Q1: Production of a hollow product by inflation of a tube or parison is called the __________ process.

ANS:A - blow moulding

Blow molding is a manufacturing process used to produce hollow plastic products. It is particularly well-suited for creating containers, bottles, and other hollow shapes with complex geometries. The process involves several steps:

1. Extrusion of Parison: The process starts with the extrusion of a molten tube of thermoplastic material called a parison. This parison is typically made from materials like polyethylene (PE), polypropylene (PP), or polyethylene terephthalate (PET).
2. Mold Closure: The parison is then placed between two halves of a mold, which are usually made of metal and have the desired shape of the final product.
3. Inflation: The mold closes around the parison, and compressed air is injected into the parison. This causes the softened plastic to expand and conform to the shape of the mold cavity. The pressure of the air also forces the molten plastic to adhere to the mold surfaces, creating a hollow shape.
4. Cooling: Once the plastic has taken the shape of the mold, it is cooled to solidify and retain its shape. Cooling can be achieved through various methods such as air cooling or water cooling, depending on the material and production requirements.
5. Mold Opening and Ejection: After the plastic has cooled and solidified, the mold halves are opened, and the newly formed hollow product is ejected from the mold cavity. The excess plastic material, called flash, is trimmed off from the product.

Blow molding offers several advantages, including the ability to produce lightweight and durable hollow products with relatively low cost and high production efficiency. It is widely used in industries such as packaging, automotive, consumer goods, and healthcare for manufacturing a variety of plastic containers and parts.