Waste

Waste: Plastic is the general common term for wide range of synthetic or semi synthetic organic amorphous solid materials derived from oil and natural gas.

PET: is also known as a wrinkle-free fiber. It’s different from the plastic bag that we commonly see at the supermarket. PET is mostly used for food and drink packaging purposes due to its strong ability to prevent oxygen from getting in and spoiling the product inside. It also helps to keep the carbon dioxide in carbonated drinks from getting out. Although PET is most likely to be picked up by recycling programs, this type of plastic contains antimony trioxide—a matter that is considered as a carcinogen—capable of causing cancer in a living tissue. The longer a liquid is left in a PET container the greater the potential for the release of the antimony. Warm temperatures inside cars, garages, and enclosed storage could also increase the release of the hazardous matter.

HDPE: Quite special compared to the other types, HDPE has long virtually unbranched polymer chains which makes them really dense and thus, stronger and thicker from PET. HDPE is commonly used as the grocery bag, opaque milk, juice container, shampoo bottles, and medicine bottle. Not only recyclable, HDPE is relatively more stable than PET. It is considered as a safer option for food and drinks use, although some studies have shown that it can leach estrogen-mimicking additive chemicals that could disrupt human’s hormonal system when exposed to ultraviolet light.

PVC: is typically used in toys, blister wrap, cling wrap, detergent bottles, loose-leaf binders, blood bags and medical tubing. PVC or vinyl used to be the second most widely used plastic resin in the world (after polyethylene), before the manufacture and disposal process of PVC has been declared as the cause of serious health risks and environmental pollution issues. In the term of toxicity, PVC is considered as the most hazardous plastic. The use of it may leach a variety of toxic chemicals such as bisphenol A (BPA), phthalates, lead, dioxins, mercury, and cadmium. Several of the chemicals mentioned may cause cancer; it could also cause allergic symptoms in children and disrupt the human’s hormonal system. PVS is also rarely accepted by recycling programs. This is why PVC is better best to be avoided at all cost.

LDPE: As said before, Polyethylenes are the most used family of plastics in the world. This type of plastic has the simplest plastic polymer chemical structure, making it very easy and very cheap to process. LDPE polymers have significant chain branching including long side chains making it less dense and less crystalline (structurally ordered) and thus a generally thinner more flexible form of polyethylene. LDPE is mostly used for bags (grocery, dry cleaning, bread, frozen food bags, newspapers, garbage), plastic wraps; coatings for paper milk cartons and hot & cold beverage cups; some squeezable bottles (honey, mustard), food storage containers, container lids. Also used for wire and cable covering. Although some studies have shown that LDPE could also cause unhealthy hormonal effects in humans, LDPE is considered as a safer plastic option for food and drink use. Unfortunately, this type of plastic is quite difficult to be recycled.

PP: Stiffer and more resistant to heat, PP is widely used for hot food containers. Its strength quality is somewhere between LDPE and HDPE. Besides in thermal vests, and car parts, PP is also included in the disposable diaper and sanitary pad liners. Same as LDPE, PP is considered a safer plastic option for food and drink use. And although it bears all those amazing qualities, PP isn’t quite recyclable and could also cause asthma and hormone disruption in human.

PS: Polystyrene is the Styrofoam we all commonly used for food containers, egg cartons, disposable cups and bowls, packaging, and also bike helmet. When exposed with hot and oily food, PS could leach styrene that is considered as brain and nervous system toxicant, it could also affect genes, lungs, liver, and immune system. On top of all of those risks, PS has a low recycling rate.

Type of Waste:

1. Defect/Rework: Defects Waste in Lean Manufacturing occur when a product is found to have flaws in it after production occurs. The affected parts must be replaced or reworked completely resulting in additional costs, delays and possible safety issues. In Lean Manufacturing, waste is called Muda, waste in the Japanese language. Two types of waste have been identified, Obvious and Hidden. Obvious Waste is waste that is easily seen, such as producing too many parts than what is needed, or producing parts which do not meet specifications. Hidden Waste is work that is necessary to produce a manufactured product that is also work that could be eliminated by using an alternative process or technology to produce product, one which requires less resources.

In general, as you’re analyzing the process to eliminate defects you’ll often find that there is:

1. a lack of standards or poor documentation

2. poor quality controls

3. a lack of a defined process altogether

4. poor or un-manufacturable product design

5. undocumented design changes that don’t marry to related parts

6. poor inventory control leading to ad-hoc manufacturing process adjustments.

This means that you should:

1. review the part or product design for ‘designed-in’ defects

2. check for standardized work plans and QC job aids such as checklists

3. check for a full understanding of product requirements and consider training

4. ask the people in that area!

2. Overproduction: Within Lean Manufacturing, lean consultants often find that Overproduction has the most significant impact on the success of the business. Anytime that a part, assembly or final product is produced that is unable to be used or sold due to lack of an (internal or external) customer, the business has created Overproduction Waste. In addition to the direct cost to the company of Overproduction Waste, Overproduction Waste can also contribute to Inventory or Transportation Waste, compounding the destruction of value for the business.

1. long setup times, leading to the desire for long production runs

2. manufacturing ‘Just in Case’ items are needed internally or externally

3. poor understanding of customer needs

4. producing for a forecast as opposed to having inventory ‘pulled’ as it’s needed

5. product design changes while existing designs are in process

6. badly implemented automation

3. Waiting: When traditional manufacturing processes are used, when one part of the manufacturing phase is completed there is usually a waiting period before the next phase can be continued. With Lean Manufacturing the waiting time (Waiting Waste) for a product is narrowed down to a much shorter period of time or eliminated completely.

With more careful planning and coordination it’s possible to get a quick return on investment from your manufacturing operation.

Types of Waiting Waste include:

1. parts or assemblies waiting in queues for the next step in the operation

2. people waiting for material, equipment or tools to perform their operation

3. finished products waiting to be shipped or sitting in stores

4. idle equipment

Typical causes of Waiting Waste include:

1. unplanned downtime

2. production bottlenecks and not balanced production workloads

3. setup times that are too long

4. producing to a forecast instead of a pull system

5. not enough people

6. people out unexpectedly

7. poor quality built into the process

8. ineffective internal communication

4. Not Clear (Confusion): Non-Utilization Waste in Lean Manufacturing is when personnel are idle waiting for the materials to come from a previous manufacturing step, or when people are under-utilized relative to their skills or knowledge set. Non-Utilization Waste is the only Lean Manufacturing waste that is not directly connected to a manufacturing process but instead is a management issue. If people are not adding the most value possible for their skill set and availability this is non-utilization waste.

Non-Utilization Waste manifests itself as people:

1. not being on task

2. not following processes

3. not having well established processes

4. not leveraging available critical thinking skills

5. and in overall demotivation due to broken processes or an inability of the person to provide feedback to the management system on how to improve processes, conditions or products.

Non-Utilization Waste can occur from:

1. administrative types of tasks that don’t add value

2. ineffective communication

3. lack of a teamwork environment

4. mis-assignment of tasks to people with the wrong skills

5. poor training

6. poor listening skills

7. rushed decisions

5. Transporting: Lean Manufacturing identifies different types of waste in manufacturing processes so that these can be identified and eliminated. In this, Part 5 in our 8 Part Series, we discuss Transport Waste. Transport waste is when a product that is meant to be used in manufacturing is moved or touched unnecessarily. Moving not only costs money, but can also result in the increased risk of that product being damaged, lost or misused. Lean Manufacturing negates the issue of transport waste due to the pre-assembly and pre-fabrication of parts that occur prior to their arrival at the manufacturing site. Once the pre assembled parts arrive at the manufacturing site they do not need to be transported again.

More often than not, Transportation Waste is caused by:

1. Unnecessary steps in a process

2. Poor production layout

3. Process flows which are not aligned

4. Not well designed systems

6. Inventory: Among the types of waste identified in Lean Manufacturing is Inventory Waste. Inventory waste is inventory that is left untouched waiting to be used. This wastes  space as well as the capital used to purchase the inventory without immediate financial returns. With the implementation of Lean Manufacturing, all inventory is accounted for prior to being ordered and the foreman on site knows exactly how inventory will be used. Lean Manufacturing enables a continuous workflow and creates a more predictable schedule, lessening the inventory that is over-ordered or never used.

Inventory Waste is often related to Motion and Transport Waste and be be driven by:

1. over-purchasing, including when perceived savings can be had through bulk discounts

2. overproduction of parts, assemblies or end products

Inventory Waste in often caused by:

1. Unreliable supply chains

2. Not understanding demand

3. Long setup times

4. Production speeds that are not aligned between production areas

5. Overcapacity in some areas and undercapacity in others

6. Poor monitoring systems

Steps to take to reduce or eliminate Inventory Waste include:

1. obtaining raw materials only as necessary and in only the quantities needed

2. reducing buffer inventory between process steps

3. moving to a ‘pull’ or Kanban system of manufacturing

7. Motion: When Lean Manufacturing approaches the issue of motion it is not related to the physical movement of products that are used to create the end result (Transport Waste), but rather the people or equipment that are used to create physical products. Motion Wasted in lean manufacturing is the increased motion of machinery or a person due to an inefficient manufacturing process. Wasted motion increases the amount of wear and tear on both workers and machinery, therefore decreasing its lifespan or ability to work on at a manufacturing site. Not only does wasted motion cost money, it can also lead to unnecessary accidents and injuries.

Motion Waste can be caused by:

1. Inefficient floor layouts

2. Improper equipment

3. Poor allocation of tasks between machinery, people or steps in a process

Motion Waste can often be categorized and measured by looking at activities such:

1. walking

2. reaching

3. lifting

4. lowering

5. bending

6. stretching

7. or otherwise unnecessary moving, such as traveling to other facilities when other forms of meetings would do

8. Excess Processing: Many factors can lead to Overprocessing Waste. Sometimes, products that are excessively processed are highly complex and expensive and it can be difficult to clearly identify overprocessing. At other times, a comparison of detailed customer specifications or the elimination of rework can eliminate overprocessing. By using Lean Manufacturing, products are designed and fabricated using equipment and design methods that help to ensure products that exactly meet end customer requirements.

Causes of Overprocessing Waste include:

1. Poorly communicated customer specifications that leave doubt as to exact requirements

2. Rework to meet product specifications or quality requirements

3. Poorly planned work processes that cause extra steps along the way

4. Including more components or material than necessary for the product to meet specifications

5. Delivering higher precision dimensional components than necessary

6. Using materials with properties that unnecessarily exceed specifications such as strength, hardness, purity etc.

Why Should We Recycle Plastic Waste?

Plastic recycling reduces C02 emitted from the manufacture of new plastic, emissions from incinerating plastic waste and prevents waste from going to landfill. It also reduces the speed at which we use the earth’s oil stocks. Further, recycling plastic is more energy-efficient than producing new polymers.