What You Should Know about Vacuum Forming Machine

We use a lot of vacuum forming products in our daily life, such as disposable dinner plates, bowls, packed lunch boxes, and food packaging in supermarkets. Many people are curious about how plastic products are made. This article briefly introduces the molding process of blister products, hoping to help those who want to know.

The principle of vacuum forming

Vacuum forming is also called thermoplastic molding. This molding process mainly uses the vacuum suction generated by the vacuum pump to heat and soften PS, PET, PVC, ABS  and other thermoplastic plastic sheets through the mold to form various shapes of vacuum covers, blister trays, blister shells, etc.

Main structure and equipment

It consists of feeding, pulling, upper and lower electric heating furnaces, lower gates, multi-functional adjustable size, lower mold plate, upper mold, upper gate, knife gate, slicing, placing and equipped with vacuum devices; the pneumatic device is the main power source, and its pulling and feeding are electric, reducer, time relay, intermediate relay, travel switch and other electrical appliances to form a fully automatic control system.

The vacuum forming equipment includes a heating device, a vacuum device, a compressed air device, a cooling device, a demoulding device and a control device.

Compression molding plastics

There are many methods for thermoforming plastics, which can be divided into compression molding and differential pressure molding according to the molding power. According to the molding mold, it can be divided into several methods: 

1. Single Positive Mold Forming
Single positive mold forming, also known as convex mold forming, bend mold forming, or straight mold forming, is a molding method that uses machinery to shape heated and softened plastic sheets into specific forms.

2. Single Negative Mold Forming
Single negative mold forming is also referred to as concave mold forming.

3. Matched Mold Forming
Matched mold forming involves a mold assembly consisting of a positive mold, a negative mold, clamps, and other accessories.

4. Composite Mold Forming
Composite mold forming (specific details not provided, to be supplemented).

Molds

There are three types of conventional molds: plaster molds, copper molds, and aluminum molds.

1. Gypsum mold: mainly used for proofing, generally cannot be used for mass production, and its production time is generally 24 hours.

2. Copper mold: a layer of copper is electroplated on the gypsum mold, which enhances strength and wear resistance, and the cost is not high. It is the most commonly used mold in production, and the general production cycle is 100 hours, and the minimum is 3 days.

3. Aluminum mold: made of pure aluminum, high cost, machine processing is required, and the general mold making time is 3-5 days. Aluminum mold production quality is good, heat dissipation is fast, product precision is high, and service life is long.

Vacuum Forming Characteristics

1. Strong adaptability of product specifications: The vacuum forming method can be used to manufacture various products of extra large, extra small, extra thick, and extra thin, and the sheet can be as thin as 1~2MM.

2. The product has a wide range of applications: daily necessities blister packaging, small hardware blister packaging, automotive products blister packaging, electronic products blister packaging, food blister packaging, cosmetics blister packaging, computer peripheral equipment blister packaging, toy blister packaging, sports goods blister packaging, stationery blister packaging, etc.

3. The production efficiency is high, the raw and auxiliary materials are saved, the weight is light, the transportation is convenient, the sealing performance is good, and it meets the requirements of environmentally friendly green packaging; the packaged products are transparent and visible, the appearance is beautiful, and it is easy to sell, and it is suitable for mechanized and automated packaging, saving manpower and improving efficiency.