Low | High |
Resources
For other resources such as Powder Suppliers and Plastic Lid Suppliers please click the buttons
Sr.No | Name of Company | Address | Contact Person | Contact Number | Email Address |
---|---|---|---|---|---|
1 | Phychem Technologies Pvt Ltd | Gut No 172, At post Khatwad Dindori, Nasik. 422002 Maharashtra | Mr Umakant Swadekar | +91 9422255035 | kanadtech@gmail.com |
2 | Ekdant Plastics | Plot no A-112, Five star MIDC Area, Shendra, Aurangabad. 431007 Maharashtra | MR Kishore Rathi | +91 9422706700 | marketingekdant@gmail.com |
3 | Heera Roto Polymer | V-21, Additional MIDC, Ajanta Road. | Mr. Bhushan Khadake | +91 982338424 | bkhadke@gmail.com |
4 | Petrotech International | Shed No: A, Sy No: 65/4-A2, 3rd Cross, Ranganathpura, Magadi Rd, Kamkshipalya, Banglore. 560079 | +91 9448478001, 80- 427743012/3/4 | All India Associates Branches |
|
5 | Alok Masterbatches Ltd | C-65/1, Okhla Industrial Area Phase II, New Delhi. 110 020 | Mr. Amit Singh | Phone : +91 41612244-47 Mobile : +91 9910178122 | amitsingh@alokindustries.com |
6 | Rotopolymers | Plot No. 11, 12, 13, Dholeshawar Ind Estate, Behind Champion Oil Mill, Changodar. Dist : Ahemdabad | Mr Rashmin | +91 9824509797 | rupasanghvi@yohoo.com |
7 | Calcutta Poly Products Industries | Jessore Road, Kalachandpara Duttapukur, North 24, Parganas. 743248 West Bengal | Mr BS Nandi | +91 9830056274 | suryacppi@gmail.com |
8 | Progressive Roto Plast | Plot No:4313/6/7, Road NO 43-D, Near Surat Floor Mill, Sachin GIDC Surat. 394 230 Gujrat | Mr Darshit Parekh & Mr Bharat Padaliya | +91 9825111533, +91 9925012699 | perfectpolymers2005@gmail.com |
9 | Pacific Poly Plast | Plot No. 5107,G.I.D.C, Estate, Ankleshwar. 393002 District-Bharuch, Gujarat | +91 08980960131 | ||
10 | Perfect Roto Polymers | Shed No. 4313/7,Road No.43-D, Near Surat Floor Mill,GIDC, sachin, Surat. 394230 Gujarat. | Phone : +91-261-6538516/2914644, Mobile : +91 9953358959 | ||
11 | Riddhi Polymers | Survey No. 736/1, B-4, Ground Floor, Raj Ind Compound, Ringanwada, Daman. 396 210 (UT) | Mr Jagdish Thakkar. | +91 260 2241154 | riddhipolyp@sancharnet.in |
12 | Sunrise Polymers | D-67, Phave V, Jeedimetla, Hyderbad-500055 | (+91)- 9849023052 | sunrisepoly1@gmail.com |
Sr.No | Name of Company | Address | Contact Person | Contact Number | Email Address |
---|---|---|---|---|---|
1 | Yogi Polymer | 27-28, Nijanand Estate, kunjadiya street,opp,Gupta Mill, Pipodra, GIDC, Surat. 394110 Gujarat | Mukeshbhai Mangroliya | +91 9979187722 | www.yogipolymers.com |
2 | Ornate Polymers | Paramount commercial complex,3, Rajputpara, Rajkot. 36000 Gujarat | +91 9824507575 / 9824506363 | www.ornateplastic.com | |
3 | Sona plastic Udjog | Khasra,No.30, Gram Bhoytawale, Jaipur. 302013 | Mr. Bhushan Khadake | Ph : +91 141 3235301 Mob : +91 9953360885 | |
4 | Manibhadra Polymers | C/1B-33 & 34 A, G.I.D.C, Nr. Bank of Baroda, Kabilpore, Navsari. 396445 | Mukesh Kothari | Ph : +91 2637 327700, 327800 Mob : +91 9427575000 | manibhadra.polymers@yahoo.com |
5 | Avani Plast | C-65/1, Okhla Industrial Area Phase II, New Delhi. 110 020 | Mr Jagdish Bhai | 9825069528 | avaniplast@yahoo.co.in |
6 | Sun Polymer | Sun Polymer | +91 9942727888 | ||
7 | Injecto Plast | 13PN 171-A Zambad Estate, New Shrey, CIDCO, Aurangabad 431001 | +91 240 2564266 | ||
8 | Singla Industries | 176, Block-A, DSIDC Industrial Area, Narela, Delhi. | Mr Naresh Singhal | +91 9818118854, 9136536625 | nareshsinghal.a176@gmail.com |
9 | ML Industries | E-44, Sector 5, DSIDC, Bawana, Delhi 110039 | Mr. Rakesh Agrawal | +91 9350885251, 98310078236 | ml.industries@yahoo.in |