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Stretch Blow Mold Bottle Construction (Single stage/dual stage)

Stretch blow molding is a manufacturing process used to create PET plastic bottles and jars. Small pellets of plastic resin are pushed into an extruder and get melted.  Then they are injected into a steel mold that shapes them into plastic tubes. These preforms are the starting point for the plastic bottles. By injecting air into this heated preform, the bottle shape is formed to the desired mold shape.

There are two types of stretch blow molding techniques: single stage and the two-stage process. In the single stage process, preforms are created and then blown into bottles in one continuous process, by one machine. This process is split into three stations: first melted plastic is injected into the preform mold.  It is switched to the second station for conditioning. And finally, at the third station, air is blown inside the heated preform stretching the plastic into the mold and your desired bottle shape. Each station takes the same amount of time since it is all part of one continuous process, on one machine. This technique is often used in applications that call for more rigid quality specifications or specialized shapes such as wide mouth jar openings.

In the two-stage process the three stages of molding are split into two machines that work independently allowing more efficient throughput and flexibility. Preforms can be produced by one machine and then warehoused for later production. Then, a batch of preforms could be loaded into another machine called a reheat blow, or RHB, machine, which is designed for blowing preforms into bottles in high quantities and faster production rates with the potential to lower piece cost.

For more information on which process is right for you, please contact one of our Packaging Specialists.  Illing Packaging is dedicated to Packaging Your Vision.

In the previous article, we have introduced Which Plastic Is Good For Water Bottles. In today&#;s article, we will take you through the process of manufacturing sports bottles. Do you know what is blow moulding? And how to make sports water bottles? Here is everything you need to know.

What plastics are used for sports water bottles blow molding?

1. PP is food-grade plastic, BPA-free, and FDA/LFGB tested. High impact resistance, temperature resistance up to 100°C, dishwasher and microwave oven safe. But it is restricted in some countries that ban plastic.

2. Tritan is BPA-free and FDA/LFGB tested. It is the safest and healthiest plastic material at present, and it is also the designated material for baby bottles in Europe and America. It is the most used material in the BPA-free bottles exported by our company, and the price is also the most expensive among plastic materials.

3. Both Tritan and SK are made of high-temperature-resistant plastic with high safety. Its overall performance is close to Tritan, and its price is lower than Tritan. It is often used in low-end temperature-resistant plastic bottles. The highest standard SK material can also pass the FDA/LFGB test, with a temperature resistance of 100°C.

For more information, please visit Water Bottle Molding Machine.

4. PETG is a low-temperature material. It has the same permeability as Tritan and is often used in sports water bottles for cold water. Due to the extrusion blow molding process, the thickness of this bottle will be relatively thin, about 0.5mm, so the resistance to falling is poor.

5. AS is a medium material, and the unit price of the material is low. Excellent light transmittance, blue background, poor impact resistance, easy to scratch. Temperature resistance 80 &#;, can not withstand too high a temperature.

What is blow moulding?

1. Moulding Process For Plastic Bottle Bodies

Blow molding, also known as hollow molding, is mainly used to make plastic bottle body. It is a method of inflating the preform in the mold into a hollow article by gas pressure. There are two main processes as follows.

&#; Injection Blow Molding (IBM)

The commonly used bottle body molding process is injection blow molding (IBM). Usually, it is used for the production of plastic objects in large quantities. In the IBM process, firstly, inject the preform in the injection mold, and then heat and soften the formed preform and put it into the blow mold for inflation molding. This bottle body process is faster than the fully automatic one. The average output of a machine is 3,000 a day, but it is more labor-intensive.

&#; Extrusion Blow Molding (EBM)

Another common method is the extrusion blowing process, a process that consists of melting down a plastic raw material and forming a hollow tube known as a parison. This parison is then captured by closing it into a cooled bottle mold. Air is then blown into the parison, inflating it into the shape of the hollow bottle. After cooling and setting, it is taken out from the mold, and the finished product is obtained after trimming the waste edge. The finished product has high softness, and there will be a seam at the bottom of the bottle. Commonly used materials are PETG and PET materials.

2. Moulding Processes for Plastic Bottle Lids

Most plastic bottle lids are made by injection molding, a technique we have already mentioned above. In this process, the raw material is heated in a metal hopper, which makes it very soft and flexible. The softened plastic is then injected into a complex, detailed steel mold. This mold forms the softened polymer into the desired shape of the bottle lids. Once the polymer material has cooled enough to harden, the mold can be opened to remove the lids.

3. Assemble lid and bottle body

Manufacturer of wholesale sports bottles

The materials of our sports water bottles are PP, PC, Tritan, SK, Petg, PCTG, AS, and other materials. They are 100% food safety grade, do not contain BPA, meet European and American food safety standards, and pass third-party testing such as LFGB. Moreover, we have more than 200 patents, including appearance patents, utility model patents, etc. Mainly applied in China, Canada, EU, Japan, etc.

We also design for our customers, many designs have registered patents by our customers. Everich has a professional and creative R&D department that can support strong custom manufacturing or private label service. We have rich experience in cooperating with tent E-commerce & Amazon clients. If there is any requirement, we can sign an NDA to protect your own design.

Everich&#;s goal is to continuously bring value to customers through high-quality drinkware. We also want to assist as many clients as possible, helping them expand their markets and save costs. If you would like to request a quote, please feel free to contact Everich. Send us an inquiry and we will get back to you in the shortest time possible. Click here and learn more about our wholesale sports bottles.

Contact us to discuss your requirements of Pet Bottle Manufacturing Machine. Our experienced sales team can help you identify the options that best suit your needs.